1 1 2 2 3 3 4 From Arctic tundras to African dunes 4 5 5 6 6 7 7 8 8 9 9 10 Siberian Peregrines in southern Africa 10 11 11 12 12 13 Text by Andrew R. Jenkins and Alan Stephenson cross its almost worldwide distribu- 13 14 14 Photographs by Andrew R. Jenkins 15 tion, the Peregrine Falcon Falco per- 15 16 16 17 egrinus varies in appearance and 17 18 A 18 19 biology to the extent that as many as 19 geneti- 19 20 20 21 cally distinct races are currently recognized. 21 22 22 23 Populations of these subtly different forms are 23 24 geographically separate, and many are essential- 24 25 25 26 ly resident within their respective breeding rang- 26 27 27 28 es throughout the year. 28 29 29 30 However, Peregrines living at northern 30 31 31 32 latitudes are forced southward by severe 32 33 33 34 winter conditions on their breeding grounds, 34 35 35 and the two northernmost races are highly 36 36 37 migratory. Pairs of F. p. tundrius and F. p. calidus 37 38 38 39 annually vacate their territories on the tundras 39 40 40 41 of arctic North America and Siberia and travel 41 42 42 43 thousands of kilometres south to spend the 43 44 44 45 boreal winter in the tropics. 45 46 46 47 47 48 An adult male calidus Peregrine feeding on a Rock Pigeon 48 49 Columba guinea on the dunes at Woody Cape in South 49 50 Africa’s Eastern Cape. 50 51 51 52 52 53 53 54 54 55 55 56 56 57 57

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  1 The secrets of Peregrine migration ornithologists in the region and could compile only 18 1 2 Extensive ringing programmes, observations of migrating acceptable calidus Peregrine records – five of which were Possible migration route of Siberian Peregrines into Africa 2 3 falcons in areas where they are particularly concentrated, museum specimens. 3 4 and studies using satellite telemetry have unlocked many One reason that so few migrants are recorded may be 4 5 of the migration secrets of Alaskan and Canadian tundrius that calidus birds are difficult to distinguish in the field Taimyr Peninsula 5 6 Peregrines, most of which overwinter in Central and from resident African Peregrines F. p. minor. Although the Kara Sea . 6 7 South America. However, the origins, routes and destina- two races supposedly represent opposite extremes in the Kola Peninsula 7 8 tions of migratory Peregrines of the Asian Arctic are poor- spectrum of Peregrine colour and size variation, casual . 8 ? 9 ly known. These calidus Peregrines are thought to move sightings of Peregrines are often made under difficult cir- 9 10 south into central and southern Asia, the Middle East and cumstances and seldom permit the observer time to study 10 11 Africa. Birds crossing into Africa probably pass through subspecific details. Confusion is exaggerated by consider- 11 12 the Red Sea region before fanning out to travel down both able variation in plumage and size within each subspecies. 12 13 coastlines. They are apparently quite numerous on pas- Perhaps significantly, seven out of 10 sexed and aged cali- 13 14 sage along the coasts of Somalia and Kenya, and have dus records from southern Africa are of adult females – 14 15 been reported using oil rigs off the Angolan coast as hunt- those most obviously different from the region’s resident 15 16 ing and roosting sites. Inland in North and Central Africa, birds. 16 17 specimens have been collected from Sudan, Cameroon While problems with identification may reduce the 17 18 and the Congo. number of migrant Peregrines recorded, data from the The broken red lines ( ) 18 19 Southern African Bird Atlas Project show no increase in indicate approximate routes of 19 20 Visitors to southern Africa the frequency of Peregrine sightings over the summer northern Eurasian Peregrines 20 21 Authentic records of calidus or other migrant Peregrines in period when the migrants should be in the region trapped on their breeding 21 22 southern Africa are scarce. Andrew Jenkins (ARJ) searched (October to March). Hence the paucity of contemporary grounds and satellite-tracked to . 22 23 the literature and canvassed a number of museums and records, which exists even in the face of a growing  wintering areas in Western Woody Cape 23 24 Europe and Pakistan. Migrants 24 25 The Alexandria dunefield is two to three kilometres wide and stretches about 50 kilometres along the coast from just north-east into Africa may originate from 25 26 of Port Elizabeth. The dunes reach a height of more than 100 metres in places, and only occasional patches of vegetation Western Siberia. 26 27 break the monotonous expanse of open sand. 27 28 28 29 number of expert falcon enthusiasts active on the to March. He saw both adult and juvenile birds, and as 29 30 subcontinent, is probably realistic, and only a relatively many as five or six individuals in the area at a time. The 30 31 small number of migrant Peregrines travel as far as south- adults seemed to prefer the coastal cliffs, whereas the 31 32 ern Africa each summer. juveniles usually perched inland on the highest crests of 32 33 the dunefield. The Peregrines were often in the company 33 34 Falcons of the dunes of Hobbies F. subbuteo which also seemed to use the dune- 34 35 In the summer of 1992, Alan Stephenson (AS) had occa- field as a perching and foraging area and generally out- 35 36 sion to visit the Woody Cape Nature Reserve which strad- numbered their larger relatives, with upwards of 10–20 36 37 dles the Alexandria dunefield along the eastern shore of birds present in the vicinity on most visits. The number 37 38 Algoa Bay, in the Eastern Cape. During this visit, he was of birds and their time of arrival on the dunes varied each 38 39 surprised to see at least two adult Peregrines apparently year, perhaps depending on the weather and foraging 39 40 occupying the long stretch of low, sandy cliffs which line conditions the birds experienced on their trip south. 