Орел-карлик в Поволжье, на Урале и в Сибири, Россия

• Main Author: Карякин, И.
• Format: Text
• Language: unknown
• Published: Общество с ограниченной ответственностью «Сибэкоцентр» 2007
• Subjects: ХИЩНЫЕ ПТИЦЫ; ПЕРНАТЫЕ ХИЩНИКИ; ОРЕЛ-КАРЛИК; Avda; Bakka; Borodin; Kama; Ochre; Sura; Tuva; Zavod; ob river; ural mountains; Siberia
• Online Access: http://cyberleninka.ru/article/n/orel-karlik-v-povolzhie-na-urale-i-v-sibiri-rossiya; http://cyberleninka.ru/article_covers/14918766.png

Methods Distribution of the Booted Eagle was investigated during field trips in 1996 2006. To estimate a number of the Booted Eagle in GIS the map of inhabitant places that encompass a total area of 42283 km2 was created. Also we set 65 study plots. The area of inhabitant places per each study plot was 20 km2, the total area of inhabitant places in the all of plots was 1300 km2. Extrapolation of data was carried out for every local population: density of breeding pairs in inhabitant places of a study plot was extrapolated for the total area of inhabitant places within a local population range. For researching breeding biology we surveyed 3 breeding pairs with using video cameras in 2004. For evaluation of breeding success we twice visited 6-9 nests a breeding season. The breeding success was estimated as a portion of fledglings per the total number of laid eggs. A diet was analyzed with using video cameras and collecting remains of preys in and under a nest. A total of 120 preys were surveyed in nests as well as 113 remains were collected, 5 pellets were analyzed and 46 facts of bringing preys in nests by adults were registered with using video camera. Statistical analysis was realized with using following software: MS Excel 2003, Spatial Statistics 1.0, Statistica 6.0. Distribution Only two notes of the Booted Eagle that considered as a vagrant was known in the Middle Volga at the end of XIX century. The Booted Eagles was found breeding in forests along the Volga and Ural rivers to 1960s (Voinstvenskiy, 1960), and the fact of his breeding was fixed in the N. Novgorod district in 1965 (Zimin, Molodovskiy, 1968). More notes of the Booted Eagle breeding in the Middle Volga region have appeared since 1980s (Borodin et al., 2003). Booted Eagles were registered regularly in two parts of the Sura river valley in 2004-2005. And no less than 5 breeding territories were known in Mordovia till 2005 (Lapshin et al., 2005). Two breeding territories were found in the Alatyr river valley in N.Novgorod district in August 2003. Booted Eagles have been regularly observed breeding at Samarskaya Luka (Samara district) since 1990s. Two breeding territories were found in pine forest on terraces of the Volga river in 1997, and 3 breeding territories were noted forests in ravines and flood-lands in the south of the Samara district in 1999. T. O. Barabashin (2006) also observed Booted Eagles in the Samara district behind the Volga river. The species have been registered in the Ural Mountains foothills since 1990s (Karyakin, 1998). A brood of 2 fledglings was observed in the Dema river flood-lands. The Booted Eagle was found breeding in the Bugulminsko-Belebeevskaya upland in 2006 (Karyakin, 2006). Also in July 2002, 2 breeding territories with nests were found in the right side of the Kama river (Nikolenko, Bekmansurov, 2006). Thus being a vagrant or rare breeding species at the beginning of XX century the Booted Eagle has made a common raptor inhabiting forest-steppe landscapes. The Booted Eagle has already inhabited almost the whole territory of the Volga region and the Ural Mountains foothills and the right side of the Kama river in Tataria, and it was happen during last decade. The Booted Eagle was not registered in Southern Ural before 1990s (Karyakin, 1989). Only adults were registered since 1996 to 2002, but a brood of 2 fledglings was observed on the Ik river in Bashkiria in August 2002. L.V. Korshikov (2001) surveyed single birds in the southern edge of Southern Ural. For the recent time the territory of Western Siberia including Northern Kazakhstan was considered to be out of the Booted Eagle's breeding range (Deventyev, 1951). However single birds were observed in the south of the Chelyabinsk district in 2002 ( Gashek, 2002) and in 2003. The species was believed to be a vagrant in the Kurgan district (Ryabitsev et al., 2001), but A.V. Moshkin (2006) found a nest and a brood of 2 chicks in