Brett L Walker
Sara J. Oyler-McCance
Jennifer A. Fike
Barry R. Noon
Jessica E. Shyvers
2023
<div class="abstract-group "><div class="article-section__content en main"><p>Sex ratio, and the extent to which it varies over time, is an important factor in the demography, management, and conservation of wildlife populations. Greater sage-grouse<span> </span><i>Centrocercus urophasianus</i><span> </span>populations in western North America are monitored using counts of males at leks in spring. Population estimates derived from lek-count data typically assume a constant, female-biased sex ratio, yet few rigorous, empirically derived estimates of sex ratio are available to test that assumption. We estimated pre-breeding sex ratio of greater sage-grouse in a peripheral, geographically isolated population in northwestern Colorado during two consecutive winters using closed-population, robust-design, multi-state, genetic mark–recapture models in program MARK. Sex ratio varied markedly between years, with estimates of 3.29 (95% CI: 2.36–4.59) females per male in winter 2012–2013 and 1.54 (95% CI: 1.22–1.95) females per male in winter 2013–2014. Rather than assuming a constant sex ratio, biologists should consider the potential for large annual variation in sex ratio of greater sage-grouse populations when estimating population size or trend from male lek-count data.</p></div></div>
application/pdf
10.1002/wlb3.01085
en
Wiley
Genetic mark–recapture analysis reveals large annual variation in pre-breeding sex ratio of greater sage-grouse
article