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Carmen Alonso
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Aqui teneis un articulo sobre sacres copiado de internet.
Saludos
Saker Falcons of the Russian Altai
Valeriy Moseikin
Ecology and Evolution Institute, Russian Academy of Sciences,
Saratov
Russia
Russian Altai covers a significant territory and is located at the border of global biological zones such as southern taiga forest, arctic and cold deserts of Central Asia and fertile steppes of Kazakhstan. The variability of biological conditions, landscapes and vegetation communities of Russian Altai predetermines the variability of animals. One can find here characteristic species of taiga forest, deserts and mountains of the Eastern Palaearctic. In the Russian Altai one can find the largest and most unusual phenotypes, legends of which are passed down amongst generations of falconers. For many years nobody was studying the questions of biology, ecology and systematics of these falcons. Although there are some works which deal with avifauna of the Altai mountains, there are limited accounts on the Altai Sakers. In recent years, the studies in the territory of the Russian Altai have been carried out by the National Avian Research Centre (UAE). For this reason it has been possible to obtain some data on the numbers and distribution of the Saker in this region.
Current systematics recognise only two subspecies of Saker living in the Russian Altai Mountains. According to the latest taxonomic list of the former USSR (Stepanyan 1979) all Altai plains are inhabited by the nominate form Falco cherrug cherrug, which throughout this paper I refer to as the Steppe Saker. The second sub-species is the Tibetan Saker F. ch. milvipes which occur in the mountainous part of the Altai and in contrast to the Steppe Saker has two colour morphs - dark and light. Here I have to comment that this taxonomic division was based on a very limited number of museum skins. In the older literature (Dementiev 1951) there was a form named the Altai Gyrfalcon or Altai Saker, however in the last decades, ornithologists seem to have ruled out the very existence of this species.
Nevertheless since the beginning of our studies in the Russian Altai, we have encountered large falcons which do not correspond to any of the forms described in the recent ornithological literature. Probably we found hybrids of the Sakers with Arctic Gyrfalcons, which theoretically could migrate to the Russian Altai. However, the fact that these birds are regularly observed here, would lead us to suspect that we have here a previously unknown form of falcon, which still survives in the remote regions of the Russian Altai. Before the systematic status of the birds becomes clear, we can call these birds F. ch. altaicus Menzbier.
Steppe Sakers (F. cherrug cherrug)
This large subspecies inhabits the plains of Altai and adjoining steppes of southern Siberia. Colour and morphometic characteristics of these birds correspond with that of the Sakers from other regions of Russia. We regularly observed Sakers with similar characteristics on the opposite side of the Altai Mountains: in the Chuya steppe and at the border with Tuva and Mongolia. It is interesting that according to the data by Kuchin (1968) the steppe Sakers were noted only in the 1960s. Kuchin (1968) explained the occurrence of Sakers here and the subsequent increase in numbers as being due to the expansion of the range and increase in numbers of Red-cheeked Sousliks (Citellus erythrogenys), which was the main food of the Steppe Sakers. Surveys of Steppe Saker numbers carried out in 1998 show that the steppes are holding a maximum of 200 pairs This is at least half the predicted forecast. We seem to be witnessing a rapid decline in Saker numbers in the Mongolian Altai, associated with the rapid disappearance of the Red-cheeked Sousliks. Previously such situations were reported in other steppe regions of Russia, and we suspect a similar reason for the decline. We consider the extinction of Sousliks was caused by degradation of the plant communities caused by global climate change. If this is true, we can predict a further decline in numbers of Sakers in the Altai plains and their complete local extinction in the next 10-15 years. So far we have found a limited number of pockets with a reasonable density of Steppe Sakers. In some locations the density can reach 5 pairs per 10 km2. The steppe Saker is using old tree nests of Black Kites (Milvus migrans) and Imperial Eagles (Aquila heliaca). Unfortunately, during the breeding period, many of the nests fall apart resulting in high chick mortality. A fact noted previously by Kuchin (1968) and Schekin (1965). According to the food data, the Sakers were feeding mostly upon sousliks, small rodents and small passerines. The proportion of diet items differs according to the season, but the most significant portion is Souslik. The steppe Saker is a migratory bird, and it appears that they overfly the populations breeding in the south. The precise location of the steppe Saker is not known, it is possible that their wintering grounds are towards Kazakhstan and the Middle Eastern countries.