a terrace pine forest of the Tobol river. The species was not registered in the Novosibirsk district for the recent time too. The first fact of breeding in the district was noted in the Berd river valley in the Salair Mountains foothills in 2002 (Karyakin et al., 2005). I.F. Zhimulev (2005) recorded a brood of Booted Eagles in the Botanical garden in Novosibirsk on 21 August 2005. Several records were fixed in the left side of the Ob river in the Altai Kray (Karyakin et al., 2005). Now the Booted Eagle seems to be settling into the east of the Western Siberia. The first who recorded the species breeding in the Republic of Altai was P.P. Sushkin (1938). He found Booted Eagles breeding in the Ulaganskoe Plateau. We observed adult birds with breeding behavior four times in June 2000, also noted a single adult in the Ursul river valley on 24 June 2003, a pair of adults in the Yabogan river flood-lands in the Kan depression, and found two living nests in the Chuya and Bugusun river valleys. Seven nests of Booted Eagles were found in flood-forests of several rivers in Tuva: Kargy, Tes-Hem, Ersin, Shuurmak and Ulug-Hem (Baranov, 1991). The Booted Eagle was found breeding in the all valleys of large rivers in steppe depressions in 1999-2006 as well as we found 74 breeding territories and nests of 44 pairs in the Balgasyn pine forest. The first registration of the species in the Kemerovo district was in the upper reaches of the Srednya Ters in the Kuznetskiy Alatau State Nature Reserve (Vasilchenko, 1999). A total of 5 nest were found in Shectakovskie bogs during 14 years of surveys (Vasilchenko, 2004). It was not known in 1970-1980s about the Booted Eagle breeding in Khakasia (Prokofyev, 1987; 1993), however we found the species breeding on the almost territory of Minusinsk depression in 2000. We registered 24 breeding territories (in 11 of them we found nests) on the territory of the republic in 2000-2003. The first information about records of the species in the Krasnoyarsk Kray was appeared in 1970s. Single birds were observed in the Gagula depression at the end of August 1971, in the Us depression on May 1982 (Syroechkovskiy, Bezborodov, 1987). We surveyed 2 breeding areas in the Us depression in 2001 and else 2, where we found a nest in the one of them (Karyakin et al., 2005). We found several breeding territories in the right side of the Enisey river: in the Shushenskiy (1), Znamenskiy (1) and Minusinsk (2) pine forests and in the Tuba river valley (2 pairs). Also we project the Booted Eagle breeding in the Kan forest-steppe, where we surveyed males hunting in the upper reaches of the Bolshaya Avda river on 23 June 2005 and in the Kan river valley near Kansk on 22 July 2005. The history of surveys of the Booted Eagle in the Baikal region has almost 150 years, unfortunately the reliable information about the Booted Eagle's breeding in the region was absent to the beginning of XXI century (Popov, 2003). We observed Booted Eagles in 6 points of the Irkutsk district, and in 2 of them we found active nests (Karyakin et al., 2006). The Booted Eagle has been observed in the Tunkinskaya valley in Buryatia since 1930s. Also we observed single birds 4 times (Karyakin et al., 2006). In the Chita district an adult of the Booted Eagle was hunted near Alexandrovskiy Zavod in September 1935 (Skalon, 1936) and another bird was observed near Kaylastuy (Gagina, 1960). Also Booted Eagles were recorded in flood-lands of several rivers: Shilka, Nerch and Aleur (Shkatulova, 1974). The modern breeding range of the Booted Eagle can be divided into 3 parts (fig. 3): 1 breeding range at the end of IX beginning of ХХ centuries (Dementiev, 1951), 2 breeding range at the end of ХХ century, 3 breeding range at the beginning of ХХI century. The territory being inhabited by Booted Eagles during last 20-30 years exceeds now the former range more than in 1.5 times. Inhabitant places The statistical analysis was shown breeding density of Booted Eagles to correlate negatively with forest fragmentation (r = 0,767; p 2 of forested area and not depends mainly on the type of forest or geological peculiarities of the territory but on a number of preys. We noted the positive correlation for density and distances from nests to Daurian Pike's colonies (Ochotona daurica)(r = 0,812; p 2 of forested area) was noted only in 12,1% of study plots (n=65), where the predominate habitats were flood-forests (n=15; 