Vol. 16 No. 4 ISSN 0036 9144 Scottish Birds The Journal of the Scottish Ornithologists' Club

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Published by the Scottish Ornithologists' Club, 21 Regent Terrace, Edinburgh EH7 5BT. Printed by Alexander Ritchie & Son Ltd., 163 Bonnington Road, Edinburgh EH6 5RE. Scottish Birds (1992) 16: 231-235 231

Research Progress Report I. NEWTON

A 20-year study of Sparrowbawks in Eskda/e In the late 1950s, Sparrowhawks Accipiter at the nest, however, they proved easier to nisus over much of Britain suddenly catch, and provided much larger samples declined in numbers, and disappeared than males. The overall objecive was to fmd altogether from some eastern districts. This what factors influenced numbers and nest was attributed to the agricultural use of success. organochlorine pesticides, which the hawks Over the 20 year period from 1972 to accumulated from their prey. The most 1991, the breeding population remained toxic chemicals, notably aldrin and dieldrin, remarkably stable (Figure 1). Nest numbers killed the hawks directly, while the less toxic fluctuated between 29 and 39, or by no more DDE (derived from DDT) lowered breeding than 15070 on either side of the mean level success through causing eggshell-thinning of 34, with no long-term trend. Within these and breakage. Hawk numbers thus declined limits, high nest numbers occurred in years from a combination of increased mortality when March-April were relatively warm and and reduced reproduction. The problem had dry, and low nest numbers when March­ been investigated in the 19605 by lan Prestt April were cold and wet. The general and Derek Ratcliffe, in the former Nature stability was associated with relative Conservancy. When I began my studies in consistency in the amount of nesting habitat the 19705, restrictions had already been over the years. imposed on the use of organochlorines, and Within areas of suitable woodland, Sparrowhawks were increasing again. In one nests were regularly spaced, about 0.6-0.8 km of the areas in which I worked, the Esk apart, reflecting the territorial spacing of Valley around Langholm in Dumfriesshire, adjacent pairs. However, most nests were the population seemed in 1972 to have much further apart, because they were recovered fully and, despite some slight shell separated by areas of open country or by thinning, showed no obvious depression in unsuitable woodland. In this mainly breeding success. At the time this population coniferous area, the woodland was managed therefore acted as a standard, against which for timber production. In every year, some to compare the trends and breeding of patches were felled and re-planted, and Sparrowhawks elsewhere. from about 20 years on, each stand was I have continued to study this thinned every five years or so, when a population to the present day, collecting proportion of trees was removed. Thus, as data from the same 200 km2 area in a a stand aged, the trees became bigger and consistent manner throughout. In each year, more widely spaced. In the absence of I have searched all the woodland in the area management, the same process would have in an attempt to find all the nests. I have occurred through tree mortality, but over climbed to the nests frequently, to obtain a longer period, as in a natural forest. Most laying dates, clutch and brood sizes, and to Sparrowhawk nests were found in young ring the young, and recovered any prey stands, about 20-35 years old, and as any items that were present. In each year I have given stand aged, occupancy and nest also trapped for ringing and identification success progressively declined (Table 1). Few as many of the breeding adults as possible, nests were found in stands older than 40 enabling their individual histories to be years, though those same stands were well followed. Because females spend more time used in earlier years. 232 I. Newton S8 16 (4)

40

~ 30 .0 E ~ 20 Ui Q) z 10

72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 8'7 88 89 90 91 Years FIGURE 7. The numbers of Sparrowhawk nests found each year during a 20-year period in a 200 kml area in Eskdale, Dumfriesshire.

In this area, then, general stability in their prey in mature, open stands than in the numbers of breeding Sparrowhawks was young, dense ones. Males fitted with radio­ associated with a system of rotational forest transmitters did most of their hunting within management, which ensured a fairly 0.5 km of their nests. Within these areas, constant age structure in the total forest over they showed a strong preference for hunting time, and plenty of stands in the younger in young woods, spending much more time age-groups. Although the number of nests there per unit area than they spent in older changed little over the years, their woods or in other, more,open habitats. In distribution within the area changed slowly, continental Europe Sparrow hawks were also as older stands were abandoned and less likely to be killed by Goshawks in young younger ones taken up. stands than in old ones, but Goshawk In the younger stands of 20-35 years predation was not important in Eskdale. old, Sparrow hawks produced, on average, The general conclusion was that more than enough young per nesting Sparrowhawks thrived best at a particular attempt to offset the usual annual adult stage in forest succession, and in Eskdale mortality, but in the older stands of 35-50 benefitted from the prevailing forest years they produced too few. These older management, which ensured a continuing stands therefore acted as 'sinks', whose availability of young woods. sporadic occupation was maintained largely From trapping records, the annual by continual net immigration from the most survival of breeding females was estimated productive younger stands. at 58070, on average, but varied between It was not obvious why Sparrowhawks 37% and 72% in different years, partly bred better in younger woods than in old associated with rainfall. In general, the more ones, but study of the causes of breeding days on which rain fell during October - failures offered clues. The main causes of March, the lower the survival between one failure were non-laying (having built a nest), breeding season and the next. These large egg desertion and chick starvation. All these annual variations in adult survival were not proximate causes could be attributed to a reflected in the year-to-year changes in nest single underlying problem, namely food­ numbers. In each year, the recruitment of shortage. Moreover, because all these types new breeders was generally sufficient to of failure occured more frequently in old make up for the loss of old breeders since woods than in young ones, Sparrow hawks the previous year, so that nest numbers were may have had more difficulty in catching largely maintained. New breeders were 1992 Research Progress Reports 233

drawn from the non-breeding contingent. territories, the turnover in occupants was These birds, mostly in their first two years high. Most birds were present on particular of life, had apparently been excluded from territories for only one year, but some nesting largely by the territorial behaviour stayed up to eight, with a mean residence of established breeders. Partly as a result of period of 1.5 years. So the continued competition for nesting tenitories, many occupation of certain territories was Sparrowhawks did not start breeding until produced by many birds occupying them in their second or third year of life. Non­ succession, but most staying for only a short breeders that were fitted with radios spent period. One territory was occupied for ten most of their time in areas not used for successive years, but by a different female breeding, such as farmland. each time. Many of these females were The trapping of adults at nesting found in later years nesting on other territories has shown that, while about 70070 territories nearby. In general, regular of survivors nest on the same territory in territories, in young woods, tended to be successive years, 30070 change territories occupied every year by birds which between one year and the next. This applied remained for longer-than-average periods, to both sexes. Territory changes did not while other territories, in older woods, were occur at random, however, because birds occupied sporadically, mainly by young were more likely to change territory after birds which later moved elsewhere. a breeding failure than after a success; they Sparrow hawks in south Scotland fed were more likely to move from a poor primarily on birds, the smaller male territory (old woodland) than a good one concentrating on smaller species (5-120g, (young woodland); and they were more especially 5-80g) than the larger female likely to move between their first and second (chiefly 20-120g, also up to 500g). About year of life than subsequently. To some 9711fo of all prey items recorded were birds, extent, these trends were inter-related, and included all the species available locally because young birds were more likely to nest up to the size of Woodpigeon Columba on poor territories and to fail in their palumbus. However, a few species were breeding than were older ones, but statistical numerically especially important, namely analysis revealed that the three trends were Chaffinch Fringilla coelebs, Song Thrush also to some extent independent of one Turdus philomelos, Blackbird T. merula, another. Robin Erithaca rubecula and Starling The combination of mortality and Stumus vulgaris in the breeding season, with movements meant that, on individual the addition of Redwing T. iliacus and

TABLE 1. Occupancy and nest success at Sparrow hawk nesting places, according to years from first occupation. Most woods were first occupied at around 20-25 years of age, when they were first thinned. Thereafter, with increasing age of wood, both occupancy and nest success gradually declined.

Years from first occupation

1-5 6-10 11-15 16-20 21-

Number of nesting opportunities· 152 114 68 36 11 Number of nests (%) 140(92) 85(75) 31(46) 9('25) 0(0) Number successful (%) 106(76) 53(62) 14(45) 4(44) 0(0)

·Calculated as the number of potential nesting places times the number of years. 234 I. Newton S8 16 (4)

Fieldfare T. pi/aris in winter. The remaining the contributions that individuals make to 3070 of the diet consistent of mammals, future generations. Among Sparrowhawks, mainly voles and young rabbits, with no lifetime reproduction depended largely on reptiles, amphibia or invertebrates. the number of breeding attempts, which in Like many other birds, Sparrowhawks turn depended on age of first breeding (1-3 nested at a time of year when food was most years) and longevity (up to 10 years). On readily available. In south Scotland, they average, some 72 % of individuals which left depended heavily on easily-caught fledgling the nest died before they could start song-birds. In each year, the first hawk eggs breeding at 1-3 years of age. A further 6% were laid around the end of April, soon nested but failed to raise young. The after fledgling prey first become available, remaining 22% bred successfully, but varied and others followed in May. By the time the greatly in the numbers of young produced. hawks had chicks, in June-July, young Most successful birds bred only once, so song-birds were at their most plentiful. raised only 3-5 young, the number usually None-the-less, as mentioned above, food­ found in a brood. Others bred more than shortage seemed to be the main cause of once, and the most productive females individual breeding failure, manifest in non­ raised more than 20 young during their lives. laying, late-laying, small-clutches, egg In fact, the most productive 5% of desertions and chick mortality. All these individuals in one generation produced problems were alleviated in experiments more than 50% of young in the next. I am when extra food was provided artificially. now trying to understand which factors Weather also affected breeding, predispose some individuals to fail and probably through its influence on food­ others to breed well. Such factors include availability. Annual variations in mean features of the birds themselves and of their breeding success ranged between 1.4 and 2.8 habitat. It is already apparent that territory chicks per nest and could be explained quality plays a major role, because birds largely in terms of the weather in March­ which spent most of the breeding lives April. The occurrence of many cold wet nesting in young woods reared the most days in this period was associated, not only young. with reduced nest numbers, as mentioned The main conclusion to emerge from above, but also with late laying and poor this work on Sparrow hawks concerns the success, whereas the occurrence of many over-riding importance of food-supply in warm dry days in this period was followed influencing breeding density and nest by early laying and good success. The success. Comparing nest spacing in forests weather seemed to influence the breeding of in different parts of Scotland, the mean the song-birds on which Sparrowhawks distance between nests was inversely relied, but also affected the hawks directly. correlated with the densities of song birds During nest watches later in the season, the measured in the local woods: hawk nests hawks brought in few prey items on wet were furthest apart in districts where prey days, so that their young often lost weight. were scarcest. The effect of food supply on It seemed that rain itself interfered with breeding density is apparently mediated by hunting. territorial beh aviour, as pairs space Because I was able to follow the same themselves according to the food-supply. Sparrowhawks year after year, I was also Through territorial behaviour in Eskdale, able to record lifetime reproductive success: annual recruitment to the breeding the total numbers of young raised by population was regulated, so that the individuals during their entire lives. The numbers of new breeders added each year importance of such measures is that they approximately matched the numbers of old approximate Darwinian fitness, reflecting ones lost. By this mechanism, the annual 1992 Research Progress Reports 235 fluctuations in breeding density were breeding success (pairs given extra food relatively small. Other factors also raised more young than unfed pairs). None­ influenced the performance of individuals, the-less, no-one who was concerned solely possibly through their influence on food with mechanisms of population regulation, availability, as shown by the correlations with no interest in the birds themselves, between forest age and performance and would choose to study Sparrowhawks. betweeq weather and performance. From a research viewpoint, Sparrowhawks are not the easiest of birds References to study. Not only are they difficult to Most scientific papers resulting from this work observe, but their nests are hard to find and are referred to in the single publication: reach. More importantly, they are not Newton, I. 1986. The Sparrowhawk. Calton, readily amenable to experiment, so most of Poyser. our understanding must rest on observational evidence only: on correlations More recent publications include the following: between changes in numbers and breeding Newton, I. 1985. Lifetime reproductive output performance on the one hand and changes of female Sparrowhawks. J. Anim. Ecol. 54: in environmental variables on the other. 241 -253 . Newton, I. 1988 . Individual performance in Some aspects have yielded to experiment, Sparrowhawks: the ecology of two sexes. Int. however, notably the role of territorial Orn. Congr. 19: 125-154. behaviour in limiting breeding density (some Newton, I. 1991. Habitat variation and population removed breeders were soon replaced by regulation in Sparrowhawks. Ibis 133, others), and the role of food supply in supplement: 76-88.

I. Newton, Institute of Terrestrial Ecology, Monks Wood, Abbots Ripton, Huntingdon, Cambs PEI7 lLS. 236 Scottish Birds (1992) 16: 236-239

Research Progress Report

JEFF GRAVES AND JOSE ORTEGO RUANO Shags on the Isle of May: Who Mates with Whom? Some birds live for many years, successfully species, but the difficulty has always been rearing one or more broods each year after to know whether it actually resulted in they become adults. Others either die young, chicks whose father was not the male of the or fail to fmd a mate, or nest in places where pair that reared them. their clutch is more likely to be lost. They New biochemical techniques have may also fail to rear young for many other allowed us to come to grips with this reasons. There is thus a lot of variation in question in the last ten years or so. Unless the numbers of descendants that birds leave. they are identical twins, individuals all have Since those that leave the most surviving a different spectrum of genes, half inherited offspring will be at an advantage, it is from each parent. Where a gene differs interesting to examine just how the between two individuals, this leads to successful achieve this feat. It is differences in one of the proteins that are straightforward to count up the numbers of a major constituent of an animal's body. By young that each pair of birds rears every examining these proteins using a method year and then, with a long-term study, to called electrophoresis, which will separate see how many they rear in a lifetime. But ones that are slightly different from each unfortunately this is not all there is to it. other, we can detect whether a bird has a When a female mammal gives birth, we can protein whose structure is different from be sure that the infant is her own; although, those of one or both parents. If it does, then if she mated with more than one male there it is very likely to be the offspring of a may be some doubt about who its father different pair or of an extra-pair mating by may be ('paternity uncertainty'). It is rather its mother. Unfortunately, proteins do not more complicated in birds. Extra-pair vary very much, and unrelated birds may mating may lead one or more of the young have a similar spectrum, so that the chick in a nest to be the offspring of some other may not belong to the pair tending it even male than the one that tends them, but there if it shares the structure of several different may also be 'egg-dumping', or intra-specific proteins with them. In a study of Indigo brood parasitism. This is where the female Buntings in the United States, David lays an egg in a nest that is not her own but Westneat (1987) estimated that only 40070 of of the same species, so that neither of the the time could he be sure that a chick was pair that rears the chick are its parents. not the offspring of the male at its nest. Given the amount of work that many birds Even if he was sure in a particular case, he must expend in raising their brood, egg- could not easily tell which of the other males dumping is rather a good strategy. A bird in the vicinity was its real father. that lays an egg a day in its own nest has Better methods were clearly required to a lot of work ahead of it; one that lays its allow us to tell who is related to whom in eggs in the nests of others has none. Only a group of birds. The new technique of in recent years has the frequency both of DNA fingerprinting, which has become well egg-dumping and of extra-pair mating known for its human applications in amongst birds been recognised. The former forensic medicine and in paternity suits, is now known to occur in over a hundred offers just such a possibility for studies of species (Andersson 1984). The latter has birds. The method was developed by Alec been observed in many different bird Jeffreys, at Leicester University (see Jeffreys 1992 Research Progress Reports 237 et 0/1985), and it permits a very high degree of uncertainty that two birds, such as a chick and the male that is rearing it, are not related. The chance of getting it wrong, and thinking the birds are parent and offspring when they are not, is less than 1 in lO,OOO! It is not therefore surprising that many 21.2 kb- recent studies of breeding systems in birds, more than 30 to date, have used DNA fingerprinting . Birds are particularly suitable for fingerprinting because, unlike mammals, their blood contains a large amount of DNA, so only a small blood sample is needed to carry out the analysis. This can easily be obtained without harming the bird. The method works because there are regions of DNA that vary enormously between individuals, but the extent of this variation depends on how closely they are related. The 7.4 DNA is split up into sections, and electrophoresis is used to separate these out on a strip of gel: the smaller pieces move more quickly and so migrate further along the gel. A piece of DNA known as a 'probe', which is radioactively labelled, is then added and this binds to the DNA on the gel. A photograph reveals the radioactivity and shows a pattern rather like a supermarket bar code, each bar being a different segment of DNA. If the bar code of a chick is compared with that of its parents, nearly all of its bars are found to match those of one or other parent. But if it has several bars FIGURE 1. An example of edrot-piir paternity with no equivalent in either parent we can revealed by DNA fingerprinting. The chick's be certain that one or both of them is not fingerprint is in the middle with the male's on really its parent at all. An example is shown the left and the female's on the right. The arrows in Figure 1. point to bands not found in either parent. The chick shares over half its bands with the female We started studying the breeding but only 25% with the male. The lengths of the behaviour of Shags on the Isle of May in DNA fragments (in thousands of bases, or kb) are April 1990. In the last two years we have shown on the left. observed all the courtship and matings that have taken place in a small colony of 25-30 and 1989, and from these we already knew pairs, all of them colour ringed. We have that some chicks (18070) were not fathered used DNA fingerprinting to identify the by the pair-male at their nest. Of the broods parents of each of the chicks that fledged we examined in those earlier years, 22% had in both these years. We also took blood at least one chick with this 'extra-pair samples from the birds in the colony in 1987 paternity' . 238 ). Graves & ).0. Ruano 5816 (4)

In 1990, the Shags on the May, in us to expect that high fledging rates in a common with several other seabird species, population will be related to high levels of had the worst breeding season for over 20 extra-pair paternity, although this is not years. The 25 pairs on our colony that got something that has so far been found in any as far as laying eggs fledged only seven other species. young (an average of 0.28 chicks per nest, Why might we get this rather curious compared with the usual 1.0-1.2). We do not result? Shags have a long reproductive life: know the reasons for this failure, though they start breeding at the age of two, and they doubtless relate to the birds' inability some live till they are 14 or 15 years old. to find enough of the sandeels on which they Once adult, only about 11 % of birds die mainly feed their young. In line with this, each year. This means that anyone brood Mike Harris and Sarah Wanless (pers. is not particularly valuable to them, as it comm.) found that the sandeels that were would be to an animal that bred only once brought back in 1990 were significantly or twice. Rather than working hard to rear smaller than in recent years. In 1991, the a brood in difficult conditions, and perhaps colony fared a little better: 22 pairs laid at stressing itself and so lowering its survival least one egg and 15 chicks fledged, giving over the winter, it may be better for a bird an average of 0.68 chicks per nest. to stop trying to breed in a particular season Surprisingly, all of the 22 chicks that and wait for better conditions. Nicholas fledged in these last two years were fathered Aebischer (1985) found that the decline in by the male at their nest, giving a the number of breeding Shags that occurred significantly different picture from what we on the Isle of May 20 years ago was not due obtained in the two earlier ones. The likely to a crash in the population, but to large explanation is that the pressures that lead numbers of birds not attempting to breed to bad breeding success also reduce extra­ for two consecutive years. This would not pair paternity, and we are going on to be an option open to birds with high annual examine this more closely with a larger mortality, because their chances of surviving group of birds. A surprise in these results to the next breeding season would be too is that extra-pair matings were just as high low. in 1990 and 1991 as before. In both years Extra-pair matings in Shags are not we observed around 2000 matings; and forced on females, but are actively sought 17-22070 of these were not with the female's by them. In most cases they take place at nesting partner. This is very much in line the male's nest after a female has with the level of extra-pair mating we had approached a displaying male. The link found earlier (Graves et al 1992) . between this behaviour on the part of the The birds vary a good deal in whether female and her lack of success in fledging they mate with individuals other than their chicks, could be because she tends her chicks nesting partner. In particular, those females less well or because her nesting partner does that successfully fledged chicks in both 1990 so. Perhaps females with partners or nest and 1991 showed very little extra-pair sites that are less satisfactory attempt to mating, and significantly less than the ones change by seeking to become the pair female that laid but failed to fledge any chicks. We on a different nest where either the male or could also detect this difference by his site is better. However, this seems comparing the behaviour of the same female unlikely as we have only twice observed between the two years: those that paired females moving to a different partner successfully fledged chicks in one year of the in this way. Another possibility is that study, but failed in the other, had females may seek extra-pair matings with significantly more extra-pair matings in the males that will father better offspring than year that they failed. This relationship leads their own partner. We have no way of 1992 Research Progress Reports 239

testing this yet, as none of these matings has has opened up new possibilities for led to any offspring in the two years we have discovering just how this effects the studied them. relationships between individuals in a Another possible reason why females colony. It has certainly shown that the that mate outside the pair fledge fewer breeding system of Shags is more complex young is an intriguing one. Perhaps males than we had hitherto imagined, and raised that have a higher risk of having chicks that some intriguing questions for the future. they did not father in the nest are less prepared to work hard at tending the brood than those with greater paternity certainty. References Anders Mj6ller (1988) found just such an Aebischer, N.I. 1985. Aspects of the biology effect in Swallows, using experiments that of the Shag (Pha/acrocorax aris/otelis). PhD altered the number of extra-pair matings thesis, University of Durham. that the females in his colony had. In Shags Andersson, M. 1984. Brood parasitism within species. In Barnard, C. (ed.), Producers and we have found no egg dumping by other Scroungers: Strategies of Exploitation and females, so female confidence that the eggs Parasitism Croom Helm, London. in their nest are their own should be very Graves, I.A., Hay, R.T., ScalJon, M. & Rowe, S. high. If we can study the birds during a 1992. Extra-pair paternity in the shag breeding season when most pairs fledge (Phalacrocorax aristote/is). J. Zool (Lond.) chicks, we will be able to test the idea that 226: 399-408. males whose partners mate outside the pair leffreys, A., Wilson, V. & Thein, S. 1985. work less hard at provisioning the chicks Hypervariable 'minisatelIite' regions in than those whose partners do not. human DNA. Nature 314: 67-73 . M,sUer, A. P., 1988. Paternity and parental care While it is true that the great majority in the swallow, Hirundo rustica. Anim. of bird species are monogamous, detailed Behav. 36: 996-1005. studies of their behaviour have shown that Westneat, D.F. 1987. Extra-pair fertilizations some extra-pair mating occurs in almost all in a predominantly monogamous bird: species studied so far. DNA fingerprinting genetic evidence. Anim. Behav. 35: 877-886.

