Field identification of large falcons in the West Palearctic Hadoram Shirihai, Dick Forsman and David A. Christie Illustrations by John Gale ABSTRACT The five species of large falcon Falco which occur in the West Palearctic present one of the more daunting identification challenges. This paper describes all plumages likely to be met with in this region, including geographical and age-related variations, and discusses the problems involved and the best ways of approaching these. Structure, silhouette and flight behaviour are important factors, and detailed examination of plumage is usually also a prerequisite for correct identification of these awe-inspiring raptors. The large falcons Fako constitute one of the most impressive and exciting groups of birds. They have long attracted great interest and attention among ornithologists, professional and amateur alike, and their appeal is such that even non-birdwatchers are drawn to them. Over the last 17 years, we have taken a major interest in these spectacular raptors. In particular, HS and DF have spent many days in the field studying all five of the large-falcon species, and their subspecies, which occur in the West Palearctic. These studies have been carried out in Europe, North Africa, the Middle East, Kazakhstan and elsewhere, and have involved detailed observation of all known plumages (in relation to age-classes), including the capturing and ringing of many individual falcons. We have also examined aE plumages at great length in zoological gardens and in most of the large museum collections in Europe. The following text, which combines and 12 [Brit. Birds 91: 12-35, January/February 1998] © British Birds Ltd 1998 British Birds, vol. 91, nos. 1 & 2, January/February 1998 13 expands our studies of these species (see Shirihai et al. 1996; Forsman in press), summarises our findings to date on their field identification. Of the five species occurring in the West Palearctic, the most familiar to most people is the Peregrine Falcon F. peregrinus: this is a cosmopolitan species which is widespread in the region, being rare to locally common, and resident, dispersive or migratory, the most migratory race (calidus of the northern tundra) wintering as far south as South Africa; it is found in a wide range of usually open habitats, from arctic/alpine to semi-desert. The Gyr Falcon F. rusticolus, by contrast, is a rare breeder, largely confined to the arctic and subarctic belt, where it is mainly resident to partially migratory, rarely extending farther south than 60°N in winter, and occurring as a vagrant in western Europe south to Portugal and Italy; it inhabits open terrain, such as tundra, barren uplands or rocky coasts, often in partly wooded areas. The Saker Falcon F. cherrug is rather widely distributed, but uncommon and generally declining, in warm-temperate zones from the Central Asiatic steppes west to southeast Europe (mainly Hungary) and Turkey; it also winters regularly in arid parts of the Middle East, with a few records from the rest of Europe and Morocco. The Lanner Falcon F. biarmicus, also declining, generally replaces the Saker in the Mediterranean region and in Africa, overlapping in range primarily in winter or on passage, with three races in the West Palearctic, all of which are mostly resident, but with a few individuals (juveniles) migrating: feldeggii breeds in Italy, the Balkans and Asia Minor, tanypterus in the Middle East and west to Libya, and erlangeri in northwest Africa; all three typically inhabit dry areas, especially semi-desert and desert in the east and south. Finally, the Barbary Falcon F. pekgrinoides is largely confined to the deserts of North Africa and the Middle East, and is mostly resident and dispersive. The taxonomic position of the Barbary Falcon has long been a matter of debate, especially with regard to its relationship witii the southern race brookei of Peregrine Falcon in areas where the two come into close contact. They closely resemble each other in size, shape and plumage. They are reported to overlap in range, but apparently without interbreeding, and they seem to be separated mainly by habitat, with Barbary totally adapted to desert environments. For the purposes of this paper, and since the two taxa can, with care, be separated in the field, we treat them as separate species. The basic identification problems