Steller's sea eagle publications list

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Articles:

FUJIMAKI, Y., HIGUCHI, H., YANAGISAVA, N., SATO, F., KOMARU, M., UMEKI, M., ALEKSEEV, S., LOBKOV, E., LADYGIN, A., BANIN, D. (1991): Birds of eastern Kamtchatka Peninnsula// Strix, p.219-228. N 10, p.219-228. (in Japan languge)

HANAVA, S., YUNOKI, O., YAMADA, M., KHRABRYI, V., SOKOLOV, E., FOKIN, S., MASTEROV, V. 1989. Breeding status of the Steller's Sea Eagles (Haliaeetus Pelagicus) on the Lake Udyl in the Far East of the USSR . Strix, vol. 8, pp. 219-232.

LADYGIN, A., LOBKOV , E., LADYGINA, O. (1991):The biggest wintering of Stellers sea eagle on Kuril lake, South Kamtchatka//Bulletin of Moscow Society of Nature Trialers., biology section, vol. 96, N 1, 48-57 (Russian languge) 

LADYGIN, A. (1991):Wintering birds of Kuril lake basin and their relationships with salmon spawning// Bulletin of Moskow Society of Nature Trialers., biology section, vol.96, N 5. P. 17-22. (in Russian)

LADYGIN, A. (1991):Morpho-ecological adaptations in Stellers sea and White-tailed sea eagles, a comparative analysis. Current Ornithology, 1991. Vol.1. P. 42-56 (in Russian languge)

LADYGIN, A. (1993): Nesting of Motacilla alba in the nests of large raptors on Kamtchatka//Bulletin Of Moscow Society of Nature trialers, biology section. 1993, vol.98, N 5 p. 34-35. (in Russian languge)

LADYGIN, A. (1994): Relationships of raptors wintering on the places of salmon spowning on the Kurilsky Lake (South Kamtchatka). Current Ornithology, , vol.1., p. 96-106 (in Russian languge)

LADYGUIN, A. (1997): Group behaviour of Stellers sea eagle on Kamtchatka // Zoological Journal, Vol 76, #1, P. 83-93 (in Russian language)

MASTEROV, V.B. and ZYKOV, V.B.1990. The perspectives application of fish-eating raptors as an indicator of condition of coastal ecosystems. Thesis. Ecological foundation of rational nature management in Sakhalin and Kuril Islands. Uzno-Sakhalinsk, pp. 106-108. (In Russian)

MASTEROV, V.B. 1991. Breeding of large birds of prey and it's limiting factors. Biological Sciences, # 12, pp. 78-83, Moscow, (In Russian, English summary).

MASTEROV, V.B. 1991. The Steller's Sea Eagle in Lower Amur. Hunt and hunting management, # 10, pp. 14-17 , (In Russian).

MASTEROV, V.B. and ZYKOV, V.B. 1992. Distribution and number of population of Steller's sea eagle (Haliaeetus pelagicus Pall.) in the North-Eastern coasts of Sakhalin. Biological Sciences, # 5, pp. 65-71 Moscow, (In Russian, English summary).

MASTEROV V.B. 1995. The postembryonic development of chicks of Steller's Sea Eagle (Haliaeetus Pelagicus). Methods of determination of sex and ages. Day Raptors and Owls in captivity. Moscow Zoo. pp. 25-34, (In Russian, English summary).

MASTEROV, V.B. 1995. Northern Sakhalin: unique zone of biodeversity in danger. Russian conservation news, 1995, August, #4, pp.23-24.

MASTEROV, V.B. 1995. Aerodynamic characteristics of wings some species of raptors (H. pelagicus, H. albicilla, P. haliaetus, M. migrans ) in connection with the peculiarities of their ecology. Thesis. Actual problems of Ecology and Zootechnics. Veterinarian Academy, Moscow, (In Russian).

MASTEROV, V.B. 1998. The recent status and biology of Steller's Sea Eagles in the South of Okhot Sea Region. The questions of conservation of rear and endangered species of the North. Material of the Red Book., Moscow, volume 1, pp. 134-146, (In Russian, English summary).

