Результаты мониторинга популяций балобана в Алтае-Саянском регионе в 2008 г. , Россия

• Main Authors: Карякин, И., Николенко, Э.
• Format: Text
• Language: unknown
• Published: Общество с ограниченной ответственностью «Сибэкоцентр» 2008
• Subjects: ХИЩНЫЕ ПТИЦЫ; ПЕРНАТЫЕ ХИЩНИКИ; БАЛОБАН; Bianchi; Dark Head; Northern Foothills; Tuva; Yenisei River; gyrfalcon; taiga
• Online Access: http://cyberleninka.ru/article/n/rezultaty-monitoringa-populyatsiy-balobana-v-altae-sayanskom-regione-v-2008-g-rossiya; http://cyberleninka.ru/article_covers/14523896.png

Introduction and Methods A field group of the Siberian Environmental Center and the Field Study Center under the project of UNDP/GEF «Biodiversity Conservation in the Russian Part of the Altai-Sayan Ecoregion» has carried out surveys to estimate numbers of the Saker Falcon (Falco cherrug) in the Russian part of the Altai-Sayan ecoregion. Territories were surveyed from 20th May to 25th July, including several study plots that have been monitored earlier in 1999, as well as some new sites in the south of the Krasnoyarsk district, the Republic of Khakassia, Tuva and Altai. The total length of survey routes was 8095 km (fig. 1). We set up 18 study plots with a total area of 12150 km2 (fig. 2, table 1). Density parameters that were calculated for habitats in the study plots were extrapolated on similar habitats of the region with ArcView 3.3 ESRI. The total area of typical habitats of the Saker in the Russian part of the Altai-Sayan region under extrapolation was 149364.7 km2 (Krasnoyarsk region and the Republic of Khakassia 20593.24 km2, Republic of Altai 34063.46 km2 and Republic of Tuva 94708.0 km2). For characterizing the breeding territories we used the following terms: Occupied breeding territory: a territory where birds were noted, breeding indisputable, Empty, abandoned or extinct breeding territory: a territory where birds were not noted for the last three years, Successful breeding territory: a territory where breeding was successful. Distribution and Number We found 372 breeding territories of the Saker in the Altai-Sayan ecoregion in 1999-2006. We noted that 50 known breeding territories had become extinct by 2006. Many territories have become extinct owing to destruction of nests in southern Tuva. Unfortunately this means that their recovery is improbable. In 2006-2008, Sakers have not been recorded in 17 breeding territories. During surveys in 2008 we found nests especially in new territories. Altogether 57 new breeding territories were found. Thus, at the moment we know 362 breeding territories of Sakers (where adult birds or breeding were recorded, i.e. territories were occupied) in the Altai-Sayan ecoregion. We surveyed 125 breeding territories in 2008 (34.53% of a total number of known territories in the Altai-Sayan ecoregion), 108 of which were noted to be occupied by birds and 55 to be successful (fig. 3, 4, table 2). The northern border of the Saker distribution in the Altai-Sayan ecoregion follows the Yenisei river basin along N 56°. In 1980's, a total of 1-2 pairs per 100 km of a route were recorded in the vicinities of Krasnoyarsk (Baranov, 1988). At present only single birds with density less than 0.11 individuals/100 km2 is registered in that territory. The large breeding group of the Saker was found in foothills of the Kuznetskiy Alatau Mountains in the northwest of Khakassia. In 2008 the density was 1.46 breeding territories/100 km2 (0.83 successful pairs/100 km2). The Saker stably inhabits the belt of foothill forest-steppe of the Kuznetskiy Alatau to the south of the Beliy Iyus River in Khakassia. The width of the forest-steppe belt inhabited by the Saker varies from 10 to 40 km. We have surveyed the wide belt of foothills including territories of the Khakasskiy State Nature Reserve, Holl-Bogaz and Kamyzjakskaja steppe, in 2008. The density was 0.63 breeding territories/100 km2 (0.31 successful pairs/100 km2). The average density in Tuva was 0.91 breeding territories /100 km2 ranging from 0.09 to 3.66 breeding territories /100 km2 (0.31 successful pairs/100 km2; range 0-1.83) (table 1). We have surveyed also the southeast part of the Chujskaja steppe (plot №17) in 2008. We found 9 occupied breeding territories; successful breeding was registered in 5 territories. The density was 1.44 breeding territories /100 km2 (0.8 successful pairs/100 km2). Also 9 breeding territories were found in the western part of the Republic of Altai. The density was 0.53 breeding territories /100 km2 (0.35 successful pairs/100 km2). A total of 1372-1646 