Abstract
The effects of urbanisation on flying vertebrates historically have been underestimated, with roads in particular impacting bat populations through vehicle collisions, habitat fragmentation and unwillingness to disperse across roads. Although vegetated fauna overpasses have not traditionally been considered as beneficial for microbats, these structures have recently been identified as a potential solution for assisting microbat communities. In Brisbane, Queensland, Australia, the Compton Road fauna overpass traverses a four–lane road, facilitating connectivity for mammals, birds, reptiles and amphibians between two forest reserves. This study examined patterns of activity and species richness of microbat assemblages in relation to the Compton Road fauna overpass. Call recordings made over seven months identified nine species and two species groups (groups of species unable to be differentiated), all of which were recorded using the overpass. Bat activity on the overpass was higher than in the adjoining forest, with higher detectability. Species richness and activity at the roadside where the overpass was present was also higher than the unvegetated roadside. Activity patterns based on feeding behaviours suggest that forest species such as Nyctophilus and Myotis spp. were using the overpass, alongside more generalist species. The vegetation on the overpass is likely to be the key factor encouraging microbat activity. The Compton Road overpass appears to lessen the impact of road presence and may facilitate permeability of a major road, suggesting potential for enhancing habitat connectivity and facilitating crossings. This study is the first indication that vegetated fauna overpasses can facilitate activity and provide natural habitat continuity for diverse Australian microbat communities.
Highlights
The effects of urbanization on highly mobile flying vertebrates, such as bats, have been historically underestimated (Threlfall et al, 2013), in part from the assumption that they are less influenced by habitat fragmentation than are non-volant species (Gilbert, 1989)
South east Queensland supports high microbat diversity, with at least 24 known species (Churchill, 1998), 18 of which occur around Brisbane (Churchill, 2009; Hourigan et al, 2010)
Previous studies conducted in Karawatha Forest detected at least nine species (Hourigan, 2011), all of which were detected in the present study
Summary
The effects of urbanization on highly mobile flying vertebrates, such as bats, have been historically underestimated (Threlfall et al, 2013), in part from the assumption that they are less influenced by habitat fragmentation than are non-volant species (Gilbert, 1989). Bat density and diversity have been shown to decrease with proximity to major roads (Berthinussen and Altringham, 2012) while the presence of vehicles themselves can restrict foraging and commuting behaviors (Kerth and Melber, 2009; Zurcher et al, 2010; Bennett et al, 2013) Direct effects such as vehicle strikes (Gaisler et al, 2009; Lesinski et al, 2011), street lighting and traffic noise (Longcore and Rich, 2004; Stone et al, 2009; Bennett and Zurcher, 2013) are known to impact urban bat communities by altering foraging, commuting, roosting and activity times (Stone et al, 2015). Vegetated fauna overpasses have the potential to mitigate these impacts for bats by reintroducing structural habitat complexity, providing safe passage across roads, as has been shown for other taxa (Bond and Jones, 2008; Mata et al, 2008; Jones and Pickvance, 2013; McGregor et al, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
