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SITE NAME
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Cape Vostochny, Piasina delta, Taimyr, Russia
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| Contact details
(phone/fax//e-mail//address): |
| +31 317 478729/+31 317 419 000 (fax) // bart.ebbinge@wur.nl // Alterra, PO Box 47, NL-6700AA, Wageningen, The Netherlands
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PROJECT DETAILS |
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Project name:
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Alterra-Heritage Institute - Pyasina Delta 2006 Expedition
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Start of survey:
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End
of survey: |
Team
size: |
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02.06
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15.08
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9
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WEATHER
CONDITIONS
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Weather conditions: |
| Snow covered 98% of flat surface on 3 June; it reduced to 50% by 14 June and completely melted by 29 June. Ice disappeared from Lidia Bay between Cape Vostochny and offshore islands on 3 July. Snowfalls did not occur after 15 June. The season was cold in early July, warm after 20 July and dry.
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| Date of 50%
snow-cover: |
14.06
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| Date of ice-break on
rivers: |
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| Date of final loss of
snow: |
29.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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Almost no Arctic Foxes were seen with just a few individuals now and then. In June and July all old fox dens were inspected, but no sign of breeding animals was found. Few fresh tracks of wolves were found, but animals were not seen. Reindeers were seen early in June near Mys Vostochny, at a maximum of 10 in a group. In late July/early August single animals were seen in vast plains of the Pyasina Delta.
In summer we frequently checked all nests of waders and passerines in the same area as in 2004 and 2005 to record nest fate. All nests were mapped by a gps. Small numbered sticks were placed exactly 10 meters northwards of each nest. Nest success was estimated according to the Mayfield method (Mayfield 1975). For the Little Stint and Curlew Sandpiper we counted 541,5 nest-days and 15 predated nests. Assuming an incubation period of 21 days, the probability that a nest will survive one day was 97% and the probability that a nest would survive the entire 21 nesting days was 56,3%. This is rather high for a season after a lemming peak year (2005). This surprisingly high nest success could be the result of very low fox numbers in our study area. However, on 4 July also flocks of Curlew Sandpipers that had apparently given up nesting were observed on Farwaterny Island. Snowy Owls were sometimes seen trying to catch adult Little Stints and also catching chicks of gulls and even adult King Eider females in the study area. Pomarine Skuas and Long-tailed Skuas were only recorded in early spring but soon left. Two nests with eggs of Arctic Skuas were found outside of the study area. Compared to other years Grey Phalaropes were nesting in exceptionally high numbers, but again, many of these assembled in flocks in late June, apparently having given up breeding. Contrary to 2005, when many Ruffs were displaying, they were hardly seen during spring migration in 2006, and were abundant migrants only in August. Gulls were regularly seen on the tundra and are probably the main egg predators. Least Weasels, an abundant and often seen predator in 2005, were absent in 2006. On the mainland tundra hardly any Greater White-fronted Geese were nesting, but on Farwaterny Island many nests of Greater White-fronted Geese were found, most of which hatched successfully, despite the presence of 1-2 Arctic Foxes on this large island. Brent Geese hardly raised any young due to high predation pressure by Taimyr Gulls. The low but increasing number of Red-breasted Geese nesting on Bird Islands were more successful and did raise some goslings successfully.
In the end of July, when hatching started, the weather was favourable, even quite warm.
About 92.000 White-fronted Geese were moulting on a surveyed stretch of 89 km of streams in the delta, while their total number in the Pyasina Delta was probably 500,000-1,000,000. We also observed not less than 7000 moulting Brent Geese, 11 Barnacle Geese and 30 Bean Geese.
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Rodent dynamics:
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Siberian Lemmings were not seen at all, except for one observation of only one live lemming in July. Intensive trapping yielded not a single caught lemming.
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus sibiricus | rare |
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Summary
of fauna studies: |
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