Evaluating precision of cementum annuli analysis for aging mule deer from southern California

Abstract

We evaluated the precision of age estimates produced by cementum annuli analysis (CAA) of blind‐duplicate specimens taken from 994 southern mule deer (Odocoileus hemionus) collected over 15 years. We found that the mean annual proportion of unreliably aged incisor pairs was greater for females (0.48, SD = 0.13) than for males (0.22, SD = 0.07). Most of the 308 unreliably aged tooth pairs disagreed by only 1 year. Sex, precipitation, and certainty codes assigned by Matson's Lab to the age estimates were the best predictors for agreement of estimated ages within incisor pairs. Our estimated overall age error rate of CAA (17%) was >2 times as large as estimated error rates from Montana and South Dakota, but less than half of error rates estimated for Mississippi and south Texas. Knowing the error rate of age estimates from a specific deer population allows wildlife managers to perform tasks requiring specific age class information such as monitoring the harvest rate of older female deer in a hunted population or performing population reconstruction. © 2011 The Wildlife Society.

Overcoming cohort effects in a Mediterranean ecosystem: The role of density and precipitation on southern mule deer body mass

“…Age was determined by tooth eruption and replacement for deer 1.5 years of age or younger (Severinghaus ). Lower, central incisor pairs (I1) were collected from deer that were ≥ 2.5 years and sent to Matson's Lab in Milltown, Montana, USA, for age estimation via cementum‐annuli analysis (Asmus and Weckerly ). Ages were categorized as fawn (0.5 years), yearling (1.5 years), and adult (2.5 years).…”

“…The base was topographically diverse, including coastline, bluffs, mesas, canyons, and mountains. The Pacific Ocean formed the western boundary, which transitioned into coastal terraces and then into coastal mountains approximately 800 m above sea level on the northeastern edge of the study area (Asmus and Weckerly ). Many vegetation communities were available for use by mule deer including sage scrub, chaparral, oak woodlands ( Quercus spp.…”

“…Pendleton experiences a Mediterranean climate in which most of the precipitation occurs during the cooler months of December through March and is nearly rainless during the summer months of May through September. Mean monthly temperatures typically ranged from 14°C in January to 22°C in August (Asmus and Weckerly ), with approximately 335 frost‐free days. Although inter‐annual variation in temperature is limited (CV = 0.03), precipitation is highly variable across years.…”

“…The Pacific Ocean formed the western boundary, which transitioned into coastal terraces and then into coastal mountains approximately 800 m above sea level on the northeastern edge of the study area (Asmus and Weckerly 2011 Pendleton experiences a Mediterranean climate in which most of the precipitation occurs during the cooler months of December through March and is nearly rainless during the summer months of May through September. Mean monthly temperatures typically ranged from 148C in January to 228C in August (Asmus and Weckerly 2011), with approximately 335 frost-free days. Although inter-annual variation in temperature is limited (CV ¼ 0.03), precipitation is highly variable across years.…”

Dentine method: Aging white-tailed deer by tooth measurements

“…These volunteers typify the types of people who would use a field technique to age harvested deer. None were informed that their scores were to be used to validate the aging technique, to prevent this information from influencing their behavior (Asmus and Weckerly ). We made deer‐aging literature available to participants to ensure maximum accuracy.…”