Abstract
Three separate populations of wild reindeer (Rangifer tarandus tarandus L.) in Norway were examined for the presence of abomasal nematodes. The following six species were recorded: Ostertagia grühneri, Skrjabinagia arctica, Trichostrongylus axei, Teladorsagia circumcincta, Teladorsagia davtiani, and Nematodirus tarandi. Ostertagia grühneri dominated both in prevalence and intensity of infection. Teladorsagia davtiani occurred in only one of the populations investigated, and N. tarandi was found in calves only. Reindeer and sheep grazed the same areas, but no evidence of transfer of parasites from sheep to reindeer was found. All 72 adult reindeer and 10 calves examined during February–April harboured adult abomasal nematodes. The mean intensity of abomasal nematodes was highest in the population with the highest density of reindeer. Reindeer from this population were in poor physical condition. The influence of abomasal nematodes on life-history parameters of the host population is discussed.