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SITE NAME
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Bikada River, Taimyr, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (499)780-16-53 // taimyr@orc.ru // Glavnaya St. 19A-193, Moscow, 105173, Russia
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PROJECT DETAILS |
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Project name:
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Expedition of Taimyr State Reserve
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Start of survey:
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End
of survey: |
Team
size: |
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1.06
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25.08
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5
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WEATHER
CONDITIONS
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Weather conditions: |
Spring was early and developed quickly: snow melt started on 4 June and completed on 14 June (except for permanent snow-patches), with 50% coverage on 11 June. Ice-break on the Bikada River on 13 June was the earliest for 20 seasons of observations, but flood was not high, although exceeded the one of 1998. Rain-flood on 7-11 July was moderately high, while the second one on 22-27 July occurred already in post-nesting period and did not affect nest success of floodplain-nesting birds (Ringed Plovers, primarily).
Air temperatures during summer remained mostly in the range of 8-14øC, and crossed the 20øC level only once, on 12 July. The season was rather rainy and very windy, with velocity of wind reaching 30 m/s in some days.
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| Season temperature: |
average
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| Date of 50%
snow-cover: |
11.06
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| Date of ice-break on
rivers: |
13-15.06
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| Date of final loss of
snow: |
14.06
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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 Foxes were rarely seen, although two animals were staying during the season in the study area on different banks of the Bikada River. None of the 30 surveyed dens was inhabited, however, breeding was confirmed by a visit of the camp by a young in late August, to feed on waste.
On our arrival on 1 June four bird species were already present in the study area, while most of birds arrived between 4 and 12 June. First nest (by Little Stint) was found on 11 June, and by 20 June almost all birds had complete clutches. First wader chicks (of Red Phalarope) appeared on 7 July, while first passerines (Lapland Buntings and Shorelarks) hatched, probably, already in the end of June and fledged on 7 July. The latest chicks were hatched in Bar-tailed Godwit between 20-30 July, when most chicks of Curlew Sandpiper, Dunlin and Little Stint already fledged.
Steller's Eider which has been becoming increasingly common in 90s was only met on 11-12 July during 16 hours on intensive migration of males to moulting grounds. Numbers increased in comparison with 1998 in Pacific Golden Plover, and especially in Lapland Buntings, decreased in Snow Bunting, Wheatear, Dunlin, Grey Plover, Ringed Plover. The latter species, however, expanded to dry sandy slopes from usual habitat riverine gravel beaches. At the same high level retained the numbers of Bar-tailed Godwit, Little Stint and Red Phalarope.
Despite low lemming numbers and rather unfavourable weather nesting was successful in most of the breeding species. Only 5 of 25 monitored nests were depredated: 2 by Arctic Foxes, 1 by Long-tailed Skua, 1 by Herring Gull, and 1 trampled by Muskox. Chicks of Rough-legged Buzzards appeared in a single nest of four, and were fed by birds. Also chick mortality was high in Herring Gulls: a colony of 25 nests on an island in the Yamu-Neru Bay produced only 6 fledgelings, while 18 chicks were found dead. One of 3 chicks survived in Pomorine Skuas, and one of 2 in Long-tailed Skuas. Wader broods in late July consisted of 1 or 2 chicks only.
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Rodent dynamics:
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| Decrease of lemming numbers continued from 1998, although in contrast with the latter season when lemmings had not been recorded at all, in 1999 four Siberian Lemmings were seen, 3 more were caught per 120 trap-nights, and 1 found in a nest of Rough-legged Buzzard.
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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: |
| Daily bird counts were carried out on two permenent transects. Found 29 nests of 16 species, of which 25 were monitored.
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