Peregrine falcons of the World

Page 1

llibre falcons 16x23.indb 2

16/10/13 10:19


16 PEREGRINE FALCONS OF THE WORLD

egrine subspecies are based on a single type specimen, sometimes not from the breeding population it subsequently came to represent. We think it is more important to understand how and in what measure natural selection has differentiated populations of falcons and to apply names that reflect these differences than it is to have inflexible rules for recognizing subspecies. We agree philosophically with Patten and Unitt (2002), Remsen (2005), Rising (2007) and Winker et al. (2007) that in a perfectly ordered world a subspecies should be clearly diagnosable by one or a suite of traits. We also concur with Winker et al. (2007: 36): “At intraspecific levels we expect the largely neutral genetic variation that dominates current geneticsequence-based data sets to be decoupled from differentiation attributable to selection. Thus, mtDNA sequence data have little bearing on the validity of named subspecies, which are based on amongpopulation differences in phenotype that are more likely than mtDNA differences to be the result of selection.” In the case of the cosmopolitan Peregrine, the insular subspecies and some Southern Hemisphere subspecies (macropus and ernesti) are clearly diagnosable. Further, we suggest that separate names for the Nearctic and Palaearctic subspecies, though the forms that they

represent are not uniquely or strongly diagnosable, represent a good indication of how variation is distributed across the falcon’s range. For example, in Eurasia north of about 35°N, Peregrines range across about 30,000,500 km2 or about 25% of the Earth’s land surface not including Antarctica. This situation is rather different from the microgeographic variation within the Sage Sparrow (Amhispiza belli), which in the United States breeds in all or parts of eleven western states and northern Baja California, used by Patten and Unitt (2002) in their example of subspecies diagnosibility. Currently, among Peregrines, four or five named subspecies (peregrinus, brookei, calidus, japonensis/ harterti) occupy the outlined Eurasian region. But, to one degree or another, peregrinus [a large, usually resident, dark form of mainly forested regions] intergrades over some undefined area with calidus [a large highly migratory pale tundra form] and both intergrade with japonensis/harterti [a smaller, migratory, dark form]. To the south, peregrinus intergrades with brookei [a yet smaller usually resident dark form often with rufous in the hind neck typical in the Mediterranean region]. Because there are character clines or mixing of traits here and there between forms, sometimes steep or sometimes

Figure 1. A representation of the various recognized subspecies, indicated by a number, some of the other forms and also some of those formerly named, indicated by a letter. Those formerly named have been placed in synonymy with a currently recognized subspecies (See Table 1). This figure is a slightly modified and rearranged plate from Friedhelm Weick’s Zur Taxonomie des Wanderfalken. 1. F. p. peregrinus: (a) ‘scandinaviae’ from Fennoscandia, (b) ‘riphaeus’ or ‘brevirostris’ from forested Russia, (c) ‘rhenanus’ Rhine River region, (d) ‘germanicus’ from central Europe. 2. F. p. calidus: (a) average variant, (b) ‘caeruleiceps’ pale variant. (3) F. p. japonensis: (a) ‘harterti’ or ‘kleinschmidti’ type from north eastern Siberia, (b) average or ‘pleskei’ type. 4. F. p. furuitii: Iwo Islands. 5. F. p. brookei: (a) average eastern Mediterranean type, (b) ‘caucasicus’ variant from Caucasus Mountains. 6. F. p. madens: Cape Verde Islands. 7. F. p. pelegrinoides: (a) pale variant, (b) eastern ‘arabicus,’ (c) darker variant, (d) North African ‘punicus.’ 8. F. p. radama: Madagasgar, 9. F. p. minor: Africa. 10 F. p. babylonicus: (a) eastern ‘gobicus,’ (b) average variant. Plate courtesy F. Weick, copyright © 2011 Friedhem Weick, Licesnegarden.com. Arrangement by Randal Baker.

