Title

Estimating Recruitment in Elk Using an Occupancy Framework

Presenter Information

Mateen Hessami

Presentation Type

Poster

Abstract

Juvenile recruitment is a key parameter in understanding ungulate population dynamics. Traditional methods in herd composition surveys can be precluded by cost, safety, and feasibility. The use of remote cameras is at the forefront of conservation biology and is a cutting-edge tool of modern wildlife sampling techniques. While the prevalence of remote cameras in ungulate studies has increased, few studies use cameras to estimate vital rates, such as recruitment or survival. We demonstrated the power of remote cameras in estimating calf:cow ratios and calf survival using the Rayle-Nichols occupancy model. Data collected from cameras on unmarked individuals can be used to estimate detection probability, occupancy, and abundance. We compared camera-based estimates to extensive long-term monitoring records where traditional means of herd composition data collection have been conducted (e.g., radio-telemetry). We illustrated this approach in a partially migratory elk population at the Ya Ha Tinda (YHT), Alberta, Canada. We deployed cameras across the YHT (n=44), which is a working horse ranch and important elk winter range. We created an occupancy model for female and young-of-year elk, estimating abundance of respective age classes. We estimated calf survival by comparing the abundance estimates of calves between primary sampling periods and determined the effect of abiotic, biotic and anthropogenic covariates on detection probability and occupancy. We then compared the estimates of calf survival and herd composition to those of traditional field estimates collected in the same time period. Our results demonstrated the utility of using remote cameras to derive important parameters for understanding ungulate population dynamics.

Category

Life Sciences

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Apr 17th, 11:00 AM Apr 17th, 12:00 PM

Estimating Recruitment in Elk Using an Occupancy Framework

UC South Ballroom

Juvenile recruitment is a key parameter in understanding ungulate population dynamics. Traditional methods in herd composition surveys can be precluded by cost, safety, and feasibility. The use of remote cameras is at the forefront of conservation biology and is a cutting-edge tool of modern wildlife sampling techniques. While the prevalence of remote cameras in ungulate studies has increased, few studies use cameras to estimate vital rates, such as recruitment or survival. We demonstrated the power of remote cameras in estimating calf:cow ratios and calf survival using the Rayle-Nichols occupancy model. Data collected from cameras on unmarked individuals can be used to estimate detection probability, occupancy, and abundance. We compared camera-based estimates to extensive long-term monitoring records where traditional means of herd composition data collection have been conducted (e.g., radio-telemetry). We illustrated this approach in a partially migratory elk population at the Ya Ha Tinda (YHT), Alberta, Canada. We deployed cameras across the YHT (n=44), which is a working horse ranch and important elk winter range. We created an occupancy model for female and young-of-year elk, estimating abundance of respective age classes. We estimated calf survival by comparing the abundance estimates of calves between primary sampling periods and determined the effect of abiotic, biotic and anthropogenic covariates on detection probability and occupancy. We then compared the estimates of calf survival and herd composition to those of traditional field estimates collected in the same time period. Our results demonstrated the utility of using remote cameras to derive important parameters for understanding ungulate population dynamics.