An official website of the United States government
For many animals, options abound when choosing a mate in socially complex environments like a breeding chorus or lek. In such environments, receivers often choose their mate based on individual differences in signal repetition rate. However, signallers also differ in the regularity with which they produce repeated signals. Irregularity in signalling introduces uncertainty in decision-making by masking the among-individual variation in signalling rate that is a target of mate choice. At present, we know little about how the complexity of the choice environment impacts selection on rate and regularity, two signalling behaviours that receivers can only compare after sampling series of signals produced by multiple signallers. In this study of female grey treefrogs (Hyla chrysoscelis), we measured multivariate sexual selection on the rate and regularity of male calling behaviour using two-, four-, and eight-choice tests. Receivers overwhelmingly chose faster, more regular calling rates in two-choice tests, but did so markedly less often when they chose among four or eight stimuli. Signalling behaviour became much less predictive of signallers’ relative fitness as choice complexity increased, suggesting noise and choice overload effects may shelter male phenotypes from sexual selection imposed by female choice in complex social environments.
more »
« less
This content will become publicly available on September 1, 2026
Complex choice environments shelter unattractive signallers from sexual selection
For many animals, options abound when choosing a mate in socially complex environments like a breeding chorus or lek. In such environments, receivers often choose their mate based on individual differences in signal repetition rate. However, signallers also differ in the regularity with which they produce repeated signals. Irregularity in signalling introduces uncertainty in decision-making by masking the among-individual variation in signalling rate that is a target of mate choice. At present, we know little about how the complexity of the choice environment affects selection on rate and regularity, two signalling behaviours that receivers can only compare after sampling series of signals produced by multiple signallers. In this study of female grey treefrogs (Hyla chrysoscelis), we measured multivariate sexual selection on the rate and regularity of male calling behaviour using two-, four- and eight-choice tests. Receivers overwhelmingly chose faster, more regular calling rates in two-choice tests, but did so markedly less often when they chose among four or eight stimuli. Sexual selection imposed by female choice became markedly weaker and differently shaped as the complexity of the social environment increased, suggesting noise and choice overload effects may allow relatively unattractive males to mate.
more »
« less
- PAR ID:
- 10636846
- Publisher / Repository:
- Royal Society
- Date Published:
- Journal Name:
- Proceedings of the Royal Society B: Biological Sciences
- Volume:
- 292
- Issue:
- 2054
- ISSN:
- 1471-2954
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Smiseth, Per (Ed.)Abstract Animal communication mediates social interactions with important fitness consequences for individuals. Receivers use signals to detect and discriminate among potential mates. Extensive research effort has focused on how receiver behavior imposes selection on signalers and signals. However, animals communicate in socially and physically complex environments with important biotic and abiotic features that are often excluded from controlled laboratory experiments, including noise. “Noise” is any factor that prevents signal detection and discrimination. The noise caused by aggregates of acoustic signalers is a well-known impediment to receivers, but how many individual signalers are required to produce the emergent effects of chorus noise on receiver behavior? In Teleogryllus oceanicus, the Australian field cricket, we assayed female preferences for a temporal property of male advertisement signals, the number of long chirp pulses, using two-, four-, six-, and eight-choice phonotaxis experiments. We found that, as the number of individual signalers increased, receivers became less likely to respond phonotactically and less likely to express their well-documented preference for more long chirp pulses. We found that very few individual signalers can create a sufficiently noisy environment, due either to acoustic interference or choice overload, to substantially impair female preference expression. Our results suggest that receivers may not always be able to express their well-documented mating preferences in nature.more » « less
-
Much is known about how the maternal environment can shape offspring traits via intergenerational effects. It is less clear, however, whether such effects may reach adult offspring sexual traits, with potential consequences for sexual selection and speciation. Here, we report effects of adult female aggregation density on the mating signals and mate preferences of their offspring in an insect that communicates via plant-borne vibrational signals. We experimentally manipulated the density of aggregations experienced by egg-laying mothers, reared the offspring in standard densities, and tested for corresponding differences in their signals and preferences. We detected a strong effect in male signals, with sons of mothers that experienced low aggregation density signalling more. We also detected a weak effect on female mate preferences, with daughters of mothers that experienced low aggregation density being less selective. These adjustments may help males and females find mates and secure matings in low densities, if the conditions they encounter correspond to those their mothers experienced. Our results thus extend theory regarding adjustments to the social environment to the scale of intergenerational effects, with maternal social environments influencing the expression of the sexual traits of adult offspring.more » « less
-
Abstract Variation in temperature can affect the expression of a variety of important fitness‐related behaviours, including those involved with mate attraction and selection, with consequences for the coordination of mating across variable environments. We examined how temperature influences the expression of male mating signals and female mate preferences—as well as the relationship between how male signals and female mate preferences change across temperatures (signal–preference temperature coupling)—inEnchenopa binotatatreehoppers. These small plant‐feeding insects communicate using plantborne vibrations, and our field surveys indicate they experience significant natural variation in temperature during the mating season. We tested for signal–preference temperature coupling in four populations ofE. binotataby manipulating temperature in a controlled laboratory environment. We measured the frequency of male signals—the trait for which females show strongest preference—and female peak preference—the signal frequency most preferred by females—across a range of biologically relevant temperatures (18°C–36°C). We found a strong effect of temperature on both male signals and female preferences, which generated signal–preference temperature coupling within each population. Even in a population in which male signals mismatched female preferences, the temperature coupling reinforces predicted directional selection across all temperatures. Additionally, we found similar thermal sensitivity in signals and preferences across populations even though populations varied in the mean frequency of male signals and female peak preference. Together, these results suggest that temperature variation should not affect the action of sexual selection via female choice, but rather should reinforce stabilizing selection in populations with signal–preference matches, and directional selection in those with signal–preference mismatches. Finally, we do not predict that thermal variation will disrupt the coordination of mating in this species by generating signal–preference mismatches at thermal extremes.more » « less
-
Noise is a common problem in animal communication. We know little, however, about how animals communicate in noise using multimodal signals. Multimodal signals are hypothesized to be favoured by evolution because they increase the efficacy of detection/discrimination in noisy environments. We tested the hypothesis that female túngara frogs’ responses to attractive male advertisement calls are improved in noise when a visual signal component is added to the available choices. We tested this at two levels of decision complexity (two and three choices). In a two-choice test, the presence of noise did not reduce female preferences for attractive calls. The visual component of a calling male, associated with an unattractive call, also did not reduce preference for attractive calls in the absence of noise. In the presence of noise, however, females were more likely to choose an unattractive call coupled with the visual component. In three-choice tests, the presence of noise alone reduced female responses to attractive calls and this was not strongly affected by the presence or absence of visual components. The responses in these experiments fail to support the multimodal signal efficacy hypothesis. Instead, the data suggest that audio-visual perception and cognitive processing, related to mate choice decisions, are dependent on the complexity of the sensory scene.more » « less
