Table 1.

Articles retrieved during our literature search relating to 1) collisions between bats and vehicles and 2) roads as barriers to the movements of bats. For road casualty data, where the information has been provided by the authors, we note the frequency and location of searches, whether these were conducted on foot, by car or by bike, and the dates between which surveys took place. We include the total number of carcasses reported by each author as well as the proportions of both sex and age classes of individuals where these data were available

Country	Method	Results	References
Collisions
France	Roadside hedgerows searched weekly, on foot, May‐October 1998–2002 (24 months)	Total 109 bats found dead	Capo et al. (2006)
Czech Republic	Emergency stopping lanes searched approx. weekly, on foot, May‐October 2007 (6 months)	Total 119 bats found dead	Gaisler et al. (2009)
Spain	Lanes, hard shoulders and ditches searched weekly on foot, 1989 (12 months)	Total 72 bats found dead	Gonzalez‐Prieto et al. (1993)
Germany	Collated incidental records, 1945–1995	Total 307 bats found dead, 211 males and 96 females	Haensel and Rackow (1996)
Montenegro	Two roads searched weekly by bike, August‐October 2013 (3 months)	Total 17 bats found dead, 8 males and 5 females	Iković et al. (2014)
Germany	Collated incidental records, 1964–1993	Total 96 bats found dead	Kiefer et al. (1995)
Poland	Approx. weekly searches, May‐October 1994–2000 (36 months)	Total 167 bats found dead, 30 males and 31 females, 56 juveniles and 29 adults	Lesiński (2007) Method 1
Poland	Irregular searches on several roads, 1992–1993 and 2001–2004		Lesiński (2007) Method 2
Poland	Roadsides, searched approx. weekly, August‐September 2004 and April‐October 2005–2006 (16 months)	Total 44 bats found dead, 9 males and 15 females	Lesiński (2008)
Poland	Roadside, verges and ditches searched weekly, by car and by foot, July 2008‐June 2009 (11 months)	Total 61 bats found dead, 20 males and 7 females, 17 adults and 8 juveniles	Lesiński et al. (2010)
Portugal	Daily search of several roads by car, March‐October 2009 (7.5 months)	Total 154 bats found dead, 44 males and 20 females, 99 adults and 17 juveniles	Medinas et al. (2012)
Germany	Collated incidental records, 1951–1993	Total 61 bats found dead	Rackow et al. (1994)
Pennsylvania, USA	Road and verges, searched approx. weekly, on foot May‐September 2001 (4 months)	Total 29 bats found dead, 4 males and 16 females, 12 adults and 15 juveniles	Russell et al. (2009)
Roads as barriers
Ireland	Acoustic monitoring of bat activity at four types of motorway crossing: over‐road bridges (×6), severed treelines (×6), underpasses (×7) and river bridges (×6). Activity at crossing sites compared to that in adjacent landscape. Road width ~65–70 m, ~20000 vehicles per day	Under‐road routes preferred to over‐road routes. An average of 23.5 fewer bat passes at over bridges, 7 fewer at severed treelines, 19.5 more passes at underpasses, 158 more passes beneath river bridges than compared to adjacent sites	Abbott et al. (2012a,b)
Ireland	Acoustic monitoring of bat activity at three under‐road passageways of different dimensions: two narrow (H = 1.23 m, 1.1 m; W = 1.48 m, 1.4 m), one wide (H = 6 m, W = 16.6 m). Road width ~60–65 m, ~11000 vehicles per day	Clutter‐adapted species less likely to use over‐road routes than open or edge‐adapted species. Clutter‐adapted species were also more likely to use the narrow under‐road passages	Abbott et al. (2012a,b)
Indiana, USA	Crossing and avoidance behaviour of bats at five survey sites observed. Species identity, flight height, presence/absence of vehicles, and local ecology recorded	Bats were more likely to avoid crossing a road in the presence of vehicles, in the absence of trees, with lower flight height (See Appendices S9 and S10)	Bennett and Zurcher (2013)
England	Bat activity monitored acoustically at varying distances (0–1600 m) from a motorway, road width 35 m, 30–40000 vehicles per day	Species diversity and bat activity declined with proximity to the road. Bat activity at 1600 m was 3.5 times that at the road	Berthinussen and Altringham (2012b)
England	Road‐crossing behaviour monitored acoustically and by observers at four roads to compare frequency with which bats used underpasses, bat gantries and commuting routes. Flight height and verge height flew were also recorded	Bats more likely to cross roads at unsafe heights than to use underpasses. Few bats crossed at gantries but where they did, most flew at unsafe heights (≤5 m). The height at which bats flew over the road was strongly correlated with verge height	Berthinussen and Altringham (2012a)
Germany	Six Barbastella barbastellus (low flying and open adapted) and 34 Myotis bechsteinii (low flying and clutter adapted) were radio‐tracked. Mist‐netting conducted in three underpasses. Road width 18–23 m, 84000 vehicles per day	More Barbastella barbastellus (5/6) crossed the road than Myotis bechsteinii (3/34). Most Barbastella barbastellus crossed above the road (21/37); all Myotis bechsteinii crossed at underpasses (36/36). Myotis bechsteinii foraging ranges were smaller closer to the road and females with smaller foraging areas had lower reproductive success	Kerth and Melber (2009)
California, USA	Bat activity monitored acoustically at three sites, at incremental distances from the road. Road widths and traffic densities: 25–45 m and 55000 vehicles per day; 40 m and 86000 vehicles per day; 15 m and 33500 vehicles per day	Activity was approximately twice as high 300 m from a road as at the road	Kitzes and Merenlender (2014)
Indiana, USA	Road‐crossing behaviour (cross/avoid, flight height) at roads was observed at five sites and the presence/absence of vehicles, noise level emitted by vehicles and their speed were recorded	Vehicles present: 40% (28/44) of bats crossed the road. Vehicles absent: 58% (103/167) of bats crossed. Noise level, speed of the vehicle and flight height had no effect on the tendency for bats to cross	Zurcher et al. (2010)