40 41 the beach to the north-east of Woody Cape. Subsequent 41 42 visits revealed that these or similar birds were present in A bird in the hand... 42 43 the area throughout that summer. AS noticed that the Since first encountering the dunes Peregrines, AS made 43 44 birds differed from African Peregrines in their appearance repeated efforts to trap one of these birds in order to study 44 45 and in the way they flew. One bird, which he took to be it in the hand. They were generally skittish and difficult 45 46 female, was obviously bigger than Peregrines he had seen to approach, and they proved to be extremely trap-shy. 46 47 before, and both seemed to have very pale undersides. However, in January 1995 his efforts were rewarded, and 47 48 When they flew around the dunes or along the shore they he bagged a juvenile male. AS and ARJ got together to 48 49 seemed lazy, big-winged and long-tailed, and lacked the measure and photograph the bird, and to take a blood 49 50 urgency and energy of the African Peregrine. When in sample with a view to perhaps confirming its identity 50 51 pursuit of prey however, they took on a different using DNA analyses. 51 52 demeanour and showed themselves to be fast, powerful In appearance, it seemed to fit the profile for a calidus 52 53 hunters, unmistakably Peregrines. AS recognized that Peregrine. The literature suggests that calidus is the palest 53 54 these must be migrant calidus birds. Peregrine subspecies, especially ventrally, with faint mark- 54 55 Over the next five years AS made numerous visits to ings on the underparts, a relatively incomplete head-cap 55 56 Woody Cape and adjacent areas of the dunefield. The and thin ‘malar stripes’ beneath the eyes, leaving the 56 57 Peregrines were there each summer from about November cheeks white. Overall, this bird was much paler than  a 57

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 1 305–330 millimetres), and longer than that of minor (aver- Destinations 1 2 age 284 millimetres, range 275–300 millimetres), and its 2 The literature suggests that Siberian Peregrines leave their 3 tail was more than two centimetres longer than that of a 3 breeding areas at the end of the northern summer in syn- 4 typical African Peregrine. With a wing area about 20 per 4 chrony with the migration of their main prey species, 5 cent larger than that of a typical minor, its wing loading 5 mostly waterbirds, and that they follow these birds to 6 (body mass to wing area ratio) was about 15 per cent 6 their wintering areas and continue to prey on them there. 7 lighter. The relatively long wings and light body of the 7 Hence, falcons visiting southern Africa might be expected 8 migrant probably facilitate long-distance flying and 8 to frequent coastal estuaries where migrant shorebirds 9 reduce energy expenditure during migration. 9 congregate. Wader biologists report that the frequency of In the 1996/97 season, there were at least three birds in 10 Peregrine strikes at major southern African estuaries is rel- the Woody Cape area, including an adult male which AS 11 atively low, but this may simply reflect the small number trapped in January 1997. Again we convened to record 12 of migrant falcons which make it this far south. the bird’s vital statistics, photograph it and take some 13 It is difficult to account for the attraction which the blood before ringing and releasing it. At 580 grams this 14 Alexandria dunefield apparently holds for calidus was another fairly small individual, with a wing length of 15 Peregrines. The area features a unique habitat, with large 300 milli- metres and a slightly heavier wing loading than 16 expanses of open sand offering little cover for prey. t h e 17 Perhaps the dunes constitute a particularly favourable juvenile bird. It featured a striking contrast between dark 18 hunting area for the migrant falcons, where they are slate dorsal plumage and white, lightly barred underparts. 19 unlikely to encounter territorial residents? Also, Woody The malar stripe was quite broad but the cheeks were 20 Cape is conveniently situated for falcons to hunt pigeons white. 21 moving over the sea between the mainland and Bird While these trapped birds were larger than African 22 Island, and migrant passerines and waders travelling Peregrine males, the size discrepancy was much less  23 along the coast and crossing Algoa Bay.  24 25 26 27 28 29 30 31 32 33 A juvenile female African Peregrine trapped in the south- An adult male African Peregrine (above) trapped on the 10 34 western Cape (above) and a juvenile male calidus trapped Cape Peninsula, and an adult male Siberian Peregrine 11 35 at Woody Cape (right). Note the thicker malar stripe, more (right) trapped at the Alexandria dunefield. The African 12 complete, dark ‘helmet’, and darkly streaked underparts of bird is typical of the subspecies, and features a coloured 36 13 the African bird. The migrant has a significant amount of ‘wash’ with dense spotting and barring on the lower chest 37 14 white on the head, quite thin malar stripes and pale, faintly and belly and a pale ‘bib’, broad malar stripes and a full, 38 15 streaked underparts. black head-cap. The calidus bird has a slightly narrower 39 16 malar stripe and is conspicuously whiter and more lightly 40 17 typical juvenile African Peregrine. Its chest and belly were marked below. 