Dynamics of radionuclide concentrations in calcified tissues of reindeer in the western Russian Arctic

The specific activities of artificial and natural nuclides were determined in bone and teeth of reindeer that had lived before, during, and after nuclear tests on the Archipelago Novaya Zemlya and of reindeer from the nearby mainland region. In bone of reindeer from Novaya Zemlya, 90Sr and 210Pb are the main source of beta-activity, the 210Po is the main source of the alpha activity. In bone of reindeer that lived on Novaya Zemlya during underground tests, the 90Sr activity was relatively high (0.75 +/- 0.20 Bq/g dry weight). In animals that lived after the tests were banned, the level was significantly lower (0.44 +/- 0.17 Bq/g) and did not differ from the level of the 90Sr activity found in the mainland reindeer bone. On Novaya Zemlya, the concentrations of the natural 210Pb in bone of the recent reindeer (0.57 +/- 0.19 Bq/g) is similar to that which was in the teeth of reindeer a hundred years ago (0.65-0.75 Bq/g) and significantly higher than in the recent mainland reindeer from different regions (0.18-0.17 Bq/g).     

The gyrfalcon, <Emphasis Type="Italic">Falco rusticolus</Emphasis>, in the Yamal Peninsula: Dynamics of brood size and nest size over the years 1973–2008

The gyrfalcon in the Yamal Peninsula nests mostly on trees. The average brood size in this species decreased from 3.1 nestlings per active nest (n = 28) between 1973 and 1989 to 2.2 (n = 22) between 1998 and 2008. This decrease is probably explained by switching to the habit of using mostly smaller nests (built by the rough-legged buzzard, raven, or hooded crow) instead of large nests built by the white-tailed eagle. The survival rate of gyrfalcon nestlings in smaller nests is considerably lower: the average brood size is only 1.6 (n = 12), compared to 2.5 (n = 20) in medium-sized and 3.0 (n = 34) in large nests. The possible role of increase in snow cover density caused by climate warming in making large nests less accessible to the gyrfalcon is discussed.