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RESPONDENT
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Vladimir Pozdnyakov
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SITE NAME
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Lena Delta, southern and eastern parts, Yakutia, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (411-2)33-68-15/(411-2)42-13-72(fax) // vpozd@mail.ru // Kulakovskogo St., 12-59, Yakutsk-7, 677077, Russia
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PROJECT DETAILS |
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Project name:
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Waterfowl monitoring in the Lena River delta
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Start of survey:
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End
of survey: |
Team
size: |
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31.05
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25.07
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2
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WEATHER
CONDITIONS
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Weather conditions: |
| Spring was earlier and warmer than average. Mean monthly air temperatures were 1.6øC above long-term average in May and 1.2øC in June according to the data from the weather station "Stolb" in the southern part of the delta (72ø24'N, 126ø48'E). Snow melted on 80% of flat surface by 1 June, and daily air temperatures rose above freezing point on 2 June. Mean daily air temperatures were relatively constant in June, although they dropped to -0.5øC during short-term cooling on 6-7 June. Mean daily temperatures rose above +5øC in mid June and exceeded +10øC during the last 3 days of the month. Ice started to break up at the usual time and rivers cleared of ice quickly, at an average increase of water level. Bykovskaya Channel, in the extreme south-east of the delta, cleared of ice in 3 days, from 7-9 June. Extreme weather events were not recorded.
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| Date of ice-break on
rivers: |
7-9.06
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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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In spite of the higher abundance of lemmings Snowy Owls nested in far smaller numbers compared with 2004. In contrast Pomarine Skuas were more abundant and occurred at a density 1.3 pair/km2 in the study plot. Arctic and Long-tailed skuas also bred. Numbers of breeding Rough-legged Buzzards in the south-western part of the delta were slightly higher than in 2004, while Arctic Foxes were not recorded, although they definitely bred in the Lena delta in 2005. Ermines bred successfully.
Arrival of birds was unusually early, although mean daily air temperatures rose above freezing on a single day during May, 18. Most species of waterbirds arrived by late May to the delta, and migration terminated by 10 June. A pair of vagrant Barn Swallows was observed in the north-east of the delta on 1 July, and 4 swallows were recorded on 2 July. All species of waterbirds typical to the Lena delta nested in higher numbers than in 2004. Depredation of clutches by Arctic Foxes was not recorded, and nest success of birds was very high. Chicks hatches in all nests of Ross's and Sabine Gulls under observation; nest success was 91.5% in Brent Geese and 82.1% in Steller's Eiders. Nest failure in 2 latter species was due to predation by large gulls and skuas. Apparent nest success in waders was 90.3% (n=31), and 3 failed nests included 1 depredated nest of Grey Plovers (of 4 found), 1 abandoned due to unknown reason nest of Grey Phalaropes (of 7) and a single found nest of Pacific Golden Plovers which was abandoned due to disturbance by fishermen. All found nests of Turnstone (n=6), Little Stint (n=7), Temminck's Stint (n=2), Curlew Sandpiper (n=3) and Ruff (n=1) survived to hatching.
Generally reproductive success was unusually high in birds in the Lena River Delta due to favourable weather conditions and low predation pressure in 2005.
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Rodent dynamics:
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| An outbreak of lemming numbers continued for the second year in a row, and they were more numerous compared with 2004 according to visual evaluation. The outbreak spread across the whole area of the delta in 2005.
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Rodent species recorded:
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Summary
of fauna studies: |
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