Male preference for a subtle posture cue that signals spawning readiness in female sticklebacks

We presented territorial male three-spined sticklebacks, Gasterosteus aculeatus, two stationary dummies simultaneously, each simulating an equally gravid female. Both dummies featured the head-up orientation indicative of a sexually receptive female but differed in more subtle aspects of posture. In one dummy the back and tail were moulded in a relaxed straight posture and the other was moulded with the raised tail and concave back posture (lordosis), which mating tests revealed to be a strong predictor of spawning readiness in females. Males courted both dummies but directed more to the lordosis posture. Male sticklebacks thus recognize and respond appropriately to relatively subtle features of female posture in addition to other cues such as the head-up angle and dorsal barring reported in earlier studies. Physiological or morphological constraints may make the lordosis posture a reliable, and hence relatively honest, indicator of spawning readiness in females. Males may therefore enhance their fitness by preferentially courting females that assume this posture. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

Do Male Veiled Chameleons,Chamaeleo calyptratus,Adjust their Courtship Displays in Response to Female Reproductive Status?

Variation in male courtship behavior may be due to inherent differences among males or may arise from males adjusting their courtship displays according to female responsiveness. Female veiled chameleons, Chamaeleo calyptratus , exhibit two distinctive suites of body coloration and behavior patterns that vary according to receptive and non-receptive stages of their reproductive cycle. We presented male chameleons with both receptive and non-receptive females, and recorded differences in their mating frequency, courtship intensity and courtship behavior patterns. As expected, males were more likely to court and attempt mating with receptive females. Although fewer males courted non-receptive females, their courtship displays were significantly longer than those directed towards receptive females. Males also adjusted the contents of their displays according to female reproductive condition. Certain behavior patterns were unique to courtship displays directed towards each class of females. Males exhibited the behavior pattern `head roll' only when paired with receptive females, and `chin rub' was displayed only during courtship of non-receptive females. We hypothesize that these differences in male courtship frequency, intensity and content reflect differences in female reproductive value. Although males may benefit from mating with both receptive and non-receptive females, the costs associated with courtship may depend on female responsiveness. Thus, males adjust their courtship tactics accordingly.     

Court Like You Mean It: Male Siamese Fighting Fish are Less Attentive to Courting Males that Have Been Exposed to an Estrogen Mimic

Endocrine disrupting chemicals (EDCs) are ubiquitous in aquatic ecosystems where they have adverse effects on exposed organisms. In addition to causing physiological changes, EDCs often target fitness‐related behaviors such as locomotion and courtship. Ethinylestradiol (EE2) is an estrogen mimic that has been found to reduce courtship and aggression in males. However, the consequences of these reductions are not always explicitly addressed. One way in which EE2 may lead to decreased fitness occurs when males respond differently to exposed vs. unexposed conspecifics. To examine this, video playback was used to determine whether male Siamese fighting fish, Betta splendens, respond differently to exposed and unexposed males. Males were presented with four different combinations of videos of males played simultaneously: exposed swimming and unexposed swimming, exposed courting and unexposed courting, unexposed courting and unexposed courting, and exposed courting and exposed courting. Males directed more behaviors to the unexposed than the exposed courting male when presented simultaneously, likely because these unexposed males were perceived as a greater threat to mating success. Additionally, males spent more time tracking and gill flaring, two behaviors that are indicative of fight intent, when presented with two courting unexposed males. This combination could be considered the most threatening because there are two rival vigorously courting males present. These results suggest that EE2 exposure could result in exposed males receiving decreased attention from other males. However, since EE2 exposure also decreases competitive and courtship abilities, this would be far outweighed by the costs.     

Habituation and development of response specificity to a sign stimulus: male preference for female courtship posture in stickleback

I examined biased patterns of habituation that occur when reproductive male three-spined stickleback, Gasterosteus aculeatus, respond to a choice of two dummy females, one displaying the head-up posture of a sexually receptive female and an otherwise identical dummy lacking this sign stimulus (i.e. a dummy in a 'neutral' horizontal posture). Males initially courted both dummies about equally, but within 5 min, their courtship to the horizontal dummy began to habituate and was eventually replaced by attack behaviour, which increased about four-fold during the 1-h trial. Courtship to the head-up dummy continued unabated throughout the trial and by 5 min exceeded courtship to the horizontal dummy. Attack to the head-up dummy increased slightly in the first half of the trial then leveled off to about one-third that directed to the horizontal dummy. Both dummies were stationary and unreactive so could not directly provide differential feedback to the males. It is speculated that the self-arousal males obtain when responding to head-up posture reinforces their response to that cue. The salience of this sign stimulus may develop through an interactive process wherein the male's predisposition to recognize and court the head-up posture and the sexual self-arousal he obtains by doing so counter habituation and help maintain his sexual response to that cue. The stimulus-response specificity of male courtship is assumed to have an innate basis but requires experience to become fully differentiated. The results also illustrate that rate or extent of habituation to different stimuli, even on the same dimension, can differ within the same individual and in an adaptive manner. Copyright 2000 The Association for the Study of Animal Behaviour.     

