Human-Wildlife Interactions (Feb 2017)
Microhabitat Selection by Greater Sage-Grouse Hens During Brood Rearing
Abstract
Greater sage-grouse (Centrocercus urophasianus) populations have declined throughout the western United States over the past century. Loss of large stands of sagebrush is a major factor leading to the decline of sage-grouse populations. We captured, marked, and tracked hen sage-grouse in Wyoming during the summer of 2012 to study where sage-grouse hens keep their chicks given the dual needs to provide them with food and to keep them safe from avian predators. Vegetation surveys and avian point counts were performed at early season brood locations, late-season brood locations, and random locations. We conducted multinomial models to determine which habitat variables were most informative in predicting site selection by hen sage-grouse. Hens with and without broods selected sites that had more shrub cover during the early-brood season but not during the late-brood season. During the early-brood season, hens without broods avoided sites where there were American kestrels (Falco sparverius) and common ravens (Corvus corax), but brood hens did not avoid these sites. During late-brood season, brood hens chose sites with fewer small-avian predators (e.g., black-billed magpies [Pica hudsonia] and American kestrels), as well as medium-sized avian predators, such as common ravens, Buteo hawks (Buteo spp.), and northern harriers (Circus cyaneus). Our results suggest that habitat selection by sage-grouse hens is focused more on avoiding predators than on finding food.
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