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RESPONDENT
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Irina Menyushina
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SITE NAME
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Wrangel Island, Neizvestnaya River, upper reaches, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (495)687-06-57 // v.n.ira@mail.ru // Prospect Mira, 103-109, Moscow, 129085, 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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Jun
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Aug
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WEATHER
CONDITIONS
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Weather conditions: |
| In the centre of Wrangel Island the spring was late: flood on Neizvestnaya river started on 6 June, intensive snowmelt started on 7 June, and tundra became basically snowfree on 18 June. Negative temperature on nights retained till 12 June. On 21-22 June a storm of wet snow occurred at a temperature -3-4^C. The warm weather established from the second decade of July and endured till early August. August was wet and cool, with frequent precipitation and night frosts in the second half.
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| Date of ice-break on
rivers: |
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| Date of final loss of
snow: |
18 June
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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| Birds arrived in spring in usual dates. Snowy Owls were breeding everywhere, except for the northern plain. Their density in the study plot (46 sq.km) was 0.26 nest/ sq.km. The plot was also populated with 5 breeding and one non-breeding pair of Arctic Foxes, 2 pairs of Pomorine and 13 of Long-tailed Skuas. The latter density is, however, higher than in other areas. Shortage of food restricted breeding performance of rodent-spesialized predators: 0-3 chicks per owl nest, 2-5 cubs per fox den. Young fledged only in 3 broods of Long-tailed Skuas, other suffered from cool weather, lack of food, predation. All predators actively fed on tundra birds. Remnants of Common Eider (adults, chicks and eggs), Turnstone (adult and chicks), Snow Bunting (adult and fledglings), chicks of Long-tailed Skua and Snow Goose were found in Snowy Owl nests. Dunlin chicks were taken by a Glaucous Gull. Wader reproduction can be considered unsuccessful, due to bad weather in the season beginning and predation. Wader broods or alarming birds were very rarely recorded from the end of July in floodplains of rivers and springs (about 500 km of surveys).
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Rodent dynamics:
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| Lemmings had low density in most regions (in central, western, and northern), but could reach average numbers locally. The latter patches were used for breeding by Pomorine Skuas, but they failed due to shortage of food. An average number of lemming undersnow nests was 8.7 per 1 km of survey, their distribution was very patchy. On average 0.5 lemming body was censused in Snowy Owl nests. The ratio of Collared to Siberian Lemmings in surveys was 1:0.6, while in owl nests - 5:1. Lemming number will supposedly increase to average in 1999.
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Rodent species recorded:
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Summary
of fauna studies: |
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