Theodore J Weller; USDA Forest Service, Pacific Southwest Research Station;; Gabriel A. Reyes, Katrina J. Smith

Hoary bats (Lasiurus cinereus) are renowned as the longest distance migratory bat species in North America, but specific details on such movements are few. During autumn, hoary bats are vulnerable to impacts from wind turbine operation and engage in two activities vitally important to their annual life cycle: mating and moving between summer and winter habitat. In 2014, we began using a new generation of lightweight devices and a newly developed suture attachment method which allowed multi-month attachment and expanded the possibilities for understanding these movements in California. Over the years, we have used geolocators, connectivity tags, and lightweight GPS tags to gain insights into their movement ecology. In 2022, we began using tags compatible with the Motus automated radio-telemetry system and its burgeoning network of receivers throughout Pacific states to enhance our understanding of seasonal movements. We demonstrate the lack of predictability in autumn movements among individuals while at the same time identifying some potential hotspots of autumn activity by hoary bats. We also compare pros and cons of the various tracking devices we have used, concluding that advancing the Motus network is the best way to enhance our understanding of the seasonal movements of bats.

Ecology and Conservation of Bats - I