Rediscovery of the Northern Myotis in Montana

Abstract

The Northern Myotis aka: Northern Long-eared Bat (Myotis septentrionalis, NLEB) may be among the rarest mammal species within Montana. Prior to 2016 its presence in the state was known from a single male collected from an abandoned coal mine south of Culbertson, MT in the winter of 1978. In 2015 this species was listed as Threatened under the Endangered Species Act because of significant declines in eastern populations due to White-Nose Syndrome (WNS). To provide information about the presence and distribution of this species within the state, we conducted mist netting surveys in 2015 and 2016 across 9 counties designated by the US Fish and Wildlife Service as part of the NLEB’s range. In 2015, forested uplands and deciduous forest were targeted over 11 nights. In 2016, we targeted deciduous forest along major river drainages for 23 nights. We captured 3 NLEBs at 2 sites in 2016 and 0 in 2015.  All Myotis species were genetically confirmed. Individuals were captured at 2 sites along the Missouri river in proximity to the previous detection in Montana and historic records in North Dakota.  Both females and the male were reproductive, indicating that this species may breed within the state. However, given the close proximity to the border of the female captures, we cannot definitively say whether these animals roost in North Dakota or Montana.  In addition to captures of NLEBs we also established records for several WNS susceptible species, providing valuable pre-WNS baseline information on bats in this region.