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RESPONDENT
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Vladimir Pozdnyakov
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SITE NAME
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Lena River delta, 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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Monitoring of birds of the Lena Delta ecosystems
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Start of survey:
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End
of survey: |
Team
size: |
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7.06
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2.09
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1
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WEATHER
CONDITIONS
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| Season phenology: |
average
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Weather conditions: |
| Spring was average in timing. According to data of the "Stolb" meteorological station at the delta south, mean daily temperatures became consistently positive after 6 June. Rapid warming from 6-9 June (with mean daily temperature on 7 June +7.8øC) resulted in complete snow-melt on plane areas. Timing of ice-break was average, likewise the level of water. Bykovskaya channel in its middle reaches (south-eastern part of delta) became ice-free on 13 June, and Bolshaya Trofimovskaya channel in its mouth (eastern part of delta) - on 18 June. A cooling between 14 and 16 June was characterized by negative mean daily temperatures, but falling snow was melting during day-time and had no adverse effect on bird nesting. Weather was very warm and dry from 28 June to 5 August, with average July temperature +14.1øC. Afterwards August was colder than usual, with strong winds and frequent, although short-termed, rains and snow-spells.
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| Date of ice-break on
rivers: |
11-18 June
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| Date of final loss of
snow: |
9 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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Lemming numbers were low, after the peak in 2000, but local patches of higher density on some delta islands were even capable to support breeding Pomorine Skuas. Arctic Skuas nested as well in usual numbers, while breeding of Long-tailed Skuas, common as wandering, was not confirmed. Arctic Foxes were rarely seen, although their tracks and evidence of predation on clutches were fairly common. Lower than one could expect abundance of foxes after peak lemming year could be due to their dieing during snow period, which was confirmed by findings of carcasses of few animals in winter fur. Inhabited dens were not discovered. Adult ermines were seen repeatedly, but never juveniles. Snowy Owls did not breed and were very rare: the only female seen during whole season was staying from 30 June to 4 July on an island with nesting pair of Pomorine Skuas. Rough-legged Buzzards were common, but nested in small numbers mostly in the southern parts of delta, while numbers of breeding Peregrine Falcons did not change in comparison with 2000. 4 Ravens, including at least 2 juveniles, were seen in the south-eastern part of delta on the Bykovskaya channel in the end of July.
Waterfowl nesting success differed among islands depending on the presence of Arctic Foxes. When present Arctic Foxes destroyed 80-90% of nests of Brent Geese and King Eiders, and up to 20-30% of nests of Herring and Glaucous gulls in mixed colonies. Only nests in central, the most densely populated parts of colonies could survive. Hatching of these species was successful on islands, which were not visited by Arctic Foxes. Steller's Eiders and Bewick's Swans had lower numbers than in 1999-2000. More than half of eider clutches was destroyed to the middle of incubation, while reproductive success of swans was high, judging by size of broods in the second half of August.
Predation of clutches of Ross' s and Sabine's gulls was not recorded even on islands with foxes. In late June-early July flocks of Ruffs, Pectoral Sandpipers, Little and Temminck's stints were seen, formed, presumably, by fail-breeders. Proportion of males was higher than in favourable years in flocks of Red Phalaropes, according to visual evaluation. Nests, broods or juveniles were seen in Red Phalaropes, Ringed, Grey and Pacific Golden plovers, Turnstones, Ruffs, Curlew Sandpipers, Dunlins, Little and Temminck's stints. Flocks of Spotted Redshanks of 10-20 birds were seen on 24 August on shallow channels in the eastern part of delta, although they had been absent there during nesting period. Feeding flocks of Brent Geese of 40-300 birds were seen in the lower reaches of the Bolshaya Trofimovskaya channel at the east of delta, but proportion of juveniles in these flocks was not determined. In the same site pre-migration aggregations of Pintail were recorded, with 2000 birds in the largest. Pintails departed on 25-29 August in large flocks of 100-500 birds.
Generally, reproductive success of birds can be evaluated as average.
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Rodent dynamics:
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus sibiricus | rare |
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Summary
of fauna studies: |
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