Introduction
“Peacocks are known to be one the most diverse, intersexually as well as intrasexual competitive species within the animal kingdom. Not only do they have lustrous, long trains for lekking in intrasexual competitions, but also the number of ocelli they show to females is intersexually selected upon. All of these sexual signals in peacocks are astounding to the human eye, but our aspiring minds must wonder; what is it that causes these multiple modalities? This question was asked and empirically tested by Girard, Elias, and Kasumovic, in their in-depth study, ‘Female preference for multi-modal courtship: multiple signals are important for male mating success in peacock spiders,’ of multi-modal signals in jumping spiders.”
Sexual selection and mating patterns form a crucial part of behavior ecology. In most of the cases, such subjects are analyzed independently (Girard and Endler 590). However, concerns have been raised over the role of sexual selection on mating patterns. As such, this paper is a review based on the work of Girard et al., on “Female preference for multi-modal courtship: multiple signals are important for male mating success in peacock spiders. The authors of this article focus on providing an explanation on a subject that not many scholars and researchers have analyzed in-depth in the past. The choice of this paper was informed by the fact that there is a need to explain the preference of females’ decisions as far as mating traits of males are concerned. With the sparse empirical evidence on sexual selection and mating patterns, the approach of this study provides the necessary insights into the subject.
According to Girard et al., many biologists are eager to understand the operations of female species in environments of increased malesâ sexually selected traits. With specific reference to the jumping spiders of the Maratus genus, the authors note that they are extraordinarily dimorphic in terms of their signaling behavior and appearance (1). Møller and Petrie presumed that the evolution of complex signals that are evident among the males is instigated by the availability of a strong sexual selection among the females (248). In spite of the fact that there are numerous examples that explain the nature of sexual selection and mating patterns, there is still limited empirical evidence to explain the use of numerous modalities for intersexual communication among various species. For this reason, this review focuses on the provision of more insights on the subject of sex and evolution with a specific focus on the explanation of female preference for multi-modal courtship and why the use of multiple signals by the males is important for male mating success in jumping peacock spiders.
Background of the Area of Study
The subject of sexual selection and mating patterns has raised a lot of concern among biologists in different parts of the world. Sexual selection describes a natural selection model in which members from one biological sex make a decision on their mating partners. According to Møller and Petrie, such an arrangement implies that there is some level of competition based on both intersexual and intrasexual selection (250). For this reason, there are members who exhibit better reproductive success in comparison to their counterparts due to either a high preference for attractive partners or being more attractive.
Charles Darwin, who noted that the process of sexual selection is not ubiquitous, first introduced its idea. As such, this concept can be described as driving speciation in which living organisms tend to develop various features to enhance their mating patterns. This explains why different male organisms have various approaches that they use for the demonstration of their attractiveness.
According to the redundant signal and multiple messages hypothesis for the evolution of multi-modal signal, it is more likely that multiple ornaments are specifically common among taxa that have relatively uncostly and fine-tuned female choice (Takahashi, Arita, Hiraiwa-Hasegawa, and Hasegawa 1209). In addition, Griskevicius et al. noted that it is more likely that females have equal attention to all secondary sex traitsâ expression for the purpose of estimating the condition of the male (85). Nevertheless, the unreliable signal hypothesis postulates that some ornaments are produced on the basis that they are uncostly and that there exist some females that are weak to such ornaments.
In support of this, Lazano notes that the presence of multiple modalities might be helpful to the males since femalesâ preference for a given modality is based on their assessment of the quality and condition of the male (37). In spite of this, Lazano points out that the use of different types of coloration and ornamentation can be costly due to predation risks and choosiness (38). This can be attributed to the fact that the choice of prospective mates in an environment with predators the selectivity is adversely affected by increased assessment costs. In support of the statement, Hunt, Brooks, and Jennions pointed out the presence of predators affects the ease of male assessment among females and hence, low selectivity (79). Such findings align with the objective of Girard et al. in their examination of the importance of multiple signals for male mating success in peacock spiders.
