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RESPONDENT
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Vasili Baranyuk
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SITE NAME
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Tundrovaya River valley, Wrangel Island, Russia
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| Contact
details (phone/fax//e-mail//address): |
| (095)441-12-16 // vvbar@vvbar.msk.ru // Lomonosovsky Pr., 35-40, Moscow, Russia |
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PROJECT DETAILS
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Start of survey:
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End
of survey:
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Team
size:
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WEATHER CONDITIONS
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| Date of ice-break
on rivers: |
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| Date of final loss
of snow: |
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BIOTIC CONDITIONS
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| Rodents abundance evaluation: |
high |
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Breeding conditions:
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Number of Arctic Foxes in the area of the main geese colony was below average. Breeding foxes were principal visitors of the colony, including animals from 4 dens with broods at the colony, and at least 4-5 pairs having dens outside the colony territory. Pomarine Skuas bred. Snowy Owls bred everywhere including flat areas of the island, where reproduction of owls is rare compared with the mountains and occures only at high density of lemmings.
Early spring and rapid snow melt resulted in extremely early dates of reproduction in Snow Geese. Spring migration in North America was also early, and, unlike 2001 season, arrival of geese to the island followed local pattern of air temperature change and appearance of snow-free patches in the colony. Total spring population was estimated at 107500 geese, slightly higher than last year. First nests appeared in the colony already on 22-23 May. Colony formation was not affected by deficiency of nesting territory which resulted in absenc of cuckoldry and egg-laying outside nests. An average clutch size was 4.00ñ0.05 (n=462), and fraction of nests with 4 eggs was 52.2% which reflect very good conditions for colony formation. Estimated number of nests was 30300, and nest success was near 81%. Good production was also observed at a smaller colony on Wrangel Island. First chicks appeared on the island already on 21 June. However, weather worsened during peak of hatching with snowstorm on 23 June and low air temperatures (below freezing point at night) until 10 July. The second half of July was warmer. August and September were also relatively warm. Generally, nesting of Snow Geese on Wrangel Island was successful, and percent of juveniles on wintering grounds was 26.7% (S.Boyd, pers. com.). |
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Rodent dynamics:
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| Lemming numbers in 2002 were higher than in 2001, and deserved 4 rank at a 5 rank scale. Siberian Lemmings were clearly more abundant than Collared Lemmings. High lemming numbers were observed both in mountains and on the plains. Given that the last peak lemming numbers occurred in 1994, and duration of previous cycles varied from 5 to 7 years, 2002 could have been a peak year and will be followed by decline in 2003. There are chances, however, that a super-peak with very high lemming numbers speareding across the whole island will happen in 2003, as it was previously in 1970 and 1981.
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Rodent species recorded:
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Summary
of fauna studies: |
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