Eggs of a female Japanese quail are more likely to be fertilized by a male that she prefers

Male Japanese quail (Coturnix japonica) that conspecific females preferred in a 10-min, forced-choice test of affiliative preference were more likely than were males not preferred in such a test to fertilize females' eggs when subsequently mated with them, although preferred and nonpreferred males mated equally often with females. Further, the probability that a nonpreferred male would fertilize a female's eggs was significantly increased if she watched while he courted and mated with another female. The results indicate that in Japanese quail (a) affiliative preference reliably predicts females' choices of fathers for their offspring and (b) females may have some degree of control over whether the males with whom they mate actually fertilize their eggs.     

Sexual fetishism in a quail (Coturnix japonica) model system: test of reproductive success

In the present study, the authors explored the reproductive consequences of fetishistic behavior in a previously developed animal model of sexual fetishism (F. K?ksal et al., 2004). Male domesticated quail (Coturnix japonica) received sexual conditioning trials in which a terrycloth object (the conditioned stimulus [CS]) was paired with the opportunity to copulate with a female quail (the unconditioned stimulus). Approximately half of the male quail came to copulate with the CS object and were considered to have developed fetishistic behavior. Each of the male quail was then tested with a female quail, whose eggs were incubated to determine rates of fertilization. The CS object was present for 30 s before and during the copulation test. Fetishistic male quail were slower to achieve cloacal contact with the female quail and showed less efficient copulatory behavior. However, they fertilized a greater proportion of eggs than nonfetishistic male quail. These results are unexpected from previous studies of the relationship between reproductive success and copulatory behavior and are discussed in terms of how fetishistic behavior directed toward an inanimate object may modify male-female interactions.     

Relative contributions of the male and the female to sexual behavior and reproductive success in the Japanese quail (Coturnix japonica)

Two contrasting investigative techniques provided evidence consistent with the interpretation that female quail (Coturnix japonica) regulate male copulatory behavior by the duration of their immobility and through this behavioral mechanism they also control the rate of fertilization of their eggs. In Experiment 1, copulation tests with males and females from different genetic lines showed that the type of female that participated in a copulatory test significantly influenced the latency of the male's grab, mount, and cloacal contact responses and also determined the efficiency of the male's copulatory behavior. These measures of male performance were correlated with female immobility in Experiment 2, which used a more homogeneous population of quail. Furthermore, 2 of these measures (copulatory efficiency and the latency to make cloacal contact) were correlated with fertilization rate.     

An automated technique for the study of cyclic fluctuations in sexual motivation in an avian species

Diurnal fluctuations in sexual behavior occur in freely interacting pairs of male and female birds. These fluctuations are difficult to interpret because they may reflect fluctuations in the motivation of the male, the motivation of the female, or both. A method was developed to study the sexual motivation of male Japanese quail in response to a standard stimulus. Sexual behavior was elicited by a taxidermic model of a female quail in a squatting posture. Sensors beneath and in the back of the model served to detect when the male mounted and made cloacal contact with the model. The technique allowed continuous recording of male sexual behavior under standard conditions. When males were maintained on a photoperiod with lights on at 0600 h and off at 2200 h, sexual behavior peaked in the early afternoon, with a secondary peak just before lights-out.     

Female Japanese quail (Coturnix japonica) mated