The main problems for the observer are to a large extent related to geography. The question of distinguishing Gyr from Peregrine arises chiefly in North Europe (but also in Central and northwest Europe), and involves in particular the darkish grey morph of Gyr (Scandinavia and northwest Russia) and non- adult Peregrine (especially large females of the race calidus). Pale juvenile grey- morph Gyr has to be separated from immature European Saker in countries where either could occur as a vagrant, while separating Lanner and Saker Falcons (mainly in non-adult plumages) is a problem chiefly in areas where the two meet in winter or on passage, or where either could occur as a vagrant. Not only is the Barbary Falcon of Middle Eastern deserts superficially similar to Lanner in most plumages, but it can also be really difficult to separate from 14 Shirihat a al.: Identification of large falcons adult Peregrine of the southern race brookei, and from any race of Peregrine when dealing with non-adults. Nowadays, however, the likelihood of falcons escaping from captivity is very high anywhere in the region, and extreme caution is required with any single large falcon outside its normal range. It is equally important to try to determine whether such individuals are escapes or true wild vagrants. In recent years, the artificial cross-breeding of falcons in captivity has been practised by a number of misguided individuals and agencies (see e.g. Gantlett & Millington 1992), and the possibility that such unnatural hybrids which result from this may escape or, worse, be deliberately released serves only to increase the difficulties that already exist in identifying large falcons. Some of these hybrids, the various combinations of which may take little account of natural genetic relationships, are almost certainly unidentifiable in the field, or even in the hand; but, when they do occur as genuine escapes, they can cause the diligent observer a great deal of head-scratching and many wasted hours in the field. Discussion of hybrids is beyond the scope of this paper, and it would in any case seem a more prudent approach to acquaint oneself with the individual and geopaphical variations that exist naturally within wild populations of large falcons. General structure, sex and age The largest species are Gyr, Saker and Lanner Falcons, all of which have more rounded wings, with outermost primary shorter than 3rd, and a proportionately longer tail than Peregrine and Barbary Falcons. The last two have more pointed wings, with outermost primary longer than 3rd, and a comparatively shorter tail. While most forms of the first three species are generally larger and heavier than any Peregrine or Barbary, males of all five species average distinctly smaller than their respective females; note that, at least in some cases, large females of smaller species can overlap in size with smallish males of larger ones. Males are usually more finely patterned than females, and normally also become paler with age. Given reasonable views, ageing is not that difficult in the case of Peregrine and Barbary Falcons, but is less straightforward for Lanner and Gyr, and can be more difficult for Saker. Juveniles are, in general, longer-tailed and narrower- winged than adults, and in most cases have bluish to greyish (not clear yellow) feet, cere and orbital ring; on some species, this colour may be retained through to their first winter. Compared with adults, they tend to have a more patterned underwing (Gyr, Saker and Lanner) and head, a more boldly streaked body (on species in which adult is barred below, the juvenile is mainly streaked), darker and less marked upperparts but (most species) with stronger rusty fringes, and a fairly prominent white tip to the tail if this is not too worn. Juveniles undergo a partial body moult during their first winter and a complete moult in the first spring/summer, although a few juvenile feathers, especially wing-coverts, are sometimes still retained. First-summers are often rather similar to adults in general appearance, but with retained juvenile remiges and most or all rectrices, as well as varying amounts of retained juvenile coverts and other body feathers, all of which are juvenile-like in British Birds, vol. 91, nos. 1 & 2, January/February 1998 15 pattern but browner and worn; some individuals which may have