Trans-Generational Influence of Human Disturbances in Japanese Quail: Egg Quality Influences Male Social and Sexual Behaviour

In many bird species prenatal exposure to yolk androgens of maternal origin has been found to influence offspring behavioural phenotype. In contrast to altricial birds, far less is known about maternal effects in precocial birds. In a previous experiment we found that female quail ( Coturnix japonica ) that were not previously habituated to humans (NH) produced eggs with less androgens (testosterone, androstenedione) and more progesterone when exposed to human disturbances than females habituated to humans (H). Here, we analysed social motivation and sexual behaviour of the male offspring of NH and H females. Classical behavioural test procedures were applied including separation, runway, partner choice and female encounter tests. As chicks, offspring of the NH females spent more time far from conspecifics than offspring of the H females. As adults, the same NH males showed less crowing and courtship behaviour (ritual preening) in female encounter tests than H males. Thus, maternal environment and egg quality may be key factors in the emergence of individual variability of appetitive behaviour, such as social proximity and courtship behaviour. Human disturbance of the mother seems to have triggered trans-generational effects resulting in consistently reduced social and sexual motivation in offspring until adulthood.     

Behavioral and hormonal correlates of social dominance in stable and disrupted groups of male domestic fowl

An experiment was conducted to determine the behavioral and hormonal correlates of social dominance in stable and disrupted groups of male domestic fowl (Gallus domesticus). In addition, the relative importance of visual and auditory cues in the maintenance of dominance status in this species was assessed. Alpha roosters were removed from their six-bird home pens for 1 week, and placed in either (1) and adjacent pen in visual contact with penmates, (2) and adjacent pen where visual, but not auditory, contact was prevented, or (3) a different building where they were in visual and auditory isolation. Dominance rank, aggressive activity, and crowing frequency were intercorrelated during the premove period. There was a significant increase in both aggression and crowing among the males remaining in the home pen following removal of the alpha male, except in the treatment in which males were still in visual contact with the removed alpha, in which only aggression increased. Increases in crowing frequency were also noted in alpha males. High levels of aggression occurred when alpha males were returned except in those pens in which visual contact had been maintained. Visual cues thus appear to be more important than auditory cues alone with respect to the maintenance of dominant social status in roosters. There were no clear correlations between behavioral variables and plasma androgen or corticosterone levels in either the stable or disrupted flocks, and no consistent changes in the levels of these hormones as a result of experimental manipulation; several possible explanations for this finding are discussed.     

Predation risk assessment by olfactory and visual cues in a coral reef fish

Assessment of predation risk is vital for the success of an individual. Primary cues for the assessment include visual and olfactory stimuli, but the relative importance of these sources of information for risk assessment has seldom been assessed for marine fishes. This study examined the importance of visual and chemical cues in assessing risk for the star goby, Asterropteryx semipunctatus. Visual and chemical cue intensities were used that were indicative of a high threat situation. The behavioural response elicited by both the visual cues of a predator (the rock cod, Cephalopholis boenak) and the chemical alarm cues from conspecifics were similar in magnitude, with responses including a decrease in feeding strikes and moves. A bobbing behaviour was exhibited when the predator was visible and not when only exposed to the chemical alarm cue. When visual and chemical cues were presented together they yielded a stronger antipredator response than when gobies were exposed solely to conspecific alarm cues. This suggests additivity of risk assessment information at the levels of threat used, however, the goby’s response is also likely to depend on the environmental and social context of the predator–prey encounter. This study highlights the importance of chemical cues in the assessment of predation risk for a coral reef fish.     

