02443nas 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/s00265-018-2632-102987nas a2200229 4500008004100000022001300041245010100054210006900155260001600224300001200240490000800252520209000260653003002350653001302380653001902393653002102412653001902433653001702452100002802469700002702497856023302524 2018 eng d a0003347200aHormonal and social correlates of courtship signal quality and behaviour in male green treefrogs0 aHormonal and social correlates of courtship signal quality and b cJan-12-2018 a13 - 220 v1463 a

Circulating hormone levels often vary considerably among males competing for mates, but how thisvariation affects the signalling phenotype is poorly understood. In the green treefrog, Hyla cinerea, malescompeting for mates engage in vocal contests that increase circulating levels of the adrenal glucocor-ticoid corticosterone (CORT) and decrease androgens in contest losers, who characteristically adopt anoncalling ‘satellite’ mating tactic. We previously showed that CORT administration to calling malesreduces vocal effort and increases the probability of satellite behaviour during simulated territorial in-trusions, suggesting that elevated CORT compromises vocal quality and decreases the propensity to callin a context-dependent manner. However, the extent to which these effects reflect variation in vocalbehaviour of males in natural choruses is unclear. Here, we examined how hormone levels, social contextand other potential determinants of vocalization, including body size and condition, relate to vocal at-tributes and behaviour in calling males and in associated satellites after removal of calling ‘host’ males.Results revealed that satellites had higher CORT and lower androgens and were smaller and in poorercondition than host males. Host removal resulted in vocalization in 74% of satellites. These males investedless effort in vocalization than hosts, and CORT level best explained these differences. The remaining 26%of satellites did not vocalize after host removal and had lower androgens than satellites that vocalized.Results provide support for context-dependent effects (i.e. host presence/absence) of elevated CORT onthe probability of vocalization and link high CORT to reduced vocal quality. In contrast, low androgenswere associated with a low probability of vocalization regardless of social context, and androgen levelwas a poor predictor of vocal attributes. Our results link high CORT and low androgens to variation insignalling quality and behaviour that potentially reduces the probability of attracting females.

10aalternative mating tactic10aandrogen10acorticosterone10acourtship signal10aglucocorticoid10amale contest1 aCrocker-Buta, Sarah, P.1 aLeary, Christopher, J. uhttps://linkinghub.elsevier.com/retrieve/pii/S0003347218303026https://api.elsevier.com/content/article/PII:S0003347218303026?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347218303026?httpAccept=text/plain00881nas a2200169 4500008004100000022001400041245006100055210005800116260001600174300001200190490000800202520040900210100001800619700001900637700001400656856004100670 1978 eng d a0036-807500aSexual Parasitism in the Green Tree Frog (Hyla cinerea).0 aSexual Parasitism in the Green Tree Frog Hyla cinerea c1978 Jun 09 a1179-800 v2003 a

Noncalling adult male tree frogs were found in close association with about 16 percent of the calling males in a pond in Georgia. In 13 of 30 field experiments a noncalling satellite male intercepted and achieved amplexus with a gravid female moving toward the calling male. This mating strategy, which conserves energy required for calling, resembles the strategy employed by other vertebrates.

1 aPerrill, S, A1 aGerhardt, H, C1 aDaniel, R uhttps://bio.acousti.ca/nl/node/5312801978nas a2200121 4500008004100000245008900041210006900130260003200199490000800231520152400239100001901763856007401782 2018 eng d00aSources of Variation in Social Plasticity in Female Mate Preferences and Male Traits0 aSources of Variation in Social Plasticity in Female Mate Prefere bThe University of Milwaukee0 vPhD3 a

Female preferences are an important cause of selection on male traits, and exploring the sources of variation in these preferences has been the focus of intense behavioral research. This is due to the fact that understanding this variation is integral to understating the maintenance of variation and complexity in male traits, as well as the evolution and divergence of populations. This project aims to explore the sources of variation in these mating preferences, as well as examine whether similar sources affect components of male traits. This was accomplished using the well-studied mating system of the Green Treefrog, Hyla cinerea that features female preferences for the male advertisement call. Using playback experiments, I dissect the constituent parts of female preferences – preference functions and choosiness, and demonstrate that sources of variation in preferences can be due to interactions between choosiness and social experience, as well as interactions between female body size and the shape of a female’s preference function and the constituent traits of the preference function curve. Further, I demonstrate that social experience also affects the male trait, and can drive variation in the presentation of advertisement calls. This work demonstrates that while sexual selection can be a strong and directional driver of the evolution of mating behaviors, substantial variation can arise from a number of sources that may have profound effects for the evolution of species.

1 aNeelon, Daniel uhttps://search.proquest.com/openview/a7b1ba820ceb30df89153941c372520604022nam a2200157 4500008004100000020001800041022001300059245007000072210006900142260001300211300001300224490000700237520353500244100001903779856006603798 2001 eng d a9780120045303 a0065345400aAcoustic communication in two groups of closely related treefrogs0 aAcoustic communication in two groups of closely related treefrog bElsevier a99 - 1670 v303 a

Studies of vocal behavior in anurans provide significant insights about the mechanisms and evolution of animal communication. Females extract the information required for a mating decision from relatively stereotyped advertisement calls that are produced by males. Aggressive signals, used in exchanges between males, are more variable in form, as might be expected of communication between rivals, but overall, their structure is more similar in closely related species than is that of advertisement calls. One open question is why, within the groups of treefrogs considered in this review, aggressive signaling is so prevalent in some species and rare or absent in close relatives.

Comparative studies of the acoustic criteria used in signal selection reveal significant differences among species. What are important properties for one species are seemingly irrelevant for its closest relative. Moreover, as exemplified by gray treefrogs and European katydids, even when females apparently base preferences on the same acoustic property, deeper analysis reveals that different mechanisms are used by each species to extract a different aspect of that property. In several of the treefrog species considered in this review, some preferences and preference-mechanisms are more divergent than call structure (Sections II.E and III.E). More research with additional species is needed before we can even attempt to make broad generalizations about the coevolution of signalers and receivers in animal communication systems.

Communication usually takes place in acoustically difficult situations: dense choruses, where background noise presents special challenges for signal detection and pattern recognition. Although they can quantify acoustic preferences, playback experiments in simplified laboratory situations are unlikely to accurately predict patterns of mate choice in nature. Studies with species in the green and gray treefrog groups show that the optimum values of particular acoustic properties can vary depending on the absolute playback level to which alternatives are equalized, the relative playback levels of alternatives, the number of sounds presented and their timing relationships, and the ambient temperature. Comparable results are available for other anurans and acoustic insects. Technology that allows researchers to monitor groups of calling males, whose signals and mating success can be quantified, promises to refine our estimates of how female selectivity contributes to mate choice in nature (e.g., Passmore et al., 1992; 156 and 157).

Studies of geographical variation in communication systems are limited because we know so little about patterns of variation in receiver selectivity. Even where acoustic properties have diverged in sympatric areas relative to allopatric areas, and hence show the pattern expected of reproductive character displacement, we often do not always know whether these properties are even relevant to females. A few studies have shown that female selectivity diverges in sympatric areas, whereas signal structure does not, a result that may reflect the fact that the choosing sex usually has more to lose from mating mistakes than the signaling sex. I predict, however, that studies of geographical variation in the acoustic criteria and selectivity of receivers will ultimately provide significant insights concerning the evolution of communication systems that will go well beyond the narrow issue of reproductive character displacement.

1 aGerhardt, Carl uhttp://linkinghub.elsevier.com/retrieve/pii/S0065345401800061