Vaginal Temperature and Activity Variations in Relation to Fecal Progestagens of Captive Moose (Alces alces)

Abstract

Accurate detection of specific reproductive events presents a challenge to scientists studying wild species, including moose. There are several established methods for monitoring reproductive activity in domestic ruminants, including the use of biologging devices. The main objective of this study was to determine whether moose show a distinct thermal and activity pattern associated with luteal activity during the estrous cycle, as documented in cattle. We measured fecal progestagen, vaginal temperature, and activity of 12 captive female moose on the Kenai Peninsula, Alaska, USA, early in the breeding season to examine the relationships between these variables. Individual fecal samples were collected from August 23rd to October 15th, 2021, to classify luteal activity. Our results support that moose display an identifiable thermal pattern during the onset of luteal activity from mid-September to mid-October, which is associated with the presumed first estrous cycle of the breeding season. We developed an algorithm to detect luteal activity based on this pattern, with a sensitivity of 71%. In contrast, we did not observe a distinct pattern in activity during this period. However, subsequent, recurring patterns in both temperature and activity were identified between mid-October and mid-November, which were likely associated with following estrous cycles.