POTAPOV, E., UTECHINA, I and McGRADY M. 1995. The Steller's Sea Eagle in the Magadan District: and axample of international cooperation. In: Kondratyev A.Ya. -ed. Beringian Sea Bird Bulletin, 1995 (3): 26-31, 27-32.

SHIRAKI, S. 1996. Distributions of Steller's Sea and White-tailed Eagles in the rivers of Hokkaido. Survey of the status and habitat conditions of threatened species, 1995. pp. 15-27. Environment Agency, Tokyo, Japan.

WORKING GROUP FOR WHITE-TAILED EAGLES AND STELLER'S SEA EAGLES. 1996. Wintering status of Steller's Sea Eagles and White-tailed Eagles in northern Japan. Survey of the status and habitat conditions of threatened species, 1995. pp. 1-9. Environment Agency, Tokyo, Japan.

WORKING GROUP ON WHITE-TAILED EAGLES AND STELLER'S SEA EAGLES & UETA, M. 1996. Wintering ecology and conservation problem of Steller's Sea Eagles. Survey of the status and habitat conditions of threatened species, 1995. pp. 29-36. Environment Agency, Tokyo, Japan.

UETA, M., LOBKOV, E.G., FUKUI, K., KATO, K. 1996. The food resources of Steller's Sea Eagles in eastern Hokkaido. Survey of the status and habitat conditions of threatened species, 1995. pp. 37-46. Environment Agency, Tokyo, Japan.

UETA, M. & KOITA, M. 1996. The relationship between distribution of Steller's Sea Eagles and salmon as their food. Survey of the status and habitat conditions of threatened species, 1995. pp. 11-14. Environment Agency, Tokyo, Japan.

UETA, M., NAKAGAWA, H. & SHIRAKI, S. 1996. Conservation Issues for the Steller's Sea Eagle in Hokkaido. Survey of the status and habitat conditions of threatened species, 1995. pp. 47-52. Environment Agency, Tokyo, Japan.

Magazine's articles

LADIGIN, A.V. (1994): Fire, Ice and Eagles. Natural History. Published by American Museum of Natural History. Vol. 103, No. 2. P.26-34

LADYGIN, A.V. (1995): Eagle Summer. BBC Wildlife. Vol. 13. No. 10. P. 30-47. 

LADYGUINA, O.N., LADYGUIN A.V. 1998. Who were fishing with Giant Kutkchu?//Nature. #3, p.45-50. (in Russian)

MASTEROV, V.B. 1994. Steller's Sea Eagles. Wild Bird; 1994, volume 8, # 8, pp. 40-43.

LADYGIN, A. (1992):Kleptoparasitism among Stellers sea eagle on Kamtchatka Peninnsula. Proceedings of the Raptor Research Foundation Annual Meeting. November 11-15, 1992. Bellevue. P.117.

LADYGIN, A. (1995): An energetic simulation model of Human Disturbance for Managing Steller's eagle populations. Proceedings of the 1995 Annual Meeting Raptor Research Foundation. Duluth, Minnesota. 1-4 November 1995. 56.

LADYGUIN, O., LADYGUIN, A. (1995): Diurnal Birds of prey as a component of a salmon spowning ground ecosystem in Kamchatka, Russia. Proceedings of the 1 International Conference on Palearctic Birds of prey and owls. April 1995, Estremadura, Badajos, Spain. P.90 

LADYGUIN, A. (1996): Foraging strategy of three raptors in salmon spowning ground in Kamtchatka Peninsula, Russian Far East. Proceedings of the Second International Conference on Raptors, Urbino, Italy, 2-5 October 1996

MASTEROV, V.B. 1991. Spatial structure of breeding Steller's and White-tailed eagles in Lower Amur and Sakhalin. Thesis. Ornithological problems of Siberia, Barnaul, Russia, pp. 148-150, (In Russian).

MASTEROV, V.B. 1995. Ecology and interspecific relations of the white-tailed (Haliaeetus albicilla) and Steller's (H. pelagicus) Sea Eagles in the Far east of Russia // "International conference Holarctic birds of prey" Badajoz, Spain, 16.04-22.04:1995, pp. 53-54.

MASTEROV, V.B. 1992. Ecological energetic and interspecific relations between White-tailed and Steller's Sea eagles (Haliaeetus albicilla L., Haliaeetus pelagicus Pall.) in Lower Amur and Sakhalin. The materials of Ph.D. work, 157 pp., (In Russian).

