Roost selection by male northern long-eared bats (Myotis septentrionalis) in a managed fire-adapted forest

Abstract

Wildlife conservation in multi-use landscapes requires identifying and conserving critical resources that may otherwise be destroyed or degraded by human activity. Summer dayroost sites are critical resources for bats, so conserving roost sites is thus a focus of many bat conservation plans. Studies quantifying day-roost characteristics typically focus on female bats due to their relative importance for reproduction, but large areas of species' ranges can be occupied predominantly by male bats due to sexual segregation. We used VHF telemetry to identify and characterize summer day-roost selection by male northern long-eared bats (Myotis septentrionalis) in a ponderosa pine (Pinus ponderosa) forest in South Dakota, USA. We tracked 18 bats to 43 tree roosts and used an information theoretic approach to determine the relative importance of tree-and plot-level characteristics on roost site selection. Bats selected roost trees that were larger in diameter, more decayed, and under denser canopy than other trees available on the landscape. Much like studies of female northern long-eared bats have shown, protecting large-diameter snags within intact forest is important for the conservation of male northern longeared bats. Unlike female-specific studies, however, many roosts in our study (39.5%) were located in short (≤ 3 m) snags. Protecting short snags may be a low-risk, high-reward strategy for conservation of resources important to male northern long-eared bats. Other tree-roosting bat species in fire-prone forests are likely to benefit from forest management practices that promote these tree characteristics, particularly in high-elevation areas where populations largely consist of males.

Systematic Review of the Roost-Site Characteristics of North American Forest Bats: Implications for Conservation

“…For example, if we were to manage a forest in such a way as to increase roosting opportunities for Myotis septentrionalis, then we would also be increasing roosting habitat for species such as M. lucifugus. M. septentrionalis is known to benefit from protecting standing dead trees in forest interiors [186]. Removing dead trees is a common practice in forest management because they could damage healthy trees or property when they fall.…”

Daily torpor reduces the energetic consequences of microhabitat selection for a widespread bat

“…We conducted our study during the summers of 2017 and 2018 on Jewel Cave National Monument (43°45′ N, 103°45′ W) and surrounding areas of the Black Hills National Forest in South Dakota, USA. Our study area is described in Alston et al ( 2019 ). Mean monthly summer high temperatures range between 22–27°C and mean monthly summer precipitation ranges between 60–80 mm (Western Regional Climate Center, 2018 ).…”

Daily torpor reduces the energetic consequences of habitat selection for a widespread bat

“…We conducted our study during the summers of 2017 and 2018 on Jewel Cave National Monument (43° 45’ N, 103° 45’ W) and surrounding areas of Black Hills National Forest in South Dakota, USA. Our study area is described in Alston, Abernethy, Keinath, & Goheen (2019). Mean monthly summer high temperatures range between 22 – 27°C and mean monthly summer precipitation ranges between 60 – 80 mm (Western Regional Climate Center 2018).…”