Williston Reservoir Northern Myotis maternal roost study

Northern Myotis is a federally endangered bat species facing devastating population declines in the eastern part of its range due to White Nose Syndrome (WNS). Little is known about the habitat requirements of this species. It is not currently known whether Northern Myotis occur on the western side of Williston Reservoir; the existing range map only assumes a presence east of the northern Rockies. Unlike Little Brown Myotis, which readily occupies anthropogenic structures, Northern Myotis is an interior forest specialist often utilizing mature deciduous trees, rock crevices and sometimes buildings for maternal colonies. This project will focus on acoustic detectors to determine presence with capture and telemetry to follow reproductive females to maternal colony locations. The outcomes of this potential multi-year study would include forestry/industry extension programs to facilitate habitat conservation, land-use planning and management for the benefit of this species at risk.

 

Update: 29 bats captured to help at-risk Northern Myotis

In Year 1, 58,322 bat passes from 895 detector nights of recording at 28 locations were analyzed. A total of 29 bats were captured, including four Northern Myotis. VHF transmitters were affixed to two lactating females; however, the transmitters were either groomed off shortly after deployment or not relocated. One of the lactating females was tracked to a stand of aspen on the north side of the Peace River; however, the following day her transmitter was found, groomed off, on an island near the Peace Canyon Dam. A single Little Brown Myotis was also tracked to a natural tree roost. Recommendations have been included to increase capture and tracking success in Year 2. Capture efforts also revealed a likely Long-eared Myotis maternal roost in rock bluffs, along the north side of the Peace Reach of Williston Lake (Torwood Bluffs). Acoustic bat monitoring yielded a number of important observations for bat species in the region.