breeding pairs (1518 pairs on average) and 703-844 successful pairs (778 on average) are estimated to inhabit the Altai-Sayan ecoregion in 2008 (table 4). However we recorded males in several unsuccessful breeding territories. Those territories are located within traditional regions of bird catching. As shown in fig. 4, the most of such territories are found in the Kosh-Agach region of the Republic of Altai and the northern part of Khakassia. The high level of catching in the Khakasskiy Nature Reserve was unexpected by us. We found 5 breeding territories of Saker in the Holl-Bogaz and Kamyzjakskaja steppe clusters of the Reserve: it turned out that one of them had been empty for a long time, only males were registered in 2 territories and only two nests located far from the mountains into a deep foothill forest-steppe were successful. Most of the breeding territories with single males remain in the category empty during the next three-four years. Fortunately pair recovering due to young females is observed in some cases. For instance, monitoring a nest located in the Agar-Dag-Taiga Mountains in Tuva during 10 years between 1999 and 2008 we recorded 4 occurrences of young females changing, while the male remained the same. Thus, the negative trend of the Saker numbers has been registered all over the Altai-Sayan region (table 4). However, while the total number decreased during the last 5 years (2003-2008) by 18%, changes in different breeding group numbers are not similar. Populations in Khakassia suffer very much; there is a steady decline of numbers for the past 5 years by 26%. While the breeding group in the northwest of the Republic remains more or less stable, the breeding groups in the central part decreased by 40%. The impact of catching in Tuva is considerably lower. A number decreased by 17% was noted only in 2003-2006, and the number has been stable for the last years or has even increased a little. The number has decreased by 15% in Altai due to the disappearance of males from territories on the periphery of the Chujskaja steppe, where females were caught in 1998-2002 and pairs have not recovered until this day. On the other hand, the number in the Western Altai has slightly increased and has remained stable along the state border for the past 9 years. Population Biology and Breeding Nesting in absolutely different habitats the pairs of Saker try to keep the distance of usually 4-7 km between nearest neighbors. The average distance between nearest neighbors in all the region is 6.44±3.32 km (n=297; range 730 m 16.3 km). Most of the Saker nests in the Altai-Sayan region (n=364) are located on rocks and cliffs (86%), the nests being originally constructed mainly by the Upland Buzzard (Buteo hemilasius). Saker generally occupies nests of the Upland Buzzard located not only on rocks or cliffs, but on trees and artificial constructions. We found 68% of the Saker nests to have been build by Buzzards (fig. 5). The raven (Corvus corax) holds the second place as a nest builder used by Saker. We found 16% of falcon nests built by ravens and all found nests were only on rocks. We found Saker nesting on trees in Khakassia and Tuva, in larch forests in foothills of the Kuznetskiy Alatau and Tannu-Ola mountains and in mountain birch forests and steppe pine forests in the Minusinsk and Tuva depressions. Precise localization of the nesting preference in the region is not noted (fig. 6). Saker nesting on electric poles and other artificial constructions were known only in extensive steppes of the Ubsunuur and Tuva depressions in Tuva before 2008. Most of the nests located on wood electric poles were destroyed by local herders. The Saker began to use metal electric poles of power lines with high voltage for nesting. Falcons in 3 breeding territories were noted to leave nests on cliffs for nests of the Upland Buzzard on electric poles. In the Altai-Sayan region the average brood size is 2.63±1.08 chicks (n=243; range 1-5 chicks). Depending on prey numbers and spring climate conditions breeding success of falcons may vary greatly (table 5). The average brood size in 2008 was 2.48±0.96 chicks per successful nest (n=33; range 1-4 chicks), but the portion of successful nets per total number of occupied nests was only 50.9%. The largest number of empty nests was found in the left side of the Tes-Hem River and on the southern slope of the Tannu-Ola Mountains in the north of the Ubsunur depression where an extensive decline of numbers of main prey species of falcons (fig. 4) was observed. Only two nests (8.7%) of 23 occupied