Effect of female brooding behaviour on male mate choice in Japanese quail, Coturnix japonica

Brooding behaviour is a likely cue to a female's reproductive status and therefore a potentially important factor in male mate assessment. We induced brooding behaviour in adult female Japanese quail by exposure to foster chicks for five 20-min trials over 3 days. In two experiments, we assessed the influence of this brooding behaviour on male mate choice in Japanese quail using an established mate choice paradigm. In each experiment we gave males a choice between two females presented simultaneously and measured preference by the time spent in proximity to each. In the first experiment, a male's preference for the initially preferred female significantly decreased after he had seen her brooding three chicks. In the control condition, male preference for an initially preferred female remained relatively consistent over consecutive trials if he did not see her brood chicks. These results suggest that females who are brooding chicks are less attractive to male Japanese quail. Further evidence from the second experiment substantiates this finding, and strongly suggests that males are averse to behavioural cues from maternal females, rather than the mere presence of chicks. Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.      

Responses of larval dragonflies to conspecific and heterospecific predator cues

Abstract.  1. In cannibalistic populations, smaller individuals are subject to predation by larger conspecifics, and small individuals commonly alter their behaviour in response to cannibals. Little is known, however, about the underlying cues that trigger such responses and how the behavioural responses to conspecific cannibals differ from heterospecific predators.
2. This study tests which cues are used for the detection of conspecific predators in the larva of the dragonfly Plathemis lydia and how the behavioural response to cannibals differed from the response to heterospecific predators.
3. Individuals were exposed to chemical cues, visual cues, and a combination of both cues from conspecifics as well as no predator and heterospecific predator controls during which their activity and feeding rates were observed.
4. Individuals increased their activity, spatial movement and feeding behaviour in response to either visual or chemical cues from conspecific predators, which was opposite to responses displayed with cues from heterospecific predators. Interestingly, the responses to visual and chemical cues from conspecifics combined were weaker than to either cue in isolation and similar to the no cue control.
5. The results clearly indicate that individuals are able to use chemical and visual cues to detect even very subtle differences in phenotype of conspecific predators.
6. The opposite response in behaviour when exposed to conspecific cannibals vs. heterospecific predators suggests that the presence of cannibals will increase the mortality risk of small individuals due to heterospecific predation. This risk-enhancement is likely to have important consequences for the dynamics of predator–prey interactions.     

The role of chemoreception in sex recognition by male crickets: Acheta domesticus and Teleogryllus oceanicus

ABSTRACT. Contact chemoreception is important in female recognition by Teleogryllus oceanicus (Le Guillou) males. Antennal contact of female conspecifics, body regions, detached antennae and conditioned substrate elicited mostly courtship responses including courtship songs. Aggressive acts were produced only in response to male conspecifics. Male body regions, detached antennae and conditioned substrate elicited very few courtship or aggressive acts and no songs. This suggests that one or several communication modes, in addition to chemical communication, are necessary to elicit aggressive responses. Acheta domesticus (L.) males cannot rely upon chemical cues for recognition of either sex. Responses to conspecifics suggest that A. domesticus males produce aggressive acts immediately after antennal contact with either sex. Aggressive response to males usually persists, but response to females often switches to courtship. Responses to body regions, detached antennae, and conditioned substrate were few, with courtship and aggressive responses elicited by both male- and female-generated stimuli. The importance of contact chemoreception in cricket communication is suggested by (1) failure of hexane-washed antennae to elicit aggressive or courtship acts, and (2) males spending more time in contact with body regions and conditioned substrates than with corresponding controls. Lack of response to male or female odour-laden air suggests that chemical signals are used by males only if directly contacted. Chemical and other signals supplement the obvious use of acoustic signals for intra- and intersexual communication in these crickets. The importance of multimodal communication in sex recognition is discussed.     

Visual signals in the courtship of Drosophila melanogaster: Mutant analysis

Visual cues are necessary for optimal mating success in Drosophila melanogaster. The male's most important visually guided behaviour is tracking. It is shown here that tracking requires intact visual receptor cells R1–6 and the presence of screening pigments in the eye. Thus flies carrying the mutation ebony as well as wild type flies affected in receptor cell R1–6 are unable to use visual cues when they track females. A similar defect was obseved in white-eyed flies lacking screening pigments. Female receptivity depends on visual signals provided by the male flies. Most important cues are the light reflection from and the shape of the male's eyes. No influence of the light reflected from the thorax could be seen. Absence of eyes in the male, however, does not depress female receptivity as much as white eyes. Some evidence is provided that male courtship behaviour is evaluated visually by the female.     

