A noninvasive automated device for remotely collaring and weighing mule deer

摘要

Wildlife biologists capture deer (Odocoileus spp.) annually to attach transmitters and collect basic information (e.g., animal mass and sex) as part of ongoing research and monitoring activities. Traditional capture techniques induce stress in animalsand can be expensive, inefficient, and dangerous. They are also impractical for some urbanized settings. We designed and evaluated a device for mule deer (O. hemionus) that automatically attached an expandable radiocollar to a ≥6‐month‐old fawn and recorded the fawn's mass and sex, without physically restraining the animal. The device did not require on‐site human presence to operate. Students and faculty in the Mechanical Engineering Department at Colorado State University produced a conceptual model and early prototype. Professional engineers at Dynamic Group Circuit Design, Inc. in Fort Collins, Colorado, USA, produced a fully functional prototype of the device. Using the device, we remotely collared, weighed, and identified sex of 8 free‐ranging mule deer fawns during winters 2010–2011 and 2011–2012. Collars were modified to shed from deer approximately 1 month after the collaring event. Two fawns were successfully recollared after they shed the first collars they received. Thus, we observed 10 successful collaring events involving 8 unique fawns. Fawns demonstrated minimal response to collaring events, either remaining in the device or calmly exiting. A fawn typically required ≥1 weeks of daily exposure before fully entering the deviceand extending its head through the outstretched collar, which was necessary for a collaring event to occur. This slow acclimation period limited utility of the device when compared with traditional capture techniques. Future work should focus on device modifications and altered baiting strategies that decrease fawn acclimation period, and in turn, increase collaring rates, providing a noninvasive and perhaps cost‐effective alternative for monitoring mid‐ to large‐sized mammal species.