Wildfowl (1973) 24:111 121 Behaviour and distribution of wild geese in south-east Scotland I. NEWTON, V. M. THOM a nd W. BROTHERSTON The distribution of wintering Greylag numbered about 60,000 individuals, and Anser anser and Pink-footed Geese A. Pinkfeet about 70,000 (Boyd & Ogilvie, brachyrhynchus in Britain is governed by 1969, 1972). the presence of suitable roosting sites, such as estuaries and lakes, from which the birds fly to nearby farmland to feed. The same M ethods roosts and associated feeding areas are used year after year. This paper examines the The first detailed information on goose dis­ dispersal of geese in south-east Scotland tribution in Scotland was built up over and, in particular, their choice of roosting several years from extensive ground and feeding sites. It forms part of a general searches and aerial surveys by Wildfowl study, more of which has been published Trust staff, helped by local observers. This elsewhere (Newton & Campbell, 1970, and information, summarized by Atkinson- 1973; Newton, Campbell & Allison, in Willes (1963), formed the starting-point press). The area involved, covering 24,000 for our survey. From 1960, V.M.T. studied km2, extended from Pitlochry in the north goose distribution around Perth. This was to beyond Biggar and Kelso in the south, done partly at weekends, but also on other and from the east coast to beyond Stirling days, because her job took her to many in the west (Figure 1). It included a repre­ farms in the study area, and provided sentative selection of roosting and feeding further opportunity to find geese and sites, and held the bulk of the immigrant question farmers (Thom & Murray, 1964). population of both species. In recent In 1952, W.B. (in Edinburgh) began autumns, Icelandic Greylag in Britain have watches at certain roosts, which came to Figure 1. Map showing position of study area, open circles = Pinkfoot; split circles = both and main roosting sites. Filled circles = Greylag; species. Inset shows area covered by Figure 2. I l l 112 I. Newton, V. M. Thom and W. Brotherston occupy nearly every winter weekend for 20 years, and from 1955 also organized Behaviour cooperative counts at all known roosts in the study area south of the Forth (Brothers­ Most Pinkfeet arrived in Britain in late Sep­ ton, 1964). He too noted feeding areas, but tember and early October and left during did not cover the ground systematically as April and early May. Most Greylag arrived did V.M.T., north of the Forth. In 1967-70 during October and left from mid-March to I.N. also searched systematically for feed­ mid-April. Thus the average Pinkfoot ing geese, and checked waters not already spent 30 weeks each year in Britain and the known to be used as roosts. This paper average Greylag 26. The difference was synthesizes all this information. Records presumably because the Pinkfeet came accumulated for 20 years, but all roosting direct from the highlands of Iceland, where and feeding areas mentioned here were the summer season was shorter than in the used regularly during 1966-70. Possibly lowlands inhabited by Greylag. some minor roosting and feeding areas Within Britain, different roosts were not were missed, but not enough to affect the self-contained, and a continual shifting of overall conclusions. birds from roost to roost around the country was confirmed by observations, counts and ringing. Recoveries of birds Population ringed near particular roosts came, within the next 3 months, from all parts of the An estimated 37,000^4-6,000 Greylag were winter range, but more often from near present in the study area in different than far (Boyd, 1955, 1957, 1959). Move­ Novembers 1966-70, with an average of ment took place on any date, not just in 41,000, and an estimated 49,000-63,000 response to hard weather or food shortage. Pinkfeet, with an average of 58,000 (Boyd In general, geese concentrated in predo­ & Ogilvie, 1969, 1972). In different years, minantly grain-growing areas in autumn, this represented 59-73% of the total im­ and in predominantly grass-growing areas migrant Greylag in the country, and in winter. As expected, day-to-day inter­ 64-93% of the total Pinkfeet. The large change was greatest between adjacent differences in numbers between autumns roosts, and in any one area certain pairs or resulted partly from variations in the size of groups of waters functioned as one, so that the total population, and also from annual large numbers of geese at one site meant variations in the regional distribution of small numbers or none at the