Xylazine at dosages of 2.7 to 3.9 mg/kg of body weight was administered to 23 captive arctic wolves. The optimal dosage was higher for excited and socialized adults and lower for juveniles than for unexcited unsocialized adults. Mean time to initial effect was 2.5 minutes and mean time to sternal recumbency was 3.7 minutes. Maximal effect was achieved within 15 minutes, with adequate sedation lasting 30 to 60 minutes. Mean recovery time was longer for old (greater than 7-year-old) adults than for young (2- to 3-year-old) ones (2.4 vs 1.7 hours). Induction of and recovery from barbiturate anesthesia was smooth and quiet. Although a few adverse reactions were found, the use of xylazine with physical restraint was an excellent combination for many clinical procedures.
Download full-text PDF |
Source |
---|
Proc Biol Sci
January 2025
Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
To forecast how fast populations can adapt to climate change, it is essential to determine the evolutionary potential of different life-cycle stages under selection. In birds, timing of gonadal development and moult are primarily regulated by photoperiod, while laying date is highly phenotypically plastic to temperature. We tested whether geographic variation in phenology of these life-cycle events between populations of great tits () has a genetic basis, indicating that contemporary genetic adaptation is possible.
View Article and Find Full Text PDFEur J Neurosci
October 2024
Swiss Ornithological Institute, Sempach, Switzerland.
Circadian clock properties vary between individuals and relate to variation in entrained timing in captivity. How this variation translates into behavioural differences in natural settings, however, is poorly understood. Here, we tested in great tits whether variation in the free-running period length (tau) under constant dim light (LL) was linked to the phase angle of the entrained rhythm ("chronotype") in captivity and in the wild, as recently indicated in our study species.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
December 2024
Department of Biology, Western Kentucky University, Bowling Green, Kentucky, USA.
Arctic-breeding birds exhibit around-the-clock activity, and these activity cycles are postulated to maximize reproductive success during the short breeding season characteristic of high-latitude regions. Two closely related species of arctic-breeding songbirds, Lapland longspurs (Calcarius lapponicus; ground-nesting) and snow buntings (Plectrophenax nivalis; cavity-nesting) exhibit extended activity cycles throughout the polar day (71° N) except for 4-5 h of daily quiescence. Ground-nesting Lapland longspurs experience higher levels of nest predation than cavity-nesting snow buntings, and this difference is reflected in elevated nest vigilance in male longspurs compared with snow buntings.
View Article and Find Full Text PDFSci Rep
July 2024
Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, QC, G5L 3A1, Canada.
Birds maintain some of the highest body temperatures among endothermic animals. Often deemed a selective advantage for heat tolerance, high body temperatures also limits birds' thermal safety margin before reaching lethal levels. Recent modelling suggests that sustained effort in Arctic birds might be restricted at mild air temperatures, which may require reductions in activity to avoid overheating, with expected negative impacts on reproductive performance.
View Article and Find Full Text PDFJ Exp Biol
April 2024
Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, Tromsø NO-9037, Norway.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!