Mountain Sakers (F. cherrug milvipes)
Distribution of Mountain Sakers is linked to mountain relief and rock formations. The nesting sites are also linked to long-tailed Sousliks (Citellus undulatus). Besides Sousliks, the Daurian Pika (Ochotona daurica) plays an important role in the diet. Numbers of these small mammals are more or less stable.The Mountain Sakers are large, and compared to the steppe Sakers look stockier with a stronger build.
The dark morph falcons live in the highlands during the breeding season and do not occur in the lower and middle forest belt i.e. where one can find the nominative race. It is possible that birds which we call the black morph birds belong to the dark morph of the Altai Saker, since during the breeding season they stay in the habitats occupied by the Altai Saker. To clearly distinguish the Mountain Saker from the Altai Saker is difficult since there are many hybrids on the marginal territories which exhibit characters of both forms.
Besides plumage differences, mountain Sakers differ from Steppe Sakers in flight. This is very obvious when after demonstration of flight of the steppe falcon one is shown a flight of the Mountain one. The mountain bird flight is heavier and stronger than that of steppe birds. It should be noted that flight amongst steep slopes and rocks requires stronger and more manoeuvrable flight. It could be hypothesised that falcons hunting in mountainous regions have evolved shorter and broader wings. The Steppe form has longer, narrower wings and so cannot compete with the mountain birds, which might act as an ecological barrier between the forms.Traditionally the mountain Sakers from the Russian Altai are considered to be rare, however this may be not so. The myth of the rarity of the mountain falcon is due to the fact that it is difficult to detect. Studies show that the Russian Altai holds at least 300 pairs of these birds.
A surprising result of the work carried out during the 1998 and 1999 breeding seasons was that only 40% of the Sakers took part in breeding. Probably this was a result of the poor food situation and large proportion of the immature birds in the population. All known nests of the Mountain falcons were located on cliffs. In the proximity of lakes, the nesting cliffs were also preferred by Ruddy Shelduck (Tadorna ferruginea). The mountain Saker starts breeding 10-14 days earlier than the Steppe Saker inhabiting the adjoining territory. It looks as if the mountain Sakers are specialised on another prey species, mainly on the long-tailed Sousliks which wake up after hibernation earlier as the snow melts on slopes earlier than in the lowlands.
The mountain Sakers would be correctly named as nomadic species, as many of them stay in the breeding grounds in late autumn and even in winter, as long-tailed Sousliks are active up to end of October, and Daurian Pikas do not hibernate. In the Chuya steppe, where the density of the Pikas is highest and there is not much snow, the Sakers sometimes concentrate in large numbers, but in severe frosts they migrate to the South to Mongolia and China. This is also supported by data obtained by satellite telemetry (Eastham 1998).
Altai Saker (F. cherrug altaicus)
This is the most mysterious falcon in the world. The very fact of its existence for more than a century suggest that there is a stable population isolation mechanism. If further studies find this isolation, I think we have a previously unknown sub-species of falcon which still survived in the remote regions of the Altai.
First of all the falcons are distinctly different in having an atypical greyish or ash-grey plumage coloration. A moustache is lacking in some falcons, in others they are very prominent. The lower part of the body is white with dark-grey spots, which form stripes on the flanks and sides of the body. A young bird examined in June 1998 had a greyish-brown back with a lot of dark spots on the lower part of the body. Some authors mention that the Altai falcon has a dark morph (Sushkin 1938, Dementiev 1951), however it is still not clear as to the degree of intergradation of dark mountain birds and Altai birds. In June 1998 we observed a bird with white colour of the lower part of the body and dark stripes across the tail and upper body.
