02141nas a2200157 4500008004100000022001300041245009300054210006900147260001600216300001600232490000700248520145600255100002001711700001901731856023301750 2013 eng d a0960982200aA Tympanal Insect Ear Exploits a Critical Oscillator for Active Amplification and Tuning0 aTympanal Insect Ear Exploits a Critical Oscillator for Active Am cJan-10-2013 a1952 - 19570 v233 a

A dominant theme of acoustic communication is the partitioning of acoustic space into exclusive, species-specific niches to enable efficient information transfer. In insects, acoustic niche partitioning is achieved through auditory frequency filtering, brought about by the mechanical properties of their ears [1]. The tuning of the antennal ears of mosquitoes [2] and flies [3], however, arises from active amplification, a process similar to that at work in the mammalian cochlea [4]. Yet, the presence of active amplification in the other type of insect ears—tympanal ears—has remained uncertain [5]. Here we demonstrate the presence of active amplification and adaptive tuning in the tympanal ear of a phylogenetically basal insect, a tree cricket. We also show that the tree cricket exploits critical oscillator-like mechanics, enabling high auditory sensitivity and tuning to conspecific songs. These findings imply that sophisticated auditory mechanisms may have appeared even earlier in the evolution of hearing and acoustic communication than currently appreciated. Our findings also raise the possibility that frequency discrimination and directional hearing in tympanal systems may rely on physiological nonlinearities, in addition to mechanical properties, effectively lifting some of the physical constraints placed on insects by their small size [6] and prompting an extensive reexamination of invertebrate audition.

1 aMhatre, Natasha1 aRobert, Daniel uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982213010348https://api.elsevier.com/content/article/PII:S0960982213010348?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982213010348?httpAccept=text/plain01923nas a2200169 4500008004100000022001300041245007400054210006900128260001600197300001600213490000700229520139000236100001801626700002201644700002001666856006701686 2019 eng d a0960982200aRemarkably loud snaps during mouth-fighting by a sponge-dwelling worm0 aRemarkably loud snaps during mouthfighting by a spongedwelling w cJan-07-2019 aR617 - R6180 v293 a

Many aquatic animals, including mammals, fishes, crustaceans and insects, produce loud sounds underwater 1, 2, 3, 4, 5, 6. Soft-bodied worms would seem unlikely to produce a loud snap or pop because such brief, intense sounds normally require extreme movements and sophisticated energy storage and release mechanisms [5]. Surprisingly, we discovered a segmented marine worm that makes loud popping sounds during a highly stereotyped intraspecific agonistic behavior we call ‘mouth fighting’. These sounds — sound pressures up to 157 dB re 1 μPa at 1 m, with frequencies in the 1–100 kHz range and a strong signal at ∼6.9 kHz — are comparable to those made by snapping shrimps, which are among the most intense biological sounds that have been measured in the sea [6]. We suggest a novel mechanism for generating ultrafast movements and loud sounds in a soft-bodied animal: thick, muscular pharyngeal walls appear to allow energy storage and cocking; this permits extremely rapid expansion of the pharynx within the worm’s body during the strike, which yields an intense popping sound (likely via cavitation) and a rapid influx of water. Clearly, even soft-bodied marine invertebrates can produce remarkably loud sounds underwater. How they do so remains an intriguing biomechanical puzzle that hints at a new type of extreme biology.

1 aGoto, Ryutaro1 aHirabayashi, Isao1 aPalmer, Richard uhttps://linkinghub.elsevier.com/retrieve/pii/S096098221930617702351nas a2200181 4500008004100000022001300041245008300054210006900137260001600206300001700222490000700239520161500246100001401861700002201875700001801897700002101915856023301936 2019 eng d a0960982200aEgg-Cracking Vibration as a Cue for Stink Bug Siblings to Synchronize Hatching0 aEggCracking Vibration as a Cue for Stink Bug Siblings to Synchro cJan-01-2019 a143 - 148.e20 v293 a

