Vaginal Implant Transmitters for Continuous Body Temperature Measurement in Moose

Measuring body temperature in free-ranging ungulates is challenging. We evaluated a vaginal implant transmitter (TVIT) modified to collect continuous body temperature of captive and wild female moose (Alces alces) in Alaska, USA. We deployed TVITs in 18 moose between 2014 and 2016. We manually removed the TVIT after 51–338 days of deployment and sampled vaginal bacterial flora to assess negative effects of TVIT retention. For comparison, we also sampled vaginal flora from moose that did not have a TVIT. Mean bacterial growth scores were greater for moose with a TVIT than representative vaginal swabs from moose without a TVIT. The TVIT adequately collected body temperature measurements; however, the TVIT design could be improved to fit young, nulliparous moose. TVITs can be easily deployed and removed, but are limited by battery life, can only be deployed in adult female moose, and may increase vaginal bacterial concentrations.