Climate Fact: Musk Ox Parasites and Warming
In the Canadian Arctic, Musk Oxen endure the long winters and short summers that characterize one of Earth’s most extreme environments. The animals have spent millennia adapting to the brutal cold, but now increases in temperature are presenting new problems. A parasitic species of nematode dwells in the musk oxen lungs and too many nematodes can inhibit respiration in the oxen making them more vulnerable to predators. The nematodes have a larval stage in slugs that live on the tundra and require a certain amount of heat to reproduce and move from larvae to adult. Traditionally, the cold has made it difficult for an adult nematode to reproduce each year and instead they would only reproduce once every two years. From the late 1970′s to 1990, temperatures were generally not warm enough to allow the nematodes to reproduce every year. Around the late 1980′s however, a threshold was reached and from 1990 to 2003 the nematodes reproduced most years and their populations expanded both in number and range. A 50 percent decline in the study area’s musk oxen population was observed from 1988 to 1994.
Seasons: Winter, Spring, Summer, Fall
Source: Kutz, SJ et al. “Global warming is changing the dynamics of Arctic host-parasite systems.” Proceedings of the Royal Society B 272 (2005): 2571-2576.