Jeff Graves and Jose Ortega Ruano, School of Biological and Medical Sciences, University of St Andrews, St Andrews, Fife KY16 9TS. 240 Scottish Birds (1992) 16: 240-259

Recent status change of some birds on Islay M.A. OGILVIE Recent status changes of a number of species of birds occurring on Islay, Inner Hebrides, are reviewed. Barnacle and Greenland White-fronted Geese have both increased roughly three-fold in the last 30 years largely due to favourable changes in farming practices, yet Greylag Geese have almost disappeared in the same time. Several species of ducks wintering on Loch Indaal have increased .. One possible reason may be nutrients reaching the loch from agricultural run-off and sewerage encouraging more plant and animal food for the birds. Common Scoters and Red-breasted Mergansers are also summering in larger numbers. Numbers of Bar-tailed Godwits have fluctuated, in Loch Gruinart as well as in Loch Indaal. Nearly all the birds of prey have increased in recent years, with a cessation of persecution probably the main reason. Corncrakes are declining, though management agreements with farmers and crofters may help. Choughs increased to a peak about five years ago but numbers have since declined a little. Nest sites in old buildings are being maintained through grants.

Introduction The following review makes no claims to be status changes of birds in Britain, and complete. It is one person's survey of what further afield, on man's activities though has happened to a number of species on one this may mean that more natural causes are island in the Inner Hebrides since about the overlooked. Certainly on Islay, almost every 1960s with, in some cases, a retrospective status change I shall discuss can probably look back to the last century. Some data be attributed to man's activities, either have been easy to come by and are presented deliberate or unwitting. here as a reasonably true record of what has My selection of species has been occurred. Almost all the original data used governed mostly by the availability of by Booth (1975) and Elliott (1989) in writing information and my personal interest in the their books on the birds of Islay have been species. Thus it will come as no surprise that available to me but I have re-analysed and, geese figure largely here, though former in some cases, re-interpreted them. Other colleagues may be surprised at my recent information remains buried in people's addiction to birds of prey. As it happens, notebooks but perhaps I shall make the majority of species discussed in detail sufficiently wild guesses to stimulate its (in have increased in the period under review, some cases, overdue) publication. but a few have decreased and others also in It is usually true to blame all negative decline are mentioned in brief. 1992 Birds on Islay 241

GEESE damage to grass", from which it would Three species of geese winter on Islay, appear that less has changed than is Barnacle Branta leucopsis, Greenland sometimes thought. There are other reports White-fronted Anser albijrons f/avirostris of large flocks from the same period and and Greylag A. anser, in that order of into the first part of the 20th century, abundance. Two have increased greatly in though information from the 1920s and the last 30 years, one has, perhaps 1930s is hard to come by. Berry (1939) surprisingly, declined. contacted five local observers who reported increases over the previous 25 years in two areas on the island, no change in two more Barnacle Goose and a decrease in a fifth, this last because This species has wintered on Islay, as well of the construction of an airfield. No figures as on many other islands in the Inner and are given, however. Outer Hebrides, for as long as records exist. Boyd (1968) assembled all post-war Precise figures, though, are unsurprisingly counts and estimates known to him, from scarce. Gray (1871) was told of "very large the earliest available, in December 1952. flocks" particularly at Loch Gruinart and Some were clearly 'guestimates', e.g. Ardnave. Harvie-Brown and Buckley (1892) "8000-10000" and "over 10000", others wrote of "thousands in Islay, Jura, gave the impression of being more accurate, Colons ay and ... on most suitable islands" e.g. "just over 5000". Boyd agreed with and also commented that "they do great Atkinson-Willes (1963) who described the

Bam«1e G~e flying, Islay. MorIey Hedley 242 MA Ogilvie S8 16 (4)

status thus: "Taking the island as a whole more than 150Jo and usually less than 1000o. the normal numbers are estimated at about A pattern apparent in the 1970s of an 5000-6000, but by February there is usually increase in the spring is now less regular, an increase to 7,500 and in some seasons as with decreases recorded during several many as 10,000 may be present for short recent winters. An arrival peak in October periods." 1983 and 1984 of considerably more birds In the early 1960s, Boyd began a series than subsequently wintered on the island, of early November counts which I took over reported by Easterbee et al (1987), has not in 1964 and have continued to the present occurred in any autumn since. day (Fig. 1). There have been many other The large and rapid growth in numbers counts during the same period, including a of Barnacle Geese on Islay that took place long run of spring counts which I started in during the 1960s and 1970s can be attributed the late 1960s. In March 1983, a team from to a combination of better feeding on the the Nature Conservancy Council began a island coupled with low mortality. series of monthly counts which continued Agricultural improvements during this until 1986-7, then reduced to two or three period included a much greater use of per winter. Variations between these counts artificial fertiliser and more frequent and my own, as well as variations through reseeding using more reliable seed mixtures, a winter, have tended to be small, rarely while the increased number of sheep kept

NUMBERS OF GEESE 30000

25000

20000

15000

10000

5000

o 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91

YEARS FIGURE 1. November counts of Barnacle and Greenland White-fronted Geese on Islay, 1961-1991. 1992 Birds on Islay 243

on the improved pastures produced the kind sharp drop to 22,000 in November 1991 was of short swards attractive to the geese. The a timely demonstration of the very marked mean breeding success during this period effect on arctic-breeding goose populations exceeded the calculated annual mortality by of the vagaries of the weather. The breeding several percentage points per annum. season of 1990 had produced 23.7010 young Shooting of Barnacle Geese on Islay was birds present in the flocks on arrival on comparatively light, being largely restricted Islay, the second highest percentage since to a few private shoots each winter. annual age samples began in 1959. This was The situation altered in the late 1970s immediately followed, in 1991, by the worst when, in response to increasing complaints ever recorded, with a mere 4.7010 young from farmers, the law was changed to allow birds. Estimates of annual mortality in the shooting throughout the winter instead of last ten years have fluctuated between about the hitherto restricted season of December 10010 and 18010. and January. This encouraged the While the management agreements and marketing of the shooting to paying visitors the RSPB reserve were clearly contributing and consequently the numbers of geese shot through the 1980s to the well-being of this more than trebled, coinciding with, and important group of Barnacle Geese, probably contributing to, a run of poor representing about two-thirds of all the breeding years. This produced the sharp discrete Greenland-breeding population, the downturn in numbers shown in Figure 1, majority of the agricultural community on when the November total dropped from the island were far from happy. Those with 24,000 in 1976 to 13,000 in 1982. management agreements were receiving The Wildlife and Countryside Act of significant annual payments, while those 1981 changed the rules again. The Barnacle outside the SSSIs, a much larger number of Goose became a fully protected species, farmers, received nothing at all. Up to 70010 though with licenced shooting permitted to of the Barnacle Geese could be found within prevent serious agricultural damage. Over the SSSIs in the autumn but this proportion the next few years, management agreements fell to below 50010 by late-winter as the birds covering three SSSIs were negotiated dispersed in search of more feeding, then between the NCC and the rather few usually picked up again in the spring. In farmers involved, compensating the latter winter 1988-9, a goose scaring scheme was for feeding the geese but also prohibiting the operated by the Islay Forestry, Farming and shooting of them. In 1983, the RSPB Wildlife Advisory Group, funded by the acquired most of the Gruinart Flats as a Manpower Services Commission. Teams of reserve. This has probably always been the scarers worked in areas outwith the SSSIs, most significant area for Barnacle Geese on endeavouring to persuade the geese by non­ the island. Although badly run down at the lethal scaring that life would be more time of acquisition, the land has since been congenial within the managed areas. This greatly improved through ploughing and was reinforced by a fairly high level of reseeding as the RSPB have successfully shooting, mainly by the large estates. encouraged as many geese as possible to In the next three winters, up to 1991-2, remain on their land. a different goose scaring scheme was With a combination of active manage­ operated, funded jointly by NCC and the ment for the geese and decreased shooting, Department of Agriculture and Fisheries for breeding success rose once more, as did total Scotland. This involved making payments numbers. The increase from the low of directly to the farmers to help them with the 13,000 in November 1982 to 28,000 in extra costs of scaring, whether through November 1990 was even steeper than the purchasing static scaring devices or paying previous period of growth. However, the for time and fuel used in mobile 244 MA Ogilvie 58 16 (4)

disturbance. The payments per farmer were be conserved at an adequate level through well below the level received by those with a scheme which effectively subsidises the managem~nt agreements, and the farmers farmers and crofters who bear the brunt of concerned were virtually unanimous in feeding them. saying that the payments were far too low It has been suggested that the scheme, and the scaring was having a negligible which will bring about a significant effect on goose numbers or distribution. My reduction, even a cessation, of licenced own observations, carried out for the shooting, will lead directly to a further Department of Agriculture, showed not just increase in numbers. Predictions about a decline in flock size through each winter, trends in goose populations have a poor which is to be expected, but a reduction in track record among goose biologists, flock size between winters 1988-9 and including myself, and on this occasion I am 1989-90 and again between 1989-90 and declining to speculate, though I will monitor 1990-1, despite increased overall numbers of future events with great interest. geese. My interpretation was that the scaring was having at least this beneficial effect of Greenland Wbite-fronted Goose breaking up the larger flocks. An increase Historical information about this species on in flock size between 1990-1 and 1991-2 Islay and on the adjacent Inner Hebrides is might be attributed to the farmers' own much harder to come by than for the belief that there was no effect, leading to Barnacle Goose; a difficulty is that this race a reduced effort. of the Whitefront was not described until No direct monitoring of the efficacy of 1948. However, Gray (1871), referring just different types and levels of scaring was to the White-fronted Goose, stated that "in carried out but some incidental observations the West of Scotland, its headquarters are suggested that devices which issued loud and in the island of Islay" and was told that they irregular warbling noises, including some showed "a great partiality for certain fields" supposedly audible to geese but not to and that "they go in flocks of from three humans, did discourage geese from coming to four to one hundred or more" , both traits too near. However, as with every other which are still exhibited today. scaring device ever tried against birds, it is Harvie-Brown and Buckley (1892) had necessary to vary the type and location of nothing to add to this but Scot-Skirving the device at frequent intervals, a strategy (1878) reported another long-standing habit, not always open to farmers with limited though one showing signs of recent change, labour available. namely that of using small fields and For winter 1992-3, and hopefully for ignoring larger ones, even at the expense of the foreseeable future, a new goose being easier to shoot on the small fields. management scheme has been proposed by More recently, Berry (1939) reported local Scottish Natural Heritage. It will apply to observers as saying that in the previous the whole island and be based on a headage thirty years Whitefronts on Islay had payment for geese on each holding. At the "increased enormously" . time of writing (August 1992) the details are Post-war counts began, as with still being discussed with interested parties, Barnacles, in the 1950s, but were fewer and but it should offer adequate payments to all nearly all demonstrably incomplete. Hugh landholders outside the SSSls as nearly Boyd and then myself commenced what we equivalent as possible to the payments being hoped were more complete counts in the made to those inside. This will be a early 1960s, though some of the early ones voluntary scheme but it is hoped that there are almost certainly under-representations. will be a high take-up, leading to a final The full series of early winter counts since recognition by all involved that the geese can 1964 is shown in Figure 1. Allowing for 1992 Birds on Islay 245

GlftfJund White-fronted G~ Isuy. Morley HftJley

increasing experience producing more Breeding success does not vary by as complete counts, there is only a slight much as in the Barnacles, a reflection of the upward trend over the first 20 years, (1964-5 easier breeding conditions in West than East to 1973-4 - 2900, range 1200-4700; 1974-5 Greenland. However, mean breeding to 1973-4 - 3700, range 2900-4560). Since success in the last seven years (20.2070) has 1983, however, the numbers have increased been higher than in any previous similar steadily to a record 10,000 in 1991. period back to the mid-1960s (1964-5 to Prior to 1981, when the subspecies was 1970-1 - 15 .8%, 1971-2 to 1977-8 - given full protection in the Wildlife and 14.0%; 1978-9 to 1984-5 - 12.9%). This Countryside Act, it was not shot particularly increase, coupled with declining mortality heavily on Islay, certainly not as much as on the island, will have played a large part the Barnacle, despite wider availability. in the growth in numbers wintering. There However, the increase in Barnacle shooting have also been significant changes elsewhere in the late 1970s, and particularly the larger in the range, with much reduced shooting numbers of shooters visiting the island, did in Ireland and considerable work on bring about an increase in Whitefront safeguarding and managing wintering shooting in some areas. Since 1981, it has haunts there, all helping to bring about an been possible to shoot Whitefronts only overall population increase from c.16,500 under licence and these have been issued in 1979 to the present 28,000. Islay's much less frequently than has been the case increase over the same period from 3700 to with the Barnacles, while the numbers shot 8000-10,000 in the last three years has thus in any winter have been very much less than been proportionately greater than the in the years prior to that date. growth in the total population. 246 M.A. Ogilvie S8 16 (4)

Simultaneously with the growth in numbers but it seems unlikely that the recent numbers wintering on Islay has come a upward trend will level off just yet. change in feeding habitat. Formerly, most of the Whitefronts fed mainly, if not Greylag Goose exclusively, on bogs, marshy and rush-filled It is remarkable to turn from the previous fields, and older pastures. Nowadays, two species, both of which have trebled their between a half and two-thirds of the birds numbers on the island in the last thirty feed on recently improved pasture, including years, to one which has declined almost to new reseeds. This change, which makes the vanishing point in the same time, without geese much more visible, could be linked to obvious reason. the virtual cessation of shooting. Certainly Greylags were wintering in small flocks the birds are much less wary than they were on Islay in the last century, though less even ten years ago. commonly than the Greenland Whitefront The increasing numbers, and greater (Gray 1871). By the time that Berry (1939) visibility, of the geese has, not unexpectedly, carried out his survey, local observers were led to complaints that they are causing reporting large fluctuations in numbers and agricultural damage. Although no suggesting that the increase in numbers of measurements of this have been made, Greenland Whitefronts over the previous whereas they have for the Barnacle Goose, thirty years (see above) had been at the the Whitefronts on improved pasture are expense of the Greylags. However, no certainly feeding on the same foods as the evidence is presented for this theory. Baxter Barnacles, albeit in smaller numbers and at and Rintoul (1953) summarised the above a much lower density. Flock size in the and other evidence and stated that "about Whitefronts remains much smaller with a 70 years ago a considerable number mean range of 80-120 compared with wintered on the Islay; they decreased and 300-600 in the Barnacles (own data). now only a few winter on that island". Occasional large flocks, 1000-1500, do occur The next statement on the situation but only on stubble fields or harvested root comes from Atkinson-Willes (1963) who crops where the birds are taking split grain reported that "although restricted to a single or discarded leaves. This compares with locality, have recently shown a striking regular counts of 3000-4000 Barnacle Geese increase, and now total upwards of 500 in a single field, especially in autumn. throughout the winter". This was based on Neither the RSPB reserve nor the SSSls counts by Boyd and myself, which have normally hold more than small numbers of continued to the present. The peak count Greenland Whitefronts, except occasionally was of 665 in November 1964, but it had on stubbles. The goose scaring schemes did dropped to 217 the next year. There were not differentiate between the species and so still about 300 in 1968-9 but there has been farmers outwith the SSSIs were receiving no count over 200 since 1975 and in some payments to scare either or both. The new recent years the total has failed to reach 100. Scottish Natural Heritage scheme will be For many years, the Greylags have making payments based on overall numbers been restricted to the upper Laggan valley of geese regardless of species thus and to sites around the head of Loch Indaal. recognising the obvious, that the The Laggan valley flock, usually the largest, Whitefronts are causing agricultural is almost always found mixed in with damage, something there has been a Greenland Whitefronts, which would seem reluctance by some conservationists to admit to deny the theory that the latter have ousted in the past. the Greylags. In nearby Kintyre, Greylags As with the Barnacles, I am loathe to and Greenland Whitefronts appear to co­ predict what will happen to Whitefront exist satisfactorily. 1992 Birds on Islay 247

The decline in Greylags on Islay took the same for all the counts, some of the place at a time of rapid increase in the earlier ones, in particular, may not have Icelandic population of this species and, included quite as much of the shoreline as although the origin of the Islay birds has have more recent ones. Also, the seaducks never been proved beyond doubt, those occasionally take some finding and it may wintering on the Kintyre peninsula, less than be that since I came to live on the shore of 30 km away, and on Bute, do belong to the Loch Indaal in 1986, I spend more time Icelandic poopulation and increased at the looking for them than did some previous same time. If, though, the Islay birds were counters. of Outer Hebridean origin, as has been The following accounts concentrate on suggested, then a change in the opposite six species, Wigeon Anas penelope, Pintail direction might not be so surprising if this A.acuta, Scaup Aythya marila, Long-tailed then poorly studied group of birds altered Duck Clangula hyemalis, Common Scoter either in numbers or wintering distribution. Melanitta nigra and Red-breasted However, despite a considerable increase in Merganser Mergus serrator, all wintering in wintering Greylags on Coli and Tiree in Loch Indaal, and all of which appear to recent years, some at least of which are have shown changes in numbers over the last Outer Hebridean birds, there has been no 20 + years. All six occur in larger numbers corresponding recovery of the species on in Loch Indaal than anywhere else on the Islay. island. At their other haunts there has either Without anyone particularly wanting been no change in status or the data are too even more geese on Islay, it does seem fragmentary to show it. strange that the Greylags have decreased at Loch Indaal is a long fairly narrow a time when farming changes so clearly sealoch though with a reasonable cycle of favourable to two other kinds of geese were about 24 hours for a complete change of taking place. Greylags have not shown water. One small river, the Som, and several themselves slow at adapting to farming burns flow into it having passed through changes elsewhere in Scotland. agricultural land. Also flowing in is the largely untreated sewage from the villages of Bowmore (c. 1()()() inhabitants), Bridgend DUCKS (c. 100), Bruichladdich (c. 100) and Port There is almost no past history of duck Charlotte (c.200). Perhaps as significant as numbers on Islay. Irregular counts of some all these put together are the waste products species were first made by visiting from two distilleries, at Bowmore and ornithologists, including goose counters, Bruichladdich. Bowmore is probably the during the 1950s and 1960s, but it was not more important as it is nearer the head of until Gordon Booth moved to the island in the loch and discharges into shallower the late 1960s that regular winter wildfowl water. The waste, which consists of a potent counts of the major wetlands began, mix of nitrates, nitrites and phosphates, particularly Loch Indaal and, less frequently together with particles of crushed barley, at first, Loch Gruinart. Since 1980, coverage has presumably been discharged into the has been almost monthly throughout the loch since the distilleries were founded, year. Freshwater lochs on the island tend to Bowmore in 1779 and Bruichladdich in hold relatively few birds. 1882. Normally three mashes are produced I have analysed all available counts every 24 hours so that the quantities of since 1969-70 for the two sealochs, adding nutrients flowing into the loch must have casual counts to the run of monthly had an enormous cumulative effect on the wildfowl counts. However, it is not certain invertebrate and plant life which in turn will that the coverage of Loch Indaal has been have affected the birds which feed on them. 248 M.A. Ogilvie S8 16 (4)

Pollution it may be to some people, but it anything to go by these have increased must surely have had an extremely beneficial substantially in the last few years. effect on the numbers of birds wintering on Additionally, in 1991 I discovered quite the loch and around its shores. Just in the large patches of Z.nana growing on the tidal last few years, the Bowmore Distillery sandflats within the area favoured by the discharge has ceased to go direct into the Wigeon. Z.nana had not previously been loch but instead goes via the settlement reported from Loch Indaal and, indeed, was tanks of the public sewer so that crushed known only from a single bay in the south­ barley probably no longer reaches the loch, east of the island. If the growth in marine but it is doubtful if there has been any algae has parallelled that of the Zostera then reduction in the other components of the an increased food supply may explain the discharge. recent increase in Wigeon numbers. The 150-250 wintering in Loch Gruinart, the Wigeon second largest flock on the island, have Loch Indaal has extensive beds of Zostera shown little change in the last few years and and marine algae particularly on the east there is no other evidence that the increase side of Bowmore, so it is not surprising that in Loch Indaal has been at the expense of it is popular with Wigeon. In the autumn other haunts on the island. and early winter, flocks of Whooper Swans Cygnus cygnus also feed here. The Wigeon Pintail take full advantage of the swans' ability to Prior to 1982-3, this species was a casual upend during the high tide period and pull visitor in very small numbers, the birds weed to the surface. Each upending swan staying for a few days or weeks at most. If quickly attracts an attendant scrum of any occurred on the island at all it was most Wigeon. likely at a fresh water loch such as Ardnave Counts of Wigeon in Loch Indaal since in the north-west. Since 1982-3, however, 1970-1 are summarised in Table 1. The two the species has become regular on Loch columns give the average annual maximum Indaal and has increased rapidly (see Table (= mean of three highest counts per season) I). They spend their time mainly in the together with the peak count. I have used channel of the River Sorn where it crosses a season of July to June, though for this the intertidal sandflats or dibbling at the tide species virtually all the counts are edge. concentrated between September and April. Thorn (1986) stated that the winter The counts in the 1970s were maxima of Pintail wintering in Scotland in reasonably complete and showed a lot of recent years varied between 1500 and 3380. fluctuation. Leaving aside the very low As in the rest of Britain, there are a few counts in 1980-1, for which I can find no large flocks and many much smaller ones. explanation, the counts for the next four Thorn listed only the Solway and Cromarty winters tended to be lower than previously. Firths as major sites, where over 1000 occur. In the last six winters, since 1986-7, there Flocks of over lOO away from these areas has been an increase in wintering Wigeon, are found regularly only on the inner Clyde. most noticeably doubling in the last two Elsewhere, hardly any flocks exceed 20, winters. which puts the Loch Indaal flock, now There have been no direct peaking at over 50 in three of the last four measurements of the amount of food for winters, as of at least regional interest. Over Wigeon in Loch Indaal but there is evidence the whole of Britain, Pintail have declined of increasing amounts of Zostera. The in recent years and in 1990-1 were only at extensive Z.marina beds lie at or below low­ about 500/0 of their level ten years previously water mark but if winter tidetrack is (Kirby et al 1991). 1992 Birds on Islay 249

TABLE 1. Average maxima and peak annual counts of ducks on Loch Indaal, Isle of Islay, 1969-70 to 1991-2.