53,3%) and terrace forests (40,0%). More than a half of that plots (53,3%) is in the Altai-Sayan region mainly in Tuva (33,3%), others in the Volga river region and the Ural Mountains foothills, especially in the Samara district and the Republic of Tatarstan (26,7%). The average distance between Booted Eagle nests in the all plots среднем 5,52±2,84 км (Ex = 0,33; n=64; range 1,19 12,87). The spatial analysis of the Booted Eagle distribution in Russia (fig. 6) was shown the existence of two distinguished population groups that are centers of two subspecies nominal (H. pennatus pennatus) and oriental (H. pennatus milvoides) (Stepanyan, 1990). Now birds spread actively from these centers on the territory of Western Siberia. A total of 1700-2600 pairs of Booted Eagles are estimated to breed on the surveyed territory of Russia. Morphs Analysis of published sources was demonstrated dark morph to dominate (n=48; 64,6%) in Booted Eagle populations inhabited the territory between the Volga and the Amur rivers. Our observations of 298 birds in different regions of Russia also show the predominance of dark morph (85,2%) in surveyed part of the range (fig. 15). Decreasing the portion of pale birds in the population is noted from west to east. If the portion registered pale morph birds in the Volga-Ural region is 34,8% but to the east from Ural it will be 6,8%. Breeding biology Phenology In Russia Booted Eagles return into breeding territories in April. Birds lay eggs mainly during 25 April-20 May. Late clutches were noted until 5 June. Earliest broods have been registered since 20 May. The chicks are hutching out mainly on 27 May 22 June. Latest broods were registered until 10 July. Chicks set in a nest 49-56 days. As a rule fledglings are fed by parents additionally in a breeding territory during 1.5-2 week. The total period of chick feeding is 60-70 days. Fledglings leave a nest on 17 July-15 August. Booted Eagle start to migrate in September. Nests Eagles prefer to build their nests (n=102) a poplar tree (38,2%) and a larch tree (31,4%). Pine as a nesting tree is at the third place (20,6%).At all in the range we registered 52% of nests on coniferous trees and 48% on deciduous. We know the single nest of the Booted Eagle located on a cliff on the Elegest river in Tuva, however we consider that fact as extraordinary and unusual for the species, because in that case eagles occupied a n old nest of the Upland Buzzard (Buteo hemilasius) after their own nest with the first clutch located on a poplar in flood-lands was perished by the reason of fire. Next year that pair built new nest on a polar where they bred last 5 years. Birds use for nesting trees growing near the edge of forest while the average distance between nesting tree and the edge of forest is 88,2±65,7 m (n=90; range 10 237 m), by the way the longest distances were noted in forests on river terraces and hilly watersheds. Frequently the edge of forest is close to a river or a water reservoir (40,2%). Birds (n=102) prefer the densest part of forest as a nesting habitat (71,6%). For nest building (fig. 17) birds (n=102) use mainly a branch fork (90,2%) in the upper part (69,6%) or in the middle part of a tree. We estimated exposition for 64 nests (fig. 18): the most part of them had southern orientations (59,4%), mainly south-eastern (21,9%).The average height of nest position was 10,8±4,44 m (n=102; range 4-22 m). As a result of position in a branch fork nests have oval forms. Nest dimensions: the average external diameter of the nest is 93,4±29,49 х 80,6±34,17 cm (n=9; 55 150 х 35 150 cm); the average height of the nest construction 100,6±27,34 cm (range 60 135 cm); the average internal diameter of the nest 19,8±3,35 х 18,3±3,08 cm (range 16 25 х 15 25 cm); the average nest depth 4,2±1,64 cm (range 2 7 cm). The most observed nests were used during many ears and only 2 were built in that year when we surveyed they. Booted Eagles often use old or new nests of other bird species: mainly Black Kites (Milvus migrans), sometimes Buzzards (Buteo buteo) or Goshawks (Accipiter gentitlis), in the east of the range Upland Buzzards, rarely Great Spotted Eagles (Aquila clanga), (Corvus cornix, C. corone) and (Ardea cinerea). We recorded 12 such facts (11,8% of observed nests). Booted Eagles use such nests in the most cases as a foundation for building their own nest, but sometimes they occupy a nest without any