Courtship feeding in Drosophila subobscura. II. Courtship feeding by males influences female mate choice

Male Drosophila subobscura provide females with a drop of regurgitated food during courtship. Males that were physically prevented from producing this drop (1) had reduced courtship success with starved, but not with fed, females; (2) positioned themselves in front of the female less frequently than males providing drops; and (3) had a smaller proportion of frontal displays which led to copulation. Males that produced small or watery drops also had reduced courtship success with starved, but not with fed, females. The starved females moved away from such males more frequently than from males providing large or yeasty drops. Evidence is presented in support of the hypothesis that the drops of food offered by males during courtship slow the moving female down, making it easier for the male to complete a frontal display, and to circle and attempt to mount before the female moves away after taking the food. The effectiveness of the drop in this role depends on its attractiveness to the female, which is influenced by the drop's size and content and by the female's nutritional status.     

Repeated Recent Aggressive Encounters Do Not Affect Behavioral Consistency in Male Siamese Fighting Fish

Consistent individual differences in behavior suggest that individuals respond in a predictable and repeatable manner in a specific situation while differing from other individuals. Male Siamese fighting fish exhibit consistent individual differences in decision‐making strategies when they encounter a receptive female and a rival male simultaneously. However, whether these differences are altered by recent experience is unknown. We examined the influence of repeated aggressive encounters on behavioral consistency and decision‐making. Males were presented with paired female–male dummies prior to any aggressive experiences to obtain a baseline measure. Next, males either won or lost three consecutive contests against rivals and then received the paired female–male dummies after each of these encounters. Overall levels of highly aggressive behaviors were affected by contest outcome, while levels of female‐directed were not. Not surprisingly, winning a fight led to an increase in male‐directed bites, an overtly aggressive behavior that only occurs after fights have escalated. Fighting a male before encountering the dummies caused males to perform more tail beats to the dummy male, perhaps as a result of increased motivation. Males exhibited similar levels of repeatability and used the same strategies when faced with conflicting stimuli regardless of fighting experience. Thus, while winning or losing a fight impacts overall aggression, it does not influence behavioral consistency. This study demonstrates that consistent individual differences and decision‐making strategies may be resistant to recent aggressive experiences, even over a period of days.     

Differential responses of yellow-breasted chats, Icteria virens, to male and female conspecific model presentations

A detailed understanding of the behavioural interactions between males and females is crucial for elucidating the selection pressures shaping mating system evolution; however, these interactions are often difficult to observe, particularly in free-living populations. We simulated extraterritorial intrusions by presenting conspecific models on to territories of a Neotropical migratory passerine, the yellow-breasted chat, Icteria virens. Simulated intrusions elicited different responses based on the sex of the focal individual and the sex and species of the model. Behavioural responses of the focal individuals were largely directed towards conspecific models, whereas simulated heterospecific intrusions, using a Carolina wren, Thryothorus ludovicianus, model, elicited minimal response. Male song was not related to any particular model presentation. Males directed mating behaviours, including courtship displays and copulations, exclusively towards the female conspecific model. Males behaved aggressively towards the conspecific male model. In contrast, females never showed any courtship behaviour towards the male model and showed significant aggression towards the conspecific female model. The results of this study reveal that territorial aggression in yellow-breasted chats is strongly intrasexual. Additionally, simulated female extraterritorial intrusions, but not male intrusions, resulted in extrapair courtship and copulation. This pattern is likely to be typical of many socially monogamous species and points to the behavioural mechanisms underlying both monogamy and extrapair mating systems.     