Egg clutches of many animals hatch synchronously due to parental control [1, 2] or environmental stimu- lation [3, 4]. In contrast, in some animals, embryos actively synchronize their hatching timing with their siblings to facilitate adaptive behavior in sibling groups, such as mass migration [5, 6]. These em- bryos require synchronization cues that are detect- able from eggs and indicative of when the siblings hatch, such as pre-hatching vocalizations in birds and crocodiles [7, 8]. Previous studies, using methods including artificial presentation of non-spe- cific mechanical stimuli, demonstrated that vibra- tions or other mechanical forces caused by sibling movements are cues used by some turtles and in- sects [9–13]. However, there is no evidence about which movements of tiny embryos or hatchlings, among multiple possibilities, can generate mechani- cal cues actually detectable through eggs. Here, we show that embryos of the brown marmorated stink bug, Halyomorpha halys, synchronize hatching by responding to single pulsed vibrations generated when siblings crack open their eggshells. An egg- cracking vibration seems to be transmitted to distant eggs within a clutch while still maintaining its func- tion as a cue, thus leading to the highly synchronized hatching pattern previously reported [14]. In this spe- cies, it is possible that embryos attempt to hatch with short lags after earlier-hatched siblings to avoid egg cannibalism by them [14]. The present study illus- trates the diversity of social-information use by ani- mal embryos for success in the sibling group.

1 aEndo, Jun1 aTakanashi, Takuma1 aMukai, Hiromi1 aNumata, Hideharu uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982218314908https://api.elsevier.com/content/article/PII:S0960982218314908?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982218314908?httpAccept=text/plain02336nas a2200157 4500008004100000022001300041245005600054210005500110260001600165520166900181100002001850700003101870700002201901700002201923856023301945 2018 eng d a0960982200aVocal Turn-Taking in Meerkat Group Calling Sessions0 aVocal TurnTaking in Meerkat Group Calling Sessions cJan-11-20183 a

Coordination is a fundamental aspect of social living, underlying processes ranging from the maintenance of group cohesion to the avoidance of competition. Coordination can manifest as synchronization, where individuals perform the same action at the same time but can also take the form of anti-synchronization or turn-taking. Turn-taking has mainly been studied in the context of the development of language [1] due to the fact that it is a universal feature in all languages and has been found to appear early in infancy [2, 3]. Recently, turn-taking has received attention in animal communication research [4, 5, 6, 7] as a potential foundation on which social communication was formed [1, 3]. In this study, we describe turn-taking in group-wide vocal interactions of meerkats (Suricata suricatta) during low-conflict sunning behavior, which is accompanied by the production of specific “sunning calls.” We show that sunning-call production is socially stimulated and that at the group level, meerkats avoid overlap, thus fulfilling a key principle of turn-taking [8]. Through observational data and playback experiments, we show that these group-level patterns arise from two individual-level rules: call inhibition over short timescales, which prevents mutual interference, and call excitation over longer timescales, which stimulates further group calling. These simple rules suggest that hierarchy formation and turn allocation are not required for achieving group-wide coordination of communication. We also suggest that the potential bonding function of turn-taking shown in humans might have similar effects in animal interactions.

1 aDemartsev, Vlad1 aStrandburg-Peshkin, Ariana1 aRuffner, Michaela1 aManser, Marta, B. uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982218312910https://api.elsevier.com/content/article/PII:S0960982218312910?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982218312910?httpAccept=text/plain03094nas a2200397 4500008004100000022001300041245005700054210005700111260001600168520180000184653000801984653002301992653001702015653001302032653000802045653002102053653001502074653001702089100002202106700002202128700001802150700001902168700001602187700002502203700003402228700002402262700002302286700001602309700001802325700002602343700002602369700002602395700002502421700001702446856023302463 2018 eng d a0960982200aResource Ephemerality Drives Social Foraging in Bats0 aResource Ephemerality Drives Social Foraging in Bats cJan-11-20183 a

Observations of animals feeding in aggregations are often interpreted as events of social foraging, but it can be difficult to determine whether the animals arrived at the foraging sites after collective search [1, 2, 3, 4] or whether they found the sites by following a leader [5, 6] or even independently, aggregating as an artifact of food availability [7, 8]. Distinguishing between these explanations is important, because functionally, they might have very different consequences. In the first case, the animals could benefit from the presence of conspecifics, whereas in the second and third, they often suffer from increased competition [3, 9, 10, 11, 12, 13]. Using novel miniature sensors, we recorded GPS tracks and audio of five species of bats, monitoring their movement and interactions with conspecifics, which could be inferred from the audio recordings. We examined the hypothesis that food distribution plays a key role in determining social foraging patterns [14, 15, 16]. Specifically, this hypothesis predicts that searching for an ephemeral resource (whose distribution in time or space is hard to predict) is more likely to favor social foraging [10, 13, 14, 15] than searching for a predictable resource. The movement and social interactions differed between bats foraging on ephemeral versus predictable resources. Ephemeral species changed foraging sites and showed large temporal variation nightly. They aggregated with conspecifics as was supported by playback experiments and computer simulations. In contrast, predictable species were never observed near conspecifics and showed high spatial fidelity to the same foraging sites over multiple nights. Our results suggest that resource (un)predictability influences the costs and benefits of social foraging.

