Acoustic lure allows for capture of a high‐flying, endangered bat

Abstract

Mist nets are commonly used to capture free-flying bats; however, some bat species are very difficult to capture because of their flight behavior, habitat preferences, and ability to avoid nets. High-flying, open-space foragers are especially underrepresented by mist-net surveys. Few studies have investigated the effectiveness of using acoustic lures (playbacks of conspecific vocalizations) to increase capture success of bats in mist nets. We tested the efficacy of an acoustic lure to capture a high-flying rare molossid, the endangered Florida bonneted bat (Eumops floridanus), which had been captured only once away from a known roost prior to our research. We used a crossover experimental design with 2 lure treatments (nets with lures playing social call recordings from 2 different roosts) and 2 control nets (no lures) in 6 sites for 2 nights each. We captured 15 Florida bonneted bats in our treatment nets and 0 in our control nets. One lure had greater capture success (n ¼ 13) than the other (n ¼ 2), with a trend for greater captures of males (n ¼ 11) than females (n ¼ 4). We suggest that these differences were due to the social context in which the calls used in the lures were recorded. Our study demonstrated the utility of acoustic lures to capture Florida bonneted bats and expands research opportunities critical to the species' conservation, such as the ability to use radio telemetry to track captured bats to unknown roosting and foraging areas. Our study also lays the foundation for future research into social call playbacks as a technique to lure other high-flying and elusive bat species into mist nets. Ó 2017 The Wildlife Society.

Activity of an endangered bat increases immediately following prescribed fire

“…Acoustic surveys are routinely used to monitor bat activity patterns and changes in habitat use (Hayes et al , Parsons and Szewczak ). They are particularly effective for high‐flying species not easily captured in mist nets, such as Florida bonneted bats (Braun de Torrez et al ), which have distinct, identifiable echolocation calls (Belwood , Bailey et al ). Further, Florida bonneted bats have low frequency, high intensity calls that are much less sensitive to attenuation (from distance and vegetation) than higher frequency calls of other species (Parsons and Szewczak ), thus reducing site‐specific biases associated with vegetation structure.…”

“…We excluded all calls that overlapped with the range of f c for Brazilian free‐tailed bats ( Tadarida brasiliensis ; 18–33 kHz; Szewczak ), or that may have been low frequency social calls from non‐target bat species, acoustic echoes, insects, birds, or electronic noise. To aid in manual validation, we compiled a reference library of echolocation calls from hand‐released bats captured in mist nets and around known roost locations in south Florida (Braun de Torrez et al , ). We further examined all files identified as Florida bonneted bats to classify those containing feeding buzzes, reflective of foraging activity (Fenton , Coleman and Barclay ).…”

“…Although Florida bonneted bats have been documented to roost and fly in fire‐dependent vegetation communities (e.g., pine [ Pinus spp.] flatwoods and prairies; Belwood ; Angell and Thompson ; Braun de Torrez et al , ; Bailey et al ), we know very little about the factors influencing habitat use by these bats. With historical fire suppression leading to declines in many of Florida's rare and endemic species (Van Lear et al , Slapcinsky et al ), prescribed burning is now used extensively to restore wildlife habitat on public lands across Florida (Fowler and Konopik ).…”

Sympatric Bat Species Prey Opportunistically on a Major Moth Pest of Pecans

“…Instead, reducing branch cropping, and planting trees in tree gaps, may increase roost availability. Broadcasting conspecific feeding buzzes or social calls also may attract bats [60,81], but may not be equally effective across species. Due to the suspected adverse effects of chemical pesticides applied to trees where bats roost in foliage and the areas in which they forage [82,83], we recommend that some areas be left unsprayed for bats to have alternate foraging and roosting sites during such management events.…”

Effectiveness of Acoustic Lures for Increasing Indiana Bat Captures in Mist-Nets

“…Acoustic lures have been used to increase capture rates for taxa such as birds (Sydeman et al 1998;Schaub et al 1999), and there is growing literature on their use for bats (Gillam 2007;Lintott et al 2014;Quackenbush et al 2016;Braun de Torrez et al 2017). Greenaway (2005, 2008) reported that even in areas where Bechstein's bat Myotis bechsteinii is known to occur in large numbers, individuals are rarely captured in nets.…”