SUMMARIES

The study of two sympatric species - Steller's Sea Eagle and White-tailed Eagle - was carried out in 1986-1990 in the Eastern Kamchatka. On these areas the Steller's Sea Eagle is a settled or partially migrating species, and the White-tailed Eagle is migrating or nomadic. The latter makes nests in the central regions of the Kamchatka Peninsula. The Steller's Sea Eagle makes nests both in the sea coast and mainland. Its feeding is specialized on the salmons. In the absence of salmons 63,1% of the fodder are sea casts. The White-tailed Eagle is a typical polyphage. The high plasticity in the choice of a place for nesting is peculiar for the Steller's Sea Eagle. Nesting of the White-tailed Eagle is determined by the presence of high trees with powerful lateral branches. The nesting territory of the White-tailed Eagle is large and strictly protected. As for the Steller's Sea Eagle only a small territory around the nest is protected.

The peculiarities of the Steller's Sea Eagle skull's structure are determined by the necessity of treatment of fodders with strong coverings.

Feeding behaviour of wintering Steller's sea eagles was studied in Kamchatka from 1987 to 1995. Kleptoparasititsm (intraspecific food stealing), which is at the high level in feeding groups of predators, was studied related to food abundance, sizes of food carcasses, eagle group size and age of eagles (n-500 conflicts). The causes of appearing kleptoparasitism are discussed. KIeptoparasitism dominated during the period of food abundance and was more frequent when the eagles feeding on large salmon carcasses. The communal feeding allowed all members of groups to find and consume food more efficiently.

WINTERING STATUS OF STELLER'S SEA EAGLES AND WHITE-TAILED EAGLES IN NORTHERN JAPAN

We report the result of the eagle census (Haliaeetus pelagicus and H. albicilla) from 1980 to 1992.

The number of wintering Steller's Sea Eagles peaked in February 1985 and next in Feb. 1986. In both years, the Steller's Sea Eagles aggregated on the seacoasts in Rausu, Shiretoko, suggesting that they are relying on the abundant resources of captured cod Theragra chalcogramma from gillnet fishery in Rausu coast. As the cod capture decreased, however, so did the number of wintering eagles there.

In Lake Furen, where the Steller's Sea Eagles have aggregated most since 1994, the eagles were eating fish discarded by ice fishing fishermen. Other wintering sites, such as the Nemuro Peninsula, also were thought to attract the wintering eagles with fish dumped from fishing and general deposit of food.

We reasoned that the number and the distributions of the eagles wintering in northern Japan were affected by the fluctuations of available food resources created by human activity.

In the several rivers in Hokkaido, however, where natural anadromous salmon ascend, the number of wintering eagles have increased since 1990. It was suggested that the natural food, salmon, in those rivers were affecting eagle distribution since they supplemented the man-related food.

In the case of White-tailed Eagles, their wintering number peaked in February 1986 and next in Feb. 1996. The decline in number of this species was not as large as that of Steller's Sea Eagles. White-tailed Eagles were suggested to be less affected by the fluctuation of man-related food than observed in the case of Steller's Sea Eagles.

We studied the factors of Steller's Sea Eagle Haliaeetus pelagicus distribution in autumn in Hokkaido. The survey was conducted on the number of Steller's Sea Eagles and salmon carcasses as their food in 19 rivers in north to northeast Hokkaido (namely from Wakkanai to Shiretoko) from November 17 to 27, 1995.

Steller's Sea Eagles were found to feed exclusively on salmon, and there was a strong correlation between the number of eagles and the salmon density in each river. The distribution of eagles was strongly affected by that of salmon as their sole food resource.

Presently, however, most of the rivers in Hokkaido are provided with fish catching devices named "Urai" to capture ascending salmon. Most of the salmon are captured in this way, and as a result, very few salmon are left for Steller's Sea Eagles. In 1995, a movement to take away the Urai will give wintering Steller's Sea Eagles natural food. We hope this trend increases to provide the eagles with natural wintering habitat with enough food.

We studied wintering ecology of Steller's Sea Eagles Haliaeetus pelagicus from November, 1995 to March, 1996 in southern Hokkaido.

