|
|
RESPONDENT
|
|
Sergei Kharitonov
|
|
|
SITE NAME
|
|
Medusa Bay, Taimyr Peninsula, Russia
|
|
| Contact details
(phone/fax//e-mail//address): |
| (499)135-9802/(499)135-9802(fax) // serpkh@gmail.com // Bird Ringing Center, Moscow, 117312, Russia
|
|
PROJECT DETAILS |
|
Project name:
|
|
Nature monitoring
|
|
|
Start of survey:
|
End
of survey: |
Team
size: |
|
9.06
|
22.07
|
6
|
|
WEATHER
CONDITIONS
|
|
|
|
Weather conditions: |
| The season phenology was very early. Snow cover reduced to 20% at arrival on 9 June and to 10% by 14 June. Ice broke up on 5-6 June on the Medusa River, which is two weeks earlier than avarege. The highest day-time air temperature in the second half of June was +15øC, and the highest temperature for the season, +19.4øC, was recorded on 6 July. Precipitation was the most abundant in the second half of June, and July was colder than usual. The first cracks in the ice of Shirokaya-Severnaya Bay appeared on 29 June, and the bay surface was ice-free on 13 July similarly to the previous year.
|
|
|
|
|
|
| Date of 50%
snow-cover: |
end May
|
|
| Date of ice-break on
rivers: |
6.06
|
|
| Date of final loss of
snow: |
>14.06
|
|
BIOTIC
CONDITIONS
|
| Rodents abundance evaluation: |
high
|
|
|
Breeding conditions:
|
Arctic Foxes were unusually abundant, and an area of 175 km2 where maximum 5 dens had been previously found even in peak lemming years was inhabited by 20 breeding pairs, using both permanent dens and temporary shelterd near stones. Population of Arctic Hares remained at a low like in 2004, while numebrs of Ermines and Wolves started to increase. First migrating Reindeers were recorded near station on 17 July, and their numbers were even lower than in 2004. Cold weather in July resulted probably in low numbers of mosqitoes in the southern Taimyr, and reindeers were reluctunt to migrate far to the north.
Rough-legged Buzzards and Snowy Owls bred at a high density, with 41 and 22 nests in the 175 km2 area, respectively. Snowy Owls nested in average time, and had average clutch size 6.9 eggs. Pomarine Skuas were numerous, with 42 nests in a 19.4 km2 area. Breeding of Short-eared Owls was recorded.
In spite of high abundance of Snowy Owls reproductive success was low in Brent Geese due to very high numbers of Arctic Foxes. Only 39 nests were found on the mainland, all in sites with locally low numbers of Arctic Foxes. Brent Geese numbers decreased also on sea islands in the Shirokaya-Severnaya Bay where only 2 nests were found compared with on average 30 in other years. Reasons for decline on islands are not clear, but it could be that Arctic Foxes crossed the bay on ice when searching for food and reached the islands.
Waders nested very early, and the first nests of the latest breeder, Little Stint, were initiated approximately on 6-8 June. First chicks were found on 30 June in this species. Other waders and Pomarine Skuas started nesting approximately 10 days earlier than average. Nesting of waders was highly successful: 83.3% in Curlew Sandpiper (n=6 nests), 80% in Little Stint (n=82), 80% in Pacific Golden Plover (n=15), 66% in Temminck's Stint (n=3), 57.6% in Dunlin (n=13), 50% in Ringed Plover (n=2), and 0% in Turnstone (n=2). Apart of that we had 3 breeding females of Pectoral Sandpiper on the study plot, one of which was recorded later with young. Also two nests with eggs of Grey Phalarope were found.
|
|
|
Rodent dynamics:
|
| Lemming populations reached "super-peak" value in 2005, corresponding to very high abundance (rank 5). Given that the previous "super-peak" was in 1994, a 11-year cycle seems to be confirmed by this dynamics. Populations of both lemming species reached maximal value during winter and spring, while in summer a rapid decline was obvious. The decline was probably due to strong pressure by abundant predators attracted by numerous lemmings in spring, and to commencing epizooty (we found dead lemmings in tundra, sometimes in heaps). Declining numbers resulted in live-trapping esimates of densities similar to those observed in the previous year: in 2005 the average density of Siberian Lemmings was 17-18 animals/ha, while the density of Collared Lemmings was 3-4 animals/ha.
|
|
Rodent species recorded:
|
| Latin | Abundance |
|---|
| Lemmus sibiricus | abundant |
| Dicrostonyx torquatus | abundant |
|
|
|
Summary
of fauna studies: |
|
|
|