Effect of capture date on nest‐attempt rate of translocated sharp‐tailed grouse Tympanuchus phasianellus

Attempts to establish functioning populations of prairie grouse by translocation often are unsuccessful due to low reproduction following release. We examined the relationship between capture date and nest attempts of Columbian sharp‐tailed grouse Tympanuchus phasianellus columbianus during an effort to restore them by translocation to their historic range in northeastern Nevada, USA, during 1999–2000. After observing that females captured relatively early in the trapping period did not attempt to nest, we hypothesized that the likelihood of female insemination is positively correlated to capture date. If females captured at source leks later in the breeding season are more likely to be inseminated, then they may be more likely to nest following release than females that are not inseminated prior to capture. We found that female grouse that were captured from source leks at later dates during the lek‐visitation period were more likely to nest following translocation than were females captured during the initial days of female visitation to leks (LogXact Test: P = 0.001). Of 40 radio‐marked female grouse, 19 (48%) were observed nesting and nest success was 44%. During 2001, we tested the effect of capture date on the presence of spermatozoa in live female grouse captured from leks. Females trapped later in the lek‐visitation period were more likely inseminated than females captured early in the lek‐visitation period (LogXact Test: P = 0.036). We recommend that wildlife managers consider capturing females from source leks several days following the onset of the lek‐visitation period to increase the frequency of female nest attempts and increase the probability of establishing a new population during reintroductions.