Studies of less familiar lyg Collared Flycatcher H. Lohrl Photographs by R. G. Carlson, H. Lohrl and A. JV. H. Peach Plates 1-4 The Collared Flycatcher albicollis is a rare vagrant to Britain with only six accepted records, all since 1945, in Shetland (May 1947), Gwynedd (May 1957), Essex (September 1962), Orkney (May 1963), Cumbria (June 1964) and Norfolk (May 1969) (BOU 1971, Smith 1970), Five other records in Sussex during 1911-22 were rejected with the Hastings Rarities (Nicholson and Ferguson-Lees 1962). The has featured previously in this series (Brit. Birds, 47: 302, plates 49-50, 52), but that was over 20 years ago and a number of studies have been published since then. Much of the information summarised here has been taken from the author's published papers on this species (particularly Lohrl 1951, 1954, 1957) and, where no references are given, these should be regarded as the source. The Collared and Pied Flycatchers F. hypoleuca are siblings with a partly overlapping breeding range, though the Pied is found only sparsely within this area of overlap and, in general, the Collared has a more south-easterly distribution which is not continuous but comprised of many areas often isolated from each other. It breeds most commonly in Austria, southern Germany, Hungary, Czecho• slovakia and southern Poland across to the Ukraine, but it also nests very locally in eastern France, southern Switzerland (one isolated area), Italy, Yugoslavia, northern Greece, Bulgaria, Romania, and Russia to Moscow; the most northerly population, completely isolated, is on the Swedish island of Gotland, in the Baltic (e.g. Brattstrom 1946). The Collared Flycatcher is replaced in parts of Greece and Bulgaria, and in Asia Minor and the Caucasus east to Transcaspia and Iran, by the Half-collared Flycatcher F. (a.) semitorquata. This is morphologically intermediate between the other two and is often regarded as a race of the Collared, but Curio (1959) showed that its social behaviour, particularly during pair-formation ceremonies, differs conspicuously from that of both the Collared and the Pied and, for this reason, he gave it the rank of a full species; this conclusion is being increasingly accepted. Like the Pied Flycatcher, the Collared is found mainly in broadleaved woodland, but in relatively warm climates, with a distinct preference for old oaks Quercus, and thus both in open

20 IBril, Birds, 69: 20-26, January 1976J Collared Flycatcher studies 21 forest and well-timbered parks and avenues. Secondarily, it also inhabits orchards, and gardens with fruit trees, though pairs which breed in such places return to the woods immediately the young have fledged; and in some areas it is found in conifers. In general, it is confined mainly to fairly low-lying districts and river valleys, as along the Danube, and it shuns situations above 600 metres. In south-west Germany, for example, the lower hills at 300-600 metres in the region of the Neckar river and its tributaries are thickly populated by Collared Flycatchers, while the lower parts of the Rhine valley at 200-250 metres, the higher hills between the Bodensee and the Schwabische Alb at 700-1,000 metres (where the Collared goes up the valleys to about 600 metres) and the forests of the upper Rhine are inhabited exclusively by Pied (Lohrl 1965). Again, in Poland, Collared Flycatchers breed in numbers in the primeval forest of the Bialowiecza (Sokolowski 1958). In breeding plumage, male Collared Flycatchers (plates la, 2a, 4b, 4c) are easy to distinguish from Pied (plate lb), not only by the conspicuous white neck band, but also by a generally much larger white patch on the forehead and by a clear white area on the primaries, usually separated from the broad white wing bar above it. The greyish-white rump, often not visible in the field, is hardly necessary as an additional character. About half of all older males have a completely black tail (Lohrl 1954), without white on the outer feathers like the Pied; older males also have black primaries with the white area clearly larger and more sharply defined than that of the first-year males, which have much browner primaries.. The male Half-collared Flycatcher is more like a Pied Flycatcher and quite likely to be overlooked as such, though it has a suggestion of a collar at the sides of the neck, and is intermediate between the other two species in the amount of white on the forehead and primaries and in its greyish rump; on the other hand, it shows more white at the sides of the tail than either of the others and this is a useful field mark. Males in non-breeding plumage, females and juveniles are much more difficult, often impossible, to distinguish. Many female Collared Flycatchers (plates 2c, 4a) do, however, have the neck band visible as a light region of ruffled feathers and also show the white area on the primaries (plate 4a), though sometimes the latter is completely lacking (plate 2 c); some females also have a white patch on the forehead. (A female Pied is shown for compari• son on plate 2b.) The juveniles of both are speckled grey-white and often cannot be separated, but many young Collared, especially males, already show the white area on the primaries and have a more pronounced wing bar, as well as a hint of the neck band (plate 3b and compare with plate 3a). 