In the "Falco" breeding centre in Barnaul in 1996 were 2 young Altai falcons taken from the wild. Both birds were large with grey plumage and many spots on the lower part of the body. The Altai Saker is distinct by its short, broad wings, resembling a Gyrfalcon. In the examined female Altai Saker the wing length was 14 mm longer than maximum wing length of the Mountain Sakers (Eastham 1998). Also the tarsi are more than half feathered (Dementiev 1951).
The range of the Altai Falcon is not clearly defined. Dementiev (1951) considered that the range covers many mountain regions of Central Asia. Currently, the Altai Saker no longer occurs in Kyrgisia (Sanin, N., Bachurin, G., pers. comm.). The current situation in Mongolia is unknown, however the country lacks suitable habitat for the Altai Saker. We believe that the Altai Saker is unique to the Altai-Sayan Mountains in the territory of Russia and Kazakhstan. We observed the bird in Altin-tu, Chulishman, Kurai, and Saylugem mountain ranges. Regular breeding of these birds in the Saylugem mountains was noted by Sushkin (1938). Irisov (1972) mentioned the breeding of the Altai falcon in the Ukok plateau. Some nests are known in the Kurai range (our data) and Tuva uplands (Sanin, pers. comm.).
According to records of Altai falcons during the breeding season and known nest records, these birds occupy the mountain tundra belt of the Russian Altai. Here there is a significant density of Ptarmigan (Lagopus mutus), and it is possible to suggest that these birds are the main quarry of this falcon. Possibly the distribution of Ptarmigan determines the range of the Altai Falcon limiting it to the belt between 2,000-2,500m above sea level.
There are no data on the biology of the Altai Falcon. Possibly they breed a bit later than the mountain ones. In the nest found on 14 July 1998 we found 2 unfledged chicks. A similar case of a late brood in Sayan Mountains was mentioned by Dementiev (1951). Later than normal dates of breeding in Altai Saker could be explained by the late fledging of young Ptarmigan. Under the nest we found a lot of ptarmigan feathers, bones of Northern Pikas (Ochotona alpina) and Siberian Chipmunk (Eutamias sibiricus). Dementiev (1951) also noted Ptarmigan as diet items. Data with other breeding dates given by Sushkin (1938) probably refers to hybrids, or to Mountain subspecies.
It appears that the Altai Saker has a sedentary way of life and has limited movements within the breeding range. Sudilovskaya (1973) mentioned the only finding of the Altai Saker in North-western China. Then a young female was shot on 15.05.1874 close to Yarkend. Cheng Tso-hsin (1955) mentioned that it is possible to find only birds of coatsii, hendersoni and saceroides in Sindzian province close to the Russian border and does not mention any references to the Altai Saker. During September-October we observed Altai Saker every day in the valleys and plains of the Russian Altai. Seasonal fluctuation of numbers is not well studied, and it appears to be insignificant.
Despite the obvious differences in biology, morphology and geography between the Altai Saker and the rest of the species, it is too soon to make any conclusions on the systematic position of the birds. More studies are needed.
References:
Cheng Tso-hsin (1955). Distribution list of Birds of China. Peking. V.1.
Dementiev, G.P. (1951). Birds of the USSR. V. 1. Nauka Publishers.
Eastham, C. (1998). Satellite tagging of Sakers in the Russian Altai. Falco: 12: 10-12.
Irisov, V.A. (1972). Peculiarities of distribution of some birds in the south-eastern Altai. Ornitologia 10: 248-250.
Kuchin, P.A. (1968). Observation on Siberian Saker in the Upper Ob river. Ornitologia, 9: 103-107.
Stepanyan, L.S. (1975). Composition and distribution of the fauna of birds of the USSR. Non-passeriformes.
Sudilovskaya, A.M. (1973). Birds of the Tarim basin and surrounding mountains. Studies of the birds of the USSR fauna. Moscow University Press: 50-154.
Sushkin, P.L. (1938). Birds of the Soviet Altai. Moscow.
Shekin, B.V. (1965). On the biology of the Mongolian Saker in the Transbaikalia depression. Ornitologia 7: 497-498.