Season Wigeon Pintail Scaup Long-tailed Common Red-breasted Duck Scoter Merganser Ave Peak Ave Peak Ave Peak Ave Peak Ave Peak Ave Peak max count max count max cont max count max count max count 1969-70 (150) 155 o 800 1100 o 10 o 1970-1 565 749 1 1191 1407 o o 36 60 97 171 1971·2 431 480 2 1082 1097 o o 3 5 52 99 1972-3 (270) 400 (1) 2 1050 1500 1 1 o 12 122 220 1973-4 562 647 o o 933 1000 1 1 18 43 27 40 1974-5 504 564 o o 1000 1000 2 2 6 113 150 1975.(, 315 345 (2) 3 1167 1300 o o 30 60 43 55 1976-7 415 450 (2) 7 1227 1300 o 5 15 46 80 197NJ 288 345 1 1083 1200 1 1 17 42 50 69 1978-9 115 3 521 nc 1 3 8 nc nc 1979-JJO 312 800 5 793 950 2 5 15 46 32 73 1980-1 46 91 o o 640 500 1 1 7 81 9 26 1981-2 419 615 o o 1052 915 2 26 45 53 101 1982-3 220 270 7 8 901 785 2 6 34 70 16 19 1983-4 169 209 2 6 557 770 o o 10 26 17 24 1984-5 312 348 7 14 836 1189 o o 61 86 14 19 1985.(, 295 341 7 11 1160 1505 4 5 45 100 70 87 1986-7 402 623 19 23 756 817 7 8 112 165 182 189 1987-8 555 688 28 32 931 1198 6 8 87 94 109 120 1988-9 431 527 44 51 858 1230 4 6 125 141 91 106 1989-90 466 615 32 37 383 442 11 13 147 171 139 240 1990-1 699 798 46 53 647 660 10 10 108 130 120 172 1991-2 1115 1799 44 61 1202 1430 12 16 223 232 264 350

Notes. Count season runs from July to June 'Ave max' is average of highest three counts in season; if placed in brackets, then only two counts available to average; "-" = only one count in season 'Peak count' is highest count in season

Scaup population has shown some marked I have been unable to discover any pre-war fluctuations since more regular counts began counts of Scaup for Islay. The bird was in 1969-70 (see Table 1). Although the flock known to winter here in the last century but of Scaup is usually quite easy to find, rarely no details are given in any of the books straying far from the inner part of the loch, consulted. Scattered counts in the 1950s it is much harder to count when the sea is enabled Atkinson-Willes (1963) to describe choppy and the coincidence of a careful Loch Indaal as an important site with counter with a really flat calm day is maxima up to 1500, dependent either probably needed to produce a really directly or indirectly on the Bowmore accurate peak count. distillery discharges. This remains the Throughout the first nine winters of situation today, but the wintering counts, the annual mean maximum hardly 250 MA Dgilvie 5816 (4)

Part of 5caupfloc:Ic, Islay. Il~y Dawson

dropped below WOO, while the peak count success and mortality being experienced by varied between WOO and 1500 birds. Since these birds which are presumed to breed in 1978-9, however, despite more frequent Iceland. One fear was that the sharp drop counts, the mean has only three times risen between 1988-9 and 1989-90 reflected the above 1000 and in only half the winters has change from direct discharge into the loch the peak count been above this level. of the Bowmore distillery waste. However, Marked annual fluctuations are shown in the return to former levels in winter 1991-2 maximum counts at other Scaup resorts in hopefully means that such an effect, if any, Britain and Northern Ireland, including at has been merely temporary. The flock the only two sites with more Scaup than remains comfortably above the level of 40 Loch Indaal, the Solway (1500-4000) and which qualifies it as of national importance Loughs Neagh and Beg, Northern Ireland (Kirby et a/1991) and not so far below the (1200-1600). National indices (Kirby et al internationally important qualifier of 1500. 1991) do not help as the long-term picture remains grossly distorted by the Long-tailed Duck disappearance after 1976 of the Numbers of this species are very small (see 10,000-30,000 + that had previously Table 1) but in the last thirty years it has wintered on the Forth. None of these, increased from a less than annual visitor, certainly, moved to Islay. with one or two individuals staying for short It is possible, therefore, that all that is periods in the 1960s and 1970s to, in each being seen is the variation in breeding of the last three winters, over ten birds on 1992 Birds on Islay 251

Loch Indaal for several months. Whilst the see them but -often hear them displaying numbers are trivial in a Scottish context, from my house. I have since paid them quite there are only a few places in Argyll and the a lot of attention including counting them Inner Hebrides where Longtails occur and at least monthly and often more frequently. no other site that currently holds even such The considerable increase in numbers shown a small regularly wintering flock. in Table 2 which seemed to begin in 1986-7 Quite why Longtails should begin to may well, therefore, be at least partly winter regularly on Loch Indaal is attributable to my efforts, but the unknown, though there is evidence from the subsequent sharp increase in 1991-2 is increasing numbers of Red-breasted certainly genuine. Mergansers (see below) that there may have Moreover, Common Scoters are now been some recent growth in fish stocks present throughout the year on Loch Indaal, within the loch. as shown in Table 2. It is as difficult to explain this change, with as many birds in Common Scoter some summer months as in the winter, as Meaningful statements concerning the status it is to explain the overall increase. of this species are perhaps more subject to However, the status of Common Scoters as counting problems than for some of the a breeding bird on Islay appears not to have other seaducks on Loch Indaal, because the changed over the last 30 years or more. birds habitually spend much time in the When they were first discovered nesting in outer part of the loch and are often only the 1950s, Meiklejohn and Stanford (1954) clearly visible through a telescope. On the reported at least five pairs present at the one other hand, there is plenty of evidence from site. This is still the situation today, though counts in the 1960s and 1970s that regular very frequent counts suggest that perhaps birdwatching visitors to the island knew of another five to seven pairs use the breeding their presence and made attempts to find loch in the early part of the summer, and count them. Thus the picture revealed presumably for feeding, and then move in Table 1 for the period up to 1984-5 of away to small pools to breed. The original a small wintering population averaging observors would not necessarily have 20-30 and peaking at 70-80 is probably close spotted these extra birds at the time of their to the truth. visit. Scoters have been seen flying from the In the winter following my arrival on main breeding site to Loch Indaal, but the the island in May 1986 I immediately true extent of the connection with the flock became aware of the presence of a flock of on the sea is unknown. Certainly there is no Common Scoters because I could not only evidence that the increase in numbers or the

TABLE 2. Monthly pealc counts of Common Seoters in Loch Indaal, Islay, 1985-1992.

jan Feb Mar Apr May jun jul Aug Sep Oct Nov Oec 1985 0 86 0 35 0 0 0 0 0 10 23 12 1986 3 4 100 6 10 0 0 0 92 56 11 9 1987 140 165 0 0 87 59 22 10 2 94 79 54 1988 82 60 88 84 65 45 18 36 76 0 10 59 1989 109 35 62 141 82 125 140 171 111 104 82 49 1990 83 104 37 125 130 96 96 96 87 87 98 68 1991 92 85 85 130 83 82 80 69 105 95 76 109 1992 124 107 232 209 228 68 92 125 160 162 252 MA Ogilvie S8 16 (4)

recent presence of the summering flock has out the summer month counts for the last made any difference to the numbers ten years. Only some tens of pairs breed on breeding. Islay, so the moulting birds are coming in Although Common Scoters occur in from elsewhere. several places on the east coast of Scotland, There is considerable variation in the including some moulting flocks, they are timing of the peak, which sometimes occurs relatively scarce on the west. The only other in June-July, but in other years not until known flock in Argyll is in the Sound of August-September. The then record count Gigha, between Kintyre and that island. of 350 in September 1991 suggested that Counts in the last few years have revealed these were birds coming in much later, a year-round and probably increasing flock though still presumably to moult. Cramp here, at its largest in summer, reaching over and Simmons (1976) state that male Red­ 300 in 1991. However, there are insufficient breasted Mergansers are flightless for about earlier counts to show whether summering one month in the period mid-July to end­ is a new phenomenon as it appears to be on August, while females are about a month Islay. later. There is no information on the sex of the moulting birds in Loch Indaal. The Red-breasted Merganser sudden surge of numbers in 1992 is so far Loch Indaal has long been known as a year­ inexplicable. It certainly indicates round site for this species, with the highest substantial numbers of small fish but there numbers in the summer through the is no direct information that would suggest presence of a moulting flock. There are fish stocks have also increased. scattered counts of up to 150 in the 1950s The changes in numbers of Red­ and 1960s. Counts since 1969-70 are breasted Mergansers in Loch Indaal over the summarised in Table 1. All the peak counts years probably are not due to variation in for the period up to 1977-8 fall in the period counting effort. The moulting flock has June-September. Then the moulting flock always preferred the head of the loch, seemed to vanish. Counts fell right away, especially on the north side around with the single exception of 101 in July 1981 . Blackrock, and are readily visible from the In 1986-7 there was a sudden return that has road. Another moulting flock of up to 100 been maintained and, most recently, birds, at Claggan Bay on the east coast of significantly improved upon. Table 3 sets Islay, also dwindled in the 1970s, to no more than 25, but has been back up to about 100 TABLE 3. Monthly counts of summering in recent years, including 98 in August 1992. (moulting) Red-breasted Mergansers on Loch Red-breasted Mergansers have 10041411, Isle of Islay, 1983-1992. increased and spread throughout Scotland and northern England in recent decades, though the national index of numbers, May Jun Ju/ Au~ Sept based on winter counts, having doubled through the 1970s, has fallen back sharply 1983 0 0 0 0 13 in the last few years so that by 1990-1 it was 1984 0 0 0 0 3 back to the level pertaining before the 1970s 1985 0 0 65 18 4 1986 6 7 64 189 180 (Kirby et 011991). Moulting flocks of Red­ 1987 3 70 100 76 17 breasted Mergansers are found quite widely 1988 22 120 106 88 80 round Scotland, though many are not easy 1989 0 76 90 240 122 to count regularly. In Argyll, up to 1000 1990 15 14 172 102 87 have been counted in the Sound of Gigha, 1991 4(j 46 45 114 350 on the west side of the Mull of Kintyre, but 1992 15 270 360 560 176 not often enough to be able to say whether 1992 Birds on Islay 253

variations there can be matched with TABLE 4. Average maxima and peak annual changes in the Loch Indaal flock. It should counts of Bar-tailed Godwits on Loch Indaal and be noted that a regular flock of 100 birds Loch Gruinart, Isle of Islay, 1969-70 to 1991-2. qualifies a site for recognition as of national importance for this species. Season Loch Indaal Loch Gruinart Ave Peak Ave Peak WADERS max count max count Several species of wader occur regularly on 1969-70 (69) 110 nc ne Islay, but it is rare for a flock of any species 1970-1 131 294 (5) 11 to reach 1000. The most numerous are 1971-2 222 250 90 175 Oystercatcher Haematopus ostralegus and 1972-3 152 280 (60) 100 Curlew Numenius arquata, both of which 1973-4 172 329 200 occur in flocks of hundreds in Loch Indaal 1974-5 210 220 ne ne and Loch Gruinart, as well as breeding 1975-0 233 280 nc ne widely. Other species, such as Ringed Plover 1976-7 129 277 ne ne 197NJ 53 80 ne ne Charadrius hiaticula, Sander ling Calidris 1978-9 17 34 ne ne alba and Dunlin Calidris alpina, can occur 1979-80 41 56 ne ne in hundreds but these larger flocks are 1980-1 118 300 ne ne mainly comprised of migrants in spring and 1981-2 145 240 76 108 autumn and their occurrence is too irregular 1982-3 129 200 29 64 to detect any pattern or trend. Just one 1983-4 56 91 74 86 estuarine species, Bar-tailed Godwit Limosa 1984-5 91 190 50 70 lapponica, has shown some changes in the 1985-0 86 106 59 62 last 20 years and is examined in detail below, 1986-7 117 161 10 12 198NJ 87 100 68 74 as is the Lapwing Vanellus vanellus, purely 1988-9 134 155 225 323 in its status as a breeding species on the 1989-90 115 119 162 184 Loch Gruinart reserve. 1990-1 172 243 129 152 1991-2 248 292 95 120 Bar-tailed Godwit Islay has regular wintering flocks of this Notes species in both Loch Indaal and Loch Count season runs from July to June Gruinart. Counts were much less complete 'Ave max' is average of highest three counts in the latter site during the 1970s but have in season; if placed in brackets, then only two been monthly since the early 1980s. The counts available to average; n_n = only one figures for both lochs are set out in Table count in season 4. Allowing for the gaps in the Loch 'Peak count' is highest count in season Gruinart data it does appear that numbers at the two lochs change in synchrony. There to shift in response to severe conditions. The was a period of high numbers in the first weather seems an unlikely factor, however, half of the 19705 then a few years with much as the numbers summering have varied more smaller numbers before a short-lived or less in line with wintering numbers. Thus recovery in the early 1980s. Numbers fell during the 19705, the peak count in June and back again but have returned to former July, when passage appears to be almost levels in the last four years. negligible, regularly reached 50-70, Reasons for these fluctuations are occasionally 100, then fell away almost to unclear but may be linked to food supply nil until a slow increase occurred through on the intertidal flats or to weather the 1980s, from under 10 in 1983-1988, to elsewhere as Bar-tailed Godwits are known 50-90 in 1989-1992. 254 M.A. Ogilvie S8 16 (4)

Lapwing Hen Harrier Most farmers and crofters say that the The concensus on past status is that this Lapwing is much scarcer than it used to be, species was more or less exterminated though there are no adequate counts to back towards the end of the last century. Nesting up this widely-held view. One, in a letter to was attempted from time to time over the the local newspaper, went so far as to put next 50 years, followed by a steady the blame on the increasing numbers of recolonisation since about 1960. The nesting geese leaving no room on the fields for the of a pair in 1969 was of sufficient interest Lapwings to feed or nest. to be noted in the Scottish Bird Report for Contrary to any such changes over the 1969. Breeding was proved in four 10-km island as a whole has been the great increase squares during 1968-72. in breeding pairs on the RSPB Loch Since 1988, annual breeding surveys Gruinart reserve. The number of pairs has have been carried out. The precise total of been censused annually from 1985 when a nesting birds, which may have just levelled total of 108 pairs were found. It has off, is still confidential, but breeding is now increased each year since to no less than 220 taking place in 12 IO-km squares, while the pairs in 1992. The area surveyed, of number of nests on the RSPB Loch approximately 250 ha (62 acres), has Gruinart reserve has increased from six in remained the same though the personnel 1985 to at least nine in 1992. involved have changed and it is likely that As well as the apparent cessation of the census technique has improved. persecution, there has been an increase in Nonetheless there is no doubt that the young forestry plantations in parts of the increase is both real and substantial and this island which seems to have been beneficial, despite rotational ploughing and reseeding at least in the short term, by providing of approximately 40 hectares each year. undisturbed nesting sites and a good supply Early nests on these latter fields of food. undoubtedly get destroyed by these farming activities, but the pairs involved have ample Sparrowbawk opportunities for further attempts on Booth (1975) was of the opinion that the neighbouring fields . status of this species had not changed for the previous 100 years, while Elliott (1989) suggested that during the 1970s and 19805 BIRDS OF PREY there were perhaps nine home ranges on There have been very encouraging increases Islay. He also considered that the species in the numbers of all seven breeding species was increasing as a result of less attention of birds of prey on Islay in recent years. In from keepers. This is borne out by the BTO most cases, these can be attributed to man Atlas surveys with positive breeding in just ceasing his former unrelenting persecution, five lO-km squares in 1968-72 but in nine in particular of Hen Harrier Circus cyaneus, in 1988-91. There has not been a thorough Buzzard Buteo buteo and Golden Eagle survey of the species on the island but Aqui/a chrysaetos, and to a lesser extent of available records suggest the population is Sparrowhawk Accipter nisus and Peregrine currently of the order of 15-20 pairs. Fa/co peregrinus, while even the Kestrel Fa/co tinnuncu/us and Merlin Fa/co Buzzard co/umbarius have suffered in the past. For This is another much persecuted species but obvious reasons it is not possible to publish one which has made a major comeback in figures for some species so the following the last few years. Breeding was proved in accounts will include statements 1968-72 in only two of the 14 100km squares unsupported by any actual data. covering the island. There seems to have 1992 Birds on Islay 255 been a slow but steady increase during the More recently, a retired keeper claimed 1970s and early 1980s. EUiott (1989) using that 57 had been killed in 12 years in the observations collected between 1975 and 1950s and 1960s on one estate; a gin trap 1987 concluded that there were about 20 (old) was removed from an eyrie about ten home ranges on the island. From the first years ago; and two birds were found year's returns (for 1988) from the new BTO poisoned in 1988. Breeding Atlas, Jardine (1989) showed that During the BTO Atlas survey of the density of Buzzards on Islay, at 1968-72, only two pairs were thought to 0.311tetrad, was significantly lower than in have bred. There has been a slow increase other areas of Argyll, where densities of 1.0 since then to a maximum of six pairs (lowland) and 0.69 (upland), were attained. breeding in 1992. There are two other My own best estimate for the present territories on the island where young pairs situation, based on observations in 1991 and have been seen in the last two years. 1992, is that at least 30 pairs are now breeding in 12 lO-km squares. Kestrel The cessation of persecution has been Ross (1913) was able to write: "the most a principal factor in the recent increase in abundant of the nesting species of hawks. numbers. Poisoned Buzzards have been Most keepers now acknowledge that it is found on the island several times but the last comparatively harmless". This did not stop certain occasion was in 1989. Pairs are now one shooting out a nest as recently as 1987. nesting freely in areas from which they were Nor is it now the most abundant nesting formerly excluded and where it would be raptor. EUiott (1989) thought that it was very easy to deal with them if this was still common in the 1970s but declined in the the policy. 1980s. However, it was recorded in nine lO-km squares in both the 1968-72 and Golden Eagle 1988-91 breeding Atlases, suggesting little Past and present records suggest that there change. The current population is probably is room for about eight pairs on the island, around 10-15 pairs. but it is doubtful whether this number have ever bred, or attempted to breed, in the Merlin same year. However, it may not be too long It always surprises me that the Merlin, before they do. whose diet consists largely of small birds The species has been much persecuted supplemented in summer by moths, should for a century or more, with many references be persecuted but as Meiklejohn and to their destruction in 19th century estate Stanford (1954) reported: "it bred on the game books (see, e.g., Booth (1975». An island in 1954, the nest being destroyed by unpublished diary, kept by a member of the a keeper". Oxford Ornithological Society Expedition It is difficult to make a lot of sense of to the island in June 1936, records that the the past records of this species, not least party glimpsed just one eagle during their because Icelandic birds are present into ten-day visit and relates how "a keeper said April so that spring sightings are not that the birds do not ordinarily nest in Islay. necessarily of potential nesting pairs. This year, however, there was a nest in an Positive breeding only occurred in one easily accessible place which was preserved lO-km square in 1968-72, plus sightings in because a friend of the laird wanted to five more, yet in 1974 a fairly thorough photograph it, but the birds deserted". They survey revealed about nine pairs present in were also told a slightly unlikely story of eight squares. The late Richard Elliott another site where the male bird was shot estimated that there were at least eight and but the female and young left unharmed. possibly 15 home ranges in 1986 (EUiott 256 M.A. Ogilvie S8 16 (4)