Involvement of a midbrain vocal nucleus in the production of both the acoustic and postural components of crowing behavior in Japanese quail

Many bird species produce vocalizations which are accompanied by distinctive postural displays, but the neural mechanisms that allow such integrated production of vocal and postural motor patterns are not understood. In the crowing behavior of Japanese quail, a characteristic vocal pattern is accompanied by and coordinated with a postural display that consists of a sequence of rapid, patterned head movements. The purpose of the present study was to investigate the role of a midbrain vocal nucleus, the nucleus intercollicularis, in the production of the acoustic and postural components of crowing in quail. Brief electrical stimuli were applied to the nucleus intercollicularis during spontaneously emitted crows in quail with chronically implanted electrodes, to determine if perturbing neural activity in the nucleus intercollicularis resulted in a disruption of ongoing crowing behavior. The most common effect of such stimuli was a concurrent, premature termination of both the acoustic and head movement components of the crow. These results imply that the nucleus intercollicularis plays a role in the production of both the acoustic and postural components of crowing in quail.     

Mirror-Directed Social Behaviors of Garnett's Greater Bush Baby (Otolemur garnettii)

Many diurnal anthropoid species direct social behaviors toward their own mirror-image as though viewing a conspecific. To determine whether a nocturnal prosimian species would behave similarly, we videotaped social responses of 45 Garnett's greater bush babies (Otolemur garnettii) observing mirror-images for the first time, scored them for frequency and duration, and compared them with the same behaviors directed elsewhere in the test apparatus. Males scentmarked more than females did, principally with the hindfoot, and most when in immediate proximity to the mirror. Bush babies displayed bipedal posture and threat gestures when oriented directly toward a mirror from a near position. Orientation toward the mirror also increased the frequency of arched-back postures; however, this behavior was not contingent on proximity to the mirror or visibility of the mirror-image. The differential expression of specific behaviors toward mirror-images by male and female bush babies supports the view that this nocturnal prosimian, thought to be dependent on olfaction and audition for communication, is capable of specific recognition by visual cues alone.     

Visual Cues in Mate Recognition by Males of the Damselfly, Coenagrion puella (L.) (Odonata: Coenagrionidae)

Coenagrion puella males search actively for mates and are not aggressive to other males. To study the role of visual cues in male–female discrimination, four types of models were used: (1) bodies of intact insects, (2) models of painted males, (3) models of male–female chimerae, and (4) models of female body parts. Abdomen coloration pattern and presence of wings were the most important cues for sexual recognition by males. Step-by-step elimination of male coloration pattern leads to an increase in the tandem response rate. A female model painted as a male repelled males like the intact male model. The absence of either the head or the thorax slightly decreased the number of tandem responses, but models without both the head and the thorax were not recognized as a mate. Abdomen thickness larger than that of a normal female decreased the attractiveness of the model. Models of the gynochrome female were significantly more attractive than models of the androchrome one. Female models containing male parts were less attractive than models without any structure at this place. Using principal-components analysis, it is shown that models repelling males usually were those containing an intact male abdomen or a female abdomen painted with blue. The results indicate that C. puella males can distinguish males from females visually by morphological structures and coloration pattern.     

Intraspecific communication in goldfish

Part I. Characteristics of locomotor behaviour of goldfish ( Carassius auratus ) were monitored automatically and the response to sensory cues provided by conspecifics was analysed. Goldfish were attracted to free-swimming conspecifics and oriented to them klinokinetically by decreasing their mean angle size of turns and increasing both their turning frequency and mean step length between turns. These locomotor changes were stimulus bound. Although the responses were mediated visually, blinded goldfish, which were not overtly attracted, nevertheless oriented orthokinetically to non-visual cues from the conspecific.
Part II. Simulation of the conspecific by models demonstrated that oval and horizontal rectangular shapes of the same area and their size interactions, elicited significant attraction whereas square and vertical rectangular shapes of the same area did not. Increasing speeds and/or size of the model tended to bring about stronger attraction.     

