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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: |
Team
size: |
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WEATHER
CONDITIONS
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Weather conditions: |
| Snowcover remained on about 98% of surface until 4 June, which allowed to settle in the colony for only about 5,000 Snow Geese. Warm spring weather started on 4 June and continued for 3 days, but this was sufficient for 30% of the colony area to become snow-free, and for 50,000 geese to start nesting. Snowstorms from 7-10 June arrested further nesting attemts. Weather was favourable in the first half of brood-raring period, but from 23 July onwards to departure of juveniles from the island in late August snowstorms and negative temperatures became ordinary events.
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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: |
low
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Breeding conditions:
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Arctic Fox numbers in the geese colony area were below the average, and reproduction was detected in 4 dens. Fox activities in the colony were recorded in a restricted area, and only in the first days of nesting when solitary nests were present. During incubation fox records in the colony were rare: none could appear during several hours of observations, while in 1989 up to 20 different animals could have been recorded during same time. As previously, Wolverines preyed upon geese nests, and bodies of adult birds were found in two food depots of this animal. Wolves again appeared on the island, but they were not registered in the colony vicinities. From the start of colony formation to depature of broods its territory was inhabited by 50-60 Glaucous Gills, which is slightly more than average.
Mean clutch size in Snow Geese was 3.54ñ0.04 (n=828), which is lower than in seasons with optimal spring conditions. With estimated numbers of spring population as 95,000 birds, number of nests in the main colony was 24,800, and nesting success 88%, the latter corresponding to a good season value. Death of birds from deseases was recorded on the colony in 2000. About 69,000 goslings left the colony, but reproductive success decreased due to adverse weather in late July, when growth of many goslings, in particular from late broods, was supressed, and they took longer to fledge. According to our evaluation, fraction of juvenile birds on wintering grounds should be 25-30%.
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Rodent dynamics:
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| Our expectations of peak of lemming numbers were not realised, possibly, due to cold winter with low amount of accumulated snow, adversely affecting under-snow reproduction of lemmings. Lemming numbers were lower than average in the Snow Geese colony area and just low in the northern parts of island. Conditions for lemming wintering are different there from the central part of island, where snow is always present in necessary amount.
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Rodent species recorded:
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Summary
of fauna studies: |
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