In spite of the fact that multiple modalities are used to draw the attention of the females, Sundie et al. noted that there are cases when such ornaments might attract predators (664). As such, they are considered non-adaptive in the event that they attract predators. Nevertheless, ornaments play a significant role in sexual reproduction. In most cases, ornaments are commonly observed in males. According to the good genes theory, females tend to choose a male that has extravagant ornament since such ornaments are considered to be “good genes” that are passable to the females’ offspring, and hence, the female increases its own reproductive fitness. In such a case, Loyau, Jalme, Cagniant, and Sorci asserted that the male offspring tend to inherit ornaments from the male that engaged in sexual reproduction with a given female, while on the other hand, the female offspring inherits the preference for the given modality hence, leads to the Fisherman runaway positive feedback loop (552).
The authors of Female preference for multi-modal courtship: Multiple signals are important for male mating success in peacock spiders focus on the exploration of the subject of sexual selection and mating patterns. Specifically, the research narrows down to examine the relationship between the use of multiple modalities and the success of mating among the male spiders.
Definition of the work
This research is based on the fact that there is limited empirical evidence to explain various practices among male species, such as the use of multiple courtship modalities and the preference of females to such modalities. In addition, the study seeks to find out whether or not there is a link between mating success and the application of several courtship signals.
Girard et al. have carried out several studies in the past that are closely related to this one, including the study on Multimodal courtship in the peacock spider, Maratus Volans. However, in most of the previous studies carried by these authors, independently or joint, the focus was on examination of various traits of sexual selection and mating patterns in isolation. For example, in their study on Multimodal courtship in the peacock spider, Maratus Volans, Girard, et al. established that the Maratus Volans spiderâs courtship is quite complex. In addition, this study provided the basis to use laser vibratory in examining the visual displays of the spiders based on the finding that some male species have a tendency of producing vibrations that are concurrent with visual displays.
As noted earlier, this study was focused on the examination of mating behaviors. This was informed by the fact that most mating behavior studies have challenges in the explanation of the important traits whenever it comes the female mating decisions. As such, to achieve the objective of the exploring the role of vibratory courtship and visual motion traits in the mating decisions of peacock spider, the study used video recording approach as well as the laser vibrometry methods for the purpose of characterizing, quantifying and examining the male courtship traits that enhance their mating success.
The study was carried out in Sydney, New South Wales, where live spiders were collected. The spiders were paired and mating trials carried out between 09.00 and 16.00hours. A stationary camera that was fixed above the study area was used to record all the activities of the spiders. In addition, a laser vibrometer was used to capture vibratory courtship, and the recordings made using a digital recorder. The mating arena was prepared such that it represented the environment in the wild.
The second mating trials were conducted using a different male for females that mated previously.
The behaviors of the female and male spiders were used to construct ethograms, while each trial was scored using a JWatcher Video. The proportionate time that the interactions took was the basis of the analysis of the female and male mating behaviors.
Even though the study was able to collect considerable data on the mating behaviors of peacock spiders, it was not without some challenges. For instance, measuring the reflectance, shape, and size of the M. Volans was not possible due to the fact that the fans of this species of spiders are small and have complex color patches. For this reason, measuring the fan ornamentation required the adoption of a traditional spectrophotometer. As such, any study in the future should use hyperspectral camera to overcome such challenges, as well as make it easy to examine the impact of color variation changes on the preferences of females to mate.
Impact of the work
The study about the mating patterns of spider peacock was very detailed and comprehensive. Based on its approach, the primary objective was to provide readers with reliable information as far as the subject of sexual selection and mating patterns is concerned. As such, the results of this study were rock solid and reliable. This can be attributed to the fact that the researchers carried out numerous trials before making the final conclusion on the subject under investigation. Specifically, the study involved 64 mating trials in which virgin female were used. Out these trials, 16% comprised of successful copulation between the male and the female.
The use of the virgin female spiders was appropriate in this case, as it gave the researchers firsthand data and experience on what transpires before successful copulation among spiders. In addition, given that 16% of the total number of trials recorded success in mating was provided enough data on the interactions of male and female spiders as far as modalities used by the male to succeed in mating are concerned. For this reason, it was evident that the results provided in this study were based on valuable data.
