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RESPONDENT
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Vasily Sokolov
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SITE NAME
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Erkatayakha and Payutayakha rivers, Yamal, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (343) 210-3858, add. 104/89028432787 // vsokolov@inbox.ru // Lab. of biocenological processes, Inst. of plant and animal ecology, 8 Marta Str, 202, Ekaterinburg, 620144 Russia
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PROJECT DETAILS |
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Project name:
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Dynamics of bird populations on the south-western Yamal Peninsula
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Start of survey:
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End
of survey: |
Team
size: |
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24.06
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1.08
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3
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WEATHER
CONDITIONS
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Weather conditions: |
| According to reports of the local people there was an exceptionally warm sunny weather, without strong winds or precipitation, in mid May, accompanied by rapid snowmelt. Daytime air temperatures reached +10°C. Cold weather returned in late May, when strong northern and north-western winds with heavy snowfalls occurred. The local people observed return southward migration of waterfowl and gulls. The adverse weather lasted until mid June. Ice-break had started on large rivers only on 18-20 June when the water table in the Erkatayakha River was still at a maximum level. Large ice floes were still moving on the Payutayakha River when we arrived on 24 June. Almost all the lakes were still frozen. Snow completely melted on 20-25 June. There was warm and dry weather after 24 June, with air temperatures reaching +25°C in the daytime. The absence of precipitation resulted in a rapid decrease of the water level in the river. July was dry and hot, with temperatures just below +30°C on most days, and above this on some days. Precipitation occurred only on 3 days in July. Pelting rain had started in the evening on 23 July and continued during the whole night, which, probably, caused the death of chicks in some nests of passerines. Thus, a nest of the Pechora Pipit with dead chicks approximately 10 days old was found. Strong wind was not recorded during the whole study period until 1 August.
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| Date of 50%
snow-cover: |
10-15.06
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| Date of ice-break on
rivers: |
18-22.06
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| Date of final loss of
snow: |
20-25.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
average
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Breeding conditions:
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It is interesting that Rough-legged Buzzards were rare, and for the first time in 9 years we did not find their nests in the study area of over 150 km2. However, 6 inhabited dens of Arctic Foxes were found with 4-8 cubs, and records of Red Foxes were more frequent. Skuas were rare, and were represented mostly by wandering flocks and single Arctic Skuas. A single nest of Long-tailed Skuas found on 28 June was deserted later.
A unique pattern of bird breeding phenology developed in 2007 due to the unusually cold spring and relatively high abundance of Arctic Foxes. In the beginning of our studies we found nests of most species at a stage of egglaying, but in July we often recorded clutches of eggs and chicks of various age as well as fledglings. For example, a nest of Willow Grouse with 9 eggs at an advanced stage of incubation was found on 24 July, and several grouse broods with chicks the size of a thrush were found on the same date. On 26 July along with fledglings of Little Buntings we recorded a nest of this species with 5 chicks 4-5 days old. The variation of breeding dates was very high in pipits and Lapland Buntings, as well as in geese. The first geese broods were recorded on the Erkatayakha River on the usual dates, in early July (n=3), but the first records of geese broods on the Payutayakha River were made on 15 July (n=5). Two nests of Pintails were found on bluffs near nests of Peregrine Falcons, but broods of ducks were not recorded.
Thus, the prolonged spring and considerable predation pressure resulted in a longer reproduction period in most species of birds. Summer weather was favourable for the reproduction of birds, but predation, primarily by Arctic Foxes, was heavy, in particular, on ducks. Some species probably laid replacement clutches. Reproductive success of geese, swans, grouse, waders and passerines can be evaluated as average based on observations of broods and fledglings.
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Rodent dynamics:
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| Numbers of Microtus voles were average based on trapping results. Collared Lemmings were observed and their breeding was recorded, but Siberian Lemmings were absent. A considerable number of lemming undersnow nests were found, but results of rodent reproduction were probably strongly affected by spring conditions.
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Rodent species recorded:
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| Latin | Abundance |
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| Dicrostonyx torquatus | rare |
| Microtus middendorffi | common |
| Microtus gregalis | rare |
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Summary
of fauna studies: |
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