Learning Influences Courtship Preferences of Male Threespine Sticklebacks (Gasterosteus aculeatus)

Male threespine sticklebacks (Gasterosteus aculeatus) prefer to court the more gravid of a pair of dummy females (Rowland 1982, 1989). In this study, males were trained to modify their courtship preferences. Males were given two pre-punishment preference trials during which two dummy females—one approximating a normally gravid female and the other, a supergravid female, possessing an abnormally large abdomen — were simultaneously presented to males. After pre-punishment trials, males were subjected to one of two punishment procedures: punishment with weak electric shock (Experiment I) or punishment by the removal of females to simulate female retreat (Experiment II). During punishment trials, males were punished each time they courted the supergravid dummy. Control males were subjected to identical trials, but were not punished for courting the supergravid dummy. Post-punishment preference trials were given to all males (Experiments I and II). The results of Experiments I and II were similar. Punished and control males did not differ in their courtship preferences in pre-punishment trials; they preferred to court the supergravid dummy. Punished males, however, spent a significantly lower proportion of time visiting and directed a smaller proportion of zigzags (a courtship display) toward the supergravid dummy than did control males during punishment training (Experiment I) and post-punishment preference trials (Experiments I and II). These results suggest that courtship preferences of male threespine sticklebacks can be modified through learning. Such a mechanism could be important for adaptive mate choice under natural conditions.     

The role of hood-building in defining territories and limiting combat in fiddler crabs

In Panama, courting males of three species of fiddler crabs sometimes construct semi-domes of mud (=hoods) over their burrow entrances. Males that do not construct hoods court in a circular area surrounding their burrow entrance. Males with hoods restrict their general activity and courtship to the semi-circular area in front of the hood opening. For Uca latimanus hoods appear to be an integral part of the courtship ritual and are constructed by all courting males. In the other two species, U. musica terpsichores and U. beebei, hood-building is associated with high population density and the presence of hoods reduces the frequency of combat among neighbouring males.     

Metabolic efficiency in courtship favors males with intermediate mass in the Australian redback spider,Latrodectus hasselti

Recent studies have suggested that metabolic efficiency may be an important factor in male mating success when females require vigorous and/or prolonged courtship. In capital breeding animals in which a male’s resource pool is fixed at adulthood the relationship between energy expenditure and courtship performance may be especially important, as males are expected to utilize their finite resources efficiently when soliciting mates. Males may benefit from being efficient, i.e., achieving a sufficiently high level of courtship signaling at low energetic cost, if it enables them to acquire mates before their limited energy reserves are depleted. We investigated the relationship between metabolic efficiency and courtship vibrational signaling in the Australian redback spider, Latrodectus hasselti, a semelparous capital breeder where males invest heavily in courtship to secure a mating. We assessed metabolic rate in a sample of males and measured two courtship components (duty cycle and amplitude) that reflected the energy content of web-borne vibrations. We then calculated two indices of metabolic efficiency for these courtship properties. There was a quadratic relationship between mass and duty cycle such that the highest duty cycle signals were performed by males having intermediate mass. Furthermore, intermediate-mass males were also the most metabolically efficient. Prolonged courtship is necessary in L. hasselti for successful mating, and the results of this study suggest that intermediate-mass males are superior courters because they utilize their finite resource pool most efficiently to produce high energy vibrational signals.     

Release of male courtship display in Periplaneta americana: evidence for female contact sex pheromone

Male American cockroaches (Periplaneta americana) are attracted to virgin females by volatile sex pheromones. After antennal contact with the female they turn through 180° and spread their wings in courtship display. A chemical contact stimulus releasing male courtship is demonstrated in the female cuticle. Experiments with standardized olfactory stimulation by volatile sex pheromones revealed that the contact stimulus is sex-specific and species-specific. It can be washed off the cuticle with non-polar solvents and was successfully transferred to glass dummies. However, it is not effective in the absence of volatile sex pheromones. Thus volatile sex pheromones are responsible for male attraction and sexual motivation, while mate recognition is accomplished through the contact pheromone.     

Cheek pouch use in relation to interspecific competition and predator risk for three guenon monkeys (Cercopithecus spp.)

Forest guenons (Cercopithecus spp.) are often found in polyspecific associations that may decrease predator risk while increasing interspecific competition for food. Cheek pouch use may mitigate interspecific competition and predator risk by reducing the time spent in areas of high competition/predator risk. I investigated these ideas in three forest guenons: Campbell’s monkey (Cercopithecus campbelli), spot-nosed monkey (C. petaurista), and Diana monkey (C. diana). I present 13 months of scan sample data from Taï Forest, Côte d’Ivoire, including 3,675, 3,330, and 5,689 records of cheek pouch distention, to quantify cheek pouch use, for Campbell’s, spot-nosed, and Diana monkeys, respectively. Cheek pouches are often used to hold fruit, so I first predicted that the most frugivorous species, Diana monkeys, would have the most cheek pouch distension. Spot-nosed monkeys ate the least amount of fruit over the study period and had the least distended cheek pouches, suggesting the importance of frugivory in relation to cheek pouch distension for this species. This was not a sufficient explanation for Campbell’s monkeys; Campbell’s ate fruit less than Diana monkeys, but had more distended cheek pouches, suggesting that cheek pouch use was not simply a reflection of high frugivory. From the interspecific competition hypothesis, I predicted that Campbell’s monkeys would have more distended cheek pouches than Diana and spot-nosed monkeys, and more distended cheek pouches when associated with Diana because Campbell’s monkeys have the highest potential for interspecific competition with dominant Diana monkeys. From the predator risk hypothesis, I predicted that Campbell’s would have more distended cheek pouches when not associated with highly vigilant Diana monkeys. Campbell’s monkeys had the most distended cheek pouches overall, but had more distended cheek pouches when not in association with Diana, suggesting the greater importance of predator risk rather than interspecific competition in Campbell’s cheek pouch use.     

