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RESPONDENT
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Nikolay Yakushev
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SITE NAME
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Meinypylgyno settlement vicinity, Chukotka, Russia
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| Contact details
(phone/fax//e-mail//address): |
| 8(8452)515738 // taksidermia@yandex.ru // Zoological Museum, Biological Faculty, Saratov State Univ., Astrakhanskaya 83, Saratov, 410012 Russia
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PROJECT DETAILS |
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Project name:
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Arctic Expedition of the Russian Academy of Sciences
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Start of survey:
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End
of survey: |
Team
size: |
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14.06
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25.07
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2
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WEATHER
CONDITIONS
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Weather conditions: |
According to local reports snow accumulation was low in winter, and spring was early in timing, with a rapid snowmelt. Snow completely melted on flat surfaces by the start of our studies on 14 June, but it was present until 20 June on slopes lying in shadow and in depressions. Ice cleared on the rivers before the start of observations, and on Pekulneiskoe Lake by 14-15 June.
The second half of June was warm and sunny with less than 5 days of dull weather. Mean monthly day-time temperature was +12°C in June. Short-term thunderstorms occurred on 24 and 25 June. Dull weather occurred on 15 of 25 days in July, but generally the month was warm with mean day-time temperature +16°C. Sea fog occurred frequently, but not on all days of the study period. No wind occurred on 3 days, while moderate and occasionally strong south-western and southern winds were recorded on other days. The entrance channel from the sea to the lagoons was blocked during autumn storms, which resulted in an unusually high water level in the rivers and lakes in mid June. The water level continued to increase until 21 June and reached approximately 2 m above average. A rapid decrease of water level continued from 21 June to mid July, after a new channel has been excavated. The resulting situation was unusual because areas in the vicinity of the lakes and lagoons were flooded or very wet, while dry conditions prevailed elsewhere due to the small amount of precipitation during the winter.
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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: |
low
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Breeding conditions:
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Red Fox was recorded once, 10 km to the north of the settlement in moraine hills. Brown Bears were regularly seen on coastal spits and in moraine hills, including close to the vicinity of the settlement. Bears fed primarily on last year berries of Crow-berry and Clusterberry and on Ground Squirrels before the period of mass spawning of salmons, but then most bears switched to fish. The number of bird clutches destroyed by bears was lower in 2007 than in previous years, but this was due to the low numbers of breeding birds rather than to a decreased activity of predators. Ermine took an incubating Spoon-billed Sandpiper and its clutch, as indicated by casts in the nest.
Breeding of birds of prey was not recorded. We rarely observed solitary Golden Eagles, juvenile White-tailed Eagles were recorded twice, Peregrine Falcons twice and Gyrfalcon once. Arctic Skuas were rare on spits before early June, and a single breeding record was made in moraine hills. Arctic Skuas became more common on spits after the mass hatching of chicks in Ringed and Mongolian plovers, and these skuas were observed catching chicks of Dunlin, Red Knot and Ringed Plover. Long-tailed Skuas were tenfold less abundant than Arctic Skuas, and they did not breed. Large gulls were numerous and occurred everywhere, breeding on the islands of Vaamychgyn and Pekulneiskoe lakes and at marginal areas of sea spits. Herring, Glaucous and Slaty-backed gulls occurred at an approximate ratio of 10 : 2 : 1. Gulls nesting on islands suffered from egging by humans, while all their clutches at the marginal areas of spits were destroyed by bears. Ravens nested successfully in the settlement and in moraine hills.
Sandhill Cranes were numerous in moraine hills, but rare on spits, where only two broods were recorded. White-fronted Geese were common in moraine hills and chicks successfully hatched, even close to the settlement. Broods contained 1-3 chicks, but their survival was not evaluated. Among ducks, breeding was indicated by observations of broods in Pintail, Greater Scaup and Common Eider. Predation pressure on eider clutches was high as usual, on sea spits primarily due to skuas and large gulls and near settlement due to humans and dogs. White-winged and Black scoters did not breed on spits due to the high water level.
Well flying juveniles of the Skylark were recorded. Numbers of this species increased tenfold compared with 2005, and it was possible to record up to 5 singing males from one point at a southern border of the moraine. Two breeding cycles could be expected in the Skylark at southern Chukotka. Successful reproduction was recorded in White Wagtails, Wheatears, Snow and Lapland buntings. The breeding success of Common Redpolls was not evaluated.
Wader numbers were generally lower than in 2005, which could be due to different hydrological regime in the beginning of the summer. The decrease was the least pronounced in species not associated with the waterbodies of the lake-river system. Thus, Dunlins were common and locally abundant in moraine hills, and Ringed Plovers were common as usual on spits. Breeding numbers of Pacific Golden Plovers and Mongolain Plovers did not change considerably, and at least 3 pairs of Red Knots nested. The abundance of Red-necked Stints increased, and nests of this species were found both in moraine hills and in depressions between hillocks on gravel spits.
A decrease in the number of breeding pairs was recorded in the Red-necked Phalarope, and one nest of the latter species was found in an unusual locality - in the centre of a 20-30 cm high willow scrub. Breeding numbers of Spoon-billed Sandpipers halved, and some territories which were flooded until the end of June were not occupied or were used for nesting with a two-week delay. Chicks hatched at the usual dates only in pairs nesting in the close vicinity of the settlement or in moraine hills. In some cases Spoon-billed Sandpipers nested in more damp habitats than normal, with higher and denser vegetation. In such a habitat a predation of incubating Spoon-billed Sandpiper by Ermine was recorded, and a destroyed nest of Red-necked Phalarope was also found 10 m away. Wood Sandpipers did not nest, and a single Temminck's Stint was observed in the beginning of the breeding season. Flying juveniles were recorded in the Ringed Plover, Dunlin and Red Knot, while chicks of other wader species had not fledge by the end of the studies on 25 July.
Generally, conditions were unfavourable for breeding of birds in 2007, primarily due to the unusual hydrological regime. This caused reduction of area of habitats suitable for breeding of several species (Spoon-billed Sandpiper, White-winged and Black scoters). Also the flooding, probably, resulted in decreased numbers of voles and, to a lesser extent, of Ground Squirrels and an associated increase of predation pressure on birds. Hence, low survival of juveniles occurred in numerous species of birds. As usual, birds, their eggs and chicks were preyed upon by Arctic Skuas and Ravens. Eggshells of over 40 eggs belonging to 6 species of waterfowl were found under one nest of Ravens.
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Rodent dynamics:
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| Lemmings were not recorded, and voles were rare, particularly, in willow stands on river banks, exposed to flooding. Numbers of Arctic Ground Squirrels were high, both on coastal spits and on moraine hills, but were considerably lower than in previous years, especially in areas adjacent to the lake-river system. As previously, Ground Squirrels were an important prey for Brown Bears, Red Foxes, gulls and Ravens.
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Rodent species recorded:
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Summary
of fauna studies: |
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