22 Collared Flycatcher studies The characteristic calls of the two species, heard when the birds are excited, are easily distinguished: the short 'bit bit' of the Pied becomes a long-drawn 'sieb' in the Collared. The songs are also clearly separable: the Collared's is slower, more drawled and of a different frequency. The remaining notes of the two species, however, particularly those used when mating and rearing young, are generally indistinguishable. This may be why, in areas where one species is much commoner than the other, interbreeding occasion• ally takes place, producing fertile hybrids (von Haartman and Lohrl 1950, Lohrl 1950b). Male Collared Flycatchers begin a body moult from their non• descript winter plumage around February and return to their breeding areas from mid-April in the conspicuous and contrasted summer dress. There are occasionally a few first-year males among the early arrivals, but generally the older males predominate. The return takes place over four weeks or more and the later arrivals are mainly the young of the previous year. Like the Pied, the Collared nests in holes (plate la, etc.) and is not too particular in its choice of these. As most other hole-nesting species already have eggs by the time it arrives, it must often make do with bad and unprotected sites. Indeed, it occasionally breeds in very large holes, more suitable for Stock Doves Columba oenas or Tawny Owls Strix aluco. It also readily takes to boxes (plates 4a, 4b). If there is a choice, however, the Collared Flycatcher likes to nest at considerable heights, the preference being about 15 metres above the ground, and it is most reluctant to use low holes. Again like Pied, Collared Flycatchers will often build their nests in a few hours on top of those of tits Parus spp at which the female is not yet incubating and so is seldom there: when the tit returns, she no longer finds her own nest but the flycatcher's, made of quite different materials. In this way occupation of the tit's nest comes about without a fight (Lohrl 1950a). In a fight a Collared Flycatcher is invariably defeated by either a Great Tit P. major or a Tree Sparrow Passer montanus. Indeed, if a flycatcher slips in to inspect a hole in which there is a nesting Great Tit, it is often killed. The male chooses the nest hole, performing a display flight to the entrance and there uttering a characteristic call; the Pied Flycatcher shows the same behaviour. After he enters the hole, a subdued song can be heard coming from it. The female also enters, whereupon the male immediately leaves (Lohrl 1951). In areas where there are many holes, the male tends to select several and offer them in turn to the female; occasionally a male will offer up to five holes in this way. After pairing, the male at first confines himself to the chosen hole, but at the time of egg-laying he loses interest and begins to display again at other, empty holes. A second female may be Collared Flycatcher studies 23 attracted and the result is polygamy, especially in the case of older males. A polygamous male may then either feed the young of two broods or at first favour the earlier hatched one, later turning to the other. The behaviour of polygamous males leads to other males not finding females during the courtship period and therefore remaining unmated. Such unmated males may then attempt to adopt the young of a neighbouring nest. If the male at this nest is a first-year bird and the unmated one is older, the latter and the nesting pair may jointly bring up the young, in which case the one-year-old is inferior at the nest hole and must wait until the older male has fed the young. Sometimes as many as three different males, as well as the female, can be seen entering a hole with food. Thus rarely does the second female of a polygamous male have to bring up the young alone or with only occasional participation by a male (Lohrl 1949, 1959). The nest is built entirely by the female, of dry grass, dead leaves, stalks and, in oak woods, sometimes of the fallen male flowers of die oak. It is lined with fine grass, not hair or feathers. The nests of Collared and Pied Flycatchers are inseparable, the eggs of both being uniform light blue. Clutch size depends on the time of laying: the earlier this begins, the more eggs are laid. In very warm springs, laying may start as early as the end of April and only then do clutches of eight eggs occur. In south-west Germany Collared Flycatchers lay an average of 5.8 eggs, this varying from 5.5 to 6.2 in