Mating patterns,mate choice,and birth season heterosexual relationships in free-ranging rhesus macaques

Birth season adult heterosexual nonkin relationships of 50 free-ranging female rhesus macaques (Macaca mulatta) in two social groups at Cayo Santiago, Puerto Rico were examined using focal follow (289 hr) and ad lib data. Eighty-eight percent of subjects had at least one relationship characterized by particularly high frequencies of spatial proximity, grooming, or both. These were designated “friendships.” Males intervened in aggressive interactions more frequently on behalf of Friends than non-Friends. Female aggressive support of males was extremely rare. Higher-ranking males experienced more friendships than lower-ranking males. High-ranking females had higher-ranking Friends than low-ranking females. Older females had higher-ranking Friends than younger females. Females groomed high-ranking Friends more than they were groomed by them, whereas they groomed low-ranking Friends less than they were groomed by them. In one social group, high-ranking females were more likely than low-ranking females to groom their Friends more than they were groomed by them. Males were more responsible than females for spatial proximity maintenance in 9 of 14 Friend dyads for which sufficient data were available. Neither male nor female dominance rank affected responsibility for proximity maintenance in Friend dyads. Eight of 24 females had friendships with males with whom they had completed copulations during their conception peri-ovulatory period of the preceding mating season. Two of 19 females completed peri-ovulatory copulations with Friends during the following mating season. Friendship was not correlated with either of two demonstrated female mate choice indicators: (1) proximity maintenance during estrus; or (2) cooperation with male “hip-grasp” courtship attempts. Males directed “muzzle-up” courtship signals at lower rates toward Friends than toward non-Friends. These and other investigators' results indicate that (1) protection from aggression is the primary benefit to female rhesus macaques of birth season heterosexual relationships; (2) the most effective protectors are in greatest demand as Friends; and (3) friendship has no effect or an inhibitory effect on mate choice in this species. Benefits to males of friendships were not apparent from this study but may include coalitional support against lower-ranking males.     

Female mating status affects male mating tactic expression in the wolf spider Rabidosa punctulata

Males and females have conflicting interests on the frequency and outcomes of mating interactions. Males maximize their fitness by mating with as many females as possible, whereas choosy females often reduce receptivity following copulation. Alternative male mating tactics can be adaptive in their expression to a variety of mating contexts, including interactions with a relatively unreceptive mated female. Male Rabidosa punctulata wolf spiders can adopt distinctive mating tactics when interacting with a female, a complex courtship display, and/or a more coercive direct mount tactic that often involves grappling with females for copulation. In this study, we set up female mating treatments with initial trials and then paired mated and unmated females with males to observe both female remating frequencies and the male mating tactics used during the interactions. Males adopted different mating tactics depending on the mating status of the female they were paired with. Males were more likely to adopt a direct mount tactic with already-mated females and courtship with unmated females. Already-mated females were considerably less receptive to males during experimental trials, although they did remate 34% of the time, the majority of which were with males using a direct mount tactic. Whereas males adjusting to these contextual cues were able to gain more copulations, the observation of multiple mating in female R. punctulata introduces the potential for sperm competition. We discuss this sexual conflict in terms of the fitness consequences of these mating outcomes for both males and females.     

Mate assessment in a cockroach,Nauphoeta cinerea

The behavioural effects of assessment of male dominance status on male and female courtship were investigated in the cockroach, Nauphoeta cinerea. Dominance hierarchies were established in laboratory groups of male N. cinerea; virgin females were then given the opportunity to (1) male with a subordinate male in the presence of dominant male odours; (2) mate with a dominant male in the presence of subordinate male odours; (3) mate with a male in the presence of another male's odour, both males lacking status; (4) mate when only a single male was present and no other male's odour was presented. The presence of the dominant male resulted in a significant delay in the approach of a female to a subordinate male and in the response of a female to a courtship display by the subordinate male. Males that lacked status were significantly slower to initiate courtship behaviours. Copulatory time was significantly shorter for subordinate males and males without status. Information concerning the dominance status of neighbouring males is used in assessment of appropriate mating behaviour by males and as a possible criterion in female choice.     

