Acute Thermal and Stress Response in Moose to Chemical Immobilization

• Published in: The Journal of Wildlife Management
• Main Authors: Thompson, Daniel P., Crouse, John A., McDonough, Thomas J., Barboza, Perry S., Jaques, Scott
• Other Authors: Alaska Department of Fish and Game
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Alces alces; Alaska
• Online Access: http://dx.doi.org/10.1002/jwmg.21871; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjwmg.21871; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jwmg.21871; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jwmg.21871

ABSTRACT Management and research of moose ( Alces alces ) in Alaska, USA, often require chemical immobilization; however, moose may be prone to capture‐induced hyperthermia while immobilized. We chemically immobilized moose with carfentanil citrate and xylazine hydrochloride to measure rump fat depth, collect blood and fecal samples, and to deploy modified vaginal implant transmitters and global positioning system (GPS)‐collars for recording body temperature and movement during and after the chemical immobilization. We predicted wild moose pursued and captured from a helicopter would have elevated body temperature at time of capture, whereas body temperature would remain stable in hand‐raised captive moose not pursued and only hand‐injected for immobilization. Additionally, we expected post‐capture body temperature would be a function of activity, time immobilized, and ambient temperature. As predicted, body temperature of wild moose was elevated 1 hour after capture (38.9°C, 95% CI = 38.7–39.1°C) but returned to baseline levels within 3 hours (38.0°C, 95% CI = 37.9–38.1°C); however, body temperatures then rose above baseline levels and remained elevated 12–48 hours post‐capture when movement rates were also elevated. Body temperatures in captive moose were not elevated 1‐hour post‐immobilization (37.9°C, 95% CI = 37.8–38.0°C). Body temperatures of wild moose were positively related to cortisol levels at time of capture. Two moose that died after immobilization had initial body temperatures similar to other immobilized moose; however, their body temperature began to rise at 17 hours and 40 hours post‐immobilization. Our study provides evidence that chemical immobilization affects body temperature and movement of wild moose up to 48 hours after capture, possibly as a result of renarcotization from carfentanil citrate. With advancements in technology, we recommend fine‐scale GPS data (<1‐hr fix rates) and continuous body temperature be evaluated to detect evidence of renarcotization during and after ...