Saludos
Saker Falcons of the Russian Altai
Valeriy Moseikin
Ecology and Evolution Institute, Russian Academy of Sciences,
Saratov
Russia
Russian Altai covers a significant territory and is located at the border of global biological zones such as southern taiga forest, arctic and cold deserts of Central Asia and fertile steppes of Kazakhstan. The variability of biological conditions, landscapes and vegetation communities of Russian Altai predetermines the variability of animals. One can find here characteristic species of taiga forest, deserts and mountains of the Eastern Palaearctic. In the Russian Altai one can find the largest and most unusual phenotypes, legends of which are passed down amongst generations of falconers. For many years nobody was studying the questions of biology, ecology and systematics of these falcons. Although there are some works which deal with avifauna of the Altai mountains, there are limited accounts on the Altai Sakers. In recent years, the studies in the territory of the Russian Altai have been carried out by the National Avian Research Centre (UAE). For this reason it has been possible to obtain some data on the numbers and distribution of the Saker in this region.
Current systematics recognise only two subspecies of Saker living in the Russian Altai Mountains. According to the latest taxonomic list of the former USSR (Stepanyan 1979) all Altai plains are inhabited by the nominate form Falco cherrug cherrug, which throughout this paper I refer to as the Steppe Saker. The second sub-species is the Tibetan Saker F. ch. milvipes which occur in the mountainous part of the Altai and in contrast to the Steppe Saker has two colour morphs - dark and light. Here I have to comment that this taxonomic division was based on a very limited number of museum skins. In the older literature (Dementiev 1951) there was a form named the Altai Gyrfalcon or Altai Saker, however in the last decades, ornithologists seem to have ruled out the very existence of this species.
Nevertheless since the beginning of our studies in the Russian Altai, we have encountered large falcons which do not correspond to any of the forms described in the recent ornithological literature. Probably we found hybrids of the Sakers with Arctic Gyrfalcons, which theoretically could migrate to the Russian Altai. However, the fact that these birds are regularly observed here, would lead us to suspect that we have here a previously unknown form of falcon, which still survives in the remote regions of the Russian Altai. Before the systematic status of the birds becomes clear, we can call these birds F. ch. altaicus Menzbier.
Steppe Sakers (F. cherrug cherrug)
This large subspecies inhabits the plains of Altai and adjoining steppes of southern Siberia. Colour and morphometic characteristics of these birds correspond with that of the Sakers from other regions of Russia. We regularly observed Sakers with similar characteristics on the opposite side of the Altai Mountains: in the Chuya steppe and at the border with Tuva and Mongolia. It is interesting that according to the data by Kuchin (1968) the steppe Sakers were noted only in the 1960s. Kuchin (1968) explained the occurrence of Sakers here and the subsequent increase in numbers as being due to the expansion of the range and increase in numbers of Red-cheeked Sousliks (Citellus erythrogenys), which was the main food of the Steppe Sakers. Surveys of Steppe Saker numbers carried out in 1998 show that the steppes are holding a maximum of 200 pairs This is at least half the predicted forecast. We seem to be witnessing a rapid decline in Saker numbers in the Mongolian Altai, associated with the rapid disappearance of the Red-cheeked Sousliks. Previously such situations were reported in other steppe regions of Russia, and we suspect a similar reason for the decline. We consider the extinction of Sousliks was caused by degradation of the plant communities caused by global climate change. If this is true, we can predict a further decline in numbers of Sakers in the Altai plains and their complete local extinction in the next 10-15 years. So far we have found a limited number of pockets with a reasonable density of Steppe Sakers. In some locations the density can reach 5 pairs per 10 km2. The steppe Saker is using old tree nests of Black Kites (Milvus migrans) and Imperial Eagles (Aquila heliaca). Unfortunately, during the breeding period, many of the nests fall apart resulting in high chick mortality. A fact noted previously by Kuchin (1968) and Schekin (1965). According to the food data, the Sakers were feeding mostly upon sousliks, small rodents and small passerines. The proportion of diet items differs according to the season, but the most significant portion is Souslik. The steppe Saker is a migratory bird, and it appears that they overfly the populations breeding in the south. The precise location of the steppe Saker is not known, it is possible that their wintering grounds are towards Kazakhstan and the Middle Eastern countries.