breeding territories were successful in the study plot located in the left side of the Tes-Hem River and both placed close to the state border with Mongolia. Comparing parameters of Saker breeding in study plots in the left side of the Tes-Hem River and in the Tannu-Ola Mountains we revealed that while the breeding success and brood sizes in the left side of the Tes-Hem River were sharply decreasing, the breeding success was stable and brood size was sufficiently high in the Tannu-Ola Mountains (fig. 7, 8). It was noted that the number of occupied breeding territories was growing while the portion of successful nests per number of breeding territories decreased in the region for the last ten years (fig. 9). This fact was registered while the species number generally decreased. This is easily explained as the visits to the extinct territories were stopped in the absence of bird registrations in those sites during three years. It seems the main reason of decrease of successful nest numbers per number of occupied territories is due to the replacement of old partners by young birds. Occupancy of breeding territories and breeding success of falcons fluctuate asynchronously in different republics of the region every year. This is connected with differing fluctuations of numbers of species that comprise the main part of the Saker's diet, varying between regions. As presented in fig. 9, in 2008 the maximum breeding success was observed in Altai where high numbers of the Mongolian Pika (Ochotona pallasi) were observed in the southeast and the Long-tailed Souslik (Spermophilus undulatus) was abundant in the west. Breeding success was the lowest in Tuva, where numbers of the Daurian Pika (Ochotona daurica) and the Mongolian Gerbil (Meriones unguiculatus) have sharply decreased in the Ubsunuur depression. The main reason for low breeding success of the Saker in the region is death of clutches or broods due to famine. Another important reason not connected with feeding is predation by the Eagle Owl (Bubo bubo). The Eagle Owl was generally observed to prey on chicks of the Saker, eating adult birds seldom. A total of 28.3% of monitored breeding territories of Saker (n=413) were unsuccessful, the reason being predation by the Eagle Owl only in 20.5% of events (n=117). The Eagle Owl was observed to prey all chicks in a brood only in 5.8% of events during last decade. The number of breeding territories where predation by the Eagle Owl was recorded is limited. We monitored several breeding territories of falcons where the Eagle Owl preyed chicks every 2 years. The Eagle Owl was observed to kill and eat adult Saker in only 12.8% of events (n=47), males and females in equal numbers. 15.6% of 429 visited breeding territories were recognized as abandoned during the 10 years of research in the Altai-Sayan region, and only 4 of them were empty owing to the Eagle Owl preying on adult birds. Eagle Owls preyed females in 2 territories, but the pairs recovered. Predatory impact of the Eagle Owl on Saker was noted only in the mountains and thus 15% of Saker pairs that do not breed on rocks avoid contact with the Eagle Owl. The harvesting of chicks from nests in the region was rarely observed. Only on 15 territories (3.5%) of 429 we noted signs of chick harvesting. The main reason of Altai-Sayan population reduction is the catching of birds that generally takes place not in the region, but outside of it in Mongolia and China (Nikolenko, 2007; Karyakin, 2008; Suhchuluun, 2008). The purposeful catching of females leads to sexual disproportion. The number of young females is not sufficient and as a result there are many territories with only males. The analysis of breeding success of pairs with old and young females in monitoring plots in 2001-2008 has shown that the average number of eggs and hatched chicks in a brood of young females is 3.08±1.24 chicks (n=12; range 1-5). Old birds have stably 3,0±0,61 eggs at average (n=17; range 2-4). Thus the perishing of offspring of pairs with young females is higher (64.86%) than with old females with which the perishing of chicks reaches only 11.76%. As a result, pairs with old females were more productive over 4 years of monitoring: the average number of fledglings was 2.65±0.79 chicks per successful nest (n=17), whereas with young females the number was only 1.08±1.16 chicks (n=12). Taxonomic Status Subspecies separation of the Altai-Sayan Saker has been discussed for more than hundred years already, but the opinion about its status has not been finally established. According to G.P. Dementyev (1954), 3 subspecies of Saker were registered breeding in the Altai-Sayan ecoregion: Falco cherrug cherrug, inhabiting the most part of the Minusinsk depression, F. ch. saceroides, inhabiting south of Khakassia and the Krasnoyarsk Kray, Altai and the most part of Tuva, and F. ch. milvipes, inhabiting southeast of Tuva. Also the Altai Gyrfalcon Falco gyrfalcon (rusticolus) altaicus inhabiting the higher zone of Altai and Sayan was treated in the report, later it was united with F. ch. milvipes. According to L.S. Stepanyan (1990) F. ch. cherrug inhabits northern foothills of Altai and the Minusinsk depression, where it intergrades with F. ch. milvipes. The author unites Falco (Hierofalco) altaicus and Falco (Hierofalco) lorenzi, described by М.А. Menzbier (1916) as F. ch. milvipes which inhabits actually all territory of Altai and Tuva. L.S. Stepanyan (1990) joined the subspecies earlier described as Gennaja saceroides Bianchi, 1907 and F. ch. Hendersoni, the range of which covered territories to the south of the Altai-Sayan region. Unfortunately the "destiny" of F. ch. saceroides records in the Altai-Sayan region was not treated in the report, and we assume that the author revealed the most part of those records as F. ch. milvipes because its range included exactly the breeding range of F. ch. saceroides, outlined by P.P. Sushkin and G.P. Dementyev. The species shows high variability in coloration of adult birds in the region see the color plate on the back cover (images 1-3 show 1st, 2nd and 3rd type of coloration). The precise geographical localization of 1st, 2nd or 3rd type of coloration is not noted and individuals with 1st and 3rd types of coloration were registered together with birds with dominating 2nd type in proportions of 11, 20 and 47%, respectively (n=436). Considering such distribution we can not believe that F. ch. cherrug breeds inside the range of F. ch. milvipes, since about a half of birds have intermediate coloration between these two subspecies. It seems to be an individual color variation because any distinctions between sizes of birds with such coloration and typical F. ch. milvipes were not noted. Birds with certain deviations to the dark morph were recorded (30%, n=436) in each of coloration groups. However these birds have only a number of dark features, and can not be undoubtedly treated as a dark morph. Birds with a deviation to the light coloration up to complete white were recorded in both groups with 2nd and 3rd type of coloration; their portion in the population was 2%. At least 20% of the Saker has very dark coloration of the body. Such birds are treated as F. ch. milvipes type altaicus. The usual coloration of such birds (without abnormal deviations to the black) is dark brown without pale spots or bars on the upper body and a tail with wide dark markings on underparts that occupied a large portion of the feather area (up to uniformly dark underparts), uniformly dark head, cheek, nape and wide moustachial streak. The portion of such colored birds in the Altai-Sayan region is 18%. Also almost black falcons are surveyed; their portion in the population is 2%. Dark juvenile Sakers are recorded in 20% of broods. Broods are generally mixed (see a color plate on the back cover, photo 4). Mixed broods were registered when one of the parents in a pair was dark or had intermediate type of coloration between 2nd or 3rd type and dark (47% of broods), both parents had typical milvipes coloration of 3rd type (18%) and 2nd type (33%). About 2% of dark pairs produced all chicks with dark color. Pairs with 1st type of coloration produced young birds with reddish tones (see color plate on the back cover, photo 5). There are several hypotheses as to the origin of the dark morph: 1. Hybridization between Sakers and Gyrfalcons (Eastham, 2000; Fox, Potapov, 2001; Potapov, Sale, 2005), 2. Species dichromatism and parallel variability (Kots, 1948; Potapov, Sale, 2005). Both hypotheses are debatable. The hypothesis of species dichromatism and parallel variability seems to be more comprehensive because dark as well as pale chicks are regularly registered in broods of pale parents. The similar situation is noted for the Upland Buzzard populations in the Altai-Sayan region. Dark birds are noted to breed in the whole territory of the region, but most of dark falcons are concentrated in mountains of southeastern Altai and southern Tuva and breed at a height of more than 1500 m. The maximum density of dark birds is observed in the territory of a southern side of the Western Tannu-Ola. Similar situation