Vibratory courtship in a web-building spider: signalling quality or stimulating the female? (original) (raw)
Related papers
2013
Abstract Web-building spiders are important models for sexual selection. While our understanding of post-copulatory mechanisms including sperm competition and cryptic female choice is considerable, our knowledge of courtship and how it influences male and female mating decisions is still extremely poor. Here, we provide the first comprehensive description of male courtship behaviour and vibrations generated in the web by the orb-web spider, Argiope keyserlingi–a recognised model species.
Behavioral Ecology and Sociobiology
Condition-dependent secondary sexual traits and signals are often crucial for mate choice decisions. Nuptial gifts, provided by the male to the female during mating, may represent an indicator of male condition, especially if production of the gift is energetically costly. Additionally, other signalling modalities may well play a role in mate choice in such systems. Females of the nursery web spider Pisaura mirabilis preferably mate with males that provide a prey item wrapped in silk. Apart from the nuptial gift, vibrational signals employed during courtship and mating may reveal additional information about male condition. We tested condition-dependence of male vibrational signals of well-fed versus starved males, when in contact with female dragline silk and during mating trials. Our results show that vibrational signals are produced in P. mirabilis, both during pre-copulatory courtship and during copulation. Male courtship signals were condition-dependent: males in good condition...
Male courtship vibrations delay predatory behaviour in female spiders
Scientific reports, 2013
During courtship, individuals transfer information about identity, mating status and quality. However, male web-building spiders face a significant problem: how to begin courting female spiders without being mistaken for prey? Male Argiope spiders generate distinctive courtship vibrations (shudders) when entering a female's web. We tested whether courtship shudders delay female predatory behaviour, even when live prey is present in the web. We presented a live cricket to females during playbacks of shudder vibrations, or white noise, and compared female responses to a control in which we presented a live cricket with no playback vibrations. Females were much slower to respond to crickets during playback of shudder vibrations. Shudder vibrations also delayed female predatory behaviour in a related spider species, showing that these vibrations do not simply function for species identity. These results suggest that male web-building spiders employ a phylogenetically conserved vibra...
Behavioral Ecology, 2012
Reproductive success relies on communication signals used by females to exert mate attraction and assessment of female reproductive value by males. During mate search males of the spider, Stegodyphus lineatus experience high mortality and low female encounter rate. Females vary in sexual maturity and mating status (virgin and mated) and hence in reproductive value for males, which should influence male mating effort. Due to high costs of remating, only virgin females are expected to signal mate attraction. Males would benefit from mating preferentially with virgins due to the costs of overcoming mated females' resistance, although they gain paternity share. Males should avoid immature females, unless guarding precopulatory to access females on maturation. Low encounter rates predict males to invest also in females of inferior reproductive value. We investigated male ability to discriminate immature, virgin, and mated females by assessing: the number of females males visit in the field; male mating effort and male discrimination of females based on silk cues in laboratory trials. In the field, males were found most frequently with virgin females. Male mating effort, copulation success, and preference based on silk cues were higher with mature compared with immature females. Our data suggest that females signal sexual receptivity and that males are able to discriminate both sexual maturity and mating status, however, males do not exert strong preference for virgins. The combination of high costs of mate search and low encounter rate likely exerts selection on males to mate indiscriminately and overcome female resistance to remating.
Extreme short-term repeatability of male courtship performance in a tropical orb-web spider
Courtship signals are expected to be consistent within but vary between males of different qualities. Such traits are, therefore, predicted to exhibit high repeatability. However, studies have shown that courtship behaviors vary greatly in their within-individual repeatability, resulting in substantial variation in their ability to reflect male quality. This has implications for the evolution of female mate choice and courtship communication, as low levels of repeatability may reflect courtship signals that do not provide accurate quality information to females. In this article, we tested whether male courtship shuddering in the tropical orb-web spider, Argiope radon, influences female mate choice. We also tested whether male shudder performance reflects male phenotypic condition and is repeatable. We found that male shudder performance and condition predicted female latency to move onto the mating thread, a measure of mate preference. Aspects of male shudder performance were positively correlated with male body condition. Further, we found surprisingly high levels of repeatability in male courtship shuddering, ranking among the highest levels recorded to date for courtship behavior. We suggest that male courtship shuddering functions as an important indicator of male quality, with strong potential to respond to selection.
