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RESPONDENT
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Mikhail Soloviev
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SITE NAME
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Verkhnyaya Taimyra River mouth, central Taimyr Peninsula, Russia
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| Contact details
(phone/fax//e-mail//address): |
| (495)9394424 // mikhail-soloviev@yandex.ru // Dept. of Vertebrate Zoology, Biological Faculty, Moscow State University, 119992 Moscow, Russia
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PROJECT DETAILS |
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Project name:
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Wader Monitoring Project on Taimyr
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Start of survey:
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End
of survey: |
Team
size: |
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11.06
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15.08
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4
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WEATHER
CONDITIONS
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Weather conditions: |
| Snow disappeared from 50% of the tundra surface on 20.06 and completely on 25.06. Ice on rivers broke up on 28.06. Summer did not differ notably from the previous 10 years in respect to the total number of days with precipitation observed during study period. However, only 4 days with precipitation occurred from 11.06-15.07, which is half of the value in the next closest season with 8 days (1997, when it was likely underestimated due to the late start of studies). In contrast, second half of July and early August were rather wet in 2004. The frequency of rains and amount of precipitation in the latter period were not high enough to have an apparent adverse impact on bird reproduction. Thus, late start of the season in 2004 was compensated by extremely low precipitation in prenesting period and during incubation, average temperatures during July and absence of extremal events.
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| Season temperature: |
average
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| Date of 50%
snow-cover: |
20.06
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| Date of ice-break on
rivers: |
28.06
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| Date of final loss of
snow: |
25.06
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BIOTIC
CONDITIONS
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| Rodents abundance evaluation: |
low
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Breeding conditions:
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Two inhabited dens of Arctic Foxes have been found in the study area. Arctic Foxes bred successfully and juvenile animals were observed in August. In total seven nests of Long-tailed Skuas were found in the whole study area of 87 km2, but this can represent an underestimate of true density, because 5 nests were found in the most intensively surveyed area of approximately 15 km2 in the vicinity of field camp. Chick hatched in a single nest of three with known fate. A single nest of Arctic Skua was found in the whole study area, but breeding of one more pair remained unconfirmed, while fate of the found nest was not determined. Migrating Pomarine Skuas were seen daily from arrival on 11.06-8.07, while after these dates only several birds were seen until departure on 15.08. Six nests of Glaucous Gulls and three nests of Herring Gulls have been found in a small area of about 2 sq.km on Bolshoy Island in the network complex of ponds in polygonal bog. A single nest with known fate of the former species was successful.
Snowy Owl did not breed, and was very rare - with solitary records in June and July. In total 3 records of Peregrine Falcons have been made in June and July. Six nests of Rough-legged Buzzards were found in the study area, and two more nests on the northern bank of the Verkhnyaya Taimyra River. Chicks hatched in all but one nest, including 3 nests containing 2 chicks, 1 nest with 3 chicks and 1 nest with 4 chicks.
Abundance of Arctic Hares was very high at least locally - up to 20 animals were seen simultaneously on the remains of first river terrace on Bolshoy Island. Tracks of wolf was seen twice in July on the river bank, and ermine was seen once also on the river.
From arrival on 11.06 reindeers were seen as solitary animals or in small flocks almost daily. They appeared in high numbers on 18.07, and at least 10000 animals passed through the area on 19.07. The flocks of thousands still occurred in the vicinity on 20-23.07, and then these thousands moved south or southeast on 26.07. Flocks of hundreds were observed from 27.07-4.08, and then abundance dropped to flocks of tens or single animals in different places. While chicks had hatched in most nests by 19.07, 30% of still remaining nests with eggs were trampled by migrating reindeers. The loss of chicks could not be evaluated, but it was probably of a similar magnitude to loss of eggs.
Thus, numbers of Arctic Foxes, skuas, large gulls, owls and birds of prey in the study site on Central Taimyr in 2004 were low and rather close to numbers recorded on southeastern Taimyr in 1994-2003. Numbers of Rough-legged Buzzards were apparently higher in the new study site, presumably due to lack of disturbance by humans which had been intensive in areas along river banks on southeastern Taimyr. It is not clear currently whether low numbers of other birds of prey and owls on Central Taimyr belonged to specific features of the site or were related to late spring in 2004.
Among nesting geese White-fronted were abundant, while Red-breasted and Bean rare. Up to 4500 of White-fronted Geese and small numbers of Red-breasted Geese were moulting in the western part of the Verkhnyaya Taimyra River delta.
The density of waders in the floodplain in 2004 (149.5 nest/sq. km) was the record highest found anywhere in the Russian Arctic. Little Stints with a density 49.8 nest/sq.km were mostly responsible for high abundance of waders. Grey Plover, which had never previously been considered a typical floodplain species, nested in floodplain of the Bolshoy Island at a density 12.5 nest/sq.km, which is the highest value ever recorded for this species.
Breeding records of Redwing, American Pipit Anthus rubescens, Willow Warbler and Ross's Gull in the area expand ranges of these species northward.
Apparent nest success was average in waders (51.5%, n=136) and other non-passerine birds (64.0%, n=25). Nest success of Dunlin (87.5%, n=16), Pectoral Sandpiper (77.8%, n=9), Grey Phalarope (73.3%, n=15) and Ruff (66.7%, n=12) was above the average for waders combined, while Little Stint (50.0%, n=26)and Curlew Sandpiper (50.0%, n=12) were very close to the group average. Breeding performance of Pacific Golden Plovers and Grey Plovers was very low with 1 and 3 nests successful from 19 and 18, respectively. Most nests were lost due to predation, and, probably, primarily by Arctic Foxes, as avian predators were rare overall. Generally, overall nest survival in 2004 was similar to survival in other years, when lemming numbers were low, but still sufficient to support reproduction of Arctic Foxes at low density. Foxes managed to find lemmings, but also did not ignore bird clutches, which resulted in moderate predation pressure.
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Rodent dynamics:
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| In total 47 lemmings were seen by 4 observers in 2004, including 34 Siberian Lemmings, 1 Collared Lemming, and 12 lemmings which were not identified. Abundance of lemmings in 2004 was apparently closer to the low range of values observed from 1994-2003 at southeastern Taimyr. On completion of snow-melt, on 25.06, lemming undersnow nests were counted on a transect, located on slopes of first river terrace and watershed slopes. In total 7 nests were recorded per 4.0 km, which is a low number.
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Rodent species recorded:
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| Latin | Abundance |
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| Lemmus sibiricus | rare |
| Dicrostonyx torquatus | rare |
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Summary
of fauna studies: |
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