High Prevalence of Leucocytozoon Parasites in Nestling Northern Goshawks (Accipiter gentilis) in the Northern Great Basin, U.S.A.

Document Type


Publication Date





The Northern Goshawk (Accipiter gentilis) is currently listed as a sensitive species by the U.S.D.A. Forest Service. Previous research in our study area, the South Hills of the Minidoka Ranger District of the Sawtooth National Forest, Idaho, identified possible signs of parasite infections among the banded adult and nestling goshawks, which could influence their survival and breeding success. Therefore, we sought to quantify the prevalence and intensity of Leucocytozoon parasites among a sample of nestling goshawks in the South Hills during the 2012 breeding season. We sampled 27 nestlings from 12 nests for Leucocytozoon parasites by examining blood smears. All sampled nestlings were infected with Leucocytozoon parasites. The infection intensity ranged from 0.82–10.05 Leucocytozoon parasites per 1000 erythrocytes (mean ± SE = 4.35 ± 0.54). Using site elevation, distance-to-water, nestling age, nestling sex and nest tree species as predictor variables for infection intensity by Leucocytozoon parasites, we employed an information theoretic approach to select a top model to determine the presence of an effect. The top model included nest tree species as the sole predictor for infection intensity. Specifically, higher Leucocytozoon parasite intensity was associated with quaking aspen (Populus tremuloides) nest trees, as compared to lodgepole pine (Pinus contorta). Further research will help identify management implications for this species of concern in this high altitude forest surrounded by a shrub-steppe ecosystem.