reconstructions and only hardly renew it during laying eggs. The nests built by Booted Eagles themselves have some particular features. Booted Eagles used for building nest only fresh branches with foliage. In coniferous forests eagles cover the bottom of a nest by a thick layer of conifer branches (obligatory with green needles), in deciduous forests it is replaced by a thick layer of green leaves especially of poplar or birch trees. Clutches Eggs of Booted Eagles are white. Often we noted small spots on the shell of eggs, the color of spots varies from ochre to red-brown. Large spots were not observed. During the all period of surveys we observed only full clutches consisted of 2 eggs (n=30). The average size of eggs was 55,8±2,41 х 46,0±1,99 mm (n=26; range 50,0 62,2 х 39,6 50,0 mm). Broods and breeding success Broods as a rule contain 2 chicks. We observed 96 broods and the size of 92,7% of them was 2 chicks or fledglings. We didn't registered facts of cannibalism amongst chicks of Booted Eagles unlike Buzzards or other species of eagles. We didn't registered facts of chick deaths too, and all surveyed chicks successfully fledged. As a result of insignificant amount of unsuccessful eggs on the stage of clutch the breeding success raises more than 90% and it is supposed to be normal for the species. Occupancy of breeding territories is sufficient high. We monitored 6 breeding territories during 1999-2006 and only 2 territories weren't occupied every year. The number of small mammals doesn't impact on the breeding success of Booted Eagles and during depressions of mammal numbers eagles successfully change them in the diet by birds. Fig. 20 shows the occupancy of breeding territories by Booted Eagles and Saker Falcons and numbers of small mammals that are preys of both species in the Tes-Hem plot in the Ubsunur depression (Tuva) in 1999-2005. Diet Analysis if preys and their remains surveyed in nests (n=233) was shown the mammals to dominate in the diet of Booted Eagles (70%), the portion of birds in the diet is 27,9%, and the portion of amphibians and reptilians is insignificant (fig. 21). However we noted the increasing of mammal portion in the east and south of the range due to the colonial steppe species. Acknowledgments We thank Elvira Nikolenko, Mikhail Kozhevnikov, Sergey Bakka, Tim Barabashin, Alexander Moshkin, Alexey Pazhenkov and other colleagues assisted in data collection and in many other phases of the project. Methods Distribution of the Booted Eagle was investigated during field trips in 1996 2006. To estimate a number of the Booted Eagle in GIS the map of inhabitant places that encompass a total area of 42283 km2 was created. Also we set 65 study plots. The area of inhabitant places per each study plot was 20 km2, the total area of inhabitant places in the all of plots was 1300 km2. Extrapolation of data was carried out for every local population: density of breeding pairs in inhabitant places of a study plot was extrapolated for the total area of inhabitant places within a local population range. For researching breeding biology we surveyed 3 breeding pairs with using video cameras in 2004. For evaluation of breeding success we twice visited 6-9 nests a breeding season. The breeding success was estimated as a portion of fledglings per the total number of laid eggs. A diet was analyzed with using video cameras and collecting remains of preys in and under a nest. A total of 120 preys were surveyed in nests as well as 113 remains were collected, 5 pellets were analyzed and 46 facts of bringing preys in nests by adults were registered with using video camera. Statistical analysis was realized with using following software: MS Excel 2003, Spatial Statistics 1.0, Statistica 6.0. Distribution Only two notes of the Booted Eagle that considered as a vagrant was known in the Middle Volga at the end of XIX century. The Booted Eagles was found breeding in forests along the Volga and Ural rivers to 1960s (Voinstvenskiy, 1960), and the fact of his breeding was fixed in the N. Novgorod district in 1965 (Zimin, Molodovskiy, 1968). More notes of the Booted Eagle breeding in the Middle Volga region have appeared since 1980s (Borodin et al., 2003). Booted Eagles were registered regularly in two parts of the Sura river valley in 2004-2005. And no less than 5 breeding territories were known in Mordovia till 2005 (Lapshin et al., 2005). Two breeding territories were