Animal Behaviour
Female and male preferences for various features of the male's vibratory courtship signals are described for the wandering spider Cupiennius getazi (Ctenidae). Preferences were determined by replaying synthetic and natural, but altered, conspecific male signals to the spiders. Although the number of females responding varied between the different test situations, the number of responses per replayed signal were not significantly different. The latency of the first female response was not correlated with the number of females responding, that is, with the quality of the male's signal. Females responded on average around the third replayed signal. Thus females appeared to follow an all-or-none response rule. They were only broadly tuned to the average properties of the male's releaser (e.g. they tolerated large variations of amplitudes, durations and repetition rates). Moreover, they did not prefer high to low amplitudes, long to short signals, or frequently repeated to rarely displayed signals or syllables. It thus seems unlikely that they differentiated between conspecific males during the vibratory communication phase of courtship. In contrast, females exhibited clear preferences for syllables longer than 240 ms and consisting of two 'subsyllables'. These patterns are typical for conspecific signals, but atypical for heterospecific signals. This strongly suggests that female preferences serve species recognition. Theory predicts that when male investment is small relative to that of females, males will be less selective in responding to cues indicating the presence of a potential mate. In C. getazi, displaytng males are such a cue for both sexes. In response to male vibrations, males had few preferences and were either as selective as females or less so (in two and flve of the seven tested parameters, respectively).
Behavioral Ecology and Sociobiology, 1996
Males of the brush-legged wolf spider, Schizocosa ocreata (Araneae: Lycosidae), possess a conspicuous male secondary sexual character: dark pigmentation and tufts of bristles on the tibiae of their forelegs. We tested several hypotheses relating to the role of this conspicuous trait in sexual selection. Triad mating experiments suggest that the tufts do not play an obvious role in the operation of sexual selection by either male competition or female choice, as there were no significant differences in the mating success of intact and experimentally shaved males. However, females mated more often with males that initiated courtship first, suggesting that capture of a female's attention by male signalling may play a critical role. In behavioral experiments that paired a single male with a female in arenas that allowed both visual and vibratory signal transmission during courtship, female receptivity did not vary significantly with the presence or absence of tufts. However, experiments that isolated the visual component of communication (by eliminating vibratory communication) revealed a significant effect of the presence of tufts: females showed receptivity less often to males with tufts removed. Female response to visual signals was much greater in S. ocreata than in its sibling congener, Schizocosa rovneri, which lacks male tufts. We hypothesize that the tufts serve to increase the efficacy of visual displays of S. ocreata, as vibratory communication is constrained by the complex leaf litter habitat of some populations. Such environmental constraints may make visual signalling over distance a critical factor for effective courtship communication, which may in turn strongly influence male fitness.
Juvenile vibratory experience affects adult mate preferences in a wolf spider
Behavioral Ecology and Sociobiology, 2023
While members of the choosier sex often prefer courting mates with bright, large, or loud phenotypes, social experience can result in variation in mate preferences. Fewer studies, though, have investigated how multiple social parameters might interact to affect such preferences. In the brush-legged wolf spider, Schizocosa ocreata, asynchrony of maturation between sexes provides a time period in which females might be exposed to male courtship prior to making a mating decision. We tested whether adult females demonstrated plasticity in their preferences for vibratory signal amplitude after experience with vibratory playback during their penultimate stage. Penultimate instar females were presented unimodal vibratory courtship signals via piezoelectric disc benders, manipulating the perceived encounter rate (every other day or once per day), the number of males (one or two), and/or the vibratory amplitude (low or high). As adults, each female was presented vibratory playback of a low-or high-amplitude courtship signal in both no-choice and two-choice designs. In no-choice trials, previous experience with different amplitude signals significantly affected adult preferences, while other social parameters did not. Specifically, female S. ocreata preferred high-amplitude signals to low-amplitude signals if previously exposed to high-amplitude signals, while those previously exposed to low-amplitude signals preferred low-amplitude signals. In twochoice trials, however, females preferred high-amplitude signals regardless of their previous social experience, suggesting that innate preferences for high-amplitude signals might outweigh any learned preferences in some contexts. Results from this study complement previous social experience studies in S. ocreata, by clearly demonstrating a second sensory modality through which social learning can occur. Significance statement Social experience affects subsequent mate preferences in a variety of taxa, but in many instances, single parameters are examined at a time. Furthermore, in species that use multimodal communication, there remain questions about whether a single sensory modality is sufficient to elicit such plasticity. In this study, we manipulated multiple parameters using vibratory playback to examine whether social experience during the brush-legged wolf spider's juvenile stage affected preferences for low-and high-amplitude signals as an adult. Ultimately, only the amplitude of the male's signals that they were exposed to as a juvenile impacted adult mate preference-not the number of perceived males or how often they encountered the males. These results, along with previous studies, demonstrate that S. ocreata is capable of plasticity in response to social cues in multiple modalities.