1989), though this seems high and I have including such obvious ones as the arrival been unable to discover on what he based of the Collared Dove Streptopelia decaocto. his estimate. Red Grouse Laqopus laqopus and Black No particular effort has been put into Grouse Tetrao tetrix have both declined looking for Merlins in recent summers, but disastrously, the former almost certainly pairs have bred or been present in five because of the same adverse conditions different locations since 1989. On the other pertaining over other grouse moors of hand, a number of former known Merlin western Scotland, namely increased localities seem to have been deserted. The numbers of deer and sheep, and therefore national survey of Merlins due in 1993 will , ticks carrying louping ill, as well as it is hoped, stimulate sufficient fieldwork to decreasing management of the heather. provide a clearer picture. There seems to be Annual bags of 500-700 Red Grouse on a plenty of suitable habitat for them, with single estate were commonplace in the 1930s good heather banks to nest on and an but such a number probably comfortably abundance of small birds for food . If there exceeds today's total island population. has been a recent decline then perhaps one Woodcock Scolopax rusticola have may hazard that increasing numbers of always been subject to wide fluctuations in other birds of prey might be working to the numbers, not least in the size of winter detriment of the Merlins. This thought is immigrations, but it is over 50 years since reinforced by the drama I saw this summer influxes of the size that produced a kill of when a male Merlin, flying in with food to over 1000 in two weeks on one estate in a nest site, had the narrowest of escapes 1937-8 have taken place. from a Peregrine stooping at him at the very Islay lost its Puffins Fratercula arctica moment the Merlin was passing the food to many years ago. Meiklejohn and Stanford his female. The Merlin dived to the ground (1954) found five pairs at Sanaig in the and escaped while the unsuccessful north-west of the island, and breeding was Peregrine disappeared at speed closely proved there in 1969 but since then only pursued by the female. occasional birds have been seen though it is not inconceivable that breeding is Peregrine attempted in some years. At the turn of the This species is also increasing and again century Puffins were reported as being there have been no recent signs of numerous on the aa, but had deserted the persecution though only in 1990 a farm area by the 1930s or soon after. Introduced owner, recently arrived from the South of land predators such as cats and, more England, who claimed that a pair nesting recently, ferrets, may well have been close to his land were taking his lambs (!), responsible for the species' demise as a had to be discouraged from taking drastic nesting bird. action against the birds. The 1991 census Another disappearance as a breeding found about 300/0 more occupied territories bird is the Corn Bunting Milaria calandra than in 1981. which last certainly bred in the 1930s and 194Os, as the farming began its steady change from small mixed arable to mainly OTHER SPECIES pasture. Detailed evidence and space dictates only To set against these declines and losses two more species accounts, namely are substantial increases in some woodland Corncrake Crex crex and Chough birds, particularly those favouring conifer pyrrhocorax pyrrhocorax. There have plantations. Thus Coal Tit Parus aler, undoubtedly been status changes in"sev eral Goldcrest Regulus regulus and Siskin other species in the last 20-30 years, Carduelis spinus have all bene fitted greatly 1992 Birds on Islay 257 from the large blocks of forestry planted in and it has hardly occurred as a regular the Glen east of Bowmore in the early 1960s breeder outside Islay and neighbouring and will presumably be further encouraged islands this century. In the last century it was as the 1980s plantings mature. The forestry, reported as common all over Islay and there too, has been responsible for a recent gain is mention of wandering flocks as well as of a breeding species, Crossbill Loxia pairs (Gray 1871). A little later, Scot­ curvirostra. Skirving (1876) was reporting much persecution on account of demand for skins Corncrake for natural history specimens, but Ross The first ever count was by Meiklejohn and (1913) saw flocks totalling 60 birds on the Stanford (1954) who in June that year Oa in July 1907 . "heard birds calling in thirty-one different There is little information on which to fields". Birds were recorded in ten lO-km base estimates of numbers until very squares during the BTO Atlas survey of recently. Rolfe (1966) reported a flock of 1968-72. By the time of the national survey 47 on the Oa in July 1963 which was thought in 1978, the total for the island was down to be the whole island population, though to 22-24 (Cad bury 1980). In 1985, another this seems highly improbable in view of thorough census was carried out by Moore counts of flocks in other parts of the island (1985), when a total of 20-29 calling birds in years immediately before and since. There was heard. Since then, censuses have been is no evidence that the island population has attempted almost every year as follows: ever gathered together in one locality. 1986 - 23; 1987 - no census; 1988 - 19; In 1976, a survey of coastal birds 1989 - 12; 1990 - 14; 1991 - 13; 1992 produced a total of 135-140 birds (Booth - 11. and Taylor, unpub.); adding in known or The reasons for the decline suspected inland pairs brings their total to undoubtedly include the well-documented 153-158 birds, including 39-41 breeding adverse effect of the change from hay­ pairs. A count of 134 in February 1978 is making to silage. In an attempt to reverse just attributed to "Islay" (Scottish Bird the trend, the RSPB, Scottish Natural Report 1978). In 1981, Warnes (1982) Heritage and the Scottish Crofters Union undertook thorough surveys in December have promoted an initiative to pay small 1980 and April 1981, and estimated an sums of compensation to crofters and island total of 160-180 individuals with farmers willing to delay cutting selected 58-61 breeding pairs. She drew attention to grass fields until 1st August. Four such the increasing use of buildings inland for grants were made on Islay in 1992, at sites nesting as opposed to the previous with calling birds. It is understood that the traditional cliff caves. As Choughs are prescriptions now being drawn up for the highly territorial when breeding, this Inner Hebrides Environmentally Sensitive extension of the range inland opened up Area, which is due to come into existence considerable. new areas for them. However, on 1st April 1993, will include the Warnes wrongly stated that the first known opportunity for similar Corncrake-friendly inland breeding was in 1977. When Susan management agreements. Cowdy was gathering information at the time of the 1963 census she was informed Chough of a nest in an old building in that year. Islay is the Scottish stronghold of the A repeat survey carried out in 1982 Chough with c.90OJo of the population and found a slight decrease to 141-175 birds around 40% of the total British population. including 53-61 breeding pairs (Warnes Formerly much more widespread in western 1983). However, another survey in 1986 Scotland, the range has steadily contracted found pairs of Choughs present at no less 258 M.A. Ogilvie S8 16 (4) than 95 sites, with 62 pairs confirmed The main inputs to the loch were breeding, 16 probably breeding and a pair mentioned earlier. Changes in these could present at the remaining 17 sites. A further perhaps be described if the relevant data 105-140 non-breeding birds were recorded were forthcoming. For example, it seems giving an island population of 295-330 probable that the increased use of artificial (Bignal et 01 1988). fertiliser in the catchments of the River Som Unfortunately, Bignal et 01 do not and the various burns will have led to an discuss the difference between their results increase in the amount reaching the sea, and those of Warnes just four years earlier particularly in this area of relatively high except to predict that "the population rainfall. Despite an overall decline in the should continue to expand". That, though, human popUlation on Islay in the last 30-40 it has not done. Recent information suggests years, the number of people living in the a fall in numbers probably linked to a run villages around Loch Indaal has probably of years of relatively poor breeding success increased, though whether by sufficient to and low young survival (E . Bignal, affect the quantities of nutrients in the pers.comm.). A full survey being conducted sewage might be hard to discover. in 1992 should reveal more clearly what has What this survey does confirm is that happened. few if any bird populations are static and Management agreements with farmers that the continued monitoring of numbers, on SSSIs aim to benefit the Chough by whether through national schemes such as controlling cattle grazing in order to Wildfowl Counts and Birds of Estuaries produce short swards with plenty of Enquiry, or just the assemblage of records cowpats, both of which provide the for a defined area by one or two people, can Choughs with important food supplies. In provide information of potential value. In addition, grants have been awarded by these days when more and more Scottish Natural Heritage and the bird watchers seem content merely to find Worldwide Fund for Nature to enable and identify birds, or to chase after rarities, Chough 'caves' to be incorporated in the there is a need to ensure that at least some roofs of buildings being renovated. This has of us realise the worth of noting numbers, been very successful, the birds continuing too. to nest after the renovations. References DISCUSSION Atkinson-Willes, G.L. 1963. Wildfowl in Great This personal, and patchy, account of Britain. H.M.S.O., London. Baxter, E.V. & Rintoul, L.J. 1953. The Birds of changes in status of some of the birds Scotland. Longman, Edinburgh & London. occurring on Islay, based on reasonably Berry, J. 1939. Wild Geese and Wild Duck in respectable data, has indicated what changes Scotland. C.U.P ., Cambridge. have occurred, but suggested reasons have Bignal, E., Curtis, D.J. & Matthews, J.L. 1988. had to be speculative. Islay: Land types, bird habitats and nature For the Barnacle and Greenland White­ conservation. Part I: Land use and birds in fronted Geese, it seems clear that Islay. NCC Chief Scientists Directorate. agricultural improvements coupled with low Report No. 809, Part I. mortality have been the main factors for the Booth, C.G. 1975 . Birds in [slay. Argyll Repro­ ductions Ltd., Port Charlotte. substantial increase in numbers. Changes in Boyd, H. 1968 . Barnacle Geese in the west of duck and wader numbers on Loch Indaal, Scotland, 1957-67. Wildfowl 19: 96-107 . on the other hand, whilst relatively Cadbury, J. 1980. The status and habits of the straightforward to monitor, are much Corncrake in Britain 1978-79. Bird Study 27: harder to explain. 203-218. 1992 Birds on Islay 259

Cramp, S. & Simmons, K.E.L. 1976. The Birds of Meiklejohn, M.F.M. & Stanford, J.K. 1954. June the Western Palearctic. Vol. I. O.U.P., notes on the birds of Islay. Scoll. Nat. 1954: Oxford. 129-145 . Easterbee, N., Stroud, D.A., Bignal, E.M. & Moore, P. 1985 . The status of the Corncrake on Dick, T.D. 1987. The arrival of Greenland Islay 1985. Unpub. Report, R.S.P.B. Barnacle Geese at Loch Gruinart, Islay. Rolfe .. R. 1966. The status of the Chough in the ScOIl. Birds 14: 175-179. British Isles. Bird Study 31 : 221-236. ElIiott, R.E. 1989. Birds of Islay. Christopher Ross, A. 1913. Birds of Islay. Glasgow Not. 6: Helm, London. 7-32. Gray, R. 1871. The Birds ofthe WestofScot/and. Scot-Skirving, R. 1876. The natural history of Murray, Glasgow. Islay. Proc. Roy. Phys. Soc. Edin. 4: 69-73 . Harvie-Brown, J.A. & Buckley, T.E. 1892. A Scot-Skirving, R. 1878. Notes on the natural Vertebrate Fauna of Argyll and the Inner history of Islay. Proc. Roy. Phys. Soc. £din. Hebrides. Douglas, Edinburgh. 5: 35-43 . Jardine, D.C. 1989. How many Buzzards are Thorn, V.M. 1986. Birds iti Scotland. Poyser, there in Argyll? Argyll Bird Rep. 5: 46-47. Calton. Kirby, J.S., Ferns, J.R., Waters, R.J. & Prys­ Warnes, J.M. 1982. A study of the ecology of the Jones, R.P. 1991. Wildfowl and Wader Chough on the Isle of Islay, Argyll, 1980-81 . Counts 1990-91. Wildfowl and Wetlands Unpub. Rep. , Univ. of Stirling. Trust, Slim bridge. Warnes, J .M. 1983. The status of the Chough in Scotland Scoll. Birds 12: 238-246.

M A Ogilvie, GJencaim. BruicbJaddicb, Isle of Islay, PA49 7UN.

(Typescript received 21 August/992) 260 Scottish Birds (1992) 16: 260-268

Development of an internationally important Pink-footed Goose roost at West Water Reservoir, Borders Region, 1966-1990 Allan W. & Lyndesay M. Brown This paper records the development of an internationally important Pink-footed Goose roost at West Water Reservoir, Borders Region, over the 25 years 1966-1990. The pattern of use by the geese throughout the winter is described with peak counts occuring in October/early November when the site regularly holds over 10% of the British population. The lack of disturbance at the site is highlighted as a major factor in maintaining the importance of the roost.

Introduction The Pink-footed Goose Anser West Water has been found to be of brachyrhynchus population which breeds in particular value from late September to east Greenland and Iceland and winters in early November and again in springtime, Britain totalled 72,000 in the 197()'71 winter with geese utilising feeding sites a (Ogilvie 1970), increasing to 95,000 in considerable distance from the reservoir, but 1980-81 (Ogilvie 1981) followed by a numbers declining in the area from dramatic increase to 194,000 by 1990-91 December through to February. This (Kirby & Cranswick 1991). A distinct and pattern of use is described in this paper and much smaller population, numbering over some reasons for it suggested. 30,000 birds in the 1980s (Batten et al. 1990), breeds in Spitsbergen and winters from Study Area eastern Denmark to Belgium. Together West Water Reservoir lies in the south-east these two populations, totalling about corner of the PentIand Hills, Borders 225,000 birds in 1990-91, comprise the entire Region (Fig. 1) at an altitude of 320 m and world population of Pink-footed Geese. covers an area of 42 hectares. It is a water This paper describes the development supply reservoir owned by Lothian Regional over a period of 25 years of a Pink-footed Council. Construction began in 1962 and Goose roost at West Water Reservoir, was completed by 1967 although it began Borders Region, to a site of international to fill with water by 1965. Lothian Regional importance. The first report of geese using Council shares the fishing rights with the the site was in the 1965-66 winter (W. adjoining estate which also owns the Brotherston unpub. data). The peak count shooting rights over and around the in winter 1967-68 represented 5DJo of the reservoir. The surrounding land consists of British population at that time. Since heather moor, rough pasture and wet 1980-81 the reservoir has consistently held peatIands with marshy flushes, and is .quite over 10010 of the British population with a devoid of trees. As the reservoir is not peak count in October 1988 of 40,000 birds, fenced off from the surrounding land sheep 23DJo of the British population and 20DJo of and cattle are free to roam to the water's the world population. edge but cause little disturbance to roosting 1992 Pink-footed Goose roost 261

TAYSIDE

Sco..le I ~ 1,2So,OOO

5TR ATH CL-YD!

IORDERS

ENS-L.ANe

Du,.., F RI ES ~1\.d.. ~A LL.oW"Y

FIGURE 1. Location of west Water Reservoir, Borders Region. 262 A. w. & L.M. Brown 58 16 (4)

§ o· R

~

f., 1.r it J '-I T \) 1992 Pink-footed Goose roost 263 geese. In contrast public access to the being supplied by waterkeepers Andy Dewar reservoir is restricted. and Andy Moffat. Fishing and shooting are the two Most counts were at dusk of birds principal activities which could disturb the flighting into the roost. If undisturbed, roost. At present two boats are permitted especially during the first few weeks of on West Water, one each for the estate and arrival when there was longer daylight for Regional Council, and no bank fishing is feeding, the geese frequently loafed about allowed. Most fisheries in Lothian and the reservoir until mid-morning making Borders Regions are open from 1 April to dawn counts difficult without disturbing the 30 September, but in 1990 the fishing at birds. Day-time feeding areas were found West Water Reservoir was restricted to 1 by following geese out from the roost by car May to 31 August in recognition of its and again on their return to the roost. importance to geese. In practice this affords the early goose arrivals in September a site free from disturbance allowing numbers to Results build up rapidly; likewise in April prior to Annual trends in numbers. spring migration. This may be contrasted Fig. 3 illustrates the annual maximum with Gladhouse Reservoir (Fig. 2) where up counts of wintering Pink feet at West Water to eight boats could regularly be on the Reservoir from 1966 to 1990 and shows its water until one hour after sunset throughout development into a major roost site. Geese September and April. The shooting season apparently used the site in winter 1965-66 extends from 1 September to 31 January but (W. Brotherston unpub. data) but no counts levels of shooting and associated are available. From 1966-67 to 1977-78, disturbance fluctuated at West Water during counts only once exceeded 5,000 birds the 1970s and 1980s occasionally causing whereas in every subsequent year over 6,000 changes in the roosting pattern of the geese. birds were recorded in each winter and over to,OOO in all but one of the winters 1981-82 to 1990-91. Fig. 3 also shows the annual Methods maximum counts as a percentage of the Brotherston (1964) documented the changes national population. Since 1967-68 over 1070 in numbers and behaviour of Pink-footed of the national population has annually used Geese in the Lothians and Berwickshire up the reservoir, increasing to over tOOJo to 1963 and described the establishment in annually since 1980-81 and peaking at 1955 of co-ordinated annual counts in late 22.7070 in 1988-89. Thus the increase in the October and early November at most of the number of geese using West Water was in important goose roost sites in the area. The excess of what would be expected had it latter count was subsequently incorporated merely reflected the increasing population into the National Goose count in 1960-61 wintering in Britain. Rather, the increasing (Boyd & Ogilvie 1969) while a National proportion of the national population Spring Goose count began in winter roosting on West Water suggested either a 1969-70. greater increase in population locally than In order to establish the pattern of use elsewhere in Britain, or a shift in roosting of West Water by Pinkfeet and determine behaviour from nearby localities into West peak winter counts, which did not Water. There was strong evidence for the necessarily coincide with the National Goose latter because prior to 1966 Baddinsgill count dates, we undertook more frequent Reservoir (Fig. 2) was the main goose roost counts, in addition to the co-ordinated in the south-east Pentlands and was October/ November and spring counts, from designated a Site of Special Scientific winter 1976-77 with additional valuable data Interest (SSSI) due to the numbers it held. 264 A. w. & L.M. Brown 5B 16 (4)

15

30 10 ~ ~ •<:. f/ ~ <1""- 's 25 t ... 1 ?> .. < o~ " l( P "Z :1: I' \ ; '1.0 I , 10 I ~ \ A I \ I \ I \ IS I~ I \ I \ l( I ~ \ )(

10 10

FIGURE 3. Annual maximum wintering Pink- footed Goose counts and their percentage of the national population at west Water Reservoir, 1966-90• • = number of geese in 1000's; x = percMtage of national population. 1992 Pink-footed Goose roost 265

However, by 1978 the geese were favouring West Water, utilising Baddinsgill only when heavily disturbed at West Water. This practice in turn ceased by 1980 (and Baddinsgill was subsequently de-notified as an SSSI) and if heavily disturbed at West Water they tended to delay arrival or 'park out' until well after dark, come into roost from a great height or change their direction of arrival.

Trends in numbers within winters. The first arrivals appear by mid-September .. followed by a rapid influx. This is illustrated in Fig. 4 for five winters where more complete counts are available. Some dispersal takes place after the initial mass arrival but the peak count generally occurs in October or early November and by late .. November numbers decline. Bell et ai, (1988) described a similar pattern for Pinkfeet roosting at Meikle Loch/Ythan estuary. In Lancashire in 1977-78 to 1981-82 Forshaw (1983) recorded that numbers of Pinkfeet peaked in late November or in December with high numbers remaining into January followed by a decline in February, most having left by the end of March and s the last birds gone by early May. This mirrors the pattern at West Water where 11 " declining numbers coincided with an increase in Lancashire by November/ December and conversely a decline in numbers in Lancashire in February/March coincided with a return of birds to West Water. Numbers built up at West Water from late February into March with substantial numbers recorded in April, while in 1989 and 1990 some birds lingered into May. Prior to 1977 a roost count in mid­ March was the only data available on the use of the roost in spring and thus gave no indication of its value at that time of year. From 1977 we undertook more frequent counts and Fig. 5 illustrates the peak counts in March, April and May from 1977-90. In most years since 1982 the maximum March count exceeded 4,000 birds, reaching 19,334 266 A. W. & L.M. Brown 5B 16 (4)

in 1989 and 11,000 in 1990. Peak annual April counts (Fig. 5) from 1984 regularly exs:eeded 5,000 birds. The mean of the nine ,. March peak counts 1982-90 was 7,(J)7 while for eight April peak counts (no data for 1987) it was 6,263.

Feeding areas The reservoir attracts geese from as far as Biggar, Broughton, Carnwath and the upper Clyde valley, up to 20 km distant as the geese fly (Fig. 2) . In recent years goose counters at Gladhouse and Portmore Reservoirs have occasionally noted some geese over flying their reservoirs and heading in the direction of West Water. Also counters at West Water have noted that the number of birds flighting in from east! north-east have exceeded the number of birds known to be feeding near West Linton. Perhaps the West Water roost o " 1> attracted some geese that fed in the Gladhouse area.

,,,,,-os Discussion Over the last 25 years West Water has developed into a major goose roost and has been shown to be of exceptional importance to Pinkfeet when they first arrive in Scotland. Strathearn, Locp of Strathbeg, Hule Moss, Montrose Basin (Newton et al. 1990) and Dupplin Loch (Bell & Newton .. 1991) are of similar importance. The annual peak autumn roost count at West Water Reservoir between 1966 and 1990 increased, we believe, in part due to the increase in the national population and in part to a redistribution of the geese in Lothian and Borders (Brown & Brown in prep.). It held second place in the national table of Pink­ o footed Goose roosts (Kirby et al. 1991), averaging 29,590 birds over the five FIGlJRE 4. Roost counts of Pink-footed Geese Octobers 1986-90. The Loch of Strathbeg at West Water Reservoir for winters - 1977/78, held the prime position with an averae of 1982/83, 1984/85, 1988189, 1989/90 - for which 30,030 over the five Novembers 1986-90. count data are more complete. West Water is now recognised as a site of both National and International importance having regularly held 1% of the We are extremely grateful to THE SCOTS MAGAZINE for their generous sponsorship which allows us to carry colour reproductions. WINNING SLIDE OF SOC PHOTOGRAPHIC COMPETITION 1992

Wren at nest, Troglodytes troglodytes W.E. Middleton Semi-palmated Sandpiper, Calidris pusilfa, Fair Isle, Shetland, May 1992. Paul Harvey

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Available at Newsagents or by subscription Jram: The Scots Magazine, Subscription Department, 80 Kingsway East, Dundee DD4 8SL 1.992 Pink-footed Goose roost 267

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Pink-footed Goose population. It was References designated an SSSI in 1975 and was re­ Batten, L.A. , Bibby, C.J., Clement, P., Elliott, notified in 1986 because of its Pinkfoot G.D. & Porter, R.F. 1990. Red Data Birds roost. It has been identified for designation in Britain. Poyser, London. as a Ramsar Site in addition to a Special Bell, M.V., Dunbar, J. & Parkin, J. 1988 . Protection Area. Numbers of wintering Pink-footed and Newton et al. (1973) considered that Greylag Geese in north-east Scotland disturbance was a major factor in 1950-1986. Scolt. Birds 15: 49-60. influencing goose distribution. Perhaps the Bell, M .V. & Newton, S. 1991. Central Scotland main reason for the development of such an Goose Group Newsletter No. 5. Boyd, H. & Ogilvie, M.A. 1969. Changes in the important goose roost at West Water was British-wintering population of the Pink­ the lack of disturbance, especially when the footed Goose from 1950 to 1975. Wildfowl birds first arrive and then prior to spring 20: 33-46. departure, but also for large parties of birds Brotherston, W. 1964. The Numbers and frequenting the site throughout the day in behaviour of geese in the Lothians and order to rest, wash and preen. Berwickshire. Wildfowl 15 : 57-70. Having achieved international Forshaw, W.D. 1983. Numbers, distribution importance as a goose roost it is to be hoped and behaviour of Pink-footed geese in Lancashire. Wildfowl 34: 64-76. that West Water continues to holds its Kirby, J.S. & Salmon, D.G. 1990. National position, that disrupting activities continue Census of Pink-footed and Greylag geese in to be restricted and that perhaps more Britain, November 1989. Report to goose people may be able to enjoy the spectacle counters, Wildfowl and Wetland Trust. of 30,000 birds flighting into the roost. Kirby, J.S. & Cranswick, P .A. 1991. The 1990 National Census of Pink-footed and Greylag Acknowledgements geese in Britain. Report to goose counters, Wildfowl and Wetland Trust. Data for West Water Reservoir prior to 1976 were Kirby, J.S., Ferns, J.R., WaIters, R.J. & Prys­ obtained from the records of the late WilIiam Jones, R.P. 1991. Wildfowl and Wader Brotherston who was local goose count organiser Counts 1990-91. Wildfowl and Wetlands for Lothian and Borders until his death in 1981. Trust. We are grateful to John H . Ballantyne for Newton, I. , Thorn, V.M. & Brotherston, W. extracting the relevant information. We thank 1973. Behaviour and distribution of wild Lothian Regional Council for granting us access geese in South East Scotland. Wildfowl 24: to West Water, Helen and lan Chisholm for 111-121. counting geese when we were otherwise engaged Newton, S.F., Bell, M.V., Brown, A.W. & and Andy Moffat for supplying additional data. Murray, R. 1990. Pink-footed Goose Dr M. Marquiss and Dr M.A. Ogilvie provided numbers at arrival sites in eastern and central valuable comments on a draft of this paper which Scotland. Scott. Birds 16: 35-36. was kindly typed for us by Jim Aitken . Andy Ogilvie, M.A. 1970. Greylag and Pink-footed Dewar, waterkeeper from 1970 to 1984, and Geese in Britain 7th/ gth November 1970. Maria his wife were particularly kind and helpful. Report to goose counters, Wildfowl Trust. Not only did they provide additional information, Ogilvie, M.A. 1981 . Greylag and Pink-footed they frequently thawed us out following goose Geese in Britain 7th/ 8th November 1981. counts in wet freezing conditions with mugs of Report to goose counters, Wildfowl Trust. hot coffee by their warm fireside .... then encouraged us over an alcoholic beverage to return the following weekend to repeat the exercise etc. etc! Allan W. Brown and Lyndesay M. Brown. 61 Watt's Gardens. Cupar. Fife KY15 4UG.

(Revised typescript received 13 September 1992.) Scottish Birds (1992) 16: 269-272 269

Grey geese and agriculture in north-east Scotland Jll..L MATIHEWS This paper aims to stimulate debate on the problem of the economic loss that some farmers suffer as a result of grazing by grey geese, particularly in north-east Scotland. In many areas of Scotland it would be difficult to demonstrate that geese cause any harm. But in a few places farmers have to bear the cost of large numbers of grey geese feeding on their land. Solutions tailored to local circumstances are required, and the situation in north-east Scotland is used by way of illustration.

