The Behaviour of Reproductive Female Little Brown Bats (Myotis lucifugus) in the Albertan Rocky Mountains
Date
2023-05-02
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Abstract
While there has been substantial work conducted on bat maternity colonies, there is a lack of research on females inhabiting the Rocky Mountains. I collated data from multiple sources and investigated the effect elevation and latitude has on Little Brown bat (Myotis lucifugus) reproductive timing. I conducted research in the Canadian portion of the Rocky Mountains to investigate the effect that colder, wetter nights, and a shorter summer season has on reproduction. I hypothesized that reproductive females would reduce their energy expenditure and/or energy intake would increase, compared to individuals at lower elevations. I studied diet, movement, torpor, and reproductive timings of females in a large (n=700+) maternity colony located around the Kananaskis Lakes in Alberta. To accomplish this, I caught individuals and attached 29 temperature-sensitive radio transmitters to adult females from May to August 2021, noting their reproductive status. I collected fecal samples from individuals and communal roosts for morphological and genetic analysis of prey. I recorded tagged individuals’ presence and skin temperature, and recorded bat box temperatures. Day-roosts were located by following tagged females, and nightly emergence counts were conducted multiple times a week to record changes in colony size. Females used buildings, bat boxes and rock faces for roosts, consistently emerging before sunset and in inclement weather. The majority of females' day roosts were within a 5km range throughout the season, with similar frequencies of roost switching among the various reproductive groups. The estimated gestation time was between 59 and 82 days and longer than the 50-60 average for the species. While there was no significant difference between reproductive stages in the amount of torpor used per day, non-reproductive females spent as much as 99% of the day in torpor (n=11). PCR analysis of guano confirmed consumption of spiders, which has not been confirmed in Alberta previously. These data provide insights into the additional challenges reproductive female Little Brown bats face in the Rocky Mountains and confirm my predictions regarding an extended gestation period, and foraging behaviour. It also highlights the importance of buildings as alternate roosts in the mountains, and their potential in sustaining populations.
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Keywords
reproduction, little brown myotis, myotis lucifugus
Citation
Monteiro, T. A. (2023). The behaviour of reproductive female little brown bats (Myotis lucifugus) in the Albertan Rocky Mountains (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.