Conditioning of sexual proceptivity in female quail: measures of conditioned place preference

The present experiments were conducted to explore the nature of conditioned sexual proceptivity in female quail. Females exposed to males subsequently approached the area where the males were previously housed (Experiment 1). This increased preference for the male's area reflected an increase in female sexual proceptivity and not an increase in non-directed locomotor activity (Experiment 2). These findings provide the first evidence that female quail show conditioned responses that may be considered to be proceptive responses toward male conspecifics. The proceptive responses are expressed as tonic changes in preference for areas where males have been observed in the past rather than as specific phasic conditioned responses.     

Copulatory behaviors and body condition predict post-mating female hormone concentrations, fertilization success, and primary sex ratios in Japanese quail

Environmental cues and social interactions are known to influence reproductive physiology and behavior in vertebrates. In female birds, male courtship displays can result in the growth of ovarian follicles, the production of reproductive hormones, and stimulation of oviduct development, all of which have the potential to influence maternal investment. Male Japanese quail follow a typical sequence of copulatory behaviors during a mating interaction and often force copulations with unreceptive females. We hypothesized that female Japanese quail could adjust maternal investment in response to male copulatory behaviors during a single mating interaction. We investigated the relationships between 1) male copulatory behaviors and post-mating concentrations of steroids in the female, 2) female steroid concentrations and fertilization success of inseminations and 3) female steroid concentrations and the offspring sex ratio. We found that male condition and copulatory behaviors predicted female steroid concentrations and maternal investment in eggs laid after a mating trial. The body condition of one or both mates was a significant predictor of the changes in female corticosterone and testosterone concentrations after mating, whereas specific male copulatory behaviors significantly predicted changes in female progesterone concentrations. Male and female body condition, male neck grabs and post-mating concentrations of female corticosterone, progesterone, and testosterone were all significant predictors of egg fertilization rates. Female body condition, male copulation efficiency, and female testosterone concentrations were significant predictors of offspring sex ratios. Our results show that phenotypic and behavioral characteristics of male Japanese quail modulate female steroid concentrations and result in changes in maternal investment.     

A signal detection problem and possible solution in Japanese quail (Coturnix coturnix japonica)

The ambient noise level in the environment of most species varies and consequently many animals that use acoustic signals are faced with a potential signal detection problem. A male Japanese quail emits separation crowing when separated from a female with which it has paired. These separation crows tend to be emitted in temporal groups or bouts. This study demonstrates that the ambient noise level affects the emission of separation crowing. The two related changes in emission of separation crowing found in this study were: (a) increasing the frequency of separation crowing; and (b) increasing the number of crows per bout. These related changes should help to increase the detectability of the signal and the localizability of the transmitter.     

The role of male visual and chemical cues on the activation of female courtship behaviour in the sex-role reversed peacock blenny

Chemical cues during courtship in peacock blenny Salaria pavo did not add significantly to the response of visual stimuli and females did not court when a male was not visible. The results showed that female S. pavo courtship behaviour was elicited exclusively by male visual features and not by a multicomponent signal in different sensory modalities. The time spent by females courting the male and exhibiting the nuptial colouration during visual trials correlated with the size of the male's crest, suggesting a signalling function for this trait. Alternative hypothesis for the function of the putative pheromones released by the male's anal gland are discussed. Evidence that female sexual motivation decreases towards the end of the breeding season is also provided, which should be considered in future mate choice experiments.     

The role of static features of males in the mate choice behavior of female Japanese quail (Coturnix japonica)

In two experiments, we investigated the mate choice behavior of female Japanese quail toward taxidermically-prepared male models. Both experiments consisted of four phases: (1) habituation; (2) a pre-test in which two taxidermically-prepared models of male birds were presented; (3) observation in which the respective non-preferred male model was presented either alone or with another stimulus, and (4) a post-test in which male models were again presented alone. Results showed that focal females increased their preference for a non-preferred male model that they had previously observed with a live female (Experiment 1) or with a taxidermically-prepared female model (Experiment 2). Two control groups ruled out the possibility that focal females were choosing male models either because: (1) males were presented with an additional stimulus, or (2) females were choosing an area where they observed male models with other females. The findings suggest that female quail may utilize static, species-specific features of male conspecifics in mate choice.     

