02202nas a2200157 4500008004100000245009000041210006900131260001600200520166600216100003201882700002501914700001801939700002501957700002101982856004102003 2018 eng d00aCatching insects while recording bats: impacts of light trapping on acoustic sampling0 aCatching insects while recording bats impacts of light trapping cApr-01-20203 a
Collecting information on bat prey availability usually involves the use of light traps to capture moths and flies that constitute the main prey items of most insectivorous bats. However, despite the recent awareness on the adverse effects of light on bats, little is known regarding the potential impacts of light trapping on the bat sampling outcomes when passive acoustic sampling and light trap- ping are implemented simultaneously. Using a before–after experimental design that involved the installation of a 6 W actinic light trap 1 m away from the bat detector, we tested the predictions that (1) slow-flying bat species will be less active when the light trap is present, while the opposite will be true for fast-fly- ing species; and (2) bat species richness will be lower at lit conditions compared to dark ones. Our results suggest that the use of light traps in combination with bat detectors may considerably influence the outcomes of acoustic sampling. Although the activity of fast-flying bat species did not differ between the two treatments, we found that the activity of slow-flying ones such as Rhinolophus ferrumequinum and Rhinolophus hipposideros decreased significantly at lit condi- tions. Furthermore, we recorded fewer bat species when the light trap was deployed. To overcome this issue, we strongly recommend either (1) placing light traps at a considerable distance from bat detectors; or (2) using light traps during the night that follows the bat sampling if sampling needs to be at the same position; or (3) deploying non-attractant insect traps such as Malaise traps if Lepidoptera is not the main order targeted.
1 aFroidevaux, Jérémy, S. P.1 aFialas, Penelope, C.1 aJones, Gareth1 aPettorelli, Nathalie1 aMerchant, Nathan uhttp://doi.wiley.com/10.1002/rse2.71