Body temperature patterns during pregnancy and parturition in moose.

Overview

Gestation and lactation have high energetic requirements. Up to three-fourths of the gestation period in moose (Alces alces) overlaps with the food-scarce period in winter. During this period, moose deal with the limited forage resources available through hypometabolism with decreased heart rate and body temperature (T_b). Body temperature is also an indicator of oestrus, pregnancy and parturition, which is well documented in several domestic species. In this study, we sought to determine if moose displayed a similar T_b pattern during pregnancy and parturition to domesticated ruminants, and if we could detect parturition by combining T_b and activity data. We studied the T_b pattern of 30 free-ranging adult female moose (≥1.5 years old), equipped with ruminal temperature loggers and GPS collars. We documented a 0.13-0.19°C higher T_b in pregnant compared to non-pregnant moose, depending on the study area with the T_b difference increasing along a south-north gradient, and a drop in T_b and in activity when parturition was imminent. Detection of parturition was highly successful when combining T_b and activity data with an accuracy of 91.5%. Our findings demonstrate that T_b responses to pregnancy and parturition in a wild capital-breeding ruminant are similar to those of domesticated ruminants.