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SITE NAME
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Kotuy River middle reaches, Medvezhiya River mouth, Anabar Plateau, central Siberia, 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 the reserve "Taimyrsky"
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Start of survey:
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End
of survey: |
Team
size: |
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15.06
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26.08
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6
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WEATHER
CONDITIONS
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Weather conditions: |
Spring was very early and ice broke on the Kotuy River in the first dates of June. Snow already melted at arrival on 15 June, with small patches remaining only in the upper belt of the forest, where it also melted on 16 June. The maximal water level was already over by 15 June and low streamflow level established by 1 July. The second half of June and the beginning of July were very warm, with highest air temperature +38.3øC on 3 July, and relatively dry although short-term rains occurred almost daily. The second half of July and August were characterized by avarege temperatures (mean daily temperatures +10-15øC) and abundant precipitation. During this period there were 2 days without rains, and precipitaion amount reached 20 mm on some days. Water table increased by 5 m in the Kotuy River on 15 August after 2 rainy days, and middle floodplain came under water.
Phenological autumn was early as the first indications of autumn coloration in plans was recorded on 10 August, while 70% willow shrubs and 70% of larch trees became yellow by termination of surveys on 26 August. The first frost on ground and in air (-1.9øC) was recorded on 22 August, and first snowfall occurred on 26-27 August at night.
Strong winds, exceeding 10 m/s, were generally rare, but occurred slightly more often in the fist half of summer. Winds could not have notable impact on breeding birds due to complex topography of the area and forest vegetation.
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| Date of ice-break on
rivers: |
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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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Vegetation of the area generally belongs to north-taiga type with larch forest (often sparse) reaching 300-350 m altitude. In spite of the southern locality mountain tundra closely resembs in flora and vegetation typical tundra of the central Taimyr. Bogs and lakes occupied small area mostly in the Kotuy River floodplain.
Arctic Fox does not probably reside in the area in summer time, and a single animal was recorded in mountain tundra. Ermine and Least Weasel were observed. Gulls and skuas occurred in relatively small numbers. Reindeers were not recorded in spring, but appeared en masse on 21 August on migration. Rough-legged Buzzards bred on rocks along the Kotuy River, where 12 nests were found per 27 km of river bank. Food supply was probably not sufficient for Rough-legged Buzzards, as survival of chicks in 3 monitored nests was 1 of 4, 2 of 4 and 1 of 3. Breeding was probably more successful in Merlins, as family groups consisting of 2 adult birds and 3-5 juveniles were common in the end of survers.
Most birds have already started nesting by 15 June, and migration of waterfowl (Bean Goose, Long-tailed Duck, White-winged Scoter, Wigeon, Pintail) terminated by 25 June. Breeding was very early: fledgelings were recorded on 27 June in Raven, on 5 July in Little Bunting, Willow Warbler and Pallas's Bunting, on 13 July in Dusky Thrush, and on 20 July thrush fledgelings appeared in high numbers. Chicks were found on 30 June in Pied Wagtail, on 10 July in Ringed Plover and Spotted Redshank. Nesting was later in mountain tundra, where chicks of Pacific Golden Plover were found on 15 July and fledgelings of Snow Bunting on 2 July. Chicks of Rough-legged Buzzards hatched on 5 July and fledged on 13 August. First chicks of waterfowl were recorded on 2 July and mass hatching occurred on 5 July (Wigeon, Greater Scaup, Pintail, Teal). Fledging occurred on 18 August in Pintail. First broods of Black-throated Diver were observed on 2 August. Juvenile Arctic Terns appeared in high numbers on 15 August, while juvenile Herring Gull was seen on 22 August. Second clutches were probably laid in some species, as we recorded fledgelings of Redpols until 20 August.
Waders were relatively uncommon with the exception of Temminck's Stints in floodplain shrubs, Pacific Golden Plover in mountain tundra, Ringed Plover on gravel flats of the Kotuy River and in mountain limestone tundra, Wood Sandpiper. Common Snipe was the most abundant wader species in the area, occuringin bogs of the Medvezhiya River valley at a density up to 2 birds per 1km during the whole season.
Nest of Red-breasted Geese was found on 14 July under high rocky bluff to the Kotuy River (70.9977N, 102.693E). The nest contained 2 eggs, and 1 egg damaged by an avian predator was found 20 cm from the nest. This observation represents the first nesting record of Red-breasted Geese in north taiga. We observed 3 pairs of Lesser White-fronted Geese showing breeding behaviour near rocky cliffs of the Kotuy River.
Based on the frequency of brood records reproductive success can be evaluated as high in passerines, average in waders, relatively low in Rough-legged Buzzard and high in Merlin and high in ducks.
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Rodent dynamics:
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| Siberian and Collared lemmings were not recorded, although they could be probable inhabitants of mountain tundra. Total trapping effort for small terrestrial mammals was 1740 trap-nights, which resulted in catching 60 Middendorf's Voles, 16 Northern Red-backed Voles, 1 Grey-sided Vole, 7 Wood Lemmings and 4 Arctic Shrews. Thus catches averaged 5.06 animals per 100 trap-nights. Northern Pikas inhabited boulder areas at a high density.
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Rodent species recorded:
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| Latin | Abundance |
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| Clethrionomys rufocannus | rare |
| Clethrionomys rutilus | common |
| Microtus middendorffi | abundant |
| Myopus schisticolor | rare |
| Ochotona hyperborea | abundant |
| Sorex arcticus | rare |
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Summary
of fauna studies: |
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