Avian Conservation and Ecology
Monitoring, management, and conservation of grassland birds are topics of importance because of widespread population declines. Annual estimates of survival are available for many species, however knowledge of how survival varies on a seasonal basis remains poor. Information on the relative effects of breeding, overwintering, and migratory periods on population dynamics is necessary for effective management. Mortality risks often vary with the stage of the breeding cycle. In precocial species, mortality risks of adult birds are often higher during post-hatching care than prehatching. Using a multistate modeling approach, I investigated the influence of both environmental characteristics, measured by habitat, and individual characteristics, measured by sex and body mass, on post-hatching parental mortality of a declining grassland species, the Mountain Plover (Charadrius montanus). I found minimal evidence to support the effect of habitat, sex, or body mass on post-hatching parental mortality. Daily parental mortality was 0.0037 (SE = 0.0007, CI = 0.0026, 0.0053) and survival during the 30-day post-hatching period was 0.8943 (SE = 0.0187, CI = 0.8512, 0.9255). The findings from this study provide an understanding of the associations with today’s grassland habitats and the dynamics of Mountain Plovers during the breeding season. Prior to assessing if alterations in habitats are acting more on post-hatching than the other stages of the annual cycle for the Mountain Plover, information on survival during other breeding stages and during migration is needed to assist in developing effective conservation and management plans.
©2010 Victoria J. Dreitz