Background The increase in the size of the over-wintering They are also listed on Annex Il of the EC populations of grey geese is well Directive on the Conservation of Wild documented (Owen et al 1986). The Birds. Greylag and Pink-footed Geese, population of Pink-foot Geese Anser along with some other goose species are brachyrhynchus has risen from c.30,OOO in listed on Schedule 2 part 2 of the Wildlife the 1950s to the current level of c.195,OOO and Countryside Act 1981 . This allows them and numbers of Greylag Geese A . anser to be killed during the open season, but from 26,000 in 1960 to the current toal requires a licence to kill during the close which is in the region of 120,000. Both Pink­ season. However, a licence can be issued by footed and Greylag Geese over-winter in the Scottish Office Agriculture and Fisheries many parts of lowland Scotland where they Department (SOAFD) to allow shooting to feed on a range of grass, cereal and root prevent serious damage to crops. In the crops. In most areas, the farmers are not north-east, licences are routinely issued to economically disadvantaged. However in farmers in the areas where geese regularly the north-east some evidence suggests that concentrate, such as around Loch of on farms in the immediate vicinity of the Strathbeg. Other species such as Barnacle large Pinkfeet roosts at Loch of Strathbeg Branta leucopsis, Brent B. bernicola, and and the Ythan/Meikle Loch the impact of Greenland White-fronted Geese Anser the grazing by geese has economic albi/rons f/avirostris are protected at all consequences. times, so for them there is no open season. Nonetheless a few licences have been obtained from SOAFD by farmers on Islay The Law to prevent damage to agricultural crops by Most Greylag and all Pink-footed Geese in Barnacle and Greenland White-fronted Scotland are migratory. The management Geese. The sale of dead wild geese has been of these populations is therefore an issue of outlawed since 1968. international importance as well as of In addition to the legal protection given national and local concern. Both species are to the birds themselves, the sites that the afforded some protection by the Bonn birds use can also be protected as Sites of Convention on the Conservation of Special Scientific Interest. Many of the Migratory Species of Wild Animals and the SSSIs notified for the protected species of Berne Convention on the Conservation of geese include both roost and feeding European Wildlife and Natural Habitats. grounds but for grey geese often only the 270 }. Matthews 58 16 (4) roosts are included. The larger roosts, Management Options including those at the Loch of Strathbeg and Three main techniques are used to attempt the Ythan/Meikle Loch also qualify as to manage goose numbers and distribution. internationally important and are proposed These are culling, scaring and habitat Special Protection Areas under the EC Birds management. Directive. Culling. Some farmers have advocated that The problem numbers of grey geese should be reduced to a pre-determined level by culling. However In line with national trends, the number of other people believe that the setting of geese at the major north-east roost sites has arbitrary population levels for geese is increased. In November 1980, 2200 Pinkfeet neither desirable nor practicable. A cull on were counted at Strathbeg, in November either the breeding grounds in Iceland or on 1990 the number was 37,100. Over the the over-wintering grounds in Britain could winter the roosts are also important staging be both practically and politically difficult areas for the geese on migration to and from to implement. Iceland. The spring influx, which in 1992 peaked at 37,950 (1 . Dunbar pers. comm.), Scaring. A variety of scaring devices such generates the greatest outcry from the local as gas guns, mobile scarecrows, kites and farmers because it is such an important time wires have been used to scare gf'ese, usually in the farming calendar. In late spring the with only limited success. Shooting at flocks geese feed on winter cereals and newly sown to scare them and disturbance by people are grain and compete with livestock for early more effective. But all scaring techniques bite grass (Keller & Patterson 1990). The have a cost. However, scaring only moves autumn influx does not put the same geese from one location to another, so it is pressure on agricultural crops because the most valuable when used in conjunction geese generally only stay in the area if there with habitat management. is rich feeding on spilled grain in stubble fields. If this is not available the geese Habitat Management. For some species of disperse fairly rapidly. Research at geese such as Barnacle and Brent, feeding Aberdeen University (Patterson 1991) has grounds have been provided in reserves. shown that under severe goose grazing Crops are grown specifically to feed the pressure yields of spring grass can be geese. This technique has been used depressed by up to 600/0, yields of silage by primarily for small, concentrated up to 20% and winter barley by 10-20%. populations of protected species of geese but These are extremes, normally losses would it has not been widely adopted in Scotland not be so high, but as well as reducing as a means of managing the large and yields, grazing by geese can cause other dispersed populations of grey geese, effects such as uneven ripening of crops, although at the Loch of Strathbeg on a delayed harvesting, more weeds in the crop relatively small scale the RSPB manage and a delay in the turning out of livestock some of the grassland in their reserve for onto spring grass. grey geese. After years of research attempting to measure crop losses, it is generally agreed that it is very difficult to evaluate the Current Management Practices economic cost of crop damage to individual The schemes currently operating in Scotland farmers because of a variety of complicating mainly concern protected species. On Islay, factors including weather, soil and crop the farmers in 'goose' SSSIs can be paid type. through a Management Agreement to 1992 Grey geese in N.E. Scotland 271

tolerate the grazing geese and a new scheme economic loss. The Lelystad conference has just been started to allow for payments acknowledged that although wildlife is an to farmers on the island outside SSSIs. On integral part of agriculture, it is still a the Solway at Caerlaverock there is a negligible part of agricultural policies. The sanctuary system for the Svalbard Barnacle participants at the conference recommended Geese. Here the merse or estuarine that "it is of the utmost importance to grass lands are managed to attract the broaden the scope of agricultural policies to Barnacles but this also benefits the Greylag ensure the conservation of our natural Geese in the area. At Loch Leven, the RSPB heritage" . manage land in their Vane Farm reserve for Pinkfeet. At Montrose Basin the issue of managing the increasing numbers of geese Farming with Wildlife outside the reserve areas is being Pienkowski & Stroud (1991) have proposed investigated. that for large or medium-sized dispersed In England, there is a Brent Goose populations including Greylag and Pink­ option in the Countryside Premium Scheme footed geese an approach similar to the whereby farmers in a prescribed area can Environmentally Sensitive Areas is required. enter their land into the Ministry of This would enable farmers to opt in and Agriculture, Fisheries and Food's 'Set accept payments and tolerate geese or opt Aside' Scheme. But if they manage their out and bear the losses and costs of land in a specified way farmers can qualify preventing them feeding. In a limited area for 'top up' payments from the Countryside around the largest Pinkfeet roosts in north­ Commission. east Scotland, such a scheme could be very The Dutch government is encouraging valuable in reducing tensions between the the development of regional goose local farmers and bird protectionists. It may management plans. The policy is to scare be necessary to operate a scheme only geese, in a planned and co-ordinated way, during the close season when the goose from land susceptible, to damage such as grazing competes with livestock grazing or arable crops, onto land less susceptible to damages growing crops. At other times, damage including pastures, areas of natural farmers can derive some income from the habitat and reserves. At present, goose geese by letting the shooting. Rather than damage is reimbursed from a special fund trying to compensate farmers for individual unless a licence has been issued to scare losses, the scheme could offer flat rate geese away. payments per unit area in a defined area In October 1990 a conference entitled around the roost. Payment would only be Farmers and Waterfowl: Conflict or Co­ made on the fields where significant existence was held at Lelystad in the numbers of geese actually feed. This could Netherlands. It recommended that a be determined by 'dropping counts'. management strategy for geese is required Additional payments could be made to those at the international, national and regional prepared to grow special crops for the geese. level. Work has already begun on Outside the defined area, licences could be developing international flyway readily available in order to disperse the management plans for some species, notably geese and encourage them to return to the for Greenland White-fronted Geese, but it refuge. is likely to be some time before such plans The recent reform of the Common are finalised for Greylag or Pink-footed Agricultural Policy (CAP) had introduced Geese. In the interim, a system is required new opportunities for introducing such a to assist those farmers whose land is scheme. The new Agri-Environment intensively grazed by grey geese causing Programme could be developed to 272 }. Matthews 58 16 (4)

accommodate farming with geese. This References could be integrated with the Set Aside International Waterfowl and Wetlands Research Scheme and, although this has short­ Bureau 1991. Farmers and Waterfowl: comings in its present form, it could be Conflict or Co-existence. Information modified to accommodate management of Booklet on the Lelystad Conference. 'set aside' land for geese. The international Keller, V.E. & Patterson, I.J. 1990. Feeding lifestyle of the Greylag and Pink-footed Distribution of Pink-footed and Greylag Geese seems a suitable case for EC geese around the Loch of Strathbeg SSSI, consideration. If the policy makers can be Grampian. UnpUblished report to the Nature persuaded, the wildlife on some of Conservancy Council. Scotland's farms could benefit from CAP Owen, M. Atkinson-Willes, G.L. & Salmon, D. funding in much the same way as those in 1986. Wildfowl in Great Britain (Second Environmentally Sensitive Areas. This edition). Cambridge UniverSity Press. would help offset the detrimental effects on Patterson, I.J. (1991). Conflict between geese wildlife that CAP has caused elsewhere. and agriculture; does goose grazing cause damage to crops? Ardea 79: 179-186. Acknowledgements Pienkowski, M. & Stroud, D. (1991). Conser­ I would like to thank Professor David vation: National and International in Owen, lenkins and Dr lan Francis for their helpful M. & Pienkowski .. M.W. (eds) Proceedings comments on this paper. on a goose damage and management workshop. Published by the Joint Nature Conservation Committee, Peterborough.

Jill Matthews c/o 17 Rubislaw Terrace, Aberdeen AB1 1XE.

(Typescript received 29 August 1992.) Scottish Birds (1992) 16: 273-275 273

Some post-war declines in Corn Bunting numbers in north­ east Scotland ADAMWATSON Notes based mainly on counts of singing birds along public roads are compared for 1944-48 and 1988-92. In Deeside west of Ballater, Corn Buntings were widespread in 194446 but not seen in summer 1947 and since. In the Turriff area, summer adult numbers are as high in a few places as in 1944-48, but in most places lower or absent. Adult numbers in the Turriff area were no lower in summer 1947 following a severe winter than before it. Birds were seen in mid Deeside in 194446 and a big flock in mid Donside in January 1947, but none there in 1952-55. Notes from other parts of north-east Scotland show generally fewer birds than in 194448.

Introduction and Methods The decline of Corn Buntings Miliaria Strathgirnock to Balhalach, Mains of calandra is well known from the BTO Atlas. Abergeldie to Tornauran, and above However, few observers have compared Crathie at Crathienaird, Newton, Bush and numbers on an area in widely different Lawsie, quite numerous July 1946. Balnault years, although this is the best guide to and Inver, one each, singing July 1946. changes in local distribution and numbers. North of Braemar by the A93, south Below, I give some such notes, based mainly similarly, Auchallater, Balintuim, and on counts of birds singing on fine evenings north-west of Braemar, one each, singing in May to mid August on wires and other July 1946. Tomintoul croft (420m) at song positions along public roads. Such Braemar, two in hay August 1946. I saw counts are minima, but current intensive none west of Ballater in 1947-51, in 1952-55 work (Watson, unpublished) shows that in when I searched for Goodbody's (1955) such conditions nearly all cocks are seen. I Aberdeenshire survey, and in 1988-92. also give some notes from winter. Goodbody saw none there in 1952-55.

Results Mid Deeside. mid Donside and upper West of Ballater. East and west of Bridge Speyside. Ballater to Tomnakeist, of Muick, and Dallyfour to Ardmeanach, Ballaterach to Deecastie, and Ordie to a few April 1944, "quite a number" each Tarland. several each, singing July 1944-46, July 1944-46, and flocks at ricks each winter and Loch of Aboyne, one singing July 1946. 1944-47; the foot of the Balintober road was Craigievar up from Alford, flock of at least a very favoured spot. Coilacriech, one 80 on snow free ground, 5 January 1947. singing July 1945. Bridge of Gairn to Goodbody (1955) saw none west of Crathes, Crathie, quite numerous July 1944-46 and and above Alford, in 1952-55 . Loch Alvie, flocks at ricks each winter 1944-47. one June 1947. I saw none in these places Abergairn to Prony and Culsh, in 1988-92. 274 A. Watson S8 16 (4)

Turriff area. Decreasing 1940-43, more none. Strocherie to Crudie, fairly common birds 1944-48. Above Turriff Station, 20 in June 1947 and summer 1990-91. flock April 1945, and flocks of 8-15 at In winter 1944-48, nearly all birds were Bridgend and at Millmoss to Darra in winter in flocks . Most foraging birds were on grain 1944-48; in winter 1988-92 I saw none. stubble, many at ricks (especially in snow), Forglen kirk, a pair May 1945 . Turriff to some on sown grain, turnips and roadside Deveron Brig railway, one singing June grass, and a few in pasture. Loafing birds 1945. Aberchirder to Mountblairy, fair were mostly in trees and sometimes on numbers June and winter 1944·48; none wires. I saw many cocks singing in flocks seen 1988-91 except a flock of 8 at from December onwards, and occasionally Burreldales March 1990. Greenlaw near in November, and often saw lone cocks Alvah, flock of 50 February 1946, and singing strongly on fine days from 5 January flocks totalling 60 below Hill of Alvah with onwards. These habits stilI prevail, save for 25 in one tree. Craigston to Gamrie kirk, the virtual lack of grain ricks now. "here and there" May 1946; same comment The \:>est area found in summer was the would apply summer and winter 1988-92. Fishrie crofts; on 10 August 1947 "great Brunthall south of Turriff, 19 in flock numbers, a cock was sitting singing on the February 1946; 20 in flock February 1990. wires every 200 yards for several miles and Turriff Station to Brunthall in deep snow a flock of 50 was seen, while odd birds were February 1947, flocks of up to 15 here and seen here and there not singing". there, and some birds singing; in winter Table 1 shows numbers singing along 1988-92, only one flock seen, in 1990 roads in 1944-48 and 1989-92 in the Turriff (above). Burnt Smithy to Fintry (3 km), 4 area. Numbers in a few places are as high in full song 14 and 20 August 1946; none as in the 194Os, but in others have declined seen summer 1990. Fishrie, Troup and greatly. The distribution area has retracted. Pennan, "a lot" including a flock of 10 and a few still singing 22 August 1946, and Elsewhere in north-east Scotland. On a high "lots" June 1947; fair numbers 1988-92 but wire by the A92 north-east of St Cyrus, one fewer than 1944-48, and some gaps with December 1945; birds were in this area in

TABLE 1. Numbers of singing Corn Buntings along roads in the Turriff area of Aberdeenshire and Bannfshire in summer 1944-48 and 1989·92 (blanks indicate no records made).

Road Distance 44 45 46 47 89 90 91 92 (km)

Turriff-Brunthall 3 6 4 7 7 7 2 5 7 Birkenhills·Keithen 5 '12 8 5 8 3 2 3 4 Fishrie (Cook·Overbrae) 5 22 26 2 3 4 4 Mill of Pot to west 1'12 7 6 8 1 1 0 Turriff-MiII of Delgaty 2 3 3 4 0 0 0 Braefoot-lenshie 6Y, 3 4 1 5 3 3 Turriff-Fyvie-Gordonstown 18 6 7 1 2 2 2

Turriff by Colp to Idoch, Idoch to Wood head of Delgaty, Turriff to Darra, Turriff to Mahon, and Turriff to Burnt Smithy (4, 2'12, 2'12, 3 and 2'12 km) had 4, 4, 2, 3 and 2 birds in 1946, and 0 in 1990. Turriff-Brunthall 7 in 1948. 1992 Declines in Corn Bunting 275

winter 1988-92. Newburgh to Balmedie, a Although that winter was unusually severe few May 1946; same comment would apply in the Turriff area, it was markedly less 1988-92. Both sides of Ythan estuary, a few long, snowy and frosty on this lowland area May and November 1946. Newburgh via than west of Ballater. Interestingly, Corn Ellon to Old Meldrum, "p!enty" June 1947; Buntings on lowland at Freuchie in Fife in 1988-92 I saw none near Old Meldrum. increased from 12 to 18 pairs between 1946 West of Forres, a few October 1946, and and 1947 (Dacker 1948). Spey Bay, "lots" December 1946; I saw The question is why numbers have none west of Forres and at Spey Bay on four fallen in the Turriff area. Such questions can winter visits and one spring one in 1988-91. be answered reliably only by detailed Dyce north to Goval, flocks December 1946. research, which has been lacking. Certainly, Gartly to Lessendrum, a few May 1947. farm practices have changed much since Last three miles from the south-west to 1948. One change is the lack of grain ricks, Loch of Strathbeg, fairly numerous June but this includes places where the number 1947; and Strathbeg area, "lots in flocks of singers has not fallen, such as Turriff to and many singing" February 1948; such Brunthall. There, steep uncultivated patches comments on high numbers would not apply at Brunthall and weedy barley on one farm in 1988-92. may help maintain numbers. Birds have declined greatly at the Fishrie crofts, Discussion associated with a big drop in the number of West of Ballater, many were seen in worked family farms. Most farms there had 1944-46, but none in summer 1947 following oats and turnips, but pasture has replaced the severe winter of early 1947, and none these on most of the area. Corn Buntings in 1952-55. The 1947 winter there was seldom use pasture in winter, and it is exceptionally cold, snowy and prolonged usually too short for nesting. from January till April, and the 1950-51 winter also severe. These were the two References snowiest winters at Braemar in 1939-92, Dacker, H. 1948. Mortality of birds in Scotland judged by the number of mornings with in the cold weather of January-March, 1947. snow lying (Monthly Weather Report, Scott. Nat. 60: 171 -176. Meteorological Office, Bracknell). In the Goodbody, I.M. 1955 . Field notes on the corn Turriff area, however, adult numbers were bunting (Emberiza calandra): habitat and if anything higher than usual in summer distribution in Aberdeenshire. Scott. Nat. 67 : 1947 (Table I, and Fishrie notes in Results). 90-97 .

A Watson, c/o Institute 0/ Terrestrial Ecology, Banchory, Kincardineshire AB)I 4BY.

(Revised typescript received 15 September 1992.) 276 Scottish Birds (1992) 16: 276-281

Rare Migrants S. Thomson Jnr., before the bird was lost from view, presumably going to roost. At this stage I was almost certain that the bird was a Little Swift, but I could not remember Little Swih on Fair Isle: the second whether the species showed a white throat Scottish record patch. On returning to the Observatory, I The 1st November 1991 was preceded by six telephoned Paul V. Harvey and Pete Ellis days of South easterly airflow on Fair Isle, in Shetland, describing the features we had Shetland. These classic fall conditions seen. After much discussion and checking brought a significant arrival of migrants, the relevant literature, we concluded that the which amongst others, included a Desert bird was, indeed, a Little Swift. The Wheatear Oenanthe deserti, 3 Siberian description was submitted to the British Stonechats Saxico/a (orqua/a Birds Rarities Committee and was accepted maura/ stegnegeri, a Yellow browed on first circulation. Warbler Phylloscopus inorna/us, a Spotted Crake Porzana porzana and several thousand Thrushes Turdus sp. Conditions on the 31 st October, a force 9 gale and heavy rain, made viewing very difficult, so with better conditions the following day, C.]. Orsman, A. Prior and myself decided to cover the island. A good assortment of migrants were present in the south of the isle, including an Olive backed Pipit Anthus hodgsoni. At around 1600 hrs, we were walking along the cliff tops at Bergaroo, when I saw what appeared to be a Hirundine flying away from me at the base of the cliffs. From the brief views that I obtained, I was amazed to see Swift Apus sp. like wings and a vivid square cut white rump. It rapidly flew out of sight into Easter Lother. At that stage, CJO and AP had not seen it. From what I saw, the bird was obviously a species of Swift and I suggested that it may be a Little Swift Apus affinus! Excited, we hurried to Easter Lother and relocated the bird, where it remained for the next twenty Description minutes. Looking down on it from the high SIZE AND SHAPE. No direct size cliffs, we were able to confirm my initial comparison was made, but appeared smaller impressions: fairly long sickle-like wings and than Common Swift, about the size of a an obvious square cut white rump; the tail large hirundine. Sickle shaped wings, fairly was also square cut, lacking the appendage broad based. Tail square ended, lacking the appearance of Common Swift Apus apus. forked effect of Common Swift. The colour of the underparts was noted when it made an upward glide, just metres PLUMAGE. All upperparts blackish except away, showing a white throat patch for slightly paler remiges and a vivid white contrasting with what were otherwise sooty­ rump, square cut on leading edge. The head brown underparts. We were then joined by showed a greenish tone and a slight glossy 1992 Rare Migrants 277

green sheen to the mantle was also noted. which include a single at St. Andrews, Fife, A white throat patch and white sides to the on 29th May 1985 (Dymond et al 1989; rear flanks, formed by the downward Rogers et al 1989). extension of the white rump feathers, contrasted with sooty-brown underparts. Summary A Little Swift was present on Fair Isle, FLIGHT. The bird spent most of the Shetland on 1st November 1991. This was duration gliding effortlessly, fluttering only the second record for Scotland and the 10th when banking, reminiscent of a Bat for Britain and Ireland. Chiroptera. Acknowledgements Range I am grateful to Kevin Osborn and Pete Ellis The Little Swift breeds throughout Africa for commenting on the manuscript. and Southern Asia east to Southern China, Formosa, the Philippines and Borneo, north References to Morocco, Syria, South Transcaspia and British Ornithologists' Union 1971. The Kashmir between 40 N and 35 S. The species Status of Birds in Britain and Ireland. is mainly resident but A.a.galilejensis (which Blackwell, Oxford. breeds from Morocco east to Kashmir and Dymond, N.l., Fraser, P.A. & Gantlett, south to the central Sahara and Arabia), S.l.M. 1989. Rare Birds in Britain and winters to just south of the breeding range Ireland. Poyser, Calton. (British Ornithologists' Union 1971). Rogers, M.l. & the Rarities Committee Little Swift is a vagrant to Britain and 1989. Report on rare birds in Great Ireland. There have been 9 previous records, Britain in 1985. Brit. Birds 505-563.

Hugh R. Harrop, Mew House, Bigton, Shetland ZE2 9JA.

