Sex identification and age estimation of bobcats and implications for management

Abstract

AbstractPredictions obtained from wildlife population models may be prone to influences associated with the quality of the data available for parameterization. We assessed accuracy of furtaker‐assigned sex of bobcats (Lynx rufus; n = 123) harvested during 2017–2018 across the western USA by comparing those data to genetically assigned sex, the latter of which we assumed was 100% accurate. We also compared the precision of individual age estimates obtained through cementum annuli analysis (CAA) of the canines and incisors of harvested bobcats (n = 151), where true age was unknown. Because cementum‐line deposition may vary across populations and by sex, we hypothesized that environmental factors may affect precision of age estimates obtained via CAA. Sex of bobcats as reported by furtakers was accurate 82% of the time, and the direction of sex‐assignment error was approximately equivalent. Canine teeth were more precise than incisors for estimating age, age estimates for male bobcats may be more precise than for females, and precision of age estimates may decrease with age. However, use of incisors corrected with known rates of error may be preferred in some instances, such as studies that require live capture and tooth extraction or where assignment to age class is sufficient. In addition, we found that sex, median age, and mean elevation may influence precision of age estimates, whereas mean precipitation and geographic location (latitude, longitude) were uninformative. Knowledge of different types of errors associated with sex identification and age estimation may be integrated into population modeling efforts based on management objectives.