International expedition to study the Saker Falcon in the south of Ukraine

August 10th, 2011 Posted in Field researches, Photos, Satellite telemetry

31.05-6.06.2011 a joint Ukrainian-Hungarian-Romanian expedition trip to study the Saker Falcon in the south of Ukraine was carried out. The main purpose was to mark Saker’s chicks with satellite transmitters to investigate their It is the first project in Ukraine dedicated to satellite telemetry of birds of prey.

Photo: M.Prommer, M.Gavrilyuk, V.Vetrov, H.Torok

As we wrote in the previous material, the project aimed at protection and study of the Saker Falcon has been implemented in countries of Eastern Europe since 2007. One of its directions is studying migration of these raptors using satellite telemetry. Generally, over the period 2007-2010 our colleagues marked over 30 Saker Falcons. It was found out that young birds widely roamed over the steppe zone of Eastern Europe: thus, birds born in Hungary often visited the territory of Ukraine. It has lead to the idea of marking birds in Ukraine as well.

Hungarian ornithologists supplied us with 9 satellite transmitters, for which we are sincerely grateful to the project manager Jozsef Fidloczky, and to Saker experts from Bükk National Park Directorate and MME/BirdLife Hungary. Participants of the expedition were Yury Milobog, Maxim Gavrilyuk, Vitaly Vetrov, Vladimir Strigunov, Matyas Prommer (MME/BirdLife Hungary), Hunor Török (Bükk National Park Directorate, Hungary), Szilárd Daróczi (Milvus Group, Romania).
Preliminary, it was planned to mark Saker’s chicks in several regions of Ukraine to clarify differences in directions of their further migration. Besides, we intended marking birds which nest in different places – on cliffs, power line poles and clay precipices (in case of they survive until their first breeding we will be able to find out their fidelity in selection nesting sites).