Semi-palmated Sandpiper on Fair Isle: a first record for Scotland whilst I scribbled some hasty notes. At this May 13th dawned with light south to south­ point I considered the possibility that the easterly winds and as a direct result there bird was a Semi-palmated Sandpiper C. was a sprinkling of commoner spring pusilla. migrants on Fair Isle. At around 1500 hrs Following a phonecall to the I was checking the open fields between Observatory, Paul Harvey arrived with a Bull's Park and Field when I noticed a small telescope and a copy of Shorebirds, and the wader Calidris sp. feeding along the edge next 20 minutes were spent grilling the bird; of a shallow pool. I was immediately struck with the previous experience of PH and with by the bird's small size: it was obviously a reference to the available literature we were stint and, as I continued to watch the bird, able to confirm the bird as Scotland's first the lack of any obvious rufous tones to the Semi-palmated Sandpiper. plumage and lack of pale mantle braces The bird remained on the same pool for (both features commonly associated with the remainder of the day; the following day Little Stint C. minuta) was striking. Over it moved to a flooded 'tattie' patch at Field the following ten minutes the bird continued croft, where it remained until 15 May, to feed, quite unconcerned by my presence, feeding alongside a Dunlin C. alpina. 278 Rare Migrants S8 16 (4)

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Description SIZE AND STRUCTURE. Generally appeared forming a distinct dark eye-stripe behind the eye. very similar to Little Stint, although perhaps a In certain lights the ear-coverts showed a slight little more chunky and with a slightly more chestnut tone. attenuated rear-end. Short primary projection with only two tips visible beyond the tertials. Bill UPPERPARTS. Mantle feathers greyish- or quite heavy, and straight except for an obvious golden-buff, with distinct black centres, downward kink just before the swollen tip. contrasting with the plain nape. The bird lacked any pale 'braces' or 'tram-lines'. HEAD. Crown heavily streaked blackish 0 .. Upper three rows of scapulars black -centred greyish-brown ground colour. Sides of rear crown with obvious broad golden/ buff fringes. The with a distinct chestnut tinge, although this was fourth row of scapulars with black centres, only visible at certain angles. Nape whitish with pointed at the tip, and with pale area within the fine grey streaking, contrasting with the crown black at the base of the feathers. The pale fringing to give a slight 'capped' appearance. to these feathers was chestnut-golden at the base, Supercilium white, finely streaked grey, fading to whitish grey at the tip. prominent in front of eye and broadening just A single feather on each side of the fourth above the eye, before narrowing and finally row and the entire fifth row of scapulars uniform flaring as it faded into the nape. There was no grey, with darker central streak (these feathers sign of any 'split' in the supercilium. possibly retained from winter plumage). Lores streaked dark grey, narrowest at the base of the bill, broadening in front of the eye. UNDERPARTS. Chin and throat white, Ear coverts finely streaked grey, streaking most contrasting quite markedly with grey breast intense along the upper edge of the ear-coverts, streaking. Streaks finest and narrowest in the 1992 Rare Migrants 279 centre, becoming heavier on the sides of the breast have been on the Azores, with the others forming distinct chevrons, which extended slightly spread liberally around western Europe. onto the upper flanks. The rest of the underparts The route that the Fair Isle bird took white, except for occasional fine streaks on the is debatable, as with many of the vagrants rear flanks and undertail coverts. to Britain, but a likely explanation is that WINGS. Tertials plain greyish-brown with it was on its northward spring migration, narrow white fringes. Lesser, median and greater having arrived in Europe the previous wing coverts uniform grey, except for slightly autumn. darker central streak. There was at least one differently patterned (new?) greater covert on Summary each wing, these being longer and with a distinctly black centre. The primaries and secondaries were An adult summer-plumaged Semi-palmated dark (blackish). Sandpiper Calidris pusi/la was present on In flight showed a narrow whitish wing-bar. Fair Isle, Shetland, 13-15 May 1992. This constitutes the first record for Scotland, BARE PARTS. Bill black. Legs and feet black, subject to acceptance by the relevant rarities with partial webbing clearly visible between toes, committees. although more prominent between the central and the outer toes. Surprisingly obvious when at close Acknowledgements range, or when seen through a telescope. They were also noted when footprints were examined I would like to thank Paul Harvey for his in the mud. assistance and the accompanying photograph. And also Roger Riddington CALL. The call was heard several times in flight, and Wendy Christie for their invaluable being similar to Little Stint, but distinctly fuller help. and more rolling; transcribed as 'drrrup' or 'trrrrp' . Range References Semi-palmated Sandpipers breed from Dymond, N.J., Fraser, P.A. & Gantlett, Alaska and central, through to eastern, S.J .M. 1989. Rare Birds in Britain and Canada. They winter largely in coastal parts Ireland. Poyser, Calton. of north-eastern South America, but also Lewington, I., Alstrom, P. & Colston, P. further north to the West Indies and the 1991 . A Field Guide to Rare Birds of Pacific coast of Central America. Britain and Europe. Harper, Collins. It is occurring with increasing regularity Hayman, P., Marchant, J. & Prater, T. in Western Europe, probably as a result of 1986. Shorebirds: an Identification increased observer awareness. Up to the end Guide to the Waders of the World. of 1991 there have been a total of 63 British Beckenham. and Irish records, all but two of which have Rogers, M.J. & the Rarities Committee. been in autumn. There have been a further 1991. Report on rare birds in Great 19 Western Pale arctic records, 10 of which Britain in 1990. Brit. Birds 84: 449-505.

Stephen C Votier, clo Fair Isle Bird Observatory, Shetland ZE2 9JU. 280 Rare Migrants 58 16 (4)

Dark-eyed Junco in Hamilton Europe and Rare Birds in Britain and Ireland indicated that this was the 16th On Sunday 3 May I had been out chasing record of Dark-eyed Junco in Britain and rarities since dawn and, arriving home in only the 5th for Scotland, and also that 11 Hamilton just before 7 p.m., I was taken birds out of 16 had appeared in Britain in aback when my wife, Joan, insisted that an May. unusual bird had been feeding regularly in When a small measure of calm our back garden from 8 a.m. She had taken returned, I contacted my colleague, notes on the bird and had eliminated all the Campbell Lindsay, and suggested that he likely garden birds. should get to my house as soon as possible At first I was at a loss to think what to try to photograph the bird. However, the it was but then I realized it could be a Dark­ Junco appeared to go to roost just after 8 eyed Junco, and when I showed my wife p.m., shortly before C.L. arrived. illustrations in several field guides, she was The weather was overcast with light confident that this was indeed what she had drizzle and we reckoned that, given the seen. Within minutes the bird appeared on bird's feeding behaviour throughout Sunday a plum tree in the corner of the garden, and and the distinct possibility that it was a the first impression confirmed that it was genuine vagrant, there was a good chance indeed a Dark-eyed Junco Junco hymelis. that it would remain overnight. It moved confidently around the garden, I was, however, hesitant about returning repeatedly to feed on a tray of 'releasing' the news for various reasons. I seed on the ground beside a wall and chasing anticipated problems of parking and access. off a Chaffinch Fringil/a coelebs, the only If a large number of people wanted to see other bird in the garden. the Junco without disturbing it or nearby The bill was noticeably pale pink and residents, they would have to- view it from of typical bunting shape. The head, breast the back windows of my house! After and upper parts appeared uniformly dark discussion with Angus Murray of Birdline grey and contrasted sharply with the white Scotland, I decided to hope for the best and belly and undertail coverts. The area around let the news be released. the eyes looked particularly dark, appearing The first expectant birders arrived just almost black from certain angles. The white after 5 a.m., and at 5.55 a.m. the Dark-eyed on the outer tail feathers looked particularly Junco appeared in the garden to feed for noticeable and extensive as it flitted around about five minutes. It then flew off but on the ground. In certain poses the bird did returned within the hour, a pattern it was look somewhat plump, although its tail did to follow all day. By 8 a.m. a constant not appear particularly long. It was roughly stream of birders began to appear, trudging the same size as the Chaffinch that it had up the stairs and coming back down smiling. chased from the garden, providing a suitable The bird appeared either on the garage roof, touchstone for comparison. All in all it where I had thrown seeds, or on the tray of presented itself as a neat, strikingly unusual seed on the ground. By 10 a.m. the number bunting, and the incontrovertible conclusion of birders had increased considerably and was that it was an adult male Dark-eyed bemused neighbours looked out of Junco in pristine plumage. windows, wondering what was happening. I was in a state of shock and incredulity Shortly afterwards, the advance guard for for several minutes, and could only a procession of press reporters and speculate on why this bird had turned up in photographers appeared, and the 'twitch' a suburban garden in Hamilton when it took on the air of a street party or a should have been in North America. A community celebration. Despite several quick check in The Rare Birds oJ Britain & fraught moments in the course of the day, 1992 Rare Migrants 281 the Junco appeared regularly in the garden Summary until 7.30 p.m. By this time over 300 people from all over Britain, and many neighbours A male Dark-eyed Junco Junco hymelis too, had had excellent views of this rarity spent 3-4 May 1992 in the garden of 37 for Scotland and indeed for Britain. Laburnum Lea, Hamilton, Lanarkshire. It Monday night was clear and bright and was seen by more than 300 people and was Tuesday morning was warm and sunny. The also well photographed. Although no Junco was looked for from 6 a.m. but it was problems are anticipated, it has still to be considered by the British Birds Rarities not seen again. It had probably moved on during the night or early morning. Committee, and if accepted this will However, the publicity and interest constitute the 16th record for Great Britain generated by the Dark-eyed Junco's two-day and the 5th record for Scotland. stay in our garden was nothing short of staggering, ranging from interviews on the References radio, mentions on national radio and Dymond, J.N., Fraser, P.A. & Gantlett, television, coverage in nearly all the national S.J.M., (1989). Rare Birds in Britain and Scottish dailies with perhaps the and Ireland. T. & A.D. Poyser. ultimate coverage being front page articles Ferguson-Lees, James, Willis, lan & in The Scotsman and The Times, and an Sharrock, J.T.R. (1983) The Shell interview on 'McGregor's Gathering' on Guide to the Birds of Britain and Radio Scotland. Ireland. Michael Joseph, London. Finally, however, we were hugely Lewington, lan, AIstrom, Per & Colston, gratified by the impeccable behaviour of Peter (1991). A Field Guide to the Rare and genuine warmth and gratitude expressed Birds of Britain and Europe. Harper by the 300 or so visitors for allowing them Collins. into our house to see the bird. Donations National Geographic Society (1987). Field amounting to £110 were collected for Guide to the Birds of North America, Hessilhead Wildlife Rescue Trust and a Second Edition. Washington. donation of £20 to Lega Italiana Protezione The Photographic Guide to Birds of Britain Uccelli (UPU) was also made. & Europe, (1988). Hamlyn, London.

Ian Shedden, 37 Laburnum Lea, Hamilton ML3 7LY.

The Dark-eyed Junco, also called the Slate-coloured Junco, enjoys a wide distribution in North America, where it breeds in the north-eastern USA and in parts of Canada (while other forms breed further west). It winters over much of USA and Southern Canada. Eds. 282 Scottish Birds (1992) 16: 282-288

Short Notes

Merlins' hunting effectiveness In Britain the prey of Merlins Falco Apparently, few statistics have been columbarius ranges from day-flying insects documented on the hunting success rates of to relatively large birds such as pigeons Merlins in the breeding season. Most Columba spp. and Lapwings Vanellus statistics have been on the analysis of prey vanellus, in both breeding season and in remains at nest sites. However, Bengtson winter (see e.g. Newton, I., Meek, E.R. & (1975. laktbeteende och bytesval hos en Little, B. 1984. Breeding season foods of islandsk population av stertfalk. Fauna och Merlin in Northumbria. Bird Study 31 : Flora, Upps. 70: 8-12) found that 11.40/0 of 49-56; Dickson, R.C. 1988. -Habitat 61 hunts in Iceland were successful (9.8% preference and prey of Merlins in winter. by hunting pairs). In addition, there are a Brit. Birds 81: 269-274). Hunting success few published estimates on hunting forays and techniques may vary according to in winter, often associated with large methods and defences adopted by their prey concentrations of prey. Rudebeck (1951. species to elude capture. Other variables The choice of prey and modes of hunting include the difference between experienced of predatory birds with special reference to adults and inexperienced juveniles, their selective effect. Oikos 3: 200(231) differences in hunting efficiency between recorded 139 hunts by migrating Merlins in individual birds, the number of Sweden of which seven were successful inexperienced prey species available, giving a success rate of 5 %. Meinertzhagen whether the species are tired migrants or (1959 . Pirates and Predators. London) resident winter flocks and so on. These observed 100 hunts in Iceland, Scandinavia, variables are difficult to assess but this paper Britain, Egypt and Germany of which 15 estimates hunting success rate as the (15%) were successful. Page & Whitacre percentage of individual forays that result (1975. Raptor predation and wintering in prey capture (Johnsgard, P.A . 1990. shorebirds. Condor 77: 73-83) recorded 343 Hawks, Eagles and Falcons oJ North hunts on wintering wader flocks by one of America. Smithsonian Institute Press, the North American subspecies of Falco Washington and London). columbarius in California, and in this case

Table 1. Hunting success rates of Merlins.

No. of hunts Prey % success Source 61 Breeding season birds 11.4 Bengtson 1975 139 Autumn migrants 5.0 Rudebeck 1951 100 Various species 15.0 Meinertzhagen 1959 343 Wintering waders 12.8 Page & Whitacre 1975 111 Wintering Dunlins 22.5 Buchanan et al. 1988 270 Wintering waders and 10.0 Original observation passerines 19 Passerines at roost 21 .0 Original observation 1992 Short Notes 283

Table 2. Number and success of attacks on prey species by Merlins in west Galloway in autumn and winter 1965-92.

Species attacked Attacks (n) Successful attacks (n) blue brown blue brown Waders (1) 12 2 Thrushes (2) 1 5 1 Starling 2 19 4 Skylark 8 92 6 Finches (3) 23 47 2 5 Meadow Pipit 1 23 3 Others (4) 2 8 Unidentified small passerines 5 22 1 Totals 42 228 5 22

Blue = probably cock Merlin; Brown = juvenile or female

1. Includes Turnstone, Dunlin, Ringed Plover, Lapwing, Redshank and Curlew 2. Includes Redwing, Blackbird and Fieldfare 3. Includes Greenfinch, Redpoll, Linnet, Twite and Chaffinch 4. Includes Pied Wagtail, House Sparrow, Woodpigeon and rabbit

Table 3. Number and success of attacks on prey species by Merlins at one of their winter roosts in west Galloway, 1970-91.

Species attacked No. of attacks Successful attacks blue brown blue brown Meadow Pipit 6 Red poll 2 Skylark Fieldfare Starling Unidentified small passerines 3 4 2 Totals 4 15 4

Blue = probably cock Merlin; Brown = juvenile or female. 284 Short Notes S8 16 (4)

12 .8OJo were successful. Buchanan et al. N = 5; February 4.4OJo, N = 3; March 10OJo, (1988 . Merlin predation of wintering N = 2) . Dunlin: hunting success and escape tactics. In west Galloway most hunting in Wilson Bull. 100: 108-118) studied the winter is by day but occasionally at roosts success rates of Merlins hunting Dunlin where a higher success rate was recorded Calidris aptina flocks in western from a small sample. Of 19 hunts recorded Washington State and found a success rate at roosts, four or 21OJo were successful of 22 .5OJo from III observed hunts (Table (Table 3). Sys (1982. Waarnemingen op een 1). gemeenschappelijke slaapplaats van In a study of the prey of Merlins in Smellekens Falco columbarius. Wielewall winter in west Galloway between 1965 and 48: 360-367) also stated that Merlins had a 1985 Dickson (1988; Dickson, R.e. 1989. greater hunt success at a roost in Belgium Restricted winter range of a Merlin in west but gave no details. This higher rate might Galloway. Scot. Birds 15: 131-132) recorded be because of the victims' lack of awareness 163 hunts of which 9.2OJo were successful. of the presence of the falcon in the half­ Further observations to March 1992 add light, or because of the falcons' greater need another 107 hunts, giving a total of 270 of to feed before roosting and hence greater which 27 (10OJo) were successful (Table 2). vigour, or because of the Merlins' greater The monthly differences in success rates in visual acuity than their prey. winter, however, ranged from 4.4 - 20OJo These examples suggest that Merlins (August/ September 20OJo, N = 3; October hunting birds have a low success rate in 5.7OJo, N=3; November 17.5l1fo, N = 7; autumn and winter (5-22.5OJo, average December 13 .8OJo, N=4; January 11.1OJo , 14OJo ).

R. C. Dickson, Lismore, New Luce, Newton Stewart DOS OAJ.

Great Skuas attacking a flock of moulting Eiders On 17 August 1992 I saw two loose flocks Eider before they dived too deep, mostly of c.110 and c.36O moulting drake Eiders only submerging their head and neck in the Somateria mollissima sleeping on the sea to attempt although occasionally all but the the west of Sumburgh Head, Shetland. A wingtips were underwater. Having failed at few minutes later I noticed that the birds in this, the skuas would then lunge a few times the larger flock were alert and had gathered at the birds on the surface before taking off together in a tight formation typical of and circling over the flock again. In about moulting Eiders when disturbed. The source 40 'plunge-attacks' , I only once saw an of the disturbance became obvious when a Eider caught but the skua was almost circling Great Skua Catharacta skua completely underwater by that time and the suddenly plunge-dived into the middle of the Eider escaped. After 15 minutes of fairly flock , causing the nearest Eiders to dive and continuous attack, the skuas remained the birds on the edge of the flock to splash sitting on the sea while the Eiders swam off away from the skua in panic. A second skua around the southern tip of Surnburgh Head. soon joined in and the two repeatedly The increased predation of seabirds by attacked the Eiders which kept diving, Great Skuas in Shetland in recent years splitting into smaller flocks and regrouping. (Hamer, K.C., Furness, R.W. & Caldow, Typically the skuas simply crash-landed in R.W.G. 1991. J. Zool. Lond. 223: 175-188) the middle of a flock and tried to catch an has led to some unusual observations, 1992 Short Notes 285 including the killing of adult Gannets Sula of waders and smaller gulls are now not bassana (D. Suddaby, pers. comm.), Great uncommon sights. However, this was the Black-backed Gulls Larus marinus (M. first time I had seen determined attacks on Melior, pers. comm.), and even other adult a flock of moulting, flightless Eiders. Great Skuas (pers. obs.), while aerial chases

Martin Heubeck, Department of Zoology, University of Aberdeen, TilIydrone A venue, Aberdeen AB9 2TN.

Predation of birds' eggs and chicks by herbivorous mammals Furness (1989. The predation of Tern chicks 498-499). Sheep may also take the eggs of by sheep. Bird Study 35: 199-202) described other birds on North Ronaldsay, including predation by sheep of chicks of Arctic Terns Arctic Skua and Arctic Tern. Sterna paradisaea and Arctic Skuas In Shetland, live and dead chicks of Stercorarius parasiticus on Foula, Shetland. Arctic Terns and Arctic Skuas mutilated in He could find no similar instances in the the way described by Furness (1988, 1989) literature except his own observations of have been found many times over the past predation of Manx Shearwaters Puffinus 15 years in a number of different localities, puffinus by red deer on Rhum (Furness, including Papa Stour and Whalsay (J .D. R.W. 1988. Predation of ground-nesting Okill pers. comm.). In an Arctic Tern seabirds by island populations of red deer colony on Unst, dead chicks found in 1991 Cervus elaphus and sheep Ovis. J. Zool., were believed to be the victims of Shetland Lond. 216: 565-573). However, MacDougall ponies (pers. obs.) while, during hide (MacDougall, P. 1992. Lesser Black-backed watches on Papa Stour in 1989, not only Gull corpse scavenged by sheep. Brit. Birds were sheep seen taking Arctic Tern chicks 85: 313.) pointed out that the habit of but on one occasion a rabbit dragged a chick chewing the legs of tideline bird corpses is down its burrow! (G.M. Scanlon pers. common amongst the native sheep on North comm.). In 1990, on Hermaness, Unst, two Ronaldsay, Orkney. This habit was also small Guillemot Uria aalge colonies recorded by Lockley (1938. I know an containing a total of over 600 individuals Island. London). Other observations show were completely abandoned by early June that predation by herbivorous mammals is after predation by a trapped, hungry sheep. widespread in the Northern Isles. Many predated eggs were found, crushed North Ronaldsay sheep remove the legs and punctured in a fashion consistent with and frequently the bills of almost all tideline the sheep's dentition. corpses on the island. They also eat Arctic These casual observations suggest that Tern chicks (pers. obs.), and have been predation of birds' eggs and chicks by sheep recorded eating the eggs of Ringed Plovers and other herbivorous mammals is not Charadrius hiaticula (Walker, K. 1966. The unusual, at least in conditions where mineral birds of the island. In: Scott, M. Island deficiencies in the herbivores' diet are likely. Saga. Aberdeen). This may be why many Such deficiencies were suggested by Furness Ringed Plovers on the island nest in covered (1988 , 1989) as the origins of such sites (Pennington 1992, Ringed Plovers behaviour. nesting in covered sites. Brit. Birds 85: M. G. Pennington, 9 Daisy Park, Baltasound, Unst, Shetland ZE2 9EA. 286 Short Notes S8 16 (4)

Unusual Buzzard nest sites in Glen Roy In 1985 I was shown the nest of a Buzzard Vol. 2), and in the Uists they have been Buteo buteo in Glen Roy. It was located recorded on flatter ground also (Newton, I. amongst deciduous trees in a conifer 1979. Population Ecology oJ Raptors. plantation, but its position was unusual in Poyser, London), such sites are clearly rare. that it was at ground level at the bottom of The trees around the Glen Roy site, a bank overhanging a burn at the base of although mature, did not contain suitable alder trees Alnus glutinosa. The bank typical nesting places. In the years 1985-87, extended for c.W metres at a slope of about a total of three young fledged from the 45 with bracken Pteridium aquilinum, short seven eggs laid in this nest. Only two eggs purple moor grass Molina eaerulea and were lost to predation, both in 1986. various moss species growing on it. The nest In 1988, a new nest was built on the was supported, cradle-like, principally by opposite side of the burn but close to the the alder trees (see diagram below). first. This one was in a small birch Betula Although very occasionally nests are known pendula about 2 metres above ground level. to occur on steeply sloping ground (Cramp, This is lower than the three metres normal S. & Simmons, R.E.L. (eds). 1980. The minimum for tree nests (B WP Vo12) though Birds oJ the Western Palearetic. Oxford. similar heights have been recorded in 1992 Short Notes 287

Speyside (Brown, L. 1976. British Birds of In spite of the abundance of trees, a Prey. Collins. London). A total of five lack of suitable nest sites exists in this area, young were fledged from this new nest in but this has clearly not prevented Buzzards 1988 and 1990. Neither nest was used in from breeding successfully in these unusual 1991, nor in 1992. places.