Reversal of female mate choice by copying in the guppy (Poecilia reticulata).

Ever since Fisher (1958) formalized models of sexual selection, female mate choice has been assumed to be a genetically determined trait. Females, however, may also use social cues to select mates. One such cue might be the mate choice of conspecifics. Here we report the first direct evidence that a female's preference for a particular male can in fact be reversed by social cues. In our experiments using the Trinidadian guppy (Poecilia reticulata), this reversal was mediated by mate-copying opportunities, such that a female (the 'focal' female) is given the opportunity to choose between two males, followed by a period in which she observes a second female (the 'model' female) displaying a preference for the male she herself did not prefer initially. When allowed to choose between the same males a second time, compared with control tests, a significant proportion of focal females reversed their mate choice and copied the preference of the model female. These results provide strong evidence for the role of non-genetic factors in sexual selection and underlie the need for new models of sexual selection that explicitly incorporate both genetic and cultural aspects of mate choice.     

The pairbond in the titi monkey (Callicebus moloch): intrinsic versus extrinsic contributions of the pairmates

Aspects of a monogamous relationship can be inferred by observing reactions of mated individuals to unfamiliar conspecifics. The present study examined the behaviours shown by male and female titi monkeys (Callicebus moloch) toward an opposite-sex stranger, and the effect of their pairmate's absence or presence on these encounters. Behaviours within unfamiliar heterosexual pairs showed superficial similarities to behaviours of mated pairs. Although there were few affiliative behaviours between unfamiliar individuals, animals were often in spatial proximity and even performed sexual behaviour. The visual presence of a pairmate clearly affected encounters between unfamiliar heterosexual pairs in several respects. The presence of a male pairmate had a much stronger influence on all behavioural measures compared to the presence of a female pairmate. Possible functional aspects of these results are discussed.     

Recognition of individual,sex and species odours by salamanders of the Plethodon glutinosus-P. Jordani complex

Salamanders of the Plethodon glutinosus-P. jordani complex were tested for the ability to distinguish conspecific, sex-specific, and heterospecific chemical cues. Male and female P. glutinosus preferred substrates previously occupied by conspecifics over their own, but randomly chose between substrates marked by male or female conspecifics. This suggests that while these salamanders are able to distinguish between their own and conspecific substrate odours, they are unable to identify sex by means of substrate odours. Experiments using an olfactometer showed that male P. jordani, male and female P. glutinosus, and an electrophoretically distinct and non-hybridizing sympatric phenotype in the P. glutinosus complex (here called species A), all preferred female airborne odours over male airborne odours. This demonstrates that these salamanders can identify sex by means of airborne odours. Male P. glutinosus and species A both preferred conspecific female odours over heterospecific female odours in olfactometer experiments. These results suggest an important role for olfaction in the sexual and social behaviour of these salamanders, particularly as a pre-mating isolating mechanism.     

Sexual dimorphism in responses to unfamiliar intruders in the tamarin, Saguinus oedipus

Aspects of social structure in group-living species can be inferred by observing the responses of individuals to unfamiliar animals. This study examined the responses of mated pairs of cotton-top tamarins (Saguinus oedipus oedipus) to presentation of either unfamiliar conspecifics or members of a related tamarin species, the saddle-back tamarin (Saguinus fuscicollis fuscicollis). Male and female responses to intruders differed: resident males threatened, displayed piloerection, approached, and attacked intruders, especially males, while resident females showed increases in suprapubic scentmarking in the presence of intruders. Both males and females discriminated between the species of intruders, exhibiting more threats, scent-marking, piloerection, and approaches in the presence of conspecific intruders. There are pronounced sex differences in the signals and behaviour patterns that are elicited in an aggressive or territorial encounter with unfamiliar conspecifics in this monogamous primate.