02374nas a2200181 4500008004100000245009100041210006900132260001600201300001400217490000800231520178000239100002802019700002802047700002102075700002602096700001502122856005502137 2017 eng d00aBehavioural response evoked by conspecific distress calls in two neotropical treefrogs0 aBehavioural response evoked by conspecific distress calls in two cJan-12-2017 a942 - 9480 v1233 a

Anurans emit distress calls when attacked by predators as a defensive mechanism. As distress calls may trigger antipredator behaviour even in individuals that are not under attack, we tested whether this defensive behaviour induced behavioural changes in neighbouring conspecifics. We compared the behavioural responses of two species of Neotropical hylid frogs (genus Boana) to conspecific distress calls and white noise. Individuals of both species interrupted their vocal activity and decreased call rate after hearing the distress call. Natural variation on signal intensity calibrated among the nearest neighbours did not influence the response and we did not observe negative phonotaxis after any acoustic stimulus. Despite the fact that many predators are acoustically oriented, we could not determine if such response (reduced call rate) was induced by risk assessment or by the masking effect on advertisement calls. Boana faber responded similarly to white noise and distress calls, while B. bischoffi responded more intensely to distress calls. Duration of silence after playbacks in B. faber was longer than B. bischoffi. We suggest that, if the signals are interpreted as a risk cue by neighbouring conspecifics, each species may be preyed upon by different predators, as they may have led to distinct defensive strategies and different responses to distress calls. If risk assessment information is included in distress calls, it triggers behavioural responses only in the nearest neighbours, as we did not observe responses on the vocal activity of the interspecific chorus. Our results add relevant data about acoustic communication and interpretations by anurans, highlighting the importance of considering cues within common and widespread signals.

1 aForti, Lucas, Rodriguez1 aForti, Anna, Bárbara B1 aMárquez, Rafael1 aToledo, Luís, Felipe1 aFoster, S. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1201984nas a2200217 4500008004100000245010900041210006900150260001600219300001400235490000800249520129800257653002701555653001501582653001501597653001801612100002201630700002201652700002301674700001501697856005401712 2017 eng d00aResponses of male cricket frogs ( Acris crepitans) to attenuated and degraded advertisement calls0 aResponses of male cricket frogs iAcris crepitansi to attenuated  cJan-05-2017 a357 - 3640 v1233 a

We examined the vocal and non-vocal responses of male cricket frogs (Acris crepitans) to conspecific advertisement calls that had been attenuated or degraded by reducing the depth of amplitude modulation (AM). Both are characteristic of changes to the call as it is transmitted through natural habitats. As stimulus calls became more intense or less degraded, male cricket frogs gradually decreased their call rate and increased the number of call groups and pulse groups in their calls, changes indicative of increased aggressive interactions. At the higher intensities and lower degradation levels, the probability that males would shift to one of two non-vocal behavioral responses, attacking the perceived intruder or ceasing calling and abandoning the call site, gradually increased. The results show that differences in signal attenuation and AM degradation levels are perceived by males and trigger both vocal and non-vocal behavioral responses consistent with their use in evaluating the distance to a challenging male. Furthermore, the results indicate that the male responses are graded, increasing as intensity rises and degradation falls, and hierarchical, with vocal responses preceding behavioral responses over the range of intensities and degradation levels presented.

10aacoustic communication10aaggression10aamphibians10acricket frogs1 aVenator, Kurt, R.1 aRyan, Michael, J.1 aWilczynski, Walter1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-502606nas a2200205 4500008004100000245010200041210006900143260001600212520194500228653001802173653002602191653001202217653002902229653002402258100001702282700002302299700002002322700001502342856004302357 2017 eng d00aRestricted responsiveness to noise interference in two anurans from the southern temperate forest0 aRestricted responsiveness to noise interference in two anurans f cFeb-08-20183 a

Animals adopt different strategies to communicate by means of sound in noisy envi - ronments such that some species increase, while others decrease their vocal activity in the presence of interference. Anuran amphibians from diverse latitudes exhibit both kinds of responses. Recent studies have shown that males of Batrachyla taeniata and Batrachyla antartandica from the temperate austral forest do not call in response to the presentation of advertisement calls of sympatric congeneric species. In contrast, Batrachyla leptopus responds to these signals in a similar way as to conspecific calls. The responsiveness of B. taeniata to natural abiotic interference has also been tested and found that noises of such sources produce strong increases in vocal activity. To assess the diversity in responsiveness to acoustic intrusion in this group, we exposed males of B. leptopus and B. antartandica to prolonged pre- recorded natural abiotic noises of wind, creek, rain, and to a band- pass noise centered at 2,000 Hz, at 67 dB Sound Pressure Level (SPL). The subjects did not increase their vocal activity signifi - cantly when exposed to these sounds and to band- pass noise at increasing intensities (55–79 dB SPL). These results contrast with the increase in vocal activity observed previously in B. taeniata to continuous abiotic noise and point to the existence of di - verse strategies to confront acoustic intrusion among related species. The lack of vocal activation observed also contrasts with the responsiveness of B. leptopus to het- erospecific signals, but parallels the lack of response to such sounds in B. antartandica . Furthermore, the results obtained contrast with the responsiveness of these species to synthetic prolonged sounds observed in previous studies, suggesting that the modes of responses to acoustic intrusion may depend on previous experience, rather than having a species- specific nature.

10aabiotic noise10aacoustic interference10aanurans10aaustral temperate forest10asound communication1 aPenna, Mario1 aCisternas, Javiera1 aToloza, Jessica1 aFoster, S. uhttp://doi.wiley.com/10.1111/eth.12644