Dominic Sargent, 'Cruach Innse', Roy Bridge, Inverness-shire PH]1 4AJ

Unripe grain, a major food for young finch-like birds D. MacdonaId (1965, ScOtl. Birds 3: grain field to feed young in a nest in gorse 235-246» wrote that the most frequent food 400 metres away. Later I saw Corn Buntings items brought to nestling Corn Buntings striking greenish grains against the tops of Miliaria calandra in Sutherland were "green posts, wire, stones and drystone walls, caterpillars and an unidentified whitish before feeding the paste to their young. substance which was carried in large Since then I have often seen Tree Sparrows, billfulls". While watching north-east House Sparrows, Chaffinches, Scottish nests in 1989 I noted that hens often Greenfinches and Yellowhammers (Passer fed their nestlings on a pale green or off- montanus, P. domesticus, Fringilla coelebs, white paste. In Angus in 1990 I identified Carduelis chloris and Emberiza citrinella) it. A hen with fledged young was feeding flying with grain paste to feed nestlings, and them mainly on grain. After taking a grain feeding fledged young on it at the edge of from the plant, she rolled it round inside her grain fields. It is one of the main foods open bill, using her tongue to do so, taken by Corn Buntings to young in and out whereupon the husks fell off, tom from the of the nest, often even from the day of grain by hard ridges inside the bird's bill. hatching. It is particularly predominant in I had often seen various bunting, finch and cold wet weather when insects are less sparrow species do this while feeding on available, but is less frequent in areas with grain; each grain takes several seconds of very abundant insects. bill-rolling, except for threshed wheat, Barley, wheat and oats are all used. which lacks husks. The hen Corn Bunting Adult Corn Buntings prefer ripe grain for did this, grain by grain, until she had feeding themselves, but for their young they enough to feed to a chick, and then returned prefer grain with a slightly greenish tinge. to the grain field to repeat the process. She Bright green, completely unripe grain, at a often speeded up the act by taking several stage with a high liquid content, is not used. unhusked grains in her mouth, flying to a The material used has a higher protein and nearby tarmac road, and striking each grain lower starch content than ripe grain, and so against the road, whereupon the husks approximates more to the high-protein food quickly fell off. While doing this she available in insects. In north-east Scotland, dropped some green bits but then picked winter barley provides this food in late May- them up before flying to the young. She mid July, winter wheat in mid June-mid often came to the road to husk grains, but September, and spring barley and spring once husked them by striking them against oats in late June-September. Hence the hard compacted earth at a field edge. A season when this food is available starts Linnet Carduelis cannabina repeatedly took much earlier if winter grain is present. grain paste from the tarmac road by the Adam Watson, clo Institute of Terrestrial Ecology, Banchory, Kincardineshire AB]1 4BY. 288 Short Notes 58 16 (4)

Heron attacked by Osprey On 25 August 1990, we watched two occasions. The Heron came swimming from Ospreys Pandion haliaetus sitting in a dead behind the promontory with the Osprey Scots pine on the far side of a lochan in diving towards it. The Heron reacted to the Perthshire. This tree was about 500 metres diving Osprey by retracting its head and from another pine in which their nest was neck and continued swimming for the situated. A Grey Heron Ardea cinerea was nearest shore from which it flew away from fishing on the edge of the lochan using the the lochan. It was not pursued by the Osprey 'wade or walk slowly method' (Voisin, C. which flew to a tree close to the young bird. 1991. The Herons oJ Europe. Poyser, Grey Herons have been observed London). We watched until it disappeared swallowing Mallard Anas platyrhynchos behind a low rocky heather-covered ducklings (Scot. Birds 16: 44), catching, promontory. Some time later we heard and killing and swallowing Hoopoe Upupa saw a juvenile Osprey in the heather close epops and eating birds as large as Redshank to the nest tree. The young bird called Tringa totanus and Ruff Philomachus persistently. An adult flew towards it and pugnax (Brit. Birds 84: 57-68). However, made rapid dives towards the water behind whether the Osprey attacked the Heron the promontory. These rapidly repeated because it was a competitor for food or a dives were unlike the normal fishing threat to its young we cannot say. behaviour which we have observed on many

Bruce M. Hobson and Elizabeth M. Hobson, Flat 7, 27 Castle Terrace, Edinburgh EH11EL

Correction In . the Short Note by Duncan, Cooper & ones. Amongst birds males usually nest Leitch (Scot. Bird 16: 22) on natal closer to their site of hatching than do philopatry in female wigeons, the editors females but, as stated in the note, a variety added a reference to the important article of duck species have been found to be an by Greenwood (Anim. Beha v. 28, exception to this rule. As Greenwood 1140-1167), but unfortunately the word showed, the situation is the opposite in 'female' dropped out in the printing process, mammals, where, in most species, females thus inadvertently implying that natal breed closer to their site of birth than do philopatry is rare amongst birds generally, males. We apologise to the authors for this whereas the intention was to indicate that slip and thank Cliff Henty for pointing it female birds are less philopatric than male out to us. Eds. Scottish Birds (1992) 16: 289-290 289

Correspondence (The Editor welcomes correspondence on addressed to the Editor and that personal suitable topics in Scottish Birds. It is or libellous comments should be avoided. essential, however, that all letters are Eds.)

Letters

Bail/on's Crake at Fair Isle We read with interest the article by Suddaby significance of particular specimens is not and Harvey in Scottish Birds 16(3): 211-214 always recognised until later generations. about the occurrence last autumn of a Incidentally, the 1929 Fair Isle specimen, juvenile Baillon's Crake Porzana pusi/la at referred to by Suddaby and Harvey was Fair Isle. The bird was found dead on 2 deposited in the Museum by George Stout October and rurnour has it that the specimen (Reg. no. NMSZ 1929.70). was prepared privately as a mount. This There is no indication of the current raises a general concern as to the fate of location of the 1991 crake or, indeed, dead rarities over the recent past. whether it is still in Scotland. If it has been It was not long ago that it was the mounted, will the possessor be willing to (almost) universal practice for Scottish send it to others for examination and rarities to be deposited at the Royal Museum comparison? Is it free of light damage and of Scotland for incorporation into the pest attack? (Specimens exposed even to low national collection (for example see levels of sunlight can be bleached within a countless articles in Annals of Scottish year or two.) Where will the specimen be in Natural History/Scottish Naturalist, and 10, 50 or indeed 100 years time? various species accounts in Baxter and We believe that the aims of ornithology Rintoul (1953) The Birds of Scotland and are better served if rarities are deposited in Thorn (1986) Birds in Scotland), which permanent reference collections where they means that the material is freely accessible are freely available to interested parties. to any bona fide ornithologist, and easily There have been several instances in the last compared with other series of skins. As few years where rarities have been retained mounted birds generally have a limited life by individuals. We suspect that, however and are difficult to store, most material is well-intentioned this is, it is almost certain prepared as cabinet skins which store well that these specimens will be lost to science and which are also convenient for posting in a few decades (or in any case after the locally and internationally. This widens their death of the owner). availability. This letter has been written as a Skins in the museum are maintained in reminder that the Bird Section has a light-proof and insect-proof cabinets and continuing need for new specimens, whether remain in good condition indefinitely. Some rare or common, for reference purposes. specimens here are 200 years old yet remain Perhaps the lack of public awareness of this in as good condition now as the day they reflects our own failure to make this were prepared. Furthermore, the requirement more widely known.

R. Y. McGowan & Andrew Kitchener, Bird Section, Department of Natural History, Royal Museum of Scotland, Chambers Street, Edinburgh EH] ]JF. 290 Correspondence S8 16 (4)

Discoloured Peregrines in the north of population of Fulmars, or because of Scotland consequent disputes between the two species over nest-sites. The account by G.G. Bates of a pair of dark The present incident seems increasingly Peregrines Fa/co peregrinus in north serious because not only may both members Sutherland (Scott. Birds 16: 219) seems of a pair of Peregrines have been affected, reminiscent of a number of similar reports but they nested late and the eggs apparently eventually attributed to oiling by Fulmars failed to hatch, perhaps because if eggshells Fu/marus g/acia/is in the early 1970s. They become oiled the embryo may suffocate. are discussed by Andrew Clarke (J. Zoo/., This might therefore provide one Lond. 181: 11-20), who was able to quote explanation for the decline of northern and nine incidents all in the north of Scotland. western Peregrines reported in Scottish Bird Where details were supplied all were adults News 26. Perhaps it is time for further affected in the summer, and some of the investigation of the problem, and the early birds died. Clarke speculated that the discouragement of any Fulmars settling near Peregrines may have become oiled either possible future. Peregrine nest-sites before when they tried to prey upon the increasing the falcons occupy them?

W.R.P. Bourne, Department of Zoology, Aberdeen University, Tillydrone Avenue, Aberdeen AB9 2TN.

Pied Wheatear in Shetland In our last issue under the heading 'Rare at the end of the note. The bird was found Migrants' (Scottish Birds 16: 214-216) it was by Dennis Garrett, was accepted by the stated that a Pied Wheatear Oenanthe British Birds Rarities Committee and pieschanka in Shetland on 9 October 1991 became the second record for Orkney. The was the fifth record for Scotland. Several record is mentioned by M.J. Rogers and the people have since written in to say that this Rarities Committee (1989) in 'Report on bird was in fact the sixth record, and that rare birds in Great Britain in 1988' (British a first winter female on Stronsay 16-20 Birds 82: 505-563). Our thanks to everyone October 1988 had been omited from the list who wrote in to put us right.

Eds. Scottish Birds (1992) 16: 291-296 291

Research Index especially changes in compartment size; based at Kielder, Northumberland and The following is an index of fieldwork and Cowal, Argyll. research presently undertaken with specific Patterson, I.J. & Laing, R. Monitoring Scottish interest. This index is updated every of wildfowl and wader numbers on the year and researchers are either listed Ythan estuary, Grampian. Twice­ alphabetically by the institutes where the monthly counts throughout the year, research is based, or in two cases (SNH & with special emphasis on the Eider Duck RSPB) by the topics and species researched. in the breeding season. If you are doing research in this area and Rae, S. Habitat use by Ptarmigan, especially not listed here, or know of someone who in the breeding season, in relation to is, please put us right by sending details to vegetation type and reproductivity, the editor. cover and other environmental factors (with SNH/Des Thompson, PhD Aberdeen University: study). Cosgrove, P. The importance of conser­ vation zones for bird populations in Edinburgh University: upland spruce forest, concentration on Carter, Adrian. Feeding behaviour and broadleaf strip. unplanted stream edges, micro-habitat distribution of waders on marshes, etc, in otherwise unbroken rocky shores, especially in East Lothian conifer. Based at Kielder, (MPhil study). Northumberland (PhD study). Cresswell, Will. Behaviour and ecology of Dunnet, G.M. The Fulmar on Eynhallow a predator-prey system: Sparrowhawks in Orkney (since 1950) concerned and Redshanks, concentrated on primarily with population dynamics, Tynninghame, East Lothian (PhD longevity and, recently, recruitment. study). Dunnet, G.M. & Heubeck, Martin. Deag, John. Studies on communication and Monitoring programme (since 1978) in social organization in tits, with field breeding sea bird populations in work mainly at Orrniston, East Lothian Shetland, as well as changes in seabird (PhD study). and waterfowl wintering populations in Hanna, Laurel. Barn Owl population two areas: Yell Sound and Sullom Voe genetics (PhD study). and the Bluemull/Colgrave Sounds area McAfferty, Dominic. Ecological energetics of north-east Shetland. of Barn Owl (PhD study). Gorman, Martyn L. & Reynolds, Peter. Scott, Graham. Social behaviour and Feeding ecology of raptors (Short-eared communication in Blue Tits (PhD Owl, Hen Harrier and Kestrel) in study). Orkney, particularly concerned with the Taylor, lain. Long-term study (started 1978) effects of changes in land-use. of Barn Owl ecology and conservation. Patterson, I.J. & Fuchs, R.M.E. Manage­ Has been monitoring, since 1980, ment of grassland to provide reserves changes in Lapwing breeding density in for wild geese; experiments with relation to agriculture. different mowing, grazing and fertiliser regimes at the RSPB reserve at the Loch of Strathbeg, Grampian. Glasgow University Patterson, 1.1. & Ollason, J.G. Bird Askew, C. Survival rates and ecology of population density and species diversity Great Skuas on Handa: comparison of in upland spruce plantations, in relation a small and expanding population with to different management regimes the large decreasing one on Foula. 292 Research Index 58 16 (4)

Austin, G. The ecology of Buzzards in Macedo, E. Effects of fisheries on seabird Argyll in relation to land use (PhD numbers: and assessment of net study). mortality and fishery-induced changes Barber, I. Breeding performance of sea­ in food availability (MSc study). birds on Handa in relation to industrial Madders, M. Hen Harrier ecology, especially fishing development (MSc study). their use of forestry plantations (PhD Bolton, M. Energetic costs of breeding in study). Storm Petrels. Metcalfe, N.B. Social behaviour and Calvo, B. Effects of agricultural land use ecology of flocking birds: reproductive on the breeding ecology of waders (PhD ecology of Pied Flycatchers. study). Monaghan, P. Population ecology of gulls. Calvo, B. & Furness, R.W. Endosteal Monaghan, P., Burns, M. & Walton, P. lamellae in bird bones as a means of Reproductive strategies in Black estimating the age of dead adult birds. Guillemots. Cohen, B.L., Wildon, R.H., Furness, R.W. Monaghan, P., Burns, M., Uttley, 1.D., & Willcox, S. Molecular studies of skua Walton, P. & Austin, G. Effect of prey DNA to assess the evolutionary history availability on reproductive and of skuas. foraging strategies in Shetland seabirds. Crompton, D.W.T. & Huntingford, F.A. Monteiro, L. Heavy metal accumulation Profilicollis botulus: an Eider Duck by petrels and shearwaters (PhD study). parasite in the Clyde Estuary. Muda, F. Nest material stealing in Shags Ensor, K. Breeding season diets of Great (PhD study). Skuas and gulls in relation to the Phillips, R. Population ecology of Arctic activities of the whitefish fisheries Skuas in relation to climate and around Scotland. variations in numbers and reproductive Furness, R. W . Seabird interactions with fish success of the species they rob of fish stocks and fisheries, birds as monitors (PhD study). of environmental change, long term Purton, M.D. & Solomon, E.E. Eggshell monitoring of seabird ecology on Foula, formation in cage birds. Shetland (since 1971), seabird Ratcliffe, N. Reproductive effort of Great energetics, body composition and Skuas of known ages from 4 to 30 years moult. old: a test of predictions of life history Furness, R.W, Hamer, K.C., Klomp, N.!. theory (PhD study). & Ratcliffe, N. Ecology of Great Skuas Selman, R. The role of female body con­ on Foula, Shetland: long term studies dition on egg production in birds (PhD begun in 1960s. study). Hansell, M.H. A comparative study of nest Smith, R.D. Dispersal and behaviour of building behaviour in birds. over-wintering Snow Buntings (PhD Horn, W. Diet selection and foraging study). economics in breeding terns (PhD Solomon, S.E. Comparative study of the study). ultrastructure of eggshell formation in Houston, D.e. Food quality and breeding birds. performance in Blue Tits. Stewart, R.M. Uptake, storage and Klomp, N.!. & Furness, R.W. Recruitment excretion of cadmium and lead by birds of immature Great Skuas into breeding and an assessment of birds as monitors colonies (comparative work with of cadmium and lead pollution (PhD Professor E.e. Young, University of study). Auckland, in southern hemisphere Thomas, e. The ecology of Ravens in skuas). relation to land use (PhD study). 1992 Research Index 293

Thomson, D.L. Energetics and ecology of WanIess, S., Harris, M.P. & Hector, l.A.L. Kittiwakes (PhD study). Reproductive and foraging energetics of Thompson, D.R. & Furness, R.W. Analysis Shags with particular emphasis on the of stable isotope ratios of nitrogen, influence of food availability and carbon and other elements in feathers feeding habitat. of seabirds as a means of assessing their trophic relationships in marine ecosystems and changes in diet of the Joint Nature Conservation Committee: last 150 years. Seabirds Team, Aberdeen Walsh, P .M. Feeding ecology and mercury Mark Tasker, head of Seabird Team. burdens of Gannets (PhD study). Paul Walsh, Seabirds Colony Register - Williams, l. Birds as possible carriers of collates counts of seabirds at colonies Lyme disease (PhD study). throughout the U.K. Zonfrillo, B. Breeding ecology of seabirds on Ailsa Craig (PhD study). lNCC Seabirds at Sea Team (SAST). Institute of Terrestrial Ecology, Banchory: Studies the distribution of seabirds in the offshore waters around Britain throughout Bacon, P.l. & Palmer, S.C.F. (Oxford). the year. Staff: Andy Webb (leader), Investigation and modelling of habitat Carolyn Stone (marine biologist), lames utilisation by Red Grouse. Williams (data manager), Tim Barton and Harris, M.P. & Nuttall, P. The importance lan Gordon (ornithologists). of tick-borne diseases on seabird populations. lan Carter, North Sea Database - compiling Harris, M.P. , Halley, D. (St Andrews) & database of seabirds in the North Sea using Wernham, C. (Stirling). Long-term data from seven countries bordering the studies of numbers, survival, North Sea. productivity and for some species, recruitment and body condition, of seabirds on the Isle of May in relation to food availability and environmental The Royal Society for the Protection of conditions. Birds: Marquiss, M., Carss, D. & Alexander, G. The RSPB undertakes extensive research Does Goosander and Red-breasted into all aspects of birdlife. The following Merganser predation have an impact on projects with particular Scottish interest are salmon populations. listed in order of topics and species involved. Moss, R., Parr, R., & Trenholm, I. Staff and researchers involved are given in Population regulation in Red Grouse. brackets. Further details may be had from Roles of behaviour, dispersal and the RSPB HQ, who produce an annual predation in determining population Project Register, which also gives details of size. projects on reserves ecology, too numerous Moss, R., Picozzi, N. & Catt, D.C. Studies to list here. of habitat requirements, dispersal, numbers and distribution of Fisheries statistics. Review of fisheries Capercaillie; particularly the use made statistics, for countries fishing in EC by Capercaillie of commerical waters (1992-93 l. Sears, S. Curran). woodland. Changes of Distribution of breeding birds Parr, R. A study of population size and (with BTO), using data gathered by the productivity of moorland waders and BTD atlas projects (1991-94 K.W. Red Grouse in relation to afforestation. Smith, D. Gibbons BTO). 294 Research Index 5816 (4)

Individual distinct bird calls. Investigation and productivity (with Irish Wildbird into the effectiveness of using call and Council Project to estimate the effect of song. Species include Bittern, Black­ mowing at different times of year, at throated Diver and Corncrake (K.W. different mowing speeds and patterns Smith, P. McGregor, G. Gilbert (1992-95 R.E. Green, G.A. Tylor). University of Nottingham PhD study Lowland breeding waders in Scotland and I 990-93). Northern Ireland. A joint project with Orkney and Shetland seabirds. Monitoring SOC. Designed to be repeatable numbers, breeding success and body (1992-94 R.E. Green, K.W . Smith, M. condition to contribute to the debate on O'Brian). the future of sandeel fishing and RSPB Red-necked Phalarope ecology. Iden­ marine policy (1992-93 J. Sears, D. tification of habitat requirements, Suddaby, I. Sim). particularly those susceptible to The effect of loch quality on the breeding management (1992-95 R.E. Green, M. productivity of Black-throated Divers O'Brian). and Slavonian Grebes (1992-95 R.W. Orkney and Shetland skua survey to assess Summers, D. Jackson). Arctic and Great Skua population Loch Gruinart: Goose counting, reseeding changes since 1>revious surveys (1992-93 and goose usuage experiments (M. J. Sears, P. Ellis, E. Meek, D. Suddaby, Peacock, J . Fleming, I. Bainbridge, G. I. Sim, H. Harrop, A. Williams, D. Hirons, C. Evans, J. Welstead, S. Steel, C. Whyte, R. Ribbands, RSPB Percival Durham University PhD Study and SNH wardens). 1992-95). Roseate Terns. A study to monitor the Osprey population dynamics (1992-93 R.W. breeding range of the eastern Atlantic Summers/ R.H . Dennis consultant). population, to· identify its wintering Causes of poor breeding success in White­ range, and to study threats to the tailed Eagle with JNCC. (1992 R.E. species. (1988-1994 A.J. del Nevo). Green, K.W. Smith, A . Hughes). Nightjar survey (1991-92), using amateur Golden Eagle home range use. Investigation and professional fieldworkers, to count of use of habitat by radio-tagged and map all Nightjars breeding in the Golden Eagles; relating habitat use to UK, and to assess their requirements by prey abundance, cover and topography detailed habitat measurements. (1991-95 R.E. Green, M.J. Mcgrady, J. Numbers of Crested Tits, Crossbills and Grant). Capercaillie in Highland pine woods to Merlins and land cover. Relating spacing, determine relative abundance, densities occupancy and breeding success at and tree preference (1992-95 R. W. known Merlin sites to surrounding Summers, G. R,ebecca) . vegetation and topography through Second international Chough survey (with airphoto interpretation (1992-93 R.E. Irish Wildbird Council, JNCC, Manx Green, R.W. Summers, G. Rebecca). Chough Project and others). To Breeding success and habitat selection of estimate 1992 population in Ireland and Capercaillie, especially at the Abernethy Britain by a full survey (R.E. Green). reserve (1991 -93 R.W. Summers/ R. Proctor). St Andrews University Survey and monitoring of Capercaillie Adhikerana, A.S. 'Singing behaviour in populations (with ITE, Game Coal Tits (PhD study 1988-92). Conservancy, SNH and Forestry Graves, J .A. & Ortega-Ruano, J. Mating Commission) (1991 -94 R.E. Green). and reproductive success in Shags on the Impact of mowing on Corncrake survival Isle of May. 1992 Research Index 295

Halley, D. A study of recruitment in outside protected areas in line with UK Guillemots on the Isle of May (PhD responsibilities under the EC Birds study 1988-92). Directive. JNCC. (Colin Galbraith, Povey, Fiona & Jones, Alex. Aspects of JNCC). song development in Zebra Finches in Services in wildfowl research, including the laboratory (PhD studies). the National Waterfowl Count scheme. Slater, P.J.B. Field and laboratory studies JNCC/ Wildfowl and Wetlands Trust. on the development and organisation of (Greg Mudge/David Stroud, JNCC). bird vocalisations. Conservation plans for migratory wildfowl under the Bonn Convention and Ramsar Convention. JNCC/Inter­ national Wildfowl and Wetland Scottish Natural Heritage: Research Bureau. (David Stroud, SNH is involved in a wide range of work JNCC). on birds. Much of this is currently Moorland bird surveys; techniques and contracted out to other organisations, and ecology. (Des ThompsonlAndy Brown, some is managed on its behalf by the Joint English Nature). Nature Conservation Committee (JNCC). Moorland changes and influences on birds Names of individual workers are not in the Northern Isles. (Angus attached to the following list, although the MacDonald/Des Thompson). key organisations involved are given, as is Population ecology and conservation of the apporopriate contact person in SNH or montane birds, notably Dotterel, JNCC. The first contact points for further Ptarmigan and Snow Bunting. Philip information on these projects and other Whitfield/ Des Thompson). aspects of SNH's work on birds are Greg Seabird colony register, Maintenance of a Mudge (agricultural/lowland birds) and database of counts of seabird colonies. Philip Whitfield (upland/peatland birds). JNCC/ Seabird Group. (Mark Tasker, Topics are given in order of the species JNCC). involved. Sea bird monitoring programme. Annual monitoring of breeding success at International site designations: review and seabird colonies. JNCC/ RSPBI assessment of bird numbers and SOTEAG. (Mark TAsker, JNCC). distributions with respect to Special Seabirds at sea programme, phase 4. JNCC. Protection Areas and Ramsar sites. (Andrew Webb, JNCC). JNCC. (Greg Mudge/Philip Monitoring of Black-throated Divers. With Whitfield/Colin Galbraith, JNCC). RSPB. (Greg Mudge). Services in ornithology. Including the Birds Goose monitoring on Islay, Long-term of Estuaries Enquiry; national bird monitoring of the numbers and feeding ringing scheme; integrated population distribution of Greenland White-fronted monitoring; monitoring birds of prey; and Barnacle Geese. With the Wildfowl monitoring of wetland birds; special and Wetland Trust. (Greg Mudgel surveys; habitat management research. David Stroud, JNCC). JNCC/British Trust for Ornithology. Comparative feeding ecology of predatory (Greg Mudge/Colin Galbraith, JNCC). birds. Glasgow University. (Des Monitoring of rare British breeding birds. Thompson/ Colin Galbraith, JNCC). JNCC/Rare Breeding Birds Panel. Re-introduction of Sea Eagles. Monitoring (Greg Mudge/David Stroud, JNCC). of the re-introduction population. With Conservation of vulnerable and dispersed RSPB and JNCC. (Greg Mudge/ Mike species. Measures to protect birds Pienkowski, JNCC). 296 Research Index S8 16 (4)