moulted much of their body and covert feathers are best aged by the fact that they show moult contrasts, with mostly retained juvenile flight and tail feathers. Gyr Falcon Main confusion species: Peregrine Falcon (see adult Gyr); Saker Falcon (see juvenile Gyr). Structure, silhouette andjizz The largest and heaviest of all falcons, generally appearing very big, solid, broad-bodied and powerful, with a proportionately full and broad head. Can even match Common Buzzard Buteo buteo in its robustness when perched and its wingspan in flight. Appears heavy in flight, with large, well-projecting head, full-chested barrel-shaped body and bulging vent (bulky undertail-coverts), relatively long but broad-based and rather blunt-tipped wings, and longish tail. The big body, broad wings (in particular, large arm and rather rounded tip) and longish tail often give the impression, particularly when flying away, of a female Northern Goshawk Accipiter gentilis, an impression reinforced by the rather stiff wingbeats, but that species has an even longer taE and much shorter, broader and blunter-tipped wings with S-shaped curve to trailing edge, as well as very different flight attitude and wing and tail patterns. Differs from Peregrine in being larger and heavier-bodied, with longer and fuller tail and proportionately shorter wings (typically, also broader throughout their length), with fuller hand and distinctly more rounded tip. These structural differences are most obvious when bird is soaring with wings extended. To the experienced observer, Gyr differs from Saker Falcon in having broader-armed and blunter-tipped wings (longer, narrower and more pointed on Saker), while its almost equaEy longish tail is much fuller and thicker-based, giving impression that body continues into underside of tail (Saker has distinctly slimmer tail, especially where it meets the body). Gyr is also more or less evenly broad-bodied from breast to vent (Saker's typically slim body is broadest at breast and tapers rearwards, recalling a harrier Circus). Gyr perches upright, appearing robust and deep-chested with very prominent shoulders, and with dense belly feathering and bushy trousers almost concealing the tarsi (legs more exposed on other species). Its wingtips always fall well short of the tail tip, so that tail projection is similar to or slightly longer than on Saker, but much longer than on Lanner and, especially, Peregrine Falcons. Note that Greenland Gyr Falcons average slightly larger than the Icelandic population and even more so than Scandinavian Gyrs, but this is rarely assessible in the field. Flight behaviour Flying Gyr looks powerful, with a slower action than Peregrine. Clumsy on take-off, with rather long flight before really airborne; wingbeats slower and shallower, and almost as if executed by hands alone, giving impression of more (text continues on page 22) 16 Shirihai et al.\ Identification of large falcons Fig. 1. Perched Peregrine Fako peregrinus (1-7) and Barbary Falcons F. pekgrinoides (8-12) (John Gak). Adults finely barred below; moustache prominent, dark and rounded at end. Juveniles have prominent, dark and rounded moustache; feet become yellow soon after fledging. PEREGRINE: F. p. peregrinus adult (1), juvenile (2), and first-summer in worn juvenile plumage (3). F. p. brookei adult (4) and juvenile (5): averages darker above, with broader moustache, smaller white cheek patch. F. p. calidus adult (6) and juvenile (7): averages bigger and paler than nominate. BARBARY: Head pattern of adults variable, darker birds (8) at times identical to brookei Peregrine, while those with more rufous (9) distinctive; juveniles in autumn/winter (10), spring (11) and summer (12) paler than brookei. Fig. 2. Peregrine Fako peregrinus (1-9) and Barbary Falcons F. pekgrinoides (10-15) in flight (John Gak). Rather uniformly patterned underwing, rump paler than rest of upperparts (not so on all juveniles), and moustache solid with rounded end. Extensive individual as well as age- and sex-dependent variation makes subspecific identification of single Peregrines inadvisable. PEREGRINE: F. p. peregrinus adults (1, 2) and juvenile (3). F, p. calidus adult (4) and juveniles (5, 6): averages larger and paler than nominate, but considerable overlap. F. p. brookei adults (7, 8) and juvenile (9): smallest and darkest race (equals Barbary in