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RESPONDENT
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Vasili Baranyuk
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SITE NAME
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Tundrovaya River valley, Wrangel Island, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (095)441-12-16 // vvbar@vvbar.msk.ru // Lomonosovsky Pr., 35-40, Moscow, 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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WEATHER
CONDITIONS
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Weather conditions: |
| Air temperatures increased notably in the second half of May, which indicated early spring on Wrangel Island. In contrast, the same time of warming in Pevek town vicinity, north-western Chukotka, corresponded to spring delay of 7-10 days. During our helicopter trip from Pevek to Wrangel Island on 23 May we noted that phenological events were more advanced on the island compared with mainland coastal areas north-east of Pevek. Hill slopes to the east of Pevek were completely snowcovered, and water was not present in rivers and streams. At the same time, snow patches remained only in depressions and valleys of rivers and streams on the southern coast of Wrangel Island and water was running in many rivers and streams, in particular already for several days in the Somnitelnaya River. Snow cover was more extensive in the central parts of the island. In the area of Snow Geese colony snow cover reduced to 50% very early, on 24 May and the Tundrovaya River started to run; both warm weather and low accumulation of snow during the winter favoured for that. Rain occurred on 27 May for the first time that early in many years. Frosty weather established from 29 May to 4 June, which did not affect considerably numbers of breeding geese, but delayed at almost one week mass arrival of waders and their distribution through breeding grounds. June, July and August were generally cold, sometimes with freezing air temperatures, snowstorms and snow on the ground.
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| Date of 50%
snow-cover: |
24.05
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| Date of ice-break on
rivers: |
24.05
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| Date of final loss of
snow: |
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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Breeding phenology of Snow Geese at the Tundrovaya River colony was one week earlier than average in 2006. Geese arrived en mass to the colony area on 24-25 May, first nests were initiated on 24 May, and the peak of nest initiation occurred on 29-31 May. Of all clutches only 4% remained incomplete by 7 June. Hatching started at night on 21-22 June in geese, which was earlier than the average (June 27 for the period from 1970-2004). First broods started to leave the colony already on 22 June, moving to the northern plain, which bears the name Tundra of Academy.
The first fledglings were recorded in early August, and all juvenile geese were able to fly by 10 August. Mass departure of geese with broods was observed on 14-17 August on the southern coast of the island, which was one week earlier than in 1980s.
Three Snowy Owl nests were found in the vicinity of the main geese colony. Pomarine Skuas were rarely seen there, they stayed in the first half of June mostly in areas with remaining snow patches where lemmings were wintering.
Arctic Foxes were rare in the area of the main geese colony, but one pair bred. The area was frequented by wolves in spring and summer, which apparently resulted in the absence of Muskoxen during geese breeding period.
Density of breeding Snow Geese was high and relatively uniform across the colony area of 875 hectares. According to ground transect counts 46,600 nests (or more than 93,000 geese) were present in the main colony in the Tundrovaya River valley. Mean clutch size was 4.05ñ0.03 (n=737). Proportion of nests with at least one egg hatched was 87.7% (n=40,850), mean brood size was 3.74ñ0.06 (n=510) at departure from the main colony, and the total number of departing chicks exceeded 150,000. According to transect counts only 70 birds perished from predators and diseases at the colony, which represents 0.07% of all breeding geese. This very low value indicated both low predation pressure and low liability to diseases in 2006. Generally reproduction of geese was successful and proportion of juveniles on wintering grounds was approximately 25%. Accordingly, Wrangel Island population of Snow Geese continued to grow, and we predict that its number will reach 140,000 birds by spring 2007.
Turnstone and Dunlin were common among waders regularly breeding in the study area. The Red Knot and Grey Plover occurred in lower than usual numbers, while observations of Pectoral Sandpipers were solitary, and they probably did not breed.
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Rodent dynamics:
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| Lemming numbers were low across most of the island, including area of the main colony. However, some growth occurred after the low stage in 2005, and Snowy Owls bred.
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Rodent species recorded:
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Summary
of fauna studies: |
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