was recorded for Upland Buzzard populations in the region. The analysis of distribution of dark colored birds of the species shows highest concentration in the high-mountainous zone of southern Tuva. Distribution patterns of dark Upland Buzzards and Sakers are similar (fig. 11). Introduction and Methods A field group of the Siberian Environmental Center and the Field Study Center under the project of UNDP/GEF «Biodiversity Conservation in the Russian Part of the Altai-Sayan Ecoregion» has carried out surveys to estimate numbers of the Saker Falcon (Falco cherrug) in the Russian part of the Altai-Sayan ecoregion. Territories were surveyed from 20th May to 25th July, including several study plots that have been monitored earlier in 1999, as well as some new sites in the south of the Krasnoyarsk district, the Republic of Khakassia, Tuva and Altai. The total length of survey routes was 8095 km (fig. 1). We set up 18 study plots with a total area of 12150 km2 (fig. 2, table 1). Density parameters that were calculated for habitats in the study plots were extrapolated on similar habitats of the region with ArcView 3.3 ESRI. The total area of typical habitats of the Saker in the Russian part of the Altai-Sayan region under extrapolation was 149364.7 km2 (Krasnoyarsk region and the Republic of Khakassia 20593.24 km2, Republic of Altai 34063.46 km2 and Republic of Tuva 94708.0 km2). For characterizing the breeding territories we used the following terms: Occupied breeding territory: a territory where birds were noted, breeding indisputable, Empty, abandoned or extinct breeding territory: a territory where birds were not noted for the last three years, Successful breeding territory: a territory where breeding was successful. Distribution and Number We found 372 breeding territories of the Saker in the Altai-Sayan ecoregion in 1999-2006. We noted that 50 known breeding territories had become extinct by 2006. Many territories have become extinct owing to destruction of nests in southern Tuva. Unfortunately this means that their recovery is improbable. In 2006-2008, Sakers have not been recorded in 17 breeding territories. During surveys in 2008 we found nests especially in new territories. Altogether 57 new breeding territories were found. Thus, at the moment we know 362 breeding territories of Sakers (where adult birds or breeding were recorded, i.e. territories were occupied) in the Altai-Sayan ecoregion. We surveyed 125 breeding territories in 2008 (34.53% of a total number of known territories in the Altai-Sayan ecoregion), 108 of which were noted to be occupied by birds and 55 to be successful (fig. 3, 4, table 2). The northern border of the Saker distribution in the Altai-Sayan ecoregion follows the Yenisei river basin along N 56°. In 1980's, a total of 1-2 pairs per 100 km of a route were recorded in the vicinities of Krasnoyarsk (Baranov, 1988). At present only single birds with density less than 0.11 individuals/100 km2 is registered in that territory. The large breeding group of the Saker was found in foothills of the Kuznetskiy Alatau Mountains in the northwest of Khakassia. In 2008 the density was 1.46 breeding territories/100 km2 (0.83 successful pairs/100 km2). The Saker stably inhabits the belt of foothill forest-steppe of the Kuznetskiy Alatau to the south of the Beliy Iyus River in Khakassia. The width of the forest-steppe belt inhabited by the Saker varies from 10 to 40 km. We have surveyed the wide belt of foothills including territories of the Khakasskiy State Nature Reserve, Holl-Bogaz and Kamyzjakskaja steppe, in 2008. The density was 0.63 breeding territories/100 km2 (0.31 successful pairs/100 km2). The average density in Tuva was 0.91 breeding territories /100 km2 ranging from 0.09 to 3.66 breeding territories /100 km2 (0.31 successful pairs/100 km2; range 0-1.83) (table 1). We have surveyed also the southeast part of the Chujskaja steppe (plot №17) in 2008. We found 9 occupied breeding territories; successful breeding was registered in 5 territories. The density was 1.44 breeding territories /100 km2 (0.8 successful pairs/100 km2). Also 9 breeding territories were found in the western part of the Republic of Altai. The density was 0.53 breeding territories /100 km2 (0.35 successful pairs/100 km2). A total of 1372-1646 breeding pairs (1518 pairs on average) and 703-844 successful pairs (778 on average) are estimated to inhabit the Altai-Sayan ecoregion in 2008 (table 4). However we recorded males in several unsuccessful breeding territories. Those territories are located within traditional regions