found in the Alatyr river valley in N.Novgorod district in August 2003. Booted Eagles have been regularly observed breeding at Samarskaya Luka (Samara district) since 1990s. Two breeding territories were found in pine forest on terraces of the Volga river in 1997, and 3 breeding territories were noted forests in ravines and flood-lands in the south of the Samara district in 1999. T. O. Barabashin (2006) also observed Booted Eagles in the Samara district behind the Volga river. The species have been registered in the Ural Mountains foothills since 1990s (Karyakin, 1998). A brood of 2 fledglings was observed in the Dema river flood-lands. The Booted Eagle was found breeding in the Bugulminsko-Belebeevskaya upland in 2006 (Karyakin, 2006). Also in July 2002, 2 breeding territories with nests were found in the right side of the Kama river (Nikolenko, Bekmansurov, 2006). Thus being a vagrant or rare breeding species at the beginning of XX century the Booted Eagle has made a common raptor inhabiting forest-steppe landscapes. The Booted Eagle has already inhabited almost the whole territory of the Volga region and the Ural Mountains foothills and the right side of the Kama river in Tataria, and it was happen during last decade. The Booted Eagle was not registered in Southern Ural before 1990s (Karyakin, 1989). Only adults were registered since 1996 to 2002, but a brood of 2 fledglings was observed on the Ik river in Bashkiria in August 2002. L.V. Korshikov (2001) surveyed single birds in the southern edge of Southern Ural. For the recent time the territory of Western Siberia including Northern Kazakhstan was considered to be out of the Booted Eagle's breeding range (Deventyev, 1951). However single birds were observed in the south of the Chelyabinsk district in 2002 ( Gashek, 2002) and in 2003. The species was believed to be a vagrant in the Kurgan district (Ryabitsev et al., 2001), but A.V. Moshkin (2006) found a nest and a brood of 2 chicks in a terrace pine forest of the Tobol river. The species was not registered in the Novosibirsk district for the recent time too. The first fact of breeding in the district was noted in the Berd river valley in the Salair Mountains foothills in 2002 (Karyakin et al., 2005). I.F. Zhimulev (2005) recorded a brood of Booted Eagles in the Botanical garden in Novosibirsk on 21 August 2005. Several records were fixed in the left side of the Ob river in the Altai Kray (Karyakin et al., 2005). Now the Booted Eagle seems to be settling into the east of the Western Siberia. The first who recorded the species breeding in the Republic of Altai was P.P. Sushkin (1938). He found Booted Eagles breeding in the Ulaganskoe Plateau. We observed adult birds with breeding behavior four times in June 2000, also noted a single adult in the Ursul river valley on 24 June 2003, a pair of adults in the Yabogan river flood-lands in the Kan depression, and found two living nests in the Chuya and Bugusun river valleys. Seven nests of Booted Eagles were found in flood-forests of several rivers in Tuva: Kargy, Tes-Hem, Ersin, Shuurmak and Ulug-Hem (Baranov, 1991). The Booted Eagle was found breeding in the all valleys of large rivers in steppe depressions in 1999-2006 as well as we found 74 breeding territories and nests of 44 pairs in the Balgasyn pine forest. The first registration of the species in the Kemerovo district was in the upper reaches of the Srednya Ters in the Kuznetskiy Alatau State Nature Reserve (Vasilchenko, 1999). A total of 5 nest were found in Shectakovskie bogs during 14 years of surveys (Vasilchenko, 2004). It was not known in 1970-1980s about the Booted Eagle breeding in Khakasia (Prokofyev, 1987; 1993), however we found the species breeding on the almost territory of Minusinsk depression in 2000. We registered 24 breeding territories (in 11 of them we found nests) on the territory of the republic in 2000-2003. The first information about records of the species in the Krasnoyarsk Kray was appeared in 1970s. Single birds were observed in the Gagula depression at the end of August 1971, in the Us depression on May 1982 (Syroechkovskiy, Bezborodov, 1987). We surveyed 2 breeding areas in the Us depression in 2001 and else 2, where we found a nest in the one of them (Karyakin et al., 2005). We found several breeding territories in the right side of the Enisey river: in the Shushenskiy (1), Znamenskiy (1) and Minusinsk (2) pine forests