Behavioral responses of terrestrial mammals to COVID-19 lockdowns.

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.

Immobilization of American Beaver (Castor canadensis) with Nalbuphine, Medetomidine, and Azaperone.

Thirty-two American beavers (Castor canadensis) were immobilized with a mixture of nalbuphine, medetomidine, and azaperone (NalMedA) for tail transmitter placement and health assessments prior to translocation. Inductions and reversals were very smooth, but regardless of the dose administered, which ranged from 0.02 to 0.06 mL/kg, many beavers reacted to mild stimuli such as being lifted out of the cage, drawing blood from the tail, expressing anal glands for sex determination, and turning on isoflurane to deepen anesthesia before placement of tail transmitters. On a scale from 1 to 5, a sedation score of 4 was achieved in 8/32 beavers and a sedation score of 5 in 1/32 of beavers given a mean (SD) dosage of 0.04 (0.01) mL/kg NalMedA, which equated to a mean of 1.09 (0.21) mg/kg nalbuphine, 0.43 (0.09) mg/kg medetomidine, and 0.36 (0.07) mg/kg azaperone. All other animals achieved lower sedation scores. Supplementary isoflurane was needed to deepen anesthesia before tail transmitter placement. Although Nal-MedA appeared to be safe for use in American beavers, the level of sedation achieved was quite variable. Supplementary oxygen is recommended to reduce hypoxemia.

A Mixture of Butorphanol, Azaperone, and Medetomidine for the Immobilization of American Beavers ( Castor canadensis).

A total of 58 American beavers ( Castor canadensis) was immobilized with butorphanol, azaperone, and medetomidine (BAM) for the purpose of health assessments, sex determination, and placement of very high-frequency tail transmitters in a subset of animals. Isoflurane gas anesthesia was available to aid with induction when needed, and all animals received supplementary oxygen. Thirty-one beavers immobilized with a mean (SD) dose of 0.65 (0.15) mg/kg butorphanol, 0.22 (0.05) mg/kg azaperone, and 0.26 (0.06) mg/kg medetomidine did not require supplemental isoflurane during induction and the mean induction time was 8 min (range: 3-21 min). This dose was equivalent to 0.024 (0.005) mL of BAM per kilogram. A total of 29 beavers that were immobilized with a mean (SD) of 0.51 (0.07) mg/kg butorphanol, 0.17 (0.02) mg/kg azaperone, and 0.2 (0.03) mg/kg medetomidine needed supplementary isoflurane at 5% and 5 L/min for <1 min to induce full anesthesia. In none of the beavers did BAM alone provide sufficient depth of anesthesia to drill a hole in the tail for transmitter placement, and supplementary isoflurane was administered to reach a sufficient level of analgesia for the procedure. The beavers were reversed with 5 mg of atipamezole per milligram of medetomidine and 1 mg of naltrexone per milligram of butorphanol. No adverse effects or mortalities were observed. Butorphanol-azaperone-medetomidine can be considered safe for use in American beavers for minor procedures.