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RESPONDENT
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Mikhail Soloviev
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SITE NAME
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Bludnaya River mouth, Taimyr, 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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20.06
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24.07
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2
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WEATHER
CONDITIONS
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| Season phenology: |
average
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Weather conditions: |
Observations were carried out from 20 June to 24 July in the area of approximately 65 km2, where studies had been carried out in the framework of the Wader Monitoring Project in 1994-2003. The study area is situated at the border of the typical and southern tundra subzones. A majority of quantitative data on fauna, distribution and numbers of birds were collected on 6 study plots with a total area of 268 hectares.
Mean monthly air temperatures in the study area were -3.6°C, +6.1°C and +10.0°C in May, June and July respectively in 2008, compared with the long-term average of -6.0°C, +5.7°C and +11.6°C. Thus, May was considerably warmer than average in 2008, June slightly warmer, and July considerably colder. The beginning of the study period in June was characterized by variable weather, which ended on 27 June with heavy rain. Precipitation occurred on most days until 7 July, including snowfalls on 30 June, when air temperatures dropped to +0.8°C and strong wind occurred. The weather improved on 8-9 July, but then rains occurred for 3 days in a row. The remaining period from 13 to 25 July was relatively warm, although temperature dropped on days with precipitation. The total amount of precipitation during the study period was 22.4 mm, which is very close to the median (21.4 mm; range 11.8-29.8 mm) for the same period in the years 2003-2008, when quantitative assessment of precipitation was conducted. The number of days with precipitation was above average in the study period in 2008. Our late arrival to the study area did not allow us to assess date of snow melt at 50% of the flat surface, but the snow completely melted by 24 June. This was a relatively late date for south-eastern Taimyr, which we can only explain by high accumulation of snow during the winter. Dates of flowering of early plants in 2008 were very close to the long-term average. The first mosquito was recorded slightly earlier than average in 2008, but mass appearance of these insects, and, in particular, imago of crane-flies (Tipulidae), was considerably delayed, apparently by cold and windy weather in late June and early July. Snowfalls on 30 June and rains in July had no apparent adverse impact on breeding birds. The flood was very low in 2008, and most of the middle floodplain of the Bludnaya River was not covered by the water.
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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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Arctic Foxes did not breed in the study area in 2008, but their abundance was the highest on record during 11 seasons of observations. Rough-legged Buzzards, Merlins, Gyrfalcons, Pomarine Skuas and Long-tailed Skuas were rare non-breeders in the area. This was the second year since the start of observations in 1994 when nesting of Long-tailed Skuas was not confirmed in this study area. Owls were not recorded. Arctic Skuas bred at a typical low density (0.07 nests/km2). Chick hatched from one of two nests found, and the fate of another nest remained unknown. A nest of Peregrine Falcons with 1 egg was found on 20 June by I.N.Pospelov on the bluffs of the Popigay River 8.5 km to the north-east of our camp. Three nests of Herring Gulls were spread in the area, at distances 2.2, 4.1 and 5 km from each other.
Breeding phenology was close to the long-term average in Dunlins, Pectoral Sandpipers and Lapland Buntings, but considerably delayed in Grey Phalaropes. Breeding density of waders was considerably below average in 2008 at the main study plot on the river terrace, the lowest on record at the watershed plot and the second highest on record in the floodplain. High density in the floodplain can be explained by the absence of flooding in this habitat, which probably increased its attractiveness to Grey Phalaropes. The abundance of the Lapland Bunting was unusually high everywhere.
Nest success of waders in 2008 (48.5%) was close to intermediate values. It was lower than in all the years since 2000, but not as low as in typical seasons with heavy egg predation. Hatching success of passerines and non-passerines (other than waders) was below average, but still closer to the intermediate than low range of values. Thus, despite the apparently low abundance of lemmings and record high abundance of Arctic Foxes, depredation of bird clutches was moderate. This could have been due to some extent to the very low numbers of avian predators (2 pairs of Arctic Skuas in the whole study area and the absence of breeding Long-tailed Skuas), but the low predation pressure by Arctic Foxes is still difficult to explain. In respect to the nest success of individual species of waders it is noteworthy that the variation between species in 2008, was the highest ever recorded for the study site on south-eastern Taimyr. Among common species of waders nest success ranged from 18.2% in Little Stints to 66.7% in Grey Phalaropes.
Interesting observations of birds included the first breeding record of the Raven, whose nest was found on wooden remains of an old light-house; this is the northernmost breeding record of this species in Eurasia (72°55'N).
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Rodent dynamics:
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| Lemming abundance was low in 2008 as was the density of lemming undersnow nests. Most lemming observations (14 animals) were made immediately after our arrival in the study area, in the period 20-28 June, and only 3 lemmings were observed during the following 3 weeks of July. As usual in the study area Siberian Lemmings were more numerous than Collared Lemmings with 12 of 17 identified animals belonging to the former species.
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Rodent species recorded:
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Summary
of fauna studies: |
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