WHERE ARE THEY BREEDING? ATTACHING GSM TRANSMITTERS TO BURROWING OWLS IN ORANGE COUNTY, CALIFORNIA

Alexandra Eagleton; aeagleton@endemicenvironmental.net; Barry Nerhus Jr., Peter H Bloom

The breeding population of burrowing owls (Athene cunicularia) has been extirpated from Orange County (OC), California with the last individual observed 20 April 2018. However, OC still harbors a handful of overwintering burrowing owls (BUOW), whose breeding location is not known. Color banding efforts over the last decade have yielded results of one individual returning to Fairview Park in OC two successive winters, but has not yielded information on where the OC BUOW breed. In February 2024, we attached GSM solar rechargeable transmitters to two burrowing owls overwintering in Orange County to determine their summer breeding sites. We were able to determine the breeding location for one BUOW, which showed up near Brogan, Oregon. We found success using the leg-loop harness method for transmitter attachment, and our transmitters remained on the BUOW and were not bitten or chewed off. Our challenges include selecting an appropriate duty cycle for location check-ins to retain charge, and predation potentially due to the device’s presence. Using this technology, we hope to better understand the migration patterns of the burrowing owls that overwinter in Orange County in order to learn how to best support the local population.

Poster Session