Columbian sharp‐tailed grouse female and nest survival in northwestern Colorado

Abstract

AbstractWildlife management and conservation can be challenging when the demography of a focal species is unknown or limited given that fecundity and adult survival influence population growth. The Columbian sharp‐tailed grouse (Tympanuchus phasianellus columbianus) have been reduced to ≤10% of their former range since the early 1900s. We conducted a 3‐year study (2015–2017) across 4 study sites in northwestern Colorado, USA, to evaluate female hazard and nest survival. We trapped and marked 270 female sharp‐tailed grouse and identified 275 nests for our hazard and survival analyses. Females during the breeding stage of the reproductive season experienced more hazard compared to the nesting and the early and late post‐nesting stages for females without broods. Females experienced a higher degree of hazard during the breeding stage and mortality risk was >3 times higher than the nesting stage, >7 times higher than early post‐nesting (EPN)‐no brood stage, and >5 times higher than the late post‐nesting (LPN)‐unsuccessful stage. Two reproductive season stages (LPN‐successful and EPN‐brood) provided marginal inference. Nest incubation initiation date and nest age best described nest daily survival. Females that initiated incubation of initial nests earlier in the season experienced lower nest daily survival than later in the incubation season. Because female Columbian sharp‐tailed grouse hazard varied among different reproductive season stages, we recommend that wildlife managers develop management actions that reduce hazard during the specific reproductive season stages (i.e., the breeding season). For Columbian sharp‐tailed grouse in Colorado, we recommend that Colorado Parks and Wildlife collaborate with federal farm program agencies to implement a no‐tillage restriction from 1 May through 30 June for active agricultural fields within 2 km of active Columbian sharp‐tailed grouse leks to enhance nest survival.