Calibration of a rumen bolus to measure continuous internal body temperature in moose

• Published in: Wildlife Society Bulletin
• Main Authors: Herberg, Andrew M., St‐Louis, Véronique, Carstensen, Michelle, Fieberg, John, Thompson, Daniel P., Crouse, John A., Forester, James D.
• Other Authors: Minnesota Department of Natural Resources, University of Minnesota
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Alces alces; Alaska
• Online Access: http://dx.doi.org/10.1002/wsb.894; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fwsb.894; http://onlinelibrary.wiley.com/wol1/doi/10.1002/wsb.894/fullpdf

ABSTRACT Mortality implant transmitters (MITs), a device that can record continuous rumen temperature, have been deployed in wild moose ( Alces alces ) in Minnesota, USA, to understand physiological and behavioral responses of moose to increasing ambient temperatures. We compared temperatures collected using MITs to temperatures collected using vaginal implant transmitters (VITs) in 8 captive female moose (>2 yr old) at the Kenai Moose Research Center in Alaska, USA, during 2015. Both devices collected continuous body temperature measurements at 5‐min intervals for 1 year. We directly observed moose behavior for 384 hr during 4 2‐week windows distributed seasonally within the sampling period, to assess potential effects of behavior on MIT‐recorded temperatures. We documented a decrease in MIT‐recorded temperatures following water intake and developed an approach for censoring these observations. After removing these observations, MIT‐based temperatures were, on average, 0.03° C (95% CI = −0.57–0.55° C; = 38.14° C) lower than VIT‐based temperatures ( = 38.17° C; n = 760,439). We fit linear mixed‐effects models to test the relationship between MIT and VIT‐based temperatures across seasons and individuals. On average, the difference between predicted and observed temperatures was 0.05° C (95% PI = −0.19–0.29° C) and 0.33° C (95% PI = 0.01–0.63° C) for winter and summer seasons, respectively. We conclude that minimally invasive MITs can accurately record internal body temperature in moose, and thus provide a tool for understanding physiological and behavioral responses of moose to environmental stressors. © 2018 The Wildlife Society.