different years (Lohrl 1957). In Czechoslovakia an average of 5.7 eggs was recorded, with a figure of 5.8 for broadleaved woods significantly higher than one of 5.5 for coniferous areas (Balat 1971). In southern Poland the average was 6.1 eggs and during three years never fell below 6.0 (Gfowacinski 1973). Incubation generally starts with the penultimate egg and lasts for 13 days, though longer periods do occur. Fledging is also variable: in favourable weather and feeding conditions, the young leave the nest after 15 days, but at times of rain this period may be extended up to 18 days. The young do not always leave at the same time: it is not at all uncommon for part of the brood to leave the hole and be looked after by one of the parents, while the remaining young in the nest continue to be fed by the other. About six days after leaving the nest, the young start to take food for themselves; after ten days, at the latest, they are independent. After about three weeks, they begin their first moult; and they then usually migrate before the moult has finished. The adults begin to moult as soon as the young are independent, but in cases of late broods adults may be found in moult while still tending young in the nest. In south-west Germany 90% of the eggs laid produced hatched 24 Collared Flycatcher studies young and 77% fledged young, and in Czechoslovakia Balat (1.971) recorded an even higher breeding success. It must be pointed out, however, that these success rates were achieved in nest boxes; in tree holes the figures would probably be significantly lower. Recent research in south-west Germany has also shown that nest losses are sometimes high in woods where there are Dormice Glis glis. Male Collared Flycatchers usually return in the following spring to the previous year's territory, and females are also generally faithful to one locality. The young are probably even more strongly attached to their birthplace: this is shown by the way in which many first-year birds, returning late, have to be persistently and aggressively pursued by the superior, established, older males before they will leave the area. The greatest recorded age of a male Collared Flycatcher is six years, and of a female five years. Like other flycatchers, the Collared Flycatcher does not only catch flies. The adults take both imagines and larvae of a variety of flying and wingless insects. The young are fed to a considerable extent on caterpillars (plate 4b): indeed, of 671 prey of early broods identified in south-west Germany, 32.5% were caterpillars, these forming 87% of the butterflies and moths (Lepidoptera) taken, which in turn amounted to 40% of the total food. For later broods, the percentage of caterpillars dropped quickly and the proportions of flies (Diptera) and ants (Hy- menoptera) increased from 19% to 35% and from 11% to 21% respectively. In orchard areas, Collared Flycatchers frequently take both caterpillars and other prey from the ground, though in doing so they drop down only momentarily. In tall, broadleaved woods, on the other hand, they seem never to descend to the ground in normal conditions, but only in bad weather or when there is a lack of food in the trees. This difference may be due to the height above ground of the lowest branches. In prolonged periods of rain, many young die even when there is a rich food supply: this is because few Collared Flycatchers appear to recognise motionless insects as prey. There is a marked difference in the migration routes of Pied and Collared Flycatchers from the area of overlap in west-central . The Pied pass mainly through Spain and Portugal to , and the Collared exclusively through Italy (Lohrl 1958), though of course the east European populations of both species also migrate through the eastern Mediterranean. All recoveries of ringed Collared Flycatchers from Germany have been in Italy and two from Gotland have been found in Italy and Malta, while recoveries of German Pied Flycatchers have largely come from Collared Flycatcher studies 25 Iberia. This dichotomy implies that, as Salomonsen (1955) sug• gested, the two species had separate breeding ranges in the Ice Age, the Pied being confined to south-west Europe and the Collared to south-east, and that they have met again only secondarily. Collared Flycatchers leave the breeding areas early. From July they live silently in the canopies of tall trees and some south• west German birds even reach Italy during that month, though most recoveries there have been in August and some even as late as October. The winter quarters are still not well known, partly because of the difficulty of identification at that season, but from published observations they appear to extend farther south than those of the Pied, into Zambia, Malawi and southern Zaire. The only two ringing recoveries in Africa, of birds from Hungary and Gotland, have both been from south-west Zaire in early spring.