of bird catching. As shown in fig. 4, the most of such territories are found in the Kosh-Agach region of the Republic of Altai and the northern part of Khakassia. The high level of catching in the Khakasskiy Nature Reserve was unexpected by us. We found 5 breeding territories of Saker in the Holl-Bogaz and Kamyzjakskaja steppe clusters of the Reserve: it turned out that one of them had been empty for a long time, only males were registered in 2 territories and only two nests located far from the mountains into a deep foothill forest-steppe were successful. Most of the breeding territories with single males remain in the category empty during the next three-four years. Fortunately pair recovering due to young females is observed in some cases. For instance, monitoring a nest located in the Agar-Dag-Taiga Mountains in Tuva during 10 years between 1999 and 2008 we recorded 4 occurrences of young females changing, while the male remained the same. Thus, the negative trend of the Saker numbers has been registered all over the Altai-Sayan region (table 4). However, while the total number decreased during the last 5 years (2003-2008) by 18%, changes in different breeding group numbers are not similar. Populations in Khakassia suffer very much; there is a steady decline of numbers for the past 5 years by 26%. While the breeding group in the northwest of the Republic remains more or less stable, the breeding groups in the central part decreased by 40%. The impact of catching in Tuva is considerably lower. A number decreased by 17% was noted only in 2003-2006, and the number has been stable for the last years or has even increased a little. The number has decreased by 15% in Altai due to the disappearance of males from territories on the periphery of the Chujskaja steppe, where females were caught in 1998-2002 and pairs have not recovered until this day. On the other hand, the number in the Western Altai has slightly increased and has remained stable along the state border for the past 9 years. Population Biology and Breeding Nesting in absolutely different habitats the pairs of Saker try to keep the distance of usually 4-7 km between nearest neighbors. The average distance between nearest neighbors in all the region is 6.44±3.32 km (n=297; range 730 m 16.3 km). Most of the Saker nests in the Altai-Sayan region (n=364) are located on rocks and cliffs (86%), the nests being originally constructed mainly by the Upland Buzzard (Buteo hemilasius). Saker generally occupies nests of the Upland Buzzard located not only on rocks or cliffs, but on trees and artificial constructions. We found 68% of the Saker nests to have been build by Buzzards (fig. 5). The raven (Corvus corax) holds the second place as a nest builder used by Saker. We found 16% of falcon nests built by ravens and all found nests were only on rocks. We found Saker nesting on trees in Khakassia and Tuva, in larch forests in foothills of the Kuznetskiy Alatau and Tannu-Ola mountains and in mountain birch forests and steppe pine forests in the Minusinsk and Tuva depressions. Precise localization of the nesting preference in the region is not noted (fig. 6). Saker nesting on electric poles and other artificial constructions were known only in extensive steppes of the Ubsunuur and Tuva depressions in Tuva before 2008. Most of the nests located on wood electric poles were destroyed by local herders. The Saker began to use metal electric poles of power lines with high voltage for nesting. Falcons in 3 breeding territories were noted to leave nests on cliffs for nests of the Upland Buzzard on electric poles. In the Altai-Sayan region the average brood size is 2.63±1.08 chicks (n=243; range 1-5 chicks). Depending on prey numbers and spring climate conditions breeding success of falcons may vary greatly (table 5). The average brood size in 2008 was 2.48±0.96 chicks per successful nest (n=33; range 1-4 chicks), but the portion of successful nets per total number of occupied nests was only 50.9%. The largest number of empty nests was found in the left side of the Tes-Hem River and on the southern slope of the Tannu-Ola Mountains in the north of the Ubsunur depression where an extensive decline of numbers of main prey species of falcons (fig. 4) was observed. Only two nests (8.7%) of 23 occupied breeding territories were successful in the study plot located in the left side of the Tes-Hem River and both placed close to the state border with Mongolia. Comparing parameters of Saker breeding in study plots in the left side of the Tes-Hem River and in the Tannu-Ola Mountains