size). BARBARY: Adults (10-12) paler and sandier below than Peregrine, with finer markings often concentrated on flanks, usually paler grey above (rufous of head rarely seen in flight); juveniles (13-15) paler below with finer markings than Peregrine. Fig. 3. Perched Saker Fako cherrug (1-7) and Lanner Falcons F. biarmicus (8-14) John Gak). SAKER: Fairly long-tailed and short-winged; best aged by foot colour. European adults (1, 2) with rufous fringes above, breast and flanks spotted (not barred); Asiatic milvipes (3) rufous and barred above; greyish 'saceroides' (4) can superficially resemble adult Lanner; moustache often separated from dark eye by pale area. Juveniles (5-7) streaked below, more uniform above; worn spring juvenile (7) greyish above, often a few new scapular and mantle feathers. LANNER: Adult feldeggii (8) darker and more heavily patterned than smaller and paler tanypterus (9) and erlangeri (10). Juveniles (11-14) mostly show prominent narrow moustache joining equally dark line through eye; crown yellow-buff with dark forecrown band and dark line above pale supercilium (unlike Saker, often acquires yellow feet early in first year of life); worn spring juvenile (14). Fig. 4. Saker Fako cherrug (1-6) and Lanner Falcons F. Uarnikus (7-10) in flight John Gak). Juveniles show strong contrast between darker underwing-coverts and paler remiges; adult Saker often very similar, while adult Lanner paler, with heavier bars on greater coverts only. SAKER: Ageing often truly difficult. Adult cyanopus (1, 2) and 'saceroides' (3) more spotted on underbody, remiges more clearly barred; juveniles (4-6) streaked below, secondaries greyer with less prominent barring. Both ages show brownish upperparts contrasting with darker hand and paler tail. LANNER: Adult tanypterus (7, 8) distinctly grey above, with paler tail, buffish or yellowish crown; very pale below, with barred greater coverts and darker wingtip. Juveniles (9, 10) almost identical to juvenile Saker, but most have underwings pale-spotted, belly and trousers extensively pale. (Cf. juvenile Gyr F. rusticolus (11, 12): less underwing contrast, more diffuse head pattern.) Fig. 5. Gyr Falcons Fako rusticolus (1-11) (John Gak). Perched Gyr is the shortest-winged of all large falcons. Juveniles have blue feet and cere throughout first winter. WHITE MORPH (1, 2): Extent of dark markings varies individually (and geographically). Best aged by colour of feet and cere: yellow on adults, bluish on juveniles. GREY MORPH: Adults (3-7) barred grey above, breast spotted, flanks and thighs barred, head pattern variable (mostly clear supercilium, narrow moustache, streaked cheeks); in flight, lacks Peregrine's F. peregrinus paler rump. Juveniles (8-11) greyish-brown above, most with fine pale spots, dark markings on head and underparts varying in strength; in flight, fairly uniform above, tail paler, underwing-coverts more patterned than remiges (contrast less than on juvenile Lanner/Saker F. biarmicuslF. cherrug). Cf. underwing of juvenile Peregrine (12). Fig. 1. Peregrine Falcoperegrinus (1-7) andBarbary Falcons F. pekgrinoides (8-12) (John Gate). PEREGRINE peregrinus adult (1), juvenile (2), and first-summer in worn juvenile plumage (3); brookei adult (4) and juvenile (5); calidus adult (6) and juvenile (7). BARBARY Darker-headed adult (8) and adult with more rufous on head (9); juveniles (10-12) in autumn/winter, spring and summer. F Gale). PEREGRINE adults (1, 2) and juvenile (3); calidus adult (4) and juveniles (5, 6); brookei adults (7, 8) and juvenile (9). BARBARY Adults (10-12) and juveniles (13-15). Fig. 3. Saker Falco cherrug (1-7) and Lanner Falcons F. biarmicus (8-14) (John Gale). SAKER European adults (1, 2); Asiatic mihipes (3); greyish 'saceroides' (4); juveniles (5-7); worn spring juvenile (7). LANNER Adult feldeggii (8), tanypterus (9) and erlangeri (10); juveniles (11-14), worn spring juvenile (14). Fig. 4. Saker Falco cherrug (1-6) and Lanner Falcons P. biarmicus (7-10) (John Gale). SAKER Adult cyanopus (1, 2) and 'saceroides' (3); juveniles (4-6). LANNER Adult tanypterus (7, 8); juveniles (9, 10). (Cf. juvenile Gyr F. rustieolus (11, 12): less underwing contrast, more diffuse head pattern.) Fig. 5. Gyr Falcons Falco rusticolus (1-11) (John Gale). WHITE MORPH (1, 2). GREY MORPH Adults (3-7) and juveniles (8-11); cf. juvenile Peregrine F. peregrinus (12).