Current state of forage resources and feeding of reindeer (Rangifer tarandus) and musk oxen (Ovibos moschatus) in the arctic tundras of Wrangel Island

Abstract

The species composition and aboveground biomass of plant and lichens and the composition of reindeer and musk ox diet in the arctic tundra of Wrangel Island were studied in 2004 to 2007. The above-ground phytomass in different areas of the island varied from 1105 to 2100 kg/ha. The composition of plants consumed by reindeer and musk oxen and their proportions in the diet were determined by standard micro-histological analysis of plant remains in their feces. The results showed that, either in winter or in summer, both species obviously preferred feeding on willows (Salicaceae), which comprised almost half of their diet. Moreover, their feeding was highly selective, especially with respect to sedges and rushes (Cyperaceae + Juncaceae) and legumes (Fabaceae). Although the contributions of these plant groups to the total aboveground phytomass were very small (less than 4 and 8%), their proportions in the diet reached 27 and 24%, respectively. Mosses were not a preferred forage: their proportion in the aboveground phytomass reached 40%, but that in the diets of both species was below 10% in summer and increased to 20% only in the winter diet of reindeer. At a high abundance of lichens (up to 20% of the aboveground phytomass), neither of the animals consumed them during the study period.