Mating behaviour in the Australian reptile tick Aponomma hydrosauri

Females of the Australian reptile tick Aponomma hydrosauri make few movements once they are attached to a host. Males move significantly more often on hosts with females attached. Male movement often leads to contact and courtship with females. Movement is most frequent in the early part of the dark phase of a photoperiod. After contact the courtship, both on the host and in experimentally induced off-host situations, follows a stereotyped sequence of positional orientations, here divided into six phases. Copulation does not automatically follow courtship initiation, and in particular successful courtship requires females to respond to male initiation by lifting their hind legs to allow the male to crawl under. Compared to other animal species, the males of A. hydrosauri play an unusually passive role in mate seeking. This may be explained by the extremely patchy distribution of the mate-finding environment, lizards.     

Inhibition of mating behaviour before feeding in the tick Aponomma hydrosauri

When on their host, both male and female adults of the reptile tick Aponomma hydrosauri require at least five days of feeding before normal mating behaviour will start. In off-host trials, fed females attract significantly more male contact than do unfed females, but unfed males show normal mating behaviour. All aspects of female mating behaviour are inhibited before feeding. Male mating behaviour has two stages: one comprises detachment and searching, the other, courtship behaviour. Only the former is inhibited before male feeding. This suggests the female signal has two components: one initiating searching, and the other initiating courtship. Males will always respond to the second component, but only after feeding will they respond to the first.     

Conditioning Mutations in DROSOPHILA MELANOGASTER Affect an Experience-Dependent Behavioral Modification in Courting Males

One aspect of courtship in male Drosophila melanogaster has been reported to be experience dependent. Males that have courted fertilized females are virtually unresponsive to virgin females for 2–3 hr. Here, this response was utilized as an assay for the effects of conditioning mutations on experience-dependent courtship. Seven strains expressing conditioning mutations (previously isolated and characterized for learning or memory defects in an electrical shock-odor association paradigm, independent of courtship) were all found to be mutant in expression of this experience-dependent change in courtship behavior. By comparison, three control strains that were unselected for conditioning defects all expressed normal experience-dependent courtship. Other results indicate that males of the conditioning-defective strains are able to elicit necessary cues from fertilized females, yet do not then modify their courtship with virgin females. Thus, it is suggested that experience-dependent modification of courtship and the previously reported associative olfactory conditioning with electric shock share common elements of processing. The possibility that experience-dependent courtship represents adaptive behavior is discussed.     

Changes in courtship behaviour following rejection: The influence of female phenotype in Drosophila melanogaster

Courtship can be costly and so selection should favour individual males that reduce courtship towards female types that have a low probability of resulting in copulation. One way males can do this is by associating previous courtship failure with the traits of particular rejecting females. We characterised changes in male Drosophila melanogaster courtship behaviour following a failed mating attempt with one of the four female phenotypes that varied in size, age or mating status. To do this, we assessed individual courtship behaviour for each male presented again with a female of the same phenotype that previously rejected him. Males reduced subsequent courtship most strongly for recently mated (sexually non‐receptive) females. More interestingly, males also significantly reduced courtship activity following a failed mating experience from old females but did not do so for control (large, young, virgin) or small females. As such, males significantly reduced courtship towards both female types possessing chemical cues associated with their phenotype (age and mating status), but not towards a female phenotype based on physical characteristics (body size). Our results suggest that males are able to modify their courtship behaviour following experience, but that they are better prepared to associate chemical traits that may be more reliable indicators of the likelihood of courtship failure.     

Male swordtails court with an audience in mind

Females are usually considered to be the target of male courtship behaviour. In nature, however, social interactions rarely occur without other observers; thus, it is conceivable that some male courtship behaviours are directed not towards females, but rather towards male rivals. The northern swordtail, Xiphophorus birchmanni, is a freshwater fish found in high densities in natural streams. Males court by swimming close to and in parallel with the female, raising their large sail-like dorsal fin, and quivering briefly. Here, we show that females prefer males that display small dorsal fins to those with large ones, and that males are less aggressive to other males with large dorsal fins. Male swordtails also raise their dorsal fins more frequently when courting in the presence of other males. These results suggest that, despite female avoidance of large dorsal fins, males that raise their fin during courtship benefit by intimidating potential competitors; the intended receivers of this signal are thus males, not females. Intrasexual selection can therefore offset the forces of intersexual selection, even in a courtship display.