|
|
RESPONDENT
|
|
Alexander Artyukhov
|
|
|
SITE NAME
|
|
Vaamochka River delta, Koryak highlands, Russia
|
|
| Contact details
(phone/fax//e-mail//address): |
| 8(083)4124632 // // Sovetskaya St., 3-60, Kokino, Bryanskaya oblast, 243365, Russia
|
|
PROJECT DETAILS |
|
|
|
Start of survey:
|
End
of survey: |
Team
size: |
|
12.06
|
5.08
|
|
|
WEATHER
CONDITIONS
|
|
|
|
Weather conditions: |
| Snow remained only in several depressions by 12 June, as well as in bush thickets exceeding 1 m in height. Total snow-covered area did not exceed 5% on the plane and 20-40% in mountains, depending on exposure and steepness of slopes. The last extensive snowpatches have melted by early July. Middle-size lakes became ice-free on 12-18 June, but Verkhnee Vaamochka Lake completely cleared on 25-26 June. Minimal and maximal air temperatures ranged from +2.0-10.0øC and +10.0-24.0øC, respectively, during the study period. Prolonged rains, each resulting in 20-25 mm of precipitation occurred 3 times only: on 25-26.06, 28-29.06 and 31.07-1.08, while short-time rains were rare. Water table in rivers was low during summer, and many springs and lakes among moraine hills dried out. First snowfall occurred on 15.08 in the mountains. No weather anomalies of possible relevance to bird breeding success were observed.
|
|
|
|
|
|
|
|
| Date of ice-break on
rivers: |
|
|
| Date of final loss of
snow: |
|
|
BIOTIC
CONDITIONS
|
| Rodents abundance evaluation: |
low
|
|
|
Breeding conditions:
|
Red Foxes were common and bred very early, judging by the size and high activity of cubs (we inspected 3 dens and found 5, 6 and 7 cubs) in mid July, when they were going as far as 1 km from dens and attempted hunting of juvenile ground-squirrels. Adult Red Foxes were usually seen in vicinity of the best waterfowl nesting localities and geese moulting sites, apparently preferring bird eggs to rodents. Numbers of Brown Bears were high everywhere, in particular in river valleys and on the sea coast: up to 17 animals per 10 km of a spawning river valley in august. Bears wandered widely until mid July and often digging ground-squirrels out of burrows. Some bears were seen purposefully searching for nests of geese and ducks by moving along shores of waterbodies in a zigzag manner. A pair of bears undertook concerted searches for waterfowl nests on 16 June, when they plied along lake shore breaking through bushes with noise and eating eggs. Stomach of 4-year old male bear inspected on 29 June contained egg-shells of at least 30-32 eggs of Greater Scaup and Common Eider, 2 eggs and 3 downy chicks of White-fronted Goose, as well as some mosses, sedge and cotton-grass. Wolves were rare, and we saw 2 fresh tracks only.
Rough-legged Buzzards nested at a very low density and only in the near-by mountains, while wandering birds were rare. A single nest with 4 chicks was found. Gyrfalcon, Peregrine Falcon, Merlin, Golden Eagle and Short-eared Owl were all uncommon. White-tailed Sea Eagle was common only in vicinity of spawning rivers, and immature solitary birds prevailed in records. Arctic Skuas nested in small numbers, but were more common than Long-tailed Skuas among wandering birds. Several tens of Herring Gulls nested in colonies on islands of Verkhnee and Nizhnee Vaamychgyn lakes, while Common Gulls inhabited primarily lower parts of river deltas. Most of gull nests on lake shores and near-by islands were destroyed by Red Foxes and Brown Bears.
Ravens were common, but a small fraction of them bred. They were seen destroying nests of ducks, geese and Sandhill Cranes, in particular after flashing of incubating birds by humans.
Nesting period was prolonged in most waterfowl. Considerable number of late and presumably replacement clutches of divers and Red-necked Grebes were also destroyed primarily by Herring Gulls. White-fronted Geese nested in similar dates as in 2001 and at slightly lower density. At least half of their nests were predated primarily by Red Foxes and Brown Bears. Wandering and nesting Emperor Geese were very uncommon, very few nests survived to hatching and only several broods were seen. 2-3 pairs of Whooper Swans and a pair of Bewick's Swans presumably did not nest. Pintails were the most numerous among dubbling ducks and bred successfully, although loss of clutches was considerable. European Wigeon and Teal successfully nested in small numbers in willow thickets. Northern Shovelers were rare and, probably, did not breed. Among sea ducks pressure of terrestrial predators was particular heavy on clutches of Common Eider, Melanitta americana and especially the most numerous Greater Scaup, as their nests were located in a narrow belt of grass along lake shores. While generally uncommon Long-tailed Duck and Surf Scoter bred successfully.
Numbers of most wader species were not high, but they bred successfully. Broods of Pacific Golden Plover, Lesser Sand Plovers and Red-necked Stints were often seen in August on slopes with dry shrub tundra and lichen tundra. Broods of Ringed Plovers were common on gravel shores of rivers and lakes, while Wood Sandpiper, Dunlin, Red-necked Phalarope and Common Snipe nested with fair success in cotton-grass-moss tundra in river deltas. Clutch loss in Red-necked Phalaropes was the highest as they often nested close to lake shoreline frequented by Red Foxes and Brown Bears.
Generally, breeding conditions were good for most birds with exception of rodent-specialized predators, while breeding success was average to good with exception of Emperor Geese, Herring and Common gulls which suffered heavy predation.
|
|
|
Rodent dynamics:
|
| Lemmings were not observed, and very few winter tracks of rodents were seen, which indicated low rodent numbers since autumn 2002. Summer numbers of voles were very low, while numbers of pikas (in stony tallus of the mountains) and shrews were low, but considerably increased by the end of summer in the case of shrews. Arctic Ground Squirrels were abundant on plain and in mountains, they bred with high success and became very numerous by the end of summer, in particular in vicinity of Verkhnee Vaamychgyn Lake.
|
|
Rodent species recorded:
|
|
|
|
|
Summary
of fauna studies: |
|
|
|