10abat10abehavioral ecology10aecholocation10aforaging10aGPS10amovement ecology10anavigation10asociobiology1 aEgert-Berg, Katya1 aHurme, Edward, R.1 aGreif, Stefan1 aGoldstein, Aya1 aHarten, Lee1 aM., Luis, Gerardo He1 aFlores-Martínez, José, Juan1 aValdés, Andrea, T.1 aJohnston, Dave, S.1 aEitan, Ofri1 aBorissov, Ivo1 aShipley, Jeremy, Ryan1 aMedellin, Rodrigo, A.1 aWilkinson, Gerald, S.1 aGoerlitz, Holger, R.1 aYovel, Yossi uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982218312909https://api.elsevier.com/content/article/PII:S0960982218312909?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982218312909?httpAccept=text/plain02627nas a2200241 4500008004100000022001300041245004800054210004800102260001600150300001600166490000700182520177900189100001901968700002101987700001902008700001802027700002102045700002102066700002502087700001702112700002302129856023302152 2014 eng d a0960982200aRapid Convergent Evolution in Wild Crickets0 aRapid Convergent Evolution in Wild Crickets cJan-06-2014 a1369 - 13740 v243 a

The earliest stages of convergent evolution are difficult to observe in the wild, limiting our understanding of the incipient genomic architecture underlying convergent phenotypes [1, 2]. To address this, we capitalized on a novel trait, flatwing, that arose and proliferated at the start of the 21stcentury in a population of field crickets (Teleogryllus oceanicus) on the Hawaiian island of Kauai [3]. Flatwing erases sound-producing structures on male forewings. Mutant males cannot sing to attract females, but they are protected from fatal attack by an acoustically orienting parasitoid fly (Ormia ochracea). Two years later, the silent morph appeared on the neighboring island of Oahu. We tested two hypotheses for the evolutionary origin of flatwings in Hawaii: (1) that the silent morph originated on Kauai and subsequently introgressed into Oahu and (2) that flatwing originated independently on each island. Morphometric analysis of male wings revealed that Kauai flatwings almost completely lack typical derived structures, whereas Oahu flatwings retain noticeably more wild-type wing venation. Using standard genetic crosses, we confirmed that the mutation segregates as a single-locus, sex-linked Mendelian trait on both islands. However, genome-wide scans using RAD-seq recovered almost completely distinct markers linked with flatwing on each island. The patterns of allelic association with flatwing on either island reveal different genomic architectures consistent with the timing of two mutational events on the X chromosome. Divergent wing morphologies linked to different loci thus cause identical behavioral outcomes - silence - illustrating the power of selection to rapidly shape convergent adaptations from distinct genomic starting points.

1 aPascoal, Sonia1 aCezard, Timothee1 aEik-Nes, Aasta1 aGharbi, Karim1 aMajewska, Jagoda1 aPayne, Elizabeth1 aRitchie, Michael, G.1 aZuk, Marlene1 aBailey, Nathan, W. uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982214005247https://api.elsevier.com/content/article/PII:S0960982214005247?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982214005247?httpAccept=text/plain01828nas a2200181 4500008004100000022001300041245007600054210006900130260001600199300001600215490000700231520124800238100002501486700002901511700002201540700001801562856006601580 2010 eng d a0960982200aAn Aerial-Hawking Bat Uses Stealth Echolocation to Counter Moth Hearing0 aAerialHawking Bat Uses Stealth Echolocation to Counter Moth Hear cJan-09-2010 a1568 - 15720 v203 a

Ears evolved in many nocturnal insects, including some moths, to detect bat echolocation calls and evade capture [1, 2]. Although there is evidence that some bats emit echolocation calls that are inconspicuous to eared moths, it is difficult to determine whether this was an adaptation to moth hearing or originally evolved for a different purpose [2, 3]. Aerial-hawking bats generally emit high-amplitude echolocation calls to maximize detection range [4, 5]. Here we present the first example of an echolocation counterstrategy to overcome prey hearing at the cost of reduced detection distance. We combined comparative bat flight-path tracking and moth neurophysiology with fecal DNA analysis to show that the barbastelle, Barbastella barbastellus, emits calls that are 10 to 100 times lower in amplitude than those of other aerial-hawking bats, remains undetected by moths until close, and captures mainly eared moths. Model calculations demonstrate that only bats emitting such low-amplitude calls hear moth echoes before their calls are conspicuous to moths. This stealth echolocation allows the barbastelle to exploit food resources that are difficult to catch for other aerial-hawking bats emitting calls of greater amplitude.

