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RESPONDENT
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Eugeny Syroechkovski, Jr.
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SITE NAME
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Nizhneyansk settlement, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (095)246-71-54/(095)124-79-32 // ees@gcnet.ru // Institute of Ecology and Evolution, Leninski prospekt, 33, Moscow, 117071, 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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5
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WEATHER
CONDITIONS
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Weather conditions: |
| Spring was delayed approxiamtely 15-20 days compare to multiyear average. According to weather station data June was the coldest for the period of more than 20 years. As reproted by inhabitants of Ust-yansk and Kresti villages, a return of frost about 12-15 June caused mass dying of small waders and passerines, while hundreds of birds that had arrived to tundra before concentrated along Yana R. banks and in settlements. Almost winter environment retained till 15 June. Yana R. broke only on 17 June, already after the rising water flooded low tundra areas. By 23-25 June outer delta was 70-80% flooded in a 20-30 km wide belt. Active clutch initiation by birds started after quick fall of water that occurred during one day. Most of the few clutches laid before flooding were lost. Water level in channels remained high until mid July which dramatically restricted opportunities for wader and other birds to nest on seaside islands. The weather was variable in July and August, cool and generally favourable for bird reproduction weather with small precipitation predominated.
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| Date of ice-break on
rivers: |
17.06
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| Date of final loss of
snow: |
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
average
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Breeding conditions:
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Arctic Foxes were not seen in parts of delta other than north-eastern. Red Foxes were common in the middle reaches of Ilyn-Shar channel. Long-tailed and Arctic Skuas nested sporadically. Rough-legged Buzzards and Snowy Owls were met only few times, although in certain years they were common according to survey data.
Clutch predation by Arctic Foxes and skuas was the heaviest in outer part of delta (in typical tundra subzone), in particular in its western sector. In combination with preceeding flood this resulted in a probable reproductive success of waders and passerines not exceeding 25%; tundra in the lower reaches of Ilyn-Shar channel had appearance of deserted. Around Nizhneyansk bird reproduction seemed to be more successful, but hardly exceeding 50%. Farther south predation was even lower, and few depredated nests were inspected near Kazachie village. To conclude, the season was not especially successful for birds, in particular in the outer part of delta.
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Rodent dynamics:
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| Distribution of microtine rodents was rather uneven. Voles had average numbers near Kazachie settlement, and consisted for 60% from Root Voles, and for 40% - from Ruddy Voles (S.Grigoriev data). Siberian Lemmings and Ruddy Voles were scarce in Tastakh area along the Samandon channel. Rodent diversity was the highest (though numbers not high) near Nizhneyansk village, where Siberian Lemming (60%) and Ruddy Voles (35%) predominated in upland tundra. Solitary Collared Lemmings were met, while Narrow-skulled Vole was rather common locally near human habitations. According to survey data, lemming numbers near Nizhneyansk were high in March-April, when they were met on winter roads and in tundra (this is confirmed by numerous tracks in outer delta). We found few bodies of animals drowned during flood. According to general impression about population processes small winter outbreak was already over by spring, or population increase was interrupted by extremal flood.
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Rodent species recorded:
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Summary
of fauna studies: |
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