Pneumostrongylus tenuis in Moose on a Deer-Free Island

Abstract

Analysis of fresh moose (Alces alces) feces from Isle Royale, Michigan, a deer-free island in Lake Superior, and northeastern Minnesota, an area with a low white-tailed deer (Odocoileus virginianus) population, revealed incidences of 0.8 and 0.6 percent respectively of the first-stage larva of Pneumostrongylus tenuis, the etiological agent of cerebrospinal nematodiasis in moose. The report of this parasite is from an area that has been deer-free for 30 years. The common host of the nematode Pneumostrongylus tenuis is considered to be the white-tailed deer. The parasite is now recognized as the etiological agent of cerebrospinal nematodiasis in moose (Anderson 1964). Infection is often fatal to moose, and heavy mortality has been recorded in areas where deer are abundant (Anderson 1965a, Karns 1967, Smith et al. 1964). Anderson (1965a), finding no record, raises the ques1 Joint contribution of Minnesota Division of Game and Fish and Purdue University. Field work receiving principal support from the National Science Foundation (GB-5124), the National Geographic Society, and the National Park Service: D. L. Allen, project director. Purdue University AES Journal Paper No. 3377. tion of whether this parasite can exist independently of white-tailed deer. Isle Royale, Michigan, lies 12 miles from the nearest off-shore islands and 15 miles off the north shore of Lake Superior. Woodland caribou (Rangifer tarandus) were present on the 210-square-mile island at one time and disappeared about 19'25 (Mech 1966:16). Mech and others felt that moose immigrated to the island from the mainland in the early 1900's. Twelve white-tailed deer were introduced in 1906, and may have persisted until about 1936 (Johnsson and Shelton 1964). All that we can assume about the growth and continuity of the introduced deer population is that deer were present ether this parasite can exist intl of white-tailed d er. ale, ichigan, lies 12 miles from This content downloaded from 157.55.39.102 on Mon, 03 Oct 2016 04:08:52 UTC All use subject to http://about.jstor.org/terms 432 Journal of Wildlife Management, Vol. 33, No. 2, April 1969 Table 1. Summary of moose fecal samples collected from Isle Royale, Michigan, and examined for first stage larvae of Pneumostrongylus tenuis. FECES FROM WOLFRANDOM FECES KILLED MOOSE COLLECTION COLLECTION Larvae Larvae Larvae Larvae PEmOD Present Absent Present Absent