and in the Tuba river valley (2 pairs). Also we project the Booted Eagle breeding in the Kan forest-steppe, where we surveyed males hunting in the upper reaches of the Bolshaya Avda river on 23 June 2005 and in the Kan river valley near Kansk on 22 July 2005. The history of surveys of the Booted Eagle in the Baikal region has almost 150 years, unfortunately the reliable information about the Booted Eagle's breeding in the region was absent to the beginning of XXI century (Popov, 2003). We observed Booted Eagles in 6 points of the Irkutsk district, and in 2 of them we found active nests (Karyakin et al., 2006). The Booted Eagle has been observed in the Tunkinskaya valley in Buryatia since 1930s. Also we observed single birds 4 times (Karyakin et al., 2006). In the Chita district an adult of the Booted Eagle was hunted near Alexandrovskiy Zavod in September 1935 (Skalon, 1936) and another bird was observed near Kaylastuy (Gagina, 1960). Also Booted Eagles were recorded in flood-lands of several rivers: Shilka, Nerch and Aleur (Shkatulova, 1974). The modern breeding range of the Booted Eagle can be divided into 3 parts (fig. 3): 1 breeding range at the end of IX beginning of ХХ centuries (Dementiev, 1951), 2 breeding range at the end of ХХ century, 3 breeding range at the beginning of ХХI century. The territory being inhabited by Booted Eagles during last 20-30 years exceeds now the former range more than in 1.5 times. Inhabitant places The statistical analysis was shown breeding density of Booted Eagles to correlate negatively with forest fragmentation (r = 0,767; p 2 of forested area and not depends mainly on the type of forest or geological peculiarities of the territory but on a number of preys. We noted the positive correlation for density and distances from nests to Daurian Pike's colonies (Ochotona daurica)(r = 0,812; p 2 of forested area) was noted only in 12,1% of study plots (n=65), where the predominate habitats were flood-forests (n=15; 53,3%) and terrace forests (40,0%). More than a half of that plots (53,3%) is in the Altai-Sayan region mainly in Tuva (33,3%), others in the Volga river region and the Ural Mountains foothills, especially in the Samara district and the Republic of Tatarstan (26,7%). The average distance between Booted Eagle nests in the all plots среднем 5,52±2,84 км (Ex = 0,33; n=64; range 1,19 12,87). The spatial analysis of the Booted Eagle distribution in Russia (fig. 6) was shown the existence of two distinguished population groups that are centers of two subspecies nominal (H. pennatus pennatus) and oriental (H. pennatus milvoides) (Stepanyan, 1990). Now birds spread actively from these centers on the territory of Western Siberia. A total of 1700-2600 pairs of Booted Eagles are estimated to breed on the surveyed territory of Russia. Morphs Analysis of published sources was demonstrated dark morph to dominate (n=48; 64,6%) in Booted Eagle populations inhabited the territory between the Volga and the Amur rivers. Our observations of 298 birds in different regions of Russia also show the predominance of dark morph (85,2%) in surveyed part of the range (fig. 15). Decreasing the portion of pale birds in the population is noted from west to east. If the portion registered pale morph birds in the Volga-Ural region is 34,8% but to the east from Ural it will be 6,8%. Breeding biology Phenology In Russia Booted Eagles return into breeding territories in April. Birds lay eggs mainly during 25 April-20 May. Late clutches were noted until 5 June. Earliest broods have been registered since 20 May. The chicks are hutching out mainly on 27 May 22 June. Latest broods were registered until 10 July. Chicks set in a nest 49-56 days. As a rule fledglings are fed by parents additionally in a breeding territory during 1.5-2 week. The total period of chick feeding is 60-70 days. Fledglings leave a nest on 17 July-15 August. Booted Eagle start to migrate in September. Nests Eagles prefer to build their nests (n=102) a poplar tree (38,2%) and a larch tree (31,4%). Pine as a nesting tree is at the third place (20,6%).At all in the range we registered 52% of nests on coniferous trees and 48% on deciduous. We know the single nest of the Booted Eagle located on a cliff on the Elegest river in Tuva, however we consider that fact as extraordinary and unusual for the species, because in that case eagles occupied a n old nest of the Upland Buzzard (Buteo