The use of culverts in road networks as roost sites to maintain landscape connectivity for a trawling bat: a case study of the large-footed myotis (Myotis macropus) in Australia

The use of culverts in road networks as roost sites to maintain landscape connectivity for a trawling bat: a case study of the large-footed myotis (Myotis macropus) in Australia Vanessa Gorecki1, Ramona Maggini1, Boyd Tarlinton1, Caroline Hauxwell1, Stuart Parsons1 1 School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Australia Corresponding author: vanessagorecki@gmail.com Presentation: Pitch Program topic: 1. Innovative Solutions for Linear Infrastructure Impact Assessment, Mitigation and Monitoring. d. Molecular road ecology/landscape genetics Keywords: Culvert, myotis, roost, microhabitat, connectivity Anthropogenic environments can fragment habitats and introduce barriers to movement between populations, and this can have a profound effect on the population structure and viability of wildlife populations. The large-footed myotis (Myotis macropus) is a trawling bat with a specialisation for foraging directly over water surfaces and movement across landscapes is restricted to riparian corridors. This species has adapted to roosting and breeding in concrete culverts under roads. However, little is known about the roost selection of these artificial sites and how much gene flow occurs between individuals roosting in an urban environment. We investigated M. macropus roost selection at two spatial scales and population structure in a large subtropical city in eastern Australia. We surveyed 365 concrete culverts, identified 23 roosts and collected wing tissue samples from 72 bats. Using generalized additive models, we found the distribution of M. macropus roosts in concrete culverts can be predicted at a landscape level using the variables stream order, channel width and waterway density, and culvert height. Bats preferred culverts >1.2 m in height, and a preference for box culverts was detected although pipe culverts were also occupied. Predictive modelling identified that culvert roosts were a limited resource with only 5.5% of culverts identified as potential roosts. ...