1. Steller's Sea Eagles eat Salmon Oncorhynchus keta on shores or fords, and rest on riverside trees.

2. Number of Steller's Sea Eagles reached their peak from December to February.

3. The eagle were distributed along the middle reaches of rivers in the earlier wintering season. In these areas, the distance from river to road is far, so there is no disturbance by humans. After food decreased there, the eagles were distributed along the upper and lower reaches of the river. In these areas, the distance between road and river is short, and there is much disturbance by humans.

4. In Hokkaido, most rivers have weirs to capture salmon, so few salmon can go upriver. Because the main food of Steller's Sea Eagles were salmon, it is important for conservation of Steller's Sea Eagles that salmon can go upriver. It is also important for conservation of eagles to conserve shores, fords, and riverside trees, and to keep distance between humans and the eagles' wintering sites.

In order to show whether waste fish from commercial fisheries, the main food source for Steller's Sea Eagles Haliaeetus pelagicus in eastern Hokkaido, were decreased, we measured the weight of fish left by fisherman from February 29 to March 1, 1996 at Furen Lake and Abashiri Lake, eastern Hokkaido. We measured weight of dumped fish at 38 nets in Furen Lake and 30 nets in Abashiri Lake, and compared the weight data to that of 1993 (Lobkov et al. unpublishe. data).

At Furen Lake, waste fish were primarily Myoxocephalus brandti (64.9 % in total weight). The mean weight of waste fish per net was 3.6 kg (range 0 - 22.3 kg), which is less than that of 1993 (mean 15.1, range 7.7 - 20 kg).

At Abashiri Lake, waste fish were primarily Tribolodon hakonensis (57.5 %) and Plaficntys stellatus (30.6 %). The mean weight of waste fish per net was 2.7 kg (range 0.4 - 7.9), which is less than that of 1993 (mean 37.9, range 18.0 - 37.9 kg). These results suggest that the waste fish available to Steller's Sea Eagles is decreasing or fluctuating. This phenomenon has negative consequences for the eagles, because the breeding success of the following season is low when winter food conditions are bad (Lobkov unpubl. data).

We studied the factors affecting wintering Steller's Sea Eagles Haliaeetus pelagicus, and found that the large part of their wintering population in Japan rely heavily on food disposed by human activity. It is known that small food resources in the wintering period will result in a decrease in number of eggs or breeding birds (Lobkov per. com.). Thus the decline or fluctuation of food resources is a grave problem in conserving Steller's Sea Eagles. A computer simulation also showed that when the amount of food decreased, the population declined.

In order to improve the wintering conditions of Steller's Sea Eagles and enhance their probability of sustaining their population, it is imperative to increase the natural food on which they can feed. In the light that the wintering Steller's Sea Eagles in the natural state were eating salmon carcasses, it is most important to increase the rivers which allow natural salmon ascension. As a result of this, the salmon carcasses remaining in the rivers will provide natural food for the wintering eagles. Most of the rivers in Hokkaido are installed with the fish catching device named "Urai", which capture most of the ascending salmon, allowing only remnant numbers of salmon to ascend.

The recent trend of removing "Urai" allowing salmon to ascend will give wildlife, such as Brown Bears Ursus arctos, Red Foxes Vulpes vulpes, ducks, and mergansers, an improved habitat to feed on natural food.

Steller's Sea Eagles also need habitat for resting, such as forests along streams, lakes and seacoasts, as well as foraging sites such as sandbars, mud flats, riverbeds and natural seacoasts. It is also important that in winter, the foraging site has open water, to allow access to the fish. To sum it up, the conservation of Steller's Sea Eagles will be enhanced when their wintering habitat is preserved in the conditions mentioned above; namely river systems with naturally ascending salmon populations and with quiet riverside forests.

Another issue concerning Steller's Sea Eagle conservation is their illegal hunting. Three Steller's Sea Eagle bodies were found to be illegally shot along the seacoast from Shibes to Bekkai in winter of 1995. Steller's Sea Eagles are one of the species whose adult mortality is very low, making illegal hunting a lethal factor to affect their population, as the simulation showed. Thus eliminating illegal hunting of Steller's Sea Eagles is another important effort in their conservation.