Infestations of Lice of Steppe Buzzards (Buteo buteo vulpinus) Differ from those of Common Buzzards (Buteo buteo buteo)

The Steppe Buzzard (Buteo buteo vulpinus), an eastern subspecies of the Common Buzzard (Buteo buteo), is a long-distance migrant raptor that breeds across eastern European and central Asian grasslands. The eastern European populations migrate through a geographic bottleneck in Israel and overwinter in eastern and southern Africa. To investigate how the metabolic demand of long-distance migration may affect their health, we trapped Steppe Buzzards (n = 28) at Eilat, Israel, during the spring migration of 2016 and 2017 and collected their parasitic lice (Insecta: Phthiraptera). We compared their louse infestation levels to published data on nonmigratory or short-distance migratory Common Buzzards (B. b. buteo). These Common Buzzards were divided into two groups, free-living birds (n = 59) and captive ones (n = 104). All the Steppe Buzzards we examined harbored 1-4 species of lice. The Amblyceran lice that feed partially on living tissues and are thought to be relatively more virulent (Laemobothrion maximum and Colpocephalum nanum) were significantly more prevalent on Steppe Buzzards than on Common Buzzards (either free-living or in captivity). In contrast, the less-harmful Ischnoceran lice (Craspedorrhynchus platystomus and Degeeriella fulva) were either similarly or less prevalent on Steppe Buzzards than on the nonmigratory Common Buzzards, either free-living or in captivity. We hypothesize that this difference may mirror the metabolic demands of long-distance migration or, alternatively, our Eilat sample of Steppe Buzzards might have been biased in favor of the heavily infested individuals. In the Steppe Buzzard sample, we also detected a formerly unknown negative correlation between the abundance of Laemobothrion maximum and Colpocephalum nanum.