02304nas a2200181 4500008004100000245008200041210006900123520165300192653002701845653001601872653001201888653002401900653002001924100002501944700001401969700001901983856012002002 2011 eng d00aHigh background noise shapes selective auditory filters in a tropical cricket0 aHigh background noise shapes selective auditory filters in a tro3 a

Because of call frequency overlap and masking interference, the airborne sound channel represents a limited resource for communication in a species-rich cricket community like the tropical rainforest. Here we studied the frequency tuning of an auditory neuron mediating phonotaxis in the rainforest cricket Paroecanthus podagrosus, suffering from strong competition, in comparison with the same homologous neuron in two species of European field crickets, where such competition does not exist. As predicted, the rainforest species exhibited a more selective tuning compared with the European counterparts. The filter reduced background nocturnal noise levels by 26 dB, compared with only 16 and 10 dB in the two European species. We also quantified the performance of the sensory filter under the different filter regimes by examining the representation of the species-specific amplitude modulation of the male calling song, when embedded in background noise. Again, the filter of the rainforest cricket performed significantly better in terms of representing this important signal parameter. The neuronal representation of the calling song pattern within receivers was maintained for a wide range of signal-to-noise ratios because of the more sharply tuned sensory system and selective attention mechanisms. Finally, the rainforest cricket also showed an almost perfect match between the filter for sensitivity and the peripheral filter for directional hearing, in contrast to its European counterparts. We discuss the consequences of these adaptations for intraspecific acoustic communication and reproductive isolation between species.

10aacoustic communication10acompetition10acricket10adirectional hearing10aMatched filters1 aSchmidt, Arne, K. D.1 aRiede, K.1 aRömer, Heiner uhttp://jeb.biologists.org/cgi/doi/10.1242/jeb.053819https://syndication.highwire.org/content/doi/10.1242/jeb.05381902443nas a2200217 4500008004100000245011100041210006900152520172700221653001601948653001801964653002101982653001702003653002502020100002102045700001902066700001902085700002002104700002502124700002102149856005502170 2019 eng d00aDueling frogs: do male green tree frogs (Hyla cinerea) eavesdrop on and assess nearby calling competitors?0 aDueling frogs do male green tree frogs Hyla cinerea eavesdrop on3 a

Individuals produce advertisement signals with intended purposes and targets. However, these signals can be received by “eavesdroppers,” who may extract information from them and alter their behavior according to the extracted information. In anuran systems, males congregate at breeding sites to produce advertisement calls to attract receptive females and fend off rival males. Both sexes directly assess these calls in dyadic encounters and make decisions based on the call’s characteristics, e.g., frequency. What is unknown is whether bystander males eavesdrop on these same calls to inform their future competitive decisions. Here, we examined whether male green tree frogs (Hyla cinerea) eavesdrop on competing males, assess their competitor’s call frequency, and respond accordingly. We exposed males to playbacks of two competing males that varied in call frequency—high, average, low—and quantified latency to call, time spent calling, and number of calling bouts. We found that males had reduced latency to call and called more when eavesdropping low-frequency competition, but not average or high-frequency competition. Focal male size also influenced how they responded, with larger males being more responsive than smaller males. Our results indicate that male green tree frogs are capable of eavesdropping on nearby male calls and produce behavioral responses accordingly. Further, it appears males are able to alternate between assessment strategies dependent upon the frequency of the eavesdropped competition. These findings indicate that males not only directly assess an opponent’s call in dyadic encounters, but also indirectly through eavesdropping.

10acompetition10aeavesdropping10aGreen tree frogs10aHyla cinerea10aMale call assessment1 aGarcia, Mark, J.1 aCronin, Andrew1 aBowling, Tyler1 aBushera, Hakeem1 aHunter, Kimberly, L.1 aTaylor, Ryan, C. uhttp://link.springer.com/10.1007/s00265-018-2632-102246nas a2200349 4500008004100000245010300041210006900144260001600213300001400229490000800243520124400251653001401495653001401509653001201523653001801535653001601553653002101569653001601590653001401606100002401620700002201644700002601666700002201692700002201714700002001736700002301756700001801779700001901797700002201816700001501838856004301853 2017 eng d00aNo need to shout: Effect of signal loudness on sibling communication in barn owls Tyto alba0 aNo need to shout Effect of signal loudness on sibling communicat cJan-06-2017 a419 - 4240 v1233 a

In animal communication, signal loudness is often ignored and seldom measured. We used a playback experiment to examine the role of vocal loudness (i.e., sound pressure level) in sibling to sibling communication of nestling barn owls Tyto alba. In this species, siblings vocally negotiate among each other for priority access to parental food resources. Call rate and call duration play key roles in this vocal communication system, with the most vocal nestlings deterring their siblings from competing for access to the food item next delivered by parents. Here, we broadcast calls at different loudness levels and call rate to live nestlings. The loudness of playback calls did not affect owlets' investment in call rate, call duration or call loudness. The rate at which playback calls were broadcast affected owlets' call rate but did not influence their response in terms of loudness. This suggests that selection for producing loud signals may be weak in this species, as loud calls may attract predators. Moreover, given that owlets do not overlap their calls and that they communicate to nearby siblings in the silence of the night, loud signals may not be necessary to convey reliable information about food need.

10aacoustics10aamplitude10abegging10acommunication10acompetition10amultiple signals10anegotiation10aplaybacks1 aDreiss, Amélie, N.1 aDucouret, Pauline1 aRuppli, Charlène, A.1 aRossier, Virginie1 aHernandez, Lucile1 aFalourd, Xavier1 aMarmaroli, Patrick1 aCazau, Dorian1 aLissek, Hervé1 aRoulin, Alexandre1 aFusani, L. uhttp://doi.wiley.com/10.1111/eth.12612