hemilasius) after their own nest with the first clutch located on a poplar in flood-lands was perished by the reason of fire. Next year that pair built new nest on a polar where they bred last 5 years. Birds use for nesting trees growing near the edge of forest while the average distance between nesting tree and the edge of forest is 88,2±65,7 m (n=90; range 10 237 m), by the way the longest distances were noted in forests on river terraces and hilly watersheds. Frequently the edge of forest is close to a river or a water reservoir (40,2%). Birds (n=102) prefer the densest part of forest as a nesting habitat (71,6%). For nest building (fig. 17) birds (n=102) use mainly a branch fork (90,2%) in the upper part (69,6%) or in the middle part of a tree. We estimated exposition for 64 nests (fig. 18): the most part of them had southern orientations (59,4%), mainly south-eastern (21,9%).The average height of nest position was 10,8±4,44 m (n=102; range 4-22 m). As a result of position in a branch fork nests have oval forms. Nest dimensions: the average external diameter of the nest is 93,4±29,49 х 80,6±34,17 cm (n=9; 55 150 х 35 150 cm); the average height of the nest construction 100,6±27,34 cm (range 60 135 cm); the average internal diameter of the nest 19,8±3,35 х 18,3±3,08 cm (range 16 25 х 15 25 cm); the average nest depth 4,2±1,64 cm (range 2 7 cm). The most observed nests were used during many ears and only 2 were built in that year when we surveyed they. Booted Eagles often use old or new nests of other bird species: mainly Black Kites (Milvus migrans), sometimes Buzzards (Buteo buteo) or Goshawks (Accipiter gentitlis), in the east of the range Upland Buzzards, rarely Great Spotted Eagles (Aquila clanga), (Corvus cornix, C. corone) and (Ardea cinerea). We recorded 12 such facts (11,8% of observed nests). Booted Eagles use such nests in the most cases as a foundation for building their own nest, but sometimes they occupy a nest without any reconstructions and only hardly renew it during laying eggs. The nests built by Booted Eagles themselves have some particular features. Booted Eagles used for building nest only fresh branches with foliage. In coniferous forests eagles cover the bottom of a nest by a thick layer of conifer branches (obligatory with green needles), in deciduous forests it is replaced by a thick layer of green leaves especially of poplar or birch trees. Clutches Eggs of Booted Eagles are white. Often we noted small spots on the shell of eggs, the color of spots varies from ochre to red-brown. Large spots were not observed. During the all period of surveys we observed only full clutches consisted of 2 eggs (n=30). The average size of eggs was 55,8±2,41 х 46,0±1,99 mm (n=26; range 50,0 62,2 х 39,6 50,0 mm). Broods and breeding success Broods as a rule contain 2 chicks. We observed 96 broods and the size of 92,7% of them was 2 chicks or fledglings. We didn't registered facts of cannibalism amongst chicks of Booted Eagles unlike Buzzards or other species of eagles. We didn't registered facts of chick deaths too, and all surveyed chicks successfully fledged. As a result of insignificant amount of unsuccessful eggs on the stage of clutch the breeding success raises more than 90% and it is supposed to be normal for the species. Occupancy of breeding territories is sufficient high. We monitored 6 breeding territories during 1999-2006 and only 2 territories weren't occupied every year. The number of small mammals doesn't impact on the breeding success of Booted Eagles and during depressions of mammal numbers eagles successfully change them in the diet by birds. Fig. 20 shows the occupancy of breeding territories by Booted Eagles and Saker Falcons and numbers of small mammals that are preys of both species in the Tes-Hem plot in the Ubsunur depression (Tuva) in 1999-2005. Diet Analysis if preys and their remains surveyed in nests (n=233) was shown the mammals to dominate in the diet of Booted Eagles (70%), the portion of birds in the diet is 27,9%, and the portion of amphibians and reptilians is insignificant (fig. 21). However we noted the increasing of mammal portion in the east and south of the range due to the colonial steppe species. Acknowledgments We thank Elvira Nikolenko, Mikhail Kozhevnikov, Sergey Bakka, Tim Barabashin, Alexander Moshkin, Alexey Pazhenkov and other colleagues assisted in data collection and in many other phases of the project.