National survey of Golden Eagles. To Ecology and conservation of Pied Fly­ update the results of the previous survey catchers in NW England. Leicester carried out in 1982-83. Joint project University. (Des Thompson). with RSPB and the Scottish Raptor Ecology of Corn Buntings on the Outer Study Groups. (Philip Whitfield). Isles. Leicester University. (Des Red Kite re-introduction: national and Thompson). international co-ordination. JNCC/ RSPB. (Greg Mudge/ Colin Galbraith, JNCC). Effects of predators on Red Grouse and moorland waders in southern Scotland. Stirling University: Institute of Terrestrial Ecology. (Philip Alves, Marie-Alice. Behavioural ecology Whitfield). of Sand Martins (PhD study). Past ecology of Ptarmigan in south Bell, Mike. Wildfowl counts. Breeding Scotland. (Philip Whitfield). wader surveys. Raptor monitoring. Capercaillie: status and habitat needs. Bryant, David . Energy requirements of wild Joint contract with RSPB to the birds. Populations and ecology of Institute of Terrestrial Ecology. (Greg estuarine birds (especially Forth). Mudge). Hirundine and Dipper breeding ecology. Philopatry, fidelity, matingl social systems Jalil, Sari A. Effects of land use changes and conservation in waders (Philip on waterfowl populations. A study Whitfield/ Des Thompson). based on freshwater lochs in central Long term study of Greenshanks in NW Scotland (PhD study). Scotland. (Des Thompson). Johnstone, Ian. Territorial behaviour in Population trends of gulls and other Robins and Dippers (PhD study). seabirds on the Isle of May. Institute of Hashim, Rosli. Ecology and energy Terrestrial Ecology. (Mark Tasker, requirements of Great Tits in summer JNCC). and winter (PhD study). Co-existence on moorland passerines. A Ward, Sally. Egg laying and incubation study of the effects of heather I bracken behaviour in Swallows and Dippers patchiness on the inter-relationship of (PhD study). breeding Meadow Pipits, Skylarks and Wernham, Christine. Breeding ecology of Whinchats. University of York. (Des Puffins (with ITE Banchory - PhD Thompson). study). Scottish Birds (1992) 16: 297-299 297

Items of Scottish Interest Most of the following papers and reports on birds in Scotland are available in the Waterston Library at 21 Regent Terrace for reference, and include all that have come to notice in the period March to August 1992 (the most recent list of items of Scottish interest was in SB 16(3): 226-228). We would be glad to learn of anything that has been missed, and to receive reprints or copies of papers on any aspect of ornithology or natural history. Bird reports marked with an asterisk are available from the SOC at the prices quoted, but please add SOp for postage and packing.

Scientific papers Aebischer, N.J. & Wanless, J . 1992. Relationships Ewins, P.1. 1992. Growth of Black Guillemot between colony size, adult non-breeding chicks in Shetland in 1983-84. Seabird 14: and environmental conditions for Shags on 3-14. the Isle of May, Scotland. Bird Study 39: Furness, R.W. & Aitken, A. 1992. Breeding 43-52. success of seabirds on Handa Island, Baines, D. & Aebischer, N.J. 1992. Black Grouse: Sutherland in 1991. Joint Nature the effects of predator control and Conservation Committee Report no. 48, vegetation cover. Game Conservancy 6 pp. Review of 1991: 98-101. Furness, R.W., Ensor, K. & Hudson, A.V. 1992. Booth, C.J . & Reynolds, R. 1992. Crossbill The use of fishery waste by gull populations eating slug. British Birds 85 : 245-246. around the British Isles. Ardea 80: 105-114. Strange Orkney habits. A study mainly in Scottish waters. Cobley, N. & Moss, R. 1992. Numbers and Grant, M.C. 1992. The effects of re-seeding breeding success of Capercaillie in 1991. heathland on breeding Whim brei in Game Conservancy Review of 1991 : Shetland. Pt. I. J. Appl. Ecol. 29: 501 -508. 102-103. Grant, M.C., Chambers, R.E. & Evans, P.R. Corse, C. 1992. Wader studies in Orkney. Wader 1992. The effects of re-seeding heathland Stlldy Group Bulletin 64 : 37-39. on breeding Whimbrel in Shetland. Pts. 2 Craik, J .C.A. & Becker, P .H . 1992. Temporal & 3. J. Appl. Ecol. 29: 509-523. and spatial variations in body-weights of Harris, M.P. 1991 . Isle of May seabird studies Common Terns and Arctic Terns. Seabird in 1991 . Joint Nature Conservation 14: 43-47 . Committee Report no. 18, 21 pp. Danchin, E. 1992. Food shortage as a factor in Harris, M.P. & Bailey, R.S. 1992. Mortality the 1988 Kittiwake breeding failure in rates of Pu ffin and Guillemot and fish Shetland. Ardea 80: 93·98. abundance in the North Sea. Bioi. Conserv. Danchin, E. 1992. The incidence of the tick 60: 39-46. A study on the Isle of May. parasite Ixodes uriae in Kittiwake colonies Harvey, P.V. & Orsman, C.J . 1991. Fair Isle in relation to the age of the colony, and a seabird monitoring scheme: report to mechanism for infecting new colonies. Ibis JNCC of sixth season's work in 1991 . Joint 134: 134-141. Based on studies in three Nature Conservation Committee Report breeding areas including the Isle of May. no. 22, 64 pp. Dickson, R.C. 1992. Feeding groups of Common Hudson, P . 1992. Upland ecology. Game Scoter containing other species. British Conservancy Review of 1991 : 92-97 . A Birds 85(1): 35-36. short survey of the Conservancy's work on Dowell, A. & Shaw, G. 1992. Barn Owls and Red Grouse in 1991. Tawny Owls nesting close together. British Klomp, N.1. & Furness, R.W. 1992. Non­ Birds 85(7): 379. An unusual occurrence in breeders as a buffer against environmental southwest Scotland. stress, declines in numbers of Great Skuas Elkins, N. 1992. Herring Gull using wind shear on Foula, Shetland, and prediction of over land. British Birds 85( I): 36-37. future recruitment. J. Appl. Ecol. 29: Unusual means of progression over Fife 341-348. airfield. Livingstone, I. & Morton, R. 1992. Recoveries 298 W.G. Harper S8 16 (4)

of Sand a Guillemots and Razorbills. 134: 188-190. A detailed study of a case of Seabird Group Newsletter 62: 11-12. egg destruction. Marquiss, M. & Feltham, M.l. 1991. Predation Wyllie, I. & Newton, I. 1991. Demography of of juvenile salmon by Red-breasted an increasing population of Sparrowhawks. Mergansers. Inst. Terrestrial Ecol. Ann. J. Anim. Ecol. 60: 749-766. Compares the Rep. for 1990-91.: 44-46. recent recolonisation in east-central Monaghan, P ., Uttley, 1.D. & Burns, M.D. England with the stable or decreasing 1992. Effect of changes in food availability populations in southern Scotland, and in reproductive effort in Arctic Terns. discusses causes. Ardea 80: 71-81. A study in Shetland. Okill, J .D. 1992. Natal dispersal and breeding site fidelity of Red-throated Divers in Bird Reports Shetland. Ringing and Migration 13: 57-58. Argyll Bird Report no. 8for 1991 . S.l . Petty (ed) Okill, J .D., Fowler, J .A ., Ellis, P.M. & Petrie, 1992. 67 pp. A 49 pp systematic list and G .W. 1992. The diet of Cormorant chicks short papers on Barn Owls on Islay, in Shetland in 1989. Sea bird 14: 21-26. Buzzard eyries on Colonsay, and Greylag Orchel, 1. & Shawyer, C. 1992. Barn Owl Geese on Coli and Tiree. • £3.50. conservation in southwest Scotland in 1990. Arran Birds in 1991. M.H. Dunn & T. ap Raptor 19 : 17-18. , Rheinallt (eds) 1992. 21 pp. This is the 12th Parr, R. 1992. The decline to extinction of a bird report published for the Isle of Arran population of Golden Plovers in north-east Natural History Society. It includes a Scotland. Om. Scand. 23: 152-158. special report on the Lesser Whitethroat in Percival, S.M. & Houston, D.e . 1992. The Arran. Available from Tristan ap Rheinallt, effect of winter grazing by Barnacle Geese Ashgrove, Pirnmill, Isle of Arran KA27 on grassland yields on Islay. 1. Appl. Ecol. 8HP. £1.50. 29: 35-40. Ayrshire Bird Reportjor 1991. Angus Hogg (ed) Redpath, S.M. 1992. Behavioural interactions 1992.57 pp. A systematic list, and special between Hen Harriers and their moorland articles on Garnock Estuary shorebirds, the prey. Om. Scand. 23 : 73-80. Study areas Black-throated Diver in Ayrshire, Kestrels, were Speyside and Perth shire moorlands. waders and wildfowl. • £2 .75 . Riley, S.J. i992. Purple Sandpipers feeding Dumfries and Gal/oway Region Bird Report for inland outside breeding season. British 1991. Paul Collin (ed) 1992. 34 pp. • £2.00. Birds 85(5): 241. Seen on South Uist. Fair Isle Bird Observatory Report for 1991. Smith, R.D. 1992. Age determination, wing­ P . Harvey & V. Thorn (eds) 1992. 76 pp. feather colour and wing-length changes in Includes a 25 pp systematic list and several Snow Buntings. Ringing and Migration 13 : short articles. • £3 .50. 43 -51. A study at five inland sites in Islay Bird and Natural History Report for 1991 . northeast Scotland. M. Ogilvie (ed) 1992. • £1.50. Spray, C.l. 1991 . Population dynamics of Mute Isle of May Bird Observatory Report for 1990. Swans in the Outer Hebrides, Scotland. lan Darling (ed) 1992. 48 pp. Includes a Wildjowl Supplement no.l : 143. (Abstract migration summary and a ringing report. only). • £3 .00. Swann, R.L. 1991. Canna sea bird studies in Moray and Nairn Bird Report for 1991. Martin 1991 . Joint Nature Conservation Cook (ed) 1992. 69 pp. • £2 .75 . Committee Report no. 19 , 9 pp. Orkney Bird Report jor 1991. C. Booth, Uttley, J .D. 1991. Food supply and allocation M. Cuthbert & E . Meek (eds) 1992. 78 pp. of parental effort in Arctic Terns. Ardea Includes a short report from the North 80: 83-91. A study in Shetland and Orkney. Ronaldsay Bird Observatory, and four Wanless, S. 1992. Effects of tail-mounted short articles. • £2.50. devices on the attendance behaviour of Outer Hebrides Bird Reportfor 1991. T . Dix & Kittiwakes during chick rearing. J. Field P . Cunningham (eds) 1992. 88 pp. This is Orn. 63 : 169-176. the second bird report in a new detailed Wilson, J .D. 1992. A probable case of sexually format, published by the Outer Hebrides selected infanticide by a male Dipper. Ibis Ornithologists' Group. The 67 pp 1992 Items of Scottish Interest 299

systematic list includes bird records from a 3 pp unpublished report in a long-running St Kilda, and there is a special report on series. the spring passage of Skuas off Balranald. Shetland Bird Report/or 1991. K. Osborn (ed) • £4.00. for the Shetland Bird Club 1992. 104 pp. Perthshire (Central and Southwest) Peregrines Includes six special articles and four pages and Ravens in 1991. P . Stirling-Aird 1992. of colour photographs. William G. Harper Librarian, Waterston Library 300 Scottish Birds (1992) 16: 300-301

European journals in the Waterston library The following selection of articles appeared Follestad, E. [Census of Greylag Geese in in European journals received in the Norway Autumn 199n - Vor Waterston Library between April and Fuglefauna 2/92. September 1992, and thus follows on the list Persson, H. [Impact of shooting on breeding published in Vol 16 No 3. Articles are populations of Greylag Geese] - Limosa arranged in species order; square brackets 2/92. indicate that the article is in the original Gauter, B. [Numbers and distribution of language, other articles being in English. Barnacle Geese on North Sea coast of The reference, abbreviated for reasons of Germany] - Corax 1/92. space, indicates merely the journal, its Ebbinge, B.S. Regulation of numbers of number and year of publication. Journals Dark-bellied Brent Geese on Spring quoted are as follows: staging sites - Ardea 2/92. Grussu, M. & Meloni, R. [The Ruddy Duck Netherlands: Ardea, Limosa, Dutch Birding in Europe and its first occurrence in France: Alauda, L 'Oiseau Italy] - Riv. It: di Orn. 1-2/ 91. Switzerland: Nos Oiseaux, Der Orni­ thologische Beobachter Birds of Prey: Belgium: A yes, Mergus Bavoux, C. et al. [Variations in juvenile Germany: Die Vogelwelt, Lim ico la, plumage in Marsh Harriers in Charente Corax, Journal fur Ornith­ Maritimel - Alauda 4/91. ologie, Seevogel Forsman, D. l\geins,and sexing of Rough­ Austria: Egretta Legged BuzzardsJ - Lintumies 1/ 92. Italy: Rivista Italiana di Ornitologia Jenny, D. [Reproduction and regulation Spain: Ardeola of density in an Alpine population of Sweden: Vor Fagelviirld, Ornis Svecica Golden Eagles] - Orn. Beob. 1192. Norway: Vor Fuglefauna, Cinc/us Steen,O.F. [The Peregrine in S.E. Norway Denmark: Ornis Scandinavica, Dansk 1990/ 9(] - Vor Fuglefauna 1/92. Ornitologisk Forenings Tids­ Kery, M. [Resistance of Peregrine eggs and skrift chicks to prolonged absence of adults] Finland: Ornis Fennica, Lintumies - Nos Oiseaux 5/ 92 .

Divers to Ducks: Grouse to Cranes: lborra, o. et al. [Wintering of Black­ Renard, F. [The behaviour of Black Grouse necked Grebe on the Etang de Berre, attacked by Hen Harriers on lekking S.E. Franc~ - Alauda 4/91. areas] - A yes 2-3 / 91. Debout, G. [Use of resting places and roosts Willebrand, T. Breeding and age in female by Cormorants in the non-breeding Black Grouse - Orn. Scand. 1192 . period] - L 'Oiseau 1/ 92. Frederikson, M. [Breeding population of Grey Heron in Denmark I99U - Dansk Waders to Auks Orn. For. Tidsskr. 1-2/ 92. Girard, O. [Migration of waders in Con­ Struwe, B. & Nehls H-W. [Results of the tinental France] - Alauda 1192. International Waterfowl Count on the Barbosa, A. [Identification key to European Baltic coast of Germany January 1990] waders on the basis of cranial - Seev6gel2/92. morphology] - Ardeola 2/91 . 1992 European journals 301

Pulliainen, E. & Saari, L. Breeding biology van Manen, W. [Selection of territory and of the Dotterel in Eastern Lapland - nest site by Long-eared Owls] - Limosa Orn. Fenn. 2/92. 1/92. Gebauer, E. & Nadler, T. [Behaviour and Hansson, L. Requirements of Great Spotted voice of Lesser Sand Plover] - Limicola Woodpecker for a suburban life - Orn. 3/92. Svec. 1/92. OAG Munster & OAG Schleswig-Holstein Virkkala, R. [Distribution of White-backed [Numbers of Ruff on migration in Woodpecker in Finland 1990-91J - Germany 1990J - Vogelwelt 3/92. Lintumies 3/92. Achtermann, S. [Identification of Lesser and Greater Yellowlegs] - Limicola Passerines: 2/92. Ullman, M. [The Shore Lark] - VDr Blokpoel, H. et al. Population dynamics Fagelviirld 3/92. of Lari in relation to food resources Mild, K. [The Thrush Nightingale and (Proceedings of an international Nightingale] - Velr Fagelviirld 4/92. workshop) - special issue of Ardea 1/92. Konigstedt, D.G.W. et al. [Field iden­ Mierauskas, P . & Greimas, E. Taxonomic tification of Isabelline Wheatear] - status of yellow-legged Herring Gulls in Limicola 1/92. the Eastern Baltic - Dutch Birding 3/92. Konigstedt, D.G.W. & Robel, I.D. [The Kilpi, M. et al. Change in clutch size in Isabelline Wheatear in the Balkans] - the Arctic Tern in the Northern Baltic Limicola 1/92. - Orn. Fenn. 2/92. Schulze-Hagen, K. et al. [Reed and Marsh Skov, H. et al. [pistribution and numbers Warblers in the same habitat: laying of Guillemots in the Skagerrak in late time, clutch size and breeding success] summer] - Dansk Orn. For. Tidsskr. - Vogelwelt 2/92. 1-2/92. Folvik, A. Norwegian records of Yellow­ Lust, P. [influx of Little Auks on coast of browed Warbler - Cinc/us 2/92. Flanders 1990-91] - Mergus 4/91. Jarvinen, A. Spatial pattern of nest-box occupancy by the Pied Flycatcher in Pigeons to Woodpeckers: mountain birch forest - Om. Fenn. Schulze-Hagen, K. [j>arasitism and egg 1/92. losses due to Cuckoo in Reed and Marsh Grimsby, A. & Roer, J.E. [Colonisation Warblers in Central and Western of Norway by Lesser Rc;dpoIl1962-91] EuropeJ - Jour. jiir Orn . 3/92. - Cinc/us 2/ 92. Michelat, D. & Giraudoux, P. [Nocturnal de Souza, J.A. [The Snow Bunting in the activity of Barn Owl and hunting Iberian Peninsula] - Ardeola 2/91. strategy at nest site] - Alauda 1/92. Jukema, J. & Fokkema, J. [Origin of Snow Schaden, G. Unfluence of early experience Buntings wintering in the Netherlands] on choice of nest site by Barn Owl] - - Limosa 2/92. Egretta 1/92 (special edition devoted to owls and diurnal raptors) Michael Murphy 302 Scottish Birds (1992) 16 (4)

Advice to Contributors

Authors should bear in mind that only a small italics should follow the first text reference to each proportion of the Scottish Birds readership is species and should follow Voous' 'List of Recent science-trained, and should aim to present their Holarctic Bird Species' as given in The British material concisely, interestingly' and clearly. Birds' List oJ Birds oJ the Western Palearctic Unfamiliar technical terms and symbols should (1984). be avoided wherever possible and if deemed Only single quotation marks should be used, essential should be explained. Supporting statistics and numbers one to ten should be written out should be kept to a minimum. All papers and whereas 11 and above should be written as short notes are accepted on the understanding that numerals. Dates should be written: ...... on they have not been offered for publication 5 August 1991 ...... but on the 5th (if the elsewhere and that they will be subject to editing. name of the month does not follow). Please note Papers will be acknowledged on receipt and will that papers shorter than 700 words will be treated be reviewed by at least two members of the as Short Notes where all references should be editorial panel, and in some cases also by an incorporated into the text, and not listed at the independent referee, before being accepted. They end, as in full articles. will normally be published in order of acceptance Tables, maps and diagrams should be of fully revised manuscripts. The editors will be designed to fit either a single column or the full happy to advise authors on the preparation of page width. Tables should be self-explanatory and papers. headings should be kept as simple as possible, Reference should be made to recent issues with footnotes used to provide extra details where of Scottish Birds for guidance on style of necessary. Each table should be on a separate presentation, use of capitals, form of references, sheet. Maps and diagrams should be in Indian ink etc. Papers should be typed on one side of the and be camera ready, but drawn so as to permit paper only, double-spaced and with wide margins; reduction to half their original size. two copies are required and the author should also For details of writing Research Progress retain one. Headings should NOT be underlined, Reports, please contact the editor in advance. nor typed entirely in capitals. Scientific names in Contents, continued

Correspondence Baillon's (rake at Fair Isle. R. Y. McCowan and A. Kitchener 289 Discoloured Peregrines in the north of Scotland. W.R.P. Bourne 290 Research Index. 291 Items of Scottish interest. W.C. Harper 297 European journals in Waterston Library. M.H. Murphy 300 Advice to contributors. 302 Volume 16 Part 4 December 1992 Contents

Research Progress Reports A Twenty-six year study of Sparrowhawks in Eskdale. I. Newton 231 Shags on the Isle of May: who mates with whom. 236 J. Craves and J.O. Ruano Recent status change of some birds on Islay. M.A. Ogilvie 240 Development of an internationally important Pink-footed Goose roost at 260 West Water Reservoir, Borders Region, 1966-1990. A. W. & L.M . Brown Grey Geese and Agriculture in North East Scotland. j. Matthews 269 Some post-war declines in Corn Bunting numbers in North East Scotland . 200 A. Watson

Rare Migrants Little Swifts on Fair Isle H .R. Harrop. 276 Semi-palmated Sandpiper on Fair Isle. S.c. Votier 277 Dark-eyed Junco in Hamilton. I. Shedden 280

Short Notes Merlin's hunting effectiveness. R.C. Oickson 282 Great Skuas attacking a flock of moulting Eiders. M. Heubeck 284 Predation on bird's eggs and chicks by herbivorous mammals. 285 M.C. Pennington Unusual Buzzard nest sites in Glen Ray. o. Sargent 286 Unripe grain, a major food for young finch-like birds. A. Watson 287 Heron attacked by Osprey. S.M. and E.M. Hobson 288 Continued inside back cover

Published by the Scottish Ornithologists' Club, 21 Regent Terrace, Edinburgh EH7 5BT. © 1992 Printed by Ritchie of Edinburgh