Species-specific environmental conditions for winter bat acoustic activity in North Carolina, United States

Abstract

Low winter temperatures are a major driver of hibernation and migration in temperate North American bats. Hibernation and migration in turn affect bat mortality via white-nose syndrome and collisions with wind turbines. To describe winter bat acoustic activity across a wide temperature gradient and to understand species-specific responses to low temperatures, we recorded nightly acoustic activity of bats at 15 sites across the state of North Carolina, United States, from December through February 2016 – 2018. Bat acoustic activity was recorded at all sites during both winters. Nightly probability of bat acoustic presence regressed positively on ambient temperature. Nightly probability of presence in Lasionycteris noctivagans (silver-haired bat) and Eptesicus fuscus (big brown bat) regressed negatively on wind speed. The mean probability of presence within the same winter condition was highest for L. noctivagans, followed by E. fuscus, Perimyotis subflavus (tricolored bat), and Lasiurus cinereus (hoary bat). Differences in species’ mean body weight and roosting preference explained part of the variation of the species-specific probability of presence. Our results can be used to predict bat acoustic presence for these species across the southeastern United States in winter, and better understand the potential threats to bats such as white-nose syndrome and wind turbine interactions.

Four Years Continuous Monitoring Reveals Different Effects of Urban Constructed Wetlands on Bats

“…The big brown bat was associated with most seasons except for the winter, when the hoary bat was the dominant species. All seven species have been documented to be residents in the Piedmont of North Carolina for the winter [34,72]. However, we found that the big brown bat and the silver-haired bat were the most active species in the winter in non-urban settings instead of the hoary bat [72].…”

“…To understand how constructed wetlands affected the bat community, we first examined bat species richness at all seven sites. Previous research in our area suggested that weather conditions including temperature, wind, and precipitation could affect bat acoustic activities [62,64,72]. Thus, we extracted daily weather data (temperature in • C, wind in km/h, and precipitation in cm/h) from the source as described in Li et al (2020) [62].…”

“…It is important to note that differences in bat species richness among sites could be affected by the physical conditions near a site. Sites with more vegetation coverage could usually detect bats in a smaller range [62,64,72] and possibly fewer species, given that we did not have forest interior specialist species in our study area [63,64].…”

“…All seven species have been documented to be residents in the Piedmont of North Carolina for the winter [34,72]. However, we found that the big brown bat and the silver-haired bat were the most active species in the winter in non-urban settings instead of the hoary bat [72]. We suspect that there might be local scale seasonal migrations, similar to a study on big brown bats in Colorado where urban big brown bats left the city during the winter season [82].…”

Artificial light at night (ALAN) pollution alters bat lunar chronobiology: Insights from broad-scale long-term acoustic monitoring

“…Some of the sites were monitoring over a waterbody, which was recorded as a covariate for the statistical analysis. We also recorded site region as a covariate for the statistical analysis using the region classi cation described in Parker et al (2020). At each site, either a Wildlife Acoustics SM2 bat detector (Wildlife Acoustics, Inc, Concord, Massachusetts, United States) or an AnaBat SD2 bat detector (Titley Scienti c Inc., Australia) was used for acoustic monitoring.…”