Birds and Mammals of the Lena Delta Nature Reserve, Siberia
Keywords:birds, densities, distribution, Lena Delta, mammals, predation, Siberia
The Lena Delta is the largest arctic delta covered entirely by tundra. Protected since 1986, it is one of the richest areas in the Arctic north of 71° N for both species diversity and breeding densities. Between 6 June and 17 August 1997, 16 mammal species and 76 bird species were recorded in the Lena Delta Nature Reserve and the surrounding buffer zone. Several species are new to the region: far-eastern curlew, fieldfare, redwing, arctic warbler, red-breasted flycatcher, and common rat. New breeders are merlin and arctic warbler. These 1997 records, combined with those from earlier studies, give a total of 122 bird species for the region. Of these, 67 have been found breeding at least once. Densities ranging from 245 to 641 birds per km² were recorded in two restricted study areas. Such densities are unusually high north of 70° N for non-colonial breeding birds. Lapland longspur (100-300 individuals/km²), red phalarope (up to 200 ind./km²), and several Calidris species were the most common. Ruddy turnstone and dunlin had densities higher than those previously reported from the Lena Delta and other Siberian sites. Among the shorebirds, spotted redshank, pintail snipe, grey plover, dunlin, and curlew sandpiper may have extended their breeding range or increased in population during the last 15 years. But further evidence is still needed to confirm the westward extension of spectacled eider, long-billed dowitcher, and sharp-tailed sandpiper.