others. North geese within Britain. In the study area of the Forth, two groups of waters in north of the Forth, both species were rela­ Strathmore acted more or less as two units tively numerous in 1968 and 1970, when for Greylag; and to the south Harperig/ much grain was shed before harvest, and Threipmuir and Gladhouse/Portmore were less so in other years when little grain was each linked for Greylag, as were Fala/ shed. South of the Forth, grain and geese Gladhouse and Baddinsgill/Westwater for were most plentiful in 1969. In all autumns, Pinkfeet. the two species were about equally numer­ The number of geese that used any one ous north of the Forth, but to the south water was not normally restricted by its Pinkfeet greatly predominated (Table 1). surface area. The small pond at Fala, Table 1. Numbers (in thousands) of Greylag and Pink-footed Geese in study area, each November, 1966-70, based on Wildfowl Trust Counts Greylag Pinkfoot N orth of South of Total in N orth of South of Total in Forth Forth study area Forth Forth study area 1966 39-3 1-7 41-0 (68%) 35-0 13-7 48-7 (64%) 1967 35-9 2-6 38-5 (73%) 44-0 16-3 60-3 (93%) 1968 41-8 2-6 44-4 (73%) 44-6 10-0 54-6 (84%) 1969 30-1 6-4 36-5 (59%) 44-6 16-8 61-2 (84%) 1970 41-5 4-8 46-3 (71%) 50-3 13-1 63-4 (88%) Mean 37-7 3-6 41-3 43-7 14-0 57-6 The figures in brackets show the percent of the country’s total population present in the study area each November. Wild geese in Scotland 113 which covered about 1 hectare, held for the first flocks were in, later ones flew in much of each season less than 2,000 geese, without the hesitation often shown by first but occasionally up to 6,000-an average of arrivals. There was usually a great clamour, one goose per 2-5 m2. On large roosts geese redoubled whenever a fresh detachment did not spread evenly over the water sur­ came in. Then some time after the last flock face, but remained as a flock in the lee of a had arrived, the noise steadily fell to a low shore or island, their position changing level, which was maintained until about an from night to night, according to wind hour before the dawn flight when it in­ direction. They preferred sheltered areas creased again. (This was confirmed by the near gentle open shores, where they could ‘water keepers’ at several reservoirs, and walk out during darkness. In estuaries and by M. A. Ogilvie who spent many nights coastal bays they usually stood on banks of beside goose roosts.) sand or mud that were flooded for only a During the lighter half of the moon cycle short time. They drifted on the water some geese fed at night, more so in winter at high tide, and returned to the banks when than in autumn or spring (Newton & Camp­ the water dropped again. On waters re­ bell, in press). When the moon rose early, gularly used by both species, the two kept in the birds simply remained in the fields, but separate flocks. when it rose late, they roosted as normal As a rule both species roosted by night and flew out again at night. After such light and fed by day. They left their roosts earlier nights, any geese on the roosts at daybreak with respect to sunrise, and returned later were often slow to leave. Some Greylag with respect to sunset, in mid-winter, when stayed till around noon, while Pinkfeet days were shortest, than in autumn or often flew to a resting area and did not feed spring. On mixed roosts, Pinkfeet left for an hour or more. earlier and returned later, on average, than did Greylag, though there was much over­ lap. In both, it often took more than an Influence of shooting hour for all the flocks to leave a roost in the morning, and for them to assemble Shooting and other disturbance had less again in the evening. effect on geese using large waters than on After reaching a feeding area in the those using small ones. On the large Loch morning, the first party often circled once Leven, no consistent trends in numbers were or twice before alighting, but the build-up detected after shoots, but small waters were was then rapid, with successive parties frequently deserted for several days after­ settling in without hesitation. After the wards. Pinkfeet more often deserted a roost dawn flight, the roosting assemblage usually after shooting than did Greylag. Shooting split into several feeding flocks at varying also affected the time geese arrived at a distances and directions 'from the roost. roost and, when heavily disturbed, both During the day, groups of birds moved species delayed their arrival till well after between flocks, and also between feeding dark.