Mountain Sakers (F. cherrug milvipes)
Distribution of Mountain Sakers is linked to mountain relief and rock formations. The nesting sites are also linked to long-tailed Sousliks (Citellus undulatus). Besides Sousliks, the Daurian Pika (Ochotona daurica) plays an important role in the diet. Numbers of these small mammals are more or less stable.The Mountain Sakers are large, and compared to the steppe Sakers look stockier with a stronger build.
The dark morph falcons live in the highlands during the breeding season and do not occur in the lower and middle forest belt i.e. where one can find the nominative race. It is possible that birds which we call the black morph birds belong to the dark morph of the Altai Saker, since during the breeding season they stay in the habitats occupied by the Altai Saker. To clearly distinguish the Mountain Saker from the Altai Saker is difficult since there are many hybrids on the marginal territories which exhibit characters of both forms.
Besides plumage differences, mountain Sakers differ from Steppe Sakers in flight. This is very obvious when after demonstration of flight of the steppe falcon one is shown a flight of the Mountain one. The mountain bird flight is heavier and stronger than that of steppe birds. It should be noted that flight amongst steep slopes and rocks requires stronger and more manoeuvrable flight. It could be hypothesised that falcons hunting in mountainous regions have evolved shorter and broader wings. The Steppe form has longer, narrower wings and so cannot compete with the mountain birds, which might act as an ecological barrier between the forms.Traditionally the mountain Sakers from the Russian Altai are considered to be rare, however this may be not so. The myth of the rarity of the mountain falcon is due to the fact that it is difficult to detect. Studies show that the Russian Altai holds at least 300 pairs of these birds.
A surprising result of the work carried out during the 1998 and 1999 breeding seasons was that only 40% of the Sakers took part in breeding. Probably this was a result of the poor food situation and large proportion of the immature birds in the population. All known nests of the Mountain falcons were located on cliffs. In the proximity of lakes, the nesting cliffs were also preferred by Ruddy Shelduck (Tadorna ferruginea). The mountain Saker starts breeding 10-14 days earlier than the Steppe Saker inhabiting the adjoining territory. It looks as if the mountain Sakers are specialised on another prey species, mainly on the long-tailed Sousliks which wake up after hibernation earlier as the snow melts on slopes earlier than in the lowlands.
The mountain Sakers would be correctly named as nomadic species, as many of them stay in the breeding grounds in late autumn and even in winter, as long-tailed Sousliks are active up to end of October, and Daurian Pikas do not hibernate. In the Chuya steppe, where the density of the Pikas is highest and there is not much snow, the Sakers sometimes concentrate in large numbers, but in severe frosts they migrate to the South to Mongolia and China. This is also supported by data obtained by satellite telemetry (Eastham 1998).
Altai Saker (F. cherrug altaicus)
This is the most mysterious falcon in the world. The very fact of its existence for more than a century suggest that there is a stable population isolation mechanism. If further studies find this isolation, I think we have a previously unknown sub-species of falcon which still survived in the remote regions of the Altai.
First of all the falcons are distinctly different in having an atypical greyish or ash-grey plumage coloration. A moustache is lacking in some falcons, in others they are very prominent. The lower part of the body is white with dark-grey spots, which form stripes on the flanks and sides of the body. A young bird examined in June 1998 had a greyish-brown back with a lot of dark spots on the lower part of the body. Some authors mention that the Altai falcon has a dark morph (Sushkin 1938, Dementiev 1951), however it is still not clear as to the degree of intergradation of dark mountain birds and Altai birds. In June 1998 we observed a bird with white colour of the lower part of the body and dark stripes across the tail and upper body.