Within the behavior ecology, scientists have been faced with the challenge of explaining which sexual selection traits are significant when it comes to influencing the mating decisions of female organisms. This study was very useful in shedding light on these aspects by focusing on vibratory and visual motion courtship of the spiders. Based on its contribution to such knowledge, the research was published in the Proceedings of the Royal Society B: Biological Sciences. The findings of this study are important not only for academic purposes but also as an addition to the literature on mating behaviors. For example, the study found out that male spiders use both vibratory and visual signaling for mating success, and that the use of each one of these modalities has its own advantage as far as succeeding in attracting the female is concerned. In addition, the study provides information on the relationship between copulation duration, latency to mate, visual courtship effort, and the mating success. Such findings are important as precursors for future studies focusing on specific aspects of male traits. For example, future studies would focus on the examination of the relationship between egg laying and the copulation during for spiders.
The study also provides the ground for future work to examine the abdominal fan ornamentation of the spider. This is based on the fact that the current study, though its objectives were, it did not examine the role of color variation in mating success or even, examine the relationship that was there between other courtship traits and color patterns. Based on the analysis of the results and findings of this study, it is evident that the research has great impact in the subject of behavior ecology specifically on the role of various signals used by male organism to attract females. For this reason, this research can be used widely for reference as well as a background for further studies on the subject.
This topic is quite significant as far as the field of behavior ecology is concerned. This is based on the fact that there is a need among biologists to understand the preference of female organisms to certain mating signals. In spite of this, there still are limited sources on this subject. In addition, Loyau, Jalme, and Sorci pointed out that there is scarcity in terms of studies explaining the importance of specific approaches to mating success (810). Even though the mating success can be attributed to sexual selection, it is evident that there are various traits that explain such success. For this reason, a research on the relationship between various courtship signals and the mating success would help to explain the preference of females to different signals as well as the role of multiple courtship modalities in the success of males to mate.
Prospectus and Conclusion
The study established the need to gain understanding on the role of multiple modalities among male peacock jumping spiders. This was informed by the fact that even though it is known that sexual selection account for the preference of females to choose their mating partners, there is limited empirical evidence to explain the role of different courting traits in mating success. Girard et al. found out that M. volans males combine both visual and vibratory signals to draw the attention of the females. This is attributable to the significance of multiple modalities as postulated in the redundant and multiple messages hypotheses.
The use of the two approaches is helpful to the males in that they attract females that have a high preference of either the visual or the vibratory signals. In addition, the study established that it was highly likely for female spiders to mate with the males which had more visual effort, as well as those that displayed their ornaments for the longest time. Such preference can be explained by the principles of the good gene hypotheses where the females choose their mating partners based on the need to pass the supposed âgood genesâ their offspring for a chance to ensure increased reproductive fitness.
Based on the studyâs findings, it was evident that there was a significant relationship between the mating success and the production of vibrational signals. The link was only noticeable relative to the proportion of time males spent vibrating as well as the vigour with which they signaled. In spite of this, the relationship was significantly weak when correlated with mating success. The study found out that there was a strong correlation between increased copulation durations and malesâ increased visual courtship effort. On the other hand, there was no correlation between malesâ visual courtship effort and the production of eggs. In general, it was evident that the femalesâ preference for males was based on the quality of males with respect to their performance. As evident in the study, males that succeed in mating with the females were persistent in their courtship and would continuously move close to them as well as ensure constant visual contact.
The results of this study are consistent with a number of previous findings which point out that it is more likely that courtship effort as well as motor performance is significant factors in quality male spiders as opposed to their specific trait elements. However, it is more likely that the ability of the male to maintain the mating interest of the female also has significant impact on mating success. In the case of peacock spiders, the orientation of the female determines its female preference.
Therefore, the study achieved its intended objective regarding establishing the role of multiple modalities among male peacock jumping spiders. As such, it suffices to note that the mating success of the spiders is determined by the courtship effort the males employ, as well as the quality of their performance. On the other hand, the choice of a mating partner especially for sexual reproduction among the females is influenced by the malesâ display of ornaments as well as the need to increase their reproduction fitness as postulated in the good genes hypotheses.
Works Cited
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