REFERENCES BALAT, F. 1971. 'Clutch size and mortality among the young of the Collared Flycatcher, Ficedula albicollis (Temm.), in Southern and Central Moravia'. Zool. Listy, 20: 161-175. BRATTSTROM, H. 1946. 'Iakttagelser over Halsbands Flugsnapperen (Muscicapa a. albicollis Temminck) pi Nordgotland'. Fauna och Flora, 1946: 21-31. BRITISH ORNITHOLOGISTS' UNION. 1971. The Status of Birds in Britain and Ireland. Oxford. CURIO, E. 1959. 'Beobachtungen am Halbringschnapper Ficedula semitorquata im mazedonischen Brutgebiet'. J. Orn., 100: 176-209. GLOWACINSKI, Z. 1973. 'Phenology and breeding success in a population of Collared Flycatcher, Ficedula albicollis (Temm.), in the Niepolomice Forest (southern Poland)'. Ekol. Polska, 21: 219-228. LOHRL, H. 1949. 'Polygynie, Sprengung der Ehegemeinschaft und Adoption beim Halsbandfliegenschnapper (Muscicapa albicollis)'. Vogelwarte, 15: 94-100. —— 1950a. 'Zur "Verdrangung" von Meisen durch Fliegenschnapper'. Vogelwelt, 7i:39-4i- —— 1950b. 'Ein Bastard Halsbandschnapper-Trauerschnapper (Muscicapa albicollis X M. hypoleuca)'. Orn. Ber., 3: 126-130. 1951. 'Balz und Paarbildung beim Halsbandfliegenschnapper'. J. Orn., 93: 41-60. 1954- 'Gefiedermerkmale bei einer Population des Halsbandschnappers (Muscicapa albicollis)'. Bonn. £ool. Beitr., 5: 33-48. J957- 'Populationsokologische Untersuchungen beim Halsbandschnapper (Ficedula albicollis)'. Bonn. £ool. Beitr., 8: 130-177. 1958. 'Vom Zug des Halsbandschnappers (Ficedula albicollis) nach Beringungsergebnissen'. Vogelwarte, 19: 192-193. 1959. 'Weitere Falle von Polygynie und Adoption beim Halsbandschnapper (Ficedula albicollis)'. Vogelwarte, 20: 33-34. 1965. 'Zwei regional und okologisch getrennte Formen des Trauerschnappers (Ficedula hypoleuca) in Sudwestdeutschland'. Bonn. Z°°l- Beitr., 16: 268-283. NICHOLSON, E. M., and FERGUSON-LEES, I. J. 1962. 'The Hastings Rarities'. Brit. Birds, 55: 299-384. SALOMONSEN, F. 1955. 'The evolutionary significance of bird-migration'. Dansk Biol. Medd., 22: no. 6. 26 Collared Flycatcher studies SMITH, F. R. 1970. 'Report on rare birds in Great Britain in 1969'. Brit. Birds, 63:267-293 (286). SOKOLOWSKI, J. 1958. Ptaki £wm Polskich. Warsaw, vol 1. VON HAARTMAN, L., and LOHRL, H. 1950. 'Die Lautausseruagen des Trauer- und Halsbandfliegenschnappers, Muscicapa hypoleuca Pall, und M. a. albkollis Tem- minck'. Orn. Fenn., 27: 85-97.

Dr H. Uhrl, Vogelwarte Radolfzell, 7761 Moggingen, West Germany PLATE I. Male Collared Flycatcher Ficedula albicollis by nest, Austria, June 1972: note white forehead, neck band, and patch on primaries (pages 20-26) {photo: R. G. Carlson). Inset, male Pied F. hypoleuca, Cumbria, May 1963 {photo: J. B. and S. Bottomley)

PLATES 2-3. Facing: top and lower right, male and female Collared Flycatchers Ficedula albicollis, Austria, June 1972 (photos: A. .V. H. Peach)-, lower left, female Pied F. hypoleuca, Powys, May 1974 (photo: Graham F. Date). The female Collared is greyer, often with a pale neck band of ruffled feathers (page 21). Above, Pied and, below, Collared in post-juvenile moult, Germany (photos: H. Lbhrl): the latter individual has more white on the wing, but the diagnostic point is the white primary patch—often already present, especially in males PLATE 4. Above, female and male Collared Flycatchers Ficedula albicollis at nest box, Germany (photos: H. Lbhrl): this is a well-marked female with both neck band and white patch on primaries (cf plate 2c); the male has a beakful of caterpillars, with a blade of grass probably inadvertently picked up from the ground (page 24). Below, male, Austria, June 1972 (photo: R. G. Carlson)