Factors influencing the survival of neonate sharp-tailed grouse Tympanuchus phasianellus

Abstract

Offspring survival after leaving the nest is a critical element of population viability and in the management of game species. We estimated brood survival to 35 days and examined the factors thought to influence individual chick survival during the first two weeks post-hatching in a population of sharp-tailed grouse Tympanuchus phasianellus near Fort St. John, British Columbia, Canada, during 2004-2005. Using program MARK and an information-theoretic approach, we assessed the importance of female attributes, date of hatching, distance moved from the nest and weather conditions experienced prior to hatching and during brood-rearing for survival of offspring. During 2004-2005, 67% of broods had at least one chick that survived to 35 days of age, but within these broods only 34% of the chicks survived. Later hatching dates were positively related to survival during the 0-14 day age interval, whereas the distance moved from the nest by a brood and inclement weather conditions during the first seven days post-hatching significantly reduced the survival rate of chicks to 14 days of age. Further, inclement weather prior to hatching was positively related to the survival of offspring to 14 days, perhaps because wet weather created favour-able foraging environments and habitat characteristics during brood rearing. Cohesive management of nesting and brood-rearing habitats is required to reduce offspring mortality associated with increased travel between suitable habitats, and may minimize mortality during periods when weather is unfavourable. © Wildlife Biology.