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SITE NAME
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Olen'ya River mouth, Taimyr Lake, 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 Reserve
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Start of survey:
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End
of survey: |
Team
size: |
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30.05
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25.08
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4
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WEATHER
CONDITIONS
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| Season phenology: |
average
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Weather conditions: |
| Maximal air temperatures raised above freesing already in May, but the whole June was cool and cloudy, with negative minimal temperatures, monthly mean +2.1øC, and frequent precipitation. In the second half of June snowlayer up to 25 sm thick was formed several times, and retained up to 1 day. However, phenological events in animals and plants, as well as ice-break on rivers and Taimyr Lake, developed in average dates. On arrival of birds 90% of the area were under snow, with only hills and bank crests being snow-free. Mass arrival of birds occurred between 1-10 June, while 50% snowcover was reached on 15 June, and snow went off completely on 18 June. Weather in the first half of July was average for the area, while end of July and the whole August were warmer than usual, with maximal temperature +24.1øC on 26 July, and monthly means for July and August +9.2øC and +10.3øC, respectively. Only two rainy days were recorded for the whole period, and repeatability of strong (exceeding 15 m/s) winds was below the average (except for beginning of June).
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| Date of 50%
snow-cover: |
15.06
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| Date of ice-break on
rivers: |
23.06
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| Date of final loss of
snow: |
18.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
high
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Breeding conditions:
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High lemming numbers at the season beginning confirmed also by breeding of Arctic Foxes, which had 11 and 13 pups in two dens closest to the camp, and by breeding performance of Rough-legged Buzzards which showed density of 2 nests per 1 km along deepened river valley, and had 3-6 eggs in clutches.
Rock Ptarmigans, Herring and Glaucous gulls, Long-tailed Skuas, Snowy Owls, Rough-legged Buzzards, Snow Buntings, Pied Wagtails and Shorelarks were already present in the area on our arrival on 30 May. Most other species appeared from 1-14 June, Pectoral Sandpiper being the latest to appear on 19 June. Passerines started to nest from 5-10 June, waders - from 14-20 June. First fledgeling of Lapland Bunting was seen on 7 July, mass hatching of White-fronted Geese happened on 11-13 July, and broods of most wader species appeared from 8-15 July. Worth to note substantial delay in geese moult - no more than 30% of birds became able to fly by 25 August.
Many bird species were common only on migration and did not stay to breed, which may be due to adverse weather in prenesting period, but also can be site-specific attribute. Thus, Bean Geese almost did not nest, Red-breasted Geese were rather rare in contrast to adjacent localities to the east and west. Few Long-tailed Ducks were seen migrating, and none breeding which is strange given a proximity to large lake. Long-tailed Skuas were less common compared to records proximate localities in other seasons. Pomarine Skuas were more common, but, probably, did not nest. Among waders only Pacific Golden Plovers, Grey Plovers, Curlew Sandpipers, and Dunlins were numerous, while such species as Bar-tailed Godwit, Red Phalarope, and even Little Stint were encountered infrequently.
Despite rather high lemming numbers clutch predation by Arctic Foxes was not exceptional, as lots of non-breeding foxes inhabited the area and could be recorded there several times a day in the first half of summer. However, clutch loss due to predation by skuas and gulls was not recorded. Single nest of Peregrine Falcons in the area was trampled by reindeers or muskoxes. Nesting was most successful in Pacific Golden Plovers, Grey Plovers, Ringed Plovers and Temminck's Stints, judging by frequency of brood records. None of 7 controlled nests of White-fronted Geese was depredated, and their broods were seen very often. Herring Gulls nested successfully. All chicks of Rough-legged Buzzards fledged, except for a single one in the largest brood (6 chicks). Passerines also bred successfully, despite intensive predation of Arctic Foxes on nests of Lapland Buntings.
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Rodent dynamics:
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| Lemming abundance was high in the season beginning (and, probably, in winter), with 3-4 animals recorded per one km during snowmelt in wet slope tundra. Numbers decreased in the second half of summer.
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus sibiricus | abundant |
| Dicrostonyx torquatus | abundant |
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Summary
of fauna studies: |
| Birds were counted on line transects (14 in total), nest descriptions made.
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