All participants of the expedition have met on the 30th May in Kryvyi Rih City and next morning departed to Kherson region. However, works of the first day changed further plans because after investigation of clay precipices, where during the expedition-2009 we had found 6 occupied nests of the Saker Falcon, we found only one nest with 4 chicks. In other two sites tracks evidenced presence of single Sakers. Sakers in this discovered nest were too adult for marking and there was a great danger that all of them could fly out. That is why decided to refuse their ringing. Diet of these Saker Falcons was characteristic – among food remains we observed feathers of the Slender-billed Gulls and Mediterranean Gulls which in this region were common species among gulls. Only later, in the end of expedition, we succeeded to find another nest of the Saker located on a clay precipice. Traced it from the distance we came to the nest right after the female returned with her prey. Chicks, enthusiastically eating, almost neglected our presence and we could observe their meal from the distance of only several metres. The nest contained 4 feathered chicks, one of them further was equipped with a satellite transmitter. The most unexpected was diet of this pair – in the nest and nearby we revealed remains of 11 Stone Curlews, also 4 Magpies, 4 Partridges, a Roller, Nightjar, Moorhen, Turtle Dove. And this was in spite of abundance of gulls in their breeding site.
The most numerous birds of prey among those inhabited clay precipices turned out to be Common Kestrels. On 16 kilometres of these biotopes bordering with fields and steppe areas we encountered 36 pairs of Common Kestrels, estimated their total number as at least 50-60 pairs. We revealed a nest of these birds with 5 eggs and also another nest with 2-3 feathered chicks. Among other raptors of clay precipices there were counted: Red-footed Falcon – 4 pairs, Marsh Harrier – 12, Little Owl -1. On a field we flushed the Short-eared Owl which for a long time flied in circles, being probably disturbed at the nest.
Later, during 1-5 June our route crossed steppes and foothills of the Crimea. However, Sakers continued making adjustments in our plans. On Kerch Peninsula we visited 4 known nests but only one of them was occupied. The nest sheltered 4 chicks, and we decided to mark two of them – a male and female. Diet of this pair was rather diverse – in the nest we discovered remains of 2 small sousliks, 2 Partridges, 2 Rock Doves and 1 Short-eared Owl.
Since our main aim was checking of known nests of the Saker, data on other birds of prey were collected indirectly and cannot pretend to be complete. On Kerch Peninsula we counted: Marsh Harrier – 11 ind., Hobby Falcon – 9; Common Kestrel – 9, Long—legged Buzzard – 1; Little Owl – 3. It was found a nest of the Common Kestrel with 6 downy chicks, located in an old Magpie’s nest.
In the foothills of the Crimean we visited 8 known breeding sites. Searching nests in these sites often requires a lot of time, but only in one site we observed an adult male of the Saker, an in another we found an occupied nest. In the nest located in the rock niche there were 3 feathering chicks, one of them we marked with a satellite transmitter. Here, among food remains we revealed: little souslik, 2 Rooks, 2 Common Kestrels, a Starling, Calandra Lark and Hoopoe. Fauna of birds of prey in the foothills were slightly different, though Common Kestrels still dominated (at least 20 pairs counted – underestimation), Peregrine Falcon – single and one pair with their brood; Short-toed Eagle – single and a pair; Imperial Eagle – juvenile and 2 occupied nests; Long-legged Buzzard – 2 ind. and 2 pairs; Griffon Vulture – 2; Black Vulture – 2; Buzzard – 1; Sparrowhawk – 1; Hobby Falcon – 1. A pleasant surprise for participants of the expedition was a discovery of the Imperial Eagle’s nest, located on a power line pole. In the nest there was one chick in the second downy plumage with growing flight feathers. We succeeded to see an adult bird carrying a souslik in the nest. This is only the second case of the Imperial Eagle’s nesting on poles of power lines in Ukraine though in other regions (eg. Russia) Imperial Eagles rather often make nests on poles of power lines. We also checked the tree nest of other pair of Imperial Eagles which we knew for many years and saw that it was occupied again.
Visits to breeding sites of the Saker on Tarkhankut Peninsula were not effective as well – of 8 known nests only 4 were occupied. And only one nest with chicks was found on Tarkhankut cliffs. There were 4 chicks but too old to be marked. In this region we marked with a satellite transmitter one chick from the brood composed of 4 birds in the nest located on a power line pole. In diet of this pair prevailed Rooks – 7 ind., also there were found 3 Mediterranean Gulls, a Quail and a young Night Heron. The third Saker’s nest contained at least 3 feathered chicks.
Among raptors of Tarkhankut precipices Common Kestrels again dominated – we counted 19 pairs (underestimation); Red—footed Falcon – 7; Saker – 2; Little Owl – 1. In the steppe part of Tarkhankut Peninsula the Red-footed Falcons prevailed. Here, there were counted: Red-footed Falcon – 38 ind., Common Kestrel – 18, Marsh Harrier – 2, Shot-toed Eagle – 1, Hobby Flacon – one pair at the nest, Long-legged Buzzard – 1, Buzzard – 2, Honey Buzzard – 1, Little Owl – 1. Also it should be noted several meetings with Honey Buzzards which do not breed in this region. Probably they were late migrants.
In the steppe part of Central Crimea situation with the Saker Falcon was slightly better – we visited 4 known sites, two of them had occupied nests, and also found 2 new nests. In one of these nests, located on a power line pole, one of 4 chicks was marked with a satellite transmitter. This pair preferred Corvidae in their diet – we revealed 3 Rooks, 3 Magpies and 1 Raven. In other Saker’s nest there were at least 2 chicks. Slightly unexpected was location of the nest of one of the pairs – they placed it on top of a solitary power line pole which occurs very rarely. In the nest we were able to see only one chick in the second downy plumage.
We checked also already known nest of the Imperial Eagles located on a power line pole. According to colleagues ornithologists (Yu.Andryushchenko and V.Popenko, pers. comm.) in spring the female had incubated the clutch. However, during our visit the nest was empty. Unfortunately, this pair is also well known to poachers whose for last several years didn’t give them a chance to breed. Nearby we observed a pair of adult Imperial Eagles and another juvenile bird. In this part of the Crimea the Red-footed Falcons dominated – 39 pairs counted, Common Kestrel – 27 pairs, Long-legged Buzzard – 9, Marsh Harrier – 4, Honey Buzzard – 1, Little Owl – 2. During one of our stops in the evening we counted a brood of Long-eared Owl and 2 males of Scops Owl.
In the course of Crimean expedition we also checked 6 artificial nest boxes, mounted by V.Vetrov and S.Domashevsky for the Saker in 2010, which we described in the previous web-publication. None of them in the current year was occupied with Sakers (though in 2010 Sakers nested in one of them), one nest box disappeared, and two were occupied with the Common Kestrel and Raven respectively.
Further our route again crossed Kherson Oblast where for two days we checked 10 known nests of the Saker, 8 of them were with chicks. However, two nests contained only 1 chick in each, and under one of them we saw clear tracks of the car. Two more nests evidenced recent presence of chicks in them and hardly had they fledged themselves. These facts show that poachers continue taking chicks from the nests. We marked with satellite transmitters two chicks in different nests. In other nests of Sakers in Kherson region the brood size equaled 2-3 chicks. In the Saker’s diet it was registered 2 Rooks, and the pellet contained a vole.
Within Kherson region, mainly among agricultural lands, there were dominated Kestrels – 15 pairs (including 4 nests on power lines), Buzzard – 3; Long-legged Buzzard – 1; Hobby Falcon – 1; Marsh Harrier – 1; Short-eared Owl – 2; Montagu’s Harrier – 1 female; and one Harrier’s female of light coloration which we didn’t indentified as a species. At the stop, in the evening we observed 2 males of the Scops Owl. At the shore of Kakhovske Reservoir we revealed a new pair of White-tailed Eagles – we observed an adult bird carrying a fish to the nest.
In the late evening of 6 June, having a serous breakage of one of our cars we returned to Kryvyi Rih. Next day our European colleagues visited two nests in Odessa Oblast but since they were about to fledge they did not use the last satellite transmitter. We are going to attach it in the nearest time to one of adult Saker Falcons in the Crimea.

Therefore, in the course of expedition there were checked 34 known breeding sites of the Saker and found 6 new ones. Only 19 of them had occupied nests. Undoubtedly, with more scrupulous search it could be possible to find new nests for some of these pairs. However it is clear that the breeding success of Sakers in 2011 is low. It is rather hard to reveal exact reasons; possibly cold spring of this year provided this negative effect. But, undoubtedly, Sakers still suffer from press of poachers taking chicks and catching adult females.

In the course of the expedition we discussed possible directions for further cooperation to study and protect birds of prey. In conclusion, we would like to thank our colleagues from Hungary and Romania for their sincere interest in studying the Saker in Ukraine, for profound evenings with lesson of English, Hungarian and Romanian and degustation of national dishes.

Results of satellite tracking of Sakers will be available at our website when juvenile birds leave their breeding sites – more likely in August or September.

Maxim Gavrilyuk, Yury Milobog, Vitaly Vetrov, Vladimir Strigunov.