llibre falcons 16x23.indb 16

16/10/13 10:19


chapter 1. Introduction 17 b 2a b 1a

d c

4

b

b

5a 3a

6

7a b

d c 8

9 10a

llibre falcons 16x23.indb 17

b

16/10/13 10:19


72 PEREGRINE FALCONS OF THE WORLD

Figure 24. Note the uniform paleness of the dorsal side of this female calidus on the Lena River, Siberia. Note also the easy access to the nesting platform. Photograph courtesy of Andrew Dixon.

darker Peregrines to the east of the Lena and paler birds to the west. While the name used by Pleske for those west of the Lena was griseiventris [= calidus], and to the east it was harterti or peregrinus, the point is that there was a discernable difference between the darker eastern birds that separates them from paler birds to the west of the Lena. Assuming that there was some population decline during the 1970s and 1980s, it will be interesting to see whether the studies of Andrew Dixon and colleagues in the 21st century confirm these trends as populations recover. Overall, calidus is only slightly larger in linear dimensions than F. p. peregrinus. It is best distinguished by a paler bluishgray dorsal color, a generally narrower and longer, dark facial stripe, a wider white auricular patch that usually lacks the small streaking and tick markings typical of peregrinus, and less extensively marked underparts than peregrinus. A pale whitish forehead band is usually present ranging from about 2 mm to as

llibre falcons 16x23.indb 72

much as 5 or 6 mm in width. In a few very pale birds, the white on the forehead may extend back to the middle of the crown. On average, the contrast between black ventral bars and white background is not as great as with peregrinus. The background color of the underparts can often have a slight “yellowish” tint. Adults of calidus are very similar to tundrius, but slightly larger, and the contrast in color between head and shoulders compared to the rest of the back is not as great as it is in tundrius. However, the Eurasian calidus is separated from North American tundrius by geography and by darker forms of Peregrines at either end of the calidus range, peregrinus in northern Europe and japonensis and harterti in eastern Siberia. Juvenile plumage also has a great range of variation. On average, other than the thinner facial streak and paler head than peregrinus, the crown can vary from nearly completely dark to those with only dark “eyebrow stripes” on an otherwise buffy crown [Fig. 25].

16/10/13 10:19


CHAPTER 3. SIBERIAN TUNDRA PEREGRINE 73

Figure 25. A juvenile female calidus on the wintering grounds in Thailand. Note the pale region running into the upper malar causing it to look like a break in the malar. Photograph courtesy Col. Nattapol Kirdchuchuen (Dong 2002). Figure 26. Juvenile female calidus in fresh plumage. Note the pale grayish tint and wash on the scapular feathers that frequently characterize juvenile calidus. Sometimes this tint or wash is on most of the bird. The same wash is found on many F.p. babylonicus causing some of them to be labeled as calidus in museum collections. Original illustration by Andrew Ellis based in part of specimens in the British Museum (Natural History).

llibre falcons 16x23.indb 73

16/10/13 10:19


108 PEREGRINE FALCONS OF THE WORLD

Figure 40. Fledgling brookei young in northern Spain. Photograph courtesy of Iñigo Zuberogoitia. Figure 41. Cliff nesting brookei, Burgos, Spain. Photograph courtesy of Jesús García Ubierna.

llibre falcons 16x23.indb 108

16/10/13 10:20


CHAPTER 5. MEDITERRANEAN PEREGRINE 109

Figure 42. Cliff nesting brookei using an abandoned stick nest of another species, Burgos, Spain. Photograph courtesy Jesús García Ubierna.

High Atlas mountains, in Morocco, eggs are laid in early March (Barreau and Bergier 2001). In Cyprus, eggs were still being incubated in mid-March (Flint and Stewart 1992). Near the northern edge of the range of brookei in Macedonia, near the Agia Anastasia Monastery, clutches were found between 5 and 28 March (Makatsch 1950), and on the Crimean Peninsula [Ukraine] at the northern edge of the Black Sea eggs were laid by 10 April (Kostin 1983). In the northern Caucasus Mountains, copulation has occurred as early as 22 February with eggs being laid by 10 March (Til’ba and Mnatsekanov 1998). Across the Caspian Sea in Turkmenistan around 40°N, copulation has been seen between midFebruary and late March with the first eggs also being seen in the latter part of March (Efimenko 2004). Fledging rates vary regionally. For example, in two separate areas sampled in central Spain, Doval (1991) found that the number of young fledged per occu-

llibre falcons 16x23.indb 109

pied eyrie varied from 1.14 [n = 56 nests] to 2.07 [n = 28 nests] [Fig. 40]. These values are similar to an earlier but larger sample from Spain where overall [n = 262] there were 1.73 young per pair but only 1.39 young per pair in areas densely populated by humans (Heredia et al. 1988). In the Provence, southern France, the average number of young fledged per eyrie was 1.57 [n = 97] in the 1990s [P. Bergier, pers. comm.]. The fledging rate in Sicily was similar; with about 1.6 to 2.0 young per eyrie (Iapichino and Massa 1989) and overall throughout Italy fledging rates are about 1.77 young per eyrie (Allavena 1988). In the mountain regions of the Haouz and Central High Atlas, Morocco, four eyries fledged a mean of 2.5 young (Barreau and Bergier 2001), and based on 22 broods in the Caucasus Mountains, the fledging rate was the same at 2.5 young per eyrie (Til’ba and Mnatsekanov 1998). In addition to the expected cliff ledges [Fig. 41], Mediterranean Peregrines

16/10/13 10:20


136 PEREGRINE FALCONS OF THE WORLD

Figure 57. This extremely pale [leucistic] female tundrius at Rankin Inlet has many of the features we discuss under the pallid variation of the South American cassini. The pale tail bars even showed a tint of pinkish similar to the South American bird, especially when back-lighted. Photograph courtesy of Gordon Court.

had similar markings [photograph by Gordon Court, see Wheeler (2003)]. A few, adults and juveniles, seen or trapped on migration on the Texas barrier islands also approach the pallid morph of cassini [T. Maechtle, pers. comm., pers. obs.] [Figs. 57 and 58]. The range of juvenile morphological variation has not been analyzed completely because most young examined had already left the breeding grounds. Birds in juvenile plumage trapped in migration are generally from unknown breeding regions and may be both tundrius and anatum. Compared to other subspecies, tundrius generally has extensive pale buffy edgings to dorsal feathers, more narrow streaking on breast and flanks with less broad arrowheadlike streaking on flanks, extensive pale buff extending back from the forehead onto an otherwise darker crown, extensive buff rather than rufous ocelli or nuchal spots, and darker malar stripes that frequently are broken at the base with

llibre falcons 16x23.indb 136

a narrow horizontal stripe. The ventral background color tends to be more buff rather than rufous. A stylized bird showing marking patterns is depicted in Beebe (1960: 150). These traits may also be found in some anatum, and in some pealei from the southern part of its range. The colors are more rufous, less buffy in anatum; in pealei there is a distinctive olive-yellowish tint to the buffy parts and the browns have a more slaty cast [also seen in some juvenile japonensis]. Generally, juveniles from Greenland seem darker than those from central and eastern Canada, but this has not been critically analyzed. In adult tundrius wings are slightly more narrow and attenuated than in other North American subspecies (White 1968b, White 1982). The longest primary [number nine] is 72.5% of the wing length in adult female tundrius [n = 21] compared to 70.5% in pealei [n = >14]. The wings of tundrius are narrower toward the body than in pealei with num-

16/10/13 10:20


CHAPTER 7. NORTH AMERICAN TUNDRA PEREGRINE 137

Figure 58. Throughout the 2000s, Clifford Anderson had a project of banding migrant Peregrines from the northern hemisphere on their non-breeding [winter] grounds in Chile. This female was caught near Puerto Montt. Because of her coloration, markings and size [a leucistic individual outside range of normal variation] she was thought to be a pallid morph of cassini. She had peachy-buff streaks in the crown. A satellite transmitter was nonetheless affixed to her. She started migration about the same time as other North American migrants do. She reached Central America and started overwater crossing to Belize. When about 15 km from Belize the GPS in the transmitter stopped moving and went to sea level. Over the next few days it slowly moved toward Belize. One of us [CMW] is of the opinion that she was shot from a boat by perhaps fishermen. So we never found her breeding grounds. Photograph courtesy of Clifford Anderson.

ber five primary 54% of the wing length [n = 15] against 59% in pealei [n = >14]. Although these measurements are not statistically different, we think they are

llibre falcons 16x23.indb 137

nonetheless biologically significant. Anatum tends to be intermediate in such a comparison [n = >14]. This relationship is not as clear-cut in juvenile-plumaged

16/10/13 10:20


316 PEREGRINE FALCONS OF THE WORLD

Figure 150. Here is a dark juvenile babylonicus that was wintering in the Little Rann of Kutch, India. Photograph courtesy of Raviraj V. Shah.

“stocky, peregrine-like,” while babylonicus is more “lanky”; pelegrinoides have a more “buggy-eyed” appearance –eyes larger in proportion to the head [Fig. 151]– while heads in babylonicus often suggest that of a Eurasian desert falcon in structure; pelegrinoides has a firmer, less lax plumage. When a falconer’s hood is removed from babylonicus the feathers often remain ruffled because of the “softer” plumage [J. Stoddart, pers. comm.]. To examine some of these ideas we looked at several relationships between these two forms. First, width at wing base [from the patagium where it joins the body to the tip on the innermost secondary] in babylonicus is about 34% to 35% of the wing length [n = 4], and in pelegrinoides it is similar at 36% [n = 4]. But because the inner primaries [number 1 to 5] in pelegrinoides [mainly the

llibre falcons 16x23.indb 316

males] are shorter in relation to the remainder of the primaries, 26% to 27% in pelegrinoides, 30% in male babylonicus and 35% in female babylonicus, the wing of pelegrinoides has a peculiar narrow shape giving the appearance of a narrower base. To examine head difference we measured museum specimens [n = 20] across the head just behind the eyes, a good measurement not altered by specimen preparation. Comparing this head width to tarsal length [traditionally an indicator of “mass” or “size”], the head widths of pelegrinoides were 83% of the tarsus while those of babylonicus were 77%. From a sample of adults, 49 babylonicus and 56 pelegrinoides, we compared malar stripe color and overall crown [not hind neck] color, ranking them as dark, intermediate, and pale or rufous.

16/10/13 10:20


CHAPTER 19. RED-NAPED SHAHEEN 317

Using a Kendell-tan test of association and χ2 test of independence, 68% of the malars and crowns of pelegrinoides were significantly associated [p = < 0.05] when the color was dark or intermediate. None had a rufous malar. In babylonicus they were not significantly associated, that is, some babylonicus had pale rufous malars, but intermediately colored crowns. Fifteen percent of the sample had entirely rufous malars, more frequent in males than in females, which showed no indication of a dark brown or black color [Fig. 152]. No pelegrinoides had a completely rufous malar color although some approach that condition as shown in Upton (2002: 92). Dark malars in babylonicus usually had a rufous outline while in pelegrinoides such an

outline was not always present or was as evident. To examine differences in plumage characteristics we compared them to other Peregrines such as peregrinus and macropus using a scanning electron microscope at 120 X magnifications. Nothing suggested a difference other than the barbules on the ramus of the back feathers appeared denser in pelegrinoides than in babylonicus.

Distribution Ecological and geographical distribution of babylonicus in central Asia is complex. The region includes heavily forested mountains [Kazakhstan], barren mountains [Turkmenistan], to vast open desert [Mongolia and Xinjiang,

Figure 151. A nice demonstration of the “buggy-eyed” appearance of pelegrinoides when compared to babylonicus. The “buggy-eyed” condition in this individual appears to be more conspicuous than is seen in the average condition, according to John Seabury. This falcon was trapped in Morocco to be used for falconry. Photograph courtesy of John Matthew Seabury.

llibre falcons 16x23.indb 317

16/10/13 10:20


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.