In the "Falco" breeding centre in Barnaul in 1996 were 2 young Altai falcons taken from the wild. Both birds were large with grey plumage and many spots on the lower part of the body. The Altai Saker is distinct by its short, broad wings, resembling a Gyrfalcon. In the examined female Altai Saker the wing length was 14 mm longer than maximum wing length of the Mountain Sakers (Eastham 1998). Also the tarsi are more than half feathered (Dementiev 1951).
The range of the Altai Falcon is not clearly defined. Dementiev (1951) considered that the range covers many mountain regions of Central Asia. Currently, the Altai Saker no longer occurs in Kyrgisia (Sanin, N., Bachurin, G., pers. comm.). The current situation in Mongolia is unknown, however the country lacks suitable habitat for the Altai Saker. We believe that the Altai Saker is unique to the Altai-Sayan Mountains in the territory of Russia and Kazakhstan. We observed the bird in Altin-tu, Chulishman, Kurai, and Saylugem mountain ranges. Regular breeding of these birds in the Saylugem mountains was noted by Sushkin (1938). Irisov (1972) mentioned the breeding of the Altai falcon in the Ukok plateau. Some nests are known in the Kurai range (our data) and Tuva uplands (Sanin, pers. comm.).
According to records of Altai falcons during the breeding season and known nest records, these birds occupy the mountain tundra belt of the Russian Altai. Here there is a significant density of Ptarmigan (Lagopus mutus), and it is possible to suggest that these birds are the main quarry of this falcon. Possibly the distribution of Ptarmigan determines the range of the Altai Falcon limiting it to the belt between 2,000-2,500m above sea level.
There are no data on the biology of the Altai Falcon. Possibly they breed a bit later than the mountain ones. In the nest found on 14 July 1998 we found 2 unfledged chicks. A similar case of a late brood in Sayan Mountains was mentioned by Dementiev (1951). Later than normal dates of breeding in Altai Saker could be explained by the late fledging of young Ptarmigan. Under the nest we found a lot of ptarmigan feathers, bones of Northern Pikas (Ochotona alpina) and Siberian Chipmunk (Eutamias sibiricus). Dementiev (1951) also noted Ptarmigan as diet items. Data with other breeding dates given by Sushkin (1938) probably refers to hybrids, or to Mountain subspecies.
It appears that the Altai Saker has a sedentary way of life and has limited movements within the breeding range. Sudilovskaya (1973) mentioned the only finding of the Altai Saker in North-western China. Then a young female was shot on 15.05.1874 close to Yarkend. Cheng Tso-hsin (1955) mentioned that it is possible to find only birds of coatsii, hendersoni and saceroides in Sindzian province close to the Russian border and does not mention any references to the Altai Saker. During September-October we observed Altai Saker every day in the valleys and plains of the Russian Altai. Seasonal fluctuation of numbers is not well studied, and it appears to be insignificant.
Despite the obvious differences in biology, morphology and geography between the Altai Saker and the rest of the species, it is too soon to make any conclusions on the systematic position of the birds. More studies are needed.
References:
Cheng Tso-hsin (1955). Distribution list of Birds of China. Peking. V.1.
Dementiev, G.P. (1951). Birds of the USSR. V. 1. Nauka Publishers.
Eastham, C. (1998). Satellite tagging of Sakers in the Russian Altai. Falco: 12: 10-12.
Irisov, V.A. (1972). Peculiarities of distribution of some birds in the south-eastern Altai. Ornitologia 10: 248-250.
Kuchin, P.A. (1968). Observation on Siberian Saker in the Upper Ob river. Ornitologia, 9: 103-107.
Stepanyan, L.S. (1975). Composition and distribution of the fauna of birds of the USSR. Non-passeriformes.
Sudilovskaya, A.M. (1973). Birds of the Tarim basin and surrounding mountains. Studies of the birds of the USSR fauna. Moscow University Press: 50-154.
Sushkin, P.L. (1938). Birds of the Soviet Altai. Moscow.
Shekin, B.V. (1965). On the biology of the Mongolian Saker in the Transbaikalia depression. Ornitologia 7: 497-498.
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ERIC
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poliogaster
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