41 18 off-white with light streaking, its back chocolate-brown 42 19 with the dorsal feathers broadly edged in buff. The malar than we had expected and both were well within the size 43 20 stripe was quite thin and the cheeks were pale, but the range of minor females. Russian ornithologists have sug- 44 21 most telling feature was the amount of white on its head, gested that male calidus Peregrines migrate further than 45 22 which extended from a broad, pale noseband to conspicu- females, and are more likely to venture south into Africa. 46 23 ous white eyestripes and large, white patches on the nape. If this is the case, and most of the southern African visi- 47 24 Siberian Peregrines are also thought to be one of the tors are males, our observations suggest that size may not 48 25 largest forms of the species – appreciably larger than be a good criterion for separating migrant from resident 49 26 African birds. The bird AS had trapped was not particular- birds. Apart from ‘jizz’ differences which are probably 50 27 ly large. It weighed 570 grams and was only slightly only apparent to an experienced observer, we found that 51 28 heavier than most South African minor males (which aver- the best distinguishing feature in the field is probably the 52 29 age about 530 grams, and range from 500–610 grams) and whiteness of the entire ventral surface on calidus birds, 53 30 was rather light for a calidus male which reportedly aver- compared with the white ‘bib’ and darker belly presented 54 31 age more than 700 grams and range from 678–740 grams). by minor. Greyer upperparts and narrower malar stripes 55 32 However, its wing-length measurement (310 millimetres) may not be strictly diagnostic of calidus. 56 33 was about right for calidus (average 314 millimetres, range 57

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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Above The Siberian Peregrine (left) shows a noticeably whiter, less heavily marked belly and underwing than the African 17 Peregrine (right). 18 19 Origins lish the whereabouts of her home. This summer, the 20 Recent efforts to investigate the migration routes of Eurasian WWGBP tracked two more females tagged in Saudi Arabia, 21 Peregrines have shed some light on the possible origins of but these birds migrated only as far as East Africa. 22 visitors to southern Africa. Four birds were fitted with satel- 23 Conservation implications lite transmitters in 1994 at their breeding grounds on the 24 Kola Peninsula in north-western Russia by an American biol- Little is known of the conservation status of Siberian 25 ogist, Charles Henny, and his team. All four birds overwin- Peregrines. While populations in some areas are probably 26 tered in western Europe. Further east along the Arctic Circle, substantial, there is evidence that their reproductive perfor- 27 a female from the Taimyr Peninsula was tracked to her win- mance may be impaired by organochlorine contamination, 28 tering grounds in Pakistan by workers from the Falcon which caused Peregrine populations in the United States 29 Facility of the National Avian Research Center, Abu Dhabi and Europe to crash in the 1960s and ’70s. These chemicals 30 (interestingly, a male trapped in this area weighed 625 are used in pest control, but have been outlawed in most 31 grams, a figure which compares favourably with the weights First World countries because of their persistent toxic 32 we recorded in South Africa). effects on the environment. They are still used in less- 33 This rather limited evidence could suggest that falcons developed countries, including some African states, and it 34 moving down into Africa originate from somewhere is conceivable that calidus Peregrines accumulate these poi- 35 between Kola and Taimyr, in the region of the Kara Sea. In sons on migration. 36 November 1996, Dr Bernd Meyburg of the World Working We hope to fit satellite transmitters to Peregrines visit- 37 Group on Birds of Prey & Owls (WWGBP) informed us of a ing the Alexandria dunefield in future summers in order 38 female calidus Peregrine which had been trapped and satel- to establish the path they follow on their return journey, 39 lite-tagged on southward migration through Saudi Arabia. and on their entire migration route in subsequent years. If 40 She was tracked on passage down to a point just north of we can track sufficient individuals from this popular 41 Paarl in the Western Cape, southern destination, we may be able to determine where where she apparently they might be exposed to pesticides and other dangers on 42 spent the austral sum- their annual pilgrimage from Arctic tundras to African 43  mer. Unfortu­ nately,­ dur- dunes. 44 ing her stay in the 45 Boland, she apparently Acknowledgements 46 shed her transmitter 47 package and Mey­burg 48 Andrew Jenkins would like to thank Mr Steven Phelps was unable to fol- 49 and Peregrine Properties for sponsoring his travel costs low her on her 50 to Port Elizabeth. return journey 51 Alan Stephenson would like thank the Western Region and estab- 52 District Council for allowing him the time to study the Peregrines at Alexandria, and the Officer-in-Charge Left at the Woody Cape Nature Reserve for permitting The African access to the dunes. Peregrine ROGER DE LA HARPE/ABPL

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