we revealed that while the breeding success and brood sizes in the left side of the Tes-Hem River were sharply decreasing, the breeding success was stable and brood size was sufficiently high in the Tannu-Ola Mountains (fig. 7, 8). It was noted that the number of occupied breeding territories was growing while the portion of successful nests per number of breeding territories decreased in the region for the last ten years (fig. 9). This fact was registered while the species number generally decreased. This is easily explained as the visits to the extinct territories were stopped in the absence of bird registrations in those sites during three years. It seems the main reason of decrease of successful nest numbers per number of occupied territories is due to the replacement of old partners by young birds. Occupancy of breeding territories and breeding success of falcons fluctuate asynchronously in different republics of the region every year. This is connected with differing fluctuations of numbers of species that comprise the main part of the Saker's diet, varying between regions. As presented in fig. 9, in 2008 the maximum breeding success was observed in Altai where high numbers of the Mongolian Pika (Ochotona pallasi) were observed in the southeast and the Long-tailed Souslik (Spermophilus undulatus) was abundant in the west. Breeding success was the lowest in Tuva, where numbers of the Daurian Pika (Ochotona daurica) and the Mongolian Gerbil (Meriones unguiculatus) have sharply decreased in the Ubsunuur depression. The main reason for low breeding success of the Saker in the region is death of clutches or broods due to famine. Another important reason not connected with feeding is predation by the Eagle Owl (Bubo bubo). The Eagle Owl was generally observed to prey on chicks of the Saker, eating adult birds seldom. A total of 28.3% of monitored breeding territories of Saker (n=413) were unsuccessful, the reason being predation by the Eagle Owl only in 20.5% of events (n=117). The Eagle Owl was observed to prey all chicks in a brood only in 5.8% of events during last decade. The number of breeding territories where predation by the Eagle Owl was recorded is limited. We monitored several breeding territories of falcons where the Eagle Owl preyed chicks every 2 years. The Eagle Owl was observed to kill and eat adult Saker in only 12.8% of events (n=47), males and females in equal numbers. 15.6% of 429 visited breeding territories were recognized as abandoned during the 10 years of research in the Altai-Sayan region, and only 4 of them were empty owing to the Eagle Owl preying on adult birds. Eagle Owls preyed females in 2 territories, but the pairs recovered. Predatory impact of the Eagle Owl on Saker was noted only in the mountains and thus 15% of Saker pairs that do not breed on rocks avoid contact with the Eagle Owl. The harvesting of chicks from nests in the region was rarely observed. Only on 15 territories (3.5%) of 429 we noted signs of chick harvesting. The main reason of Altai-Sayan population reduction is the catching of birds that generally takes place not in the region, but outside of it in Mongolia and China (Nikolenko, 2007; Karyakin, 2008; Suhchuluun, 2008). The purposeful catching of females leads to sexual disproportion. The number of young females is not sufficient and as a result there are many territories with only males. The analysis of breeding success of pairs with old and young females in monitoring plots in 2001-2008 has shown that the average number of eggs and hatched chicks in a brood of young females is 3.08±1.24 chicks (n=12; range 1-5). Old birds have stably 3,0±0,61 eggs at average (n=17; range 2-4). Thus the perishing of offspring of pairs with young females is higher (64.86%) than with old females with which the perishing of chicks reaches only 11.76%. As a result, pairs with old females were more productive over 4 years of monitoring: the average number of fledglings was 2.65±0.79 chicks per successful nest (n=17), whereas with young females the number was only 1.08±1.16 chicks (n=12). Taxonomic Status Subspecies separation of the Altai-Sayan Saker has been discussed for more than hundred years already, but the opinion about its status has not been finally established. According to G.P. Dementyev (1954), 3 subspecies of Saker were registered breeding in the Altai-Sayan ecoregion: Falco cherrug cherrug, inhabiting the most part of the Minusinsk depression, F. ch. saceroides, inhabiting south of Khakassia and the Krasnoyarsk Kray, Altai and the most part of Tuva, and F. ch. milvipes, inhabiting southeast of Tuva. Also the Altai Gyrfalcon Falco gyrfalcon (rusticolus) altaicus inhabiting the higher zone of Altai and Sayan was treated in the report, later it was united with F. ch. milvipes. According to L.S. Stepanyan (1990) F. ch. cherrug inhabits northern foothills of Altai and the Minusinsk depression, where it intergrades with F. ch. milvipes. The author unites Falco (Hierofalco) altaicus and Falco (Hierofalco) lorenzi, described by М.