1 aGoerlitz, Holger, R.1 aHofstede, Hannah, M. ter1 aZeale, Matt, R.K.1 aJones, Gareth uhttp://linkinghub.elsevier.com/retrieve/pii/S096098221000991700454nas a2200145 4500008004100000022001300041245005600054210005300110260001600163300001400179490000700193100001900200700002300219856006600242 2016 eng d a0960982200aSignal Evolution: 'Shaky' Evidence for Sensory Bias0 aSignal Evolution Shaky Evidence for Sensory Bias cJan-01-2016 aR78 - R800 v261 aPascoal, Sonia1 aBailey, Nathan, W. uhttp://linkinghub.elsevier.com/retrieve/pii/S096098221501439602397nas a2200181 4500008004100000022001300041245008400054210006900138260001600207300001600223490000700239520181000246100002902056700002302085700002002108700002102128856006602149 2015 eng d a0960982200aEvolution of a Communication System by Sensory Exploitation of Startle Behavior0 aEvolution of a Communication System by Sensory Exploitation of S cJan-12-2015 a3245 - 32520 v253 a

New communication signals can evolve by sensory exploitation if signaling taps into preexisting sensory biases in receivers [1 ;  2]. For mate attraction, signals are typically similar to attractive environmental cues like food [3; 4; 5 ;  6], which amplifies their attractiveness to mates, as opposed to aversive stimuli like predator cues. Female field crickets approach the low-frequency calling song of males, whereas they avoid high-frequency sounds like predatory bat calls [7]. In one group of crickets (Eneopterinae: Lebinthini), however, males produce exceptionally high-frequency calling songs in the range of bat calls [8], a surprising signal in the context of mate attraction. We found that female lebinthines, instead of approaching singing males, produce vibrational responses after male calls, and males track the source of vibrations to find females. We also demonstrate that field cricket species closely related to the Lebinthini show an acoustic startle response to high-frequency sounds that generates substrate vibrations similar to those produced by female lebinthine crickets. Therefore, the startle response is the most likely evolutionary origin of the female lebinthine vibrational signal. In field crickets, the brain receives activity from two auditory interneurons; AN1 tuned to male calling song controls positive phonotaxis, and AN2 tuned to high-frequency bat calls triggers negative phonotaxis [9 ;  10]. In lebinthine crickets, however, we found that auditory ascending neurons are only tuned to high-frequency sounds, and their tuning matches the thresholds for female vibrational signals. Our results demonstrate how sensory exploitation of anti-predator behavior can evolve into a communication system that benefits both senders and receivers.

1 aHofstede, Hannah, M. ter1 aSchöneich, Stefan1 aRobillard, Tony1 aHedwig, Berthold uhttp://linkinghub.elsevier.com/retrieve/pii/S096098221501358501893nas a2200181 4500008004100000022001300041245010200054210006900156260001600225300001800241490000700259520129300266100002101559700002101580700002301601700002101624856006601645 2016 eng d a0960982200aAuditory fovea in the ear of a duetting katydid shows male-specific adaptation to the female call0 aAuditory fovea in the ear of a duetting katydid shows malespecif cJan-12-2016 aR1222 - R12230 v263 a

Convergent evolution has led to surprising functional and mechanistic similarities between the vertebrate cochlea and some katydid ears 1 ;  2. Here we report on an ‘auditory fovea’ (Figure 1A) in the duetting katydid Ancylecha fenestrata (Tettigoniidae). The auditory fovea is a specialized inner-ear region with a disproportionate number of receptor cells tuned to a narrow frequency range, and has been described in the cochlea of some vertebrates, such as bats and mole rats 3 ;  4. In tonotopically organized ears, the location in the hearing organ of the optimal neuronal response to a tone changes gradually with the frequency of the stimulation tone. However, in the ears of A. fenestrata, the sensory cells in the auditory fovea are tuned to the dominant frequency of the female call; this area of the hearing organ is extensively expanded in males to provide an overrepresentation of this behaviorally important auditory input. Vertebrates developed an auditory fovea for improved prey or predator detection. In A. fenestrata, however, the foveal region facilitates acoustic pair finding, and the sexual dimorphism of sound-producing and hearing organs reflects the asymmetry in the mutual communication system between the sexes ( Figures 1B, S1).

1 aScherberich, Jan1 aHummel, Jennifer1 aSchöneich, Stefan1 aNowotny, Manuela uhttp://linkinghub.elsevier.com/retrieve/pii/S0960982216312611