А. Menzbier (1916) as F. ch. milvipes which inhabits actually all territory of Altai and Tuva. L.S. Stepanyan (1990) joined the subspecies earlier described as Gennaja saceroides Bianchi, 1907 and F. ch. Hendersoni, the range of which covered territories to the south of the Altai-Sayan region. Unfortunately the "destiny" of F. ch. saceroides records in the Altai-Sayan region was not treated in the report, and we assume that the author revealed the most part of those records as F. ch. milvipes because its range included exactly the breeding range of F. ch. saceroides, outlined by P.P. Sushkin and G.P. Dementyev. The species shows high variability in coloration of adult birds in the region see the color plate on the back cover (images 1-3 show 1st, 2nd and 3rd type of coloration). The precise geographical localization of 1st, 2nd or 3rd type of coloration is not noted and individuals with 1st and 3rd types of coloration were registered together with birds with dominating 2nd type in proportions of 11, 20 and 47%, respectively (n=436). Considering such distribution we can not believe that F. ch. cherrug breeds inside the range of F. ch. milvipes, since about a half of birds have intermediate coloration between these two subspecies. It seems to be an individual color variation because any distinctions between sizes of birds with such coloration and typical F. ch. milvipes were not noted. Birds with certain deviations to the dark morph were recorded (30%, n=436) in each of coloration groups. However these birds have only a number of dark features, and can not be undoubtedly treated as a dark morph. Birds with a deviation to the light coloration up to complete white were recorded in both groups with 2nd and 3rd type of coloration; their portion in the population was 2%. At least 20% of the Saker has very dark coloration of the body. Such birds are treated as F. ch. milvipes type altaicus. The usual coloration of such birds (without abnormal deviations to the black) is dark brown without pale spots or bars on the upper body and a tail with wide dark markings on underparts that occupied a large portion of the feather area (up to uniformly dark underparts), uniformly dark head, cheek, nape and wide moustachial streak. The portion of such colored birds in the Altai-Sayan region is 18%. Also almost black falcons are surveyed; their portion in the population is 2%. Dark juvenile Sakers are recorded in 20% of broods. Broods are generally mixed (see a color plate on the back cover, photo 4). Mixed broods were registered when one of the parents in a pair was dark or had intermediate type of coloration between 2nd or 3rd type and dark (47% of broods), both parents had typical milvipes coloration of 3rd type (18%) and 2nd type (33%). About 2% of dark pairs produced all chicks with dark color. Pairs with 1st type of coloration produced young birds with reddish tones (see color plate on the back cover, photo 5). There are several hypotheses as to the origin of the dark morph: 1. Hybridization between Sakers and Gyrfalcons (Eastham, 2000; Fox, Potapov, 2001; Potapov, Sale, 2005), 2. Species dichromatism and parallel variability (Kots, 1948; Potapov, Sale, 2005). Both hypotheses are debatable. The hypothesis of species dichromatism and parallel variability seems to be more comprehensive because dark as well as pale chicks are regularly registered in broods of pale parents. The similar situation is noted for the Upland Buzzard populations in the Altai-Sayan region. Dark birds are noted to breed in the whole territory of the region, but most of dark falcons are concentrated in mountains of southeastern Altai and southern Tuva and breed at a height of more than 1500 m. The maximum density of dark birds is observed in the territory of a southern side of the Western Tannu-Ola. Similar situation was recorded for Upland Buzzard populations in the region. The analysis of distribution of dark colored birds of the species shows highest concentration in the high-mountainous zone of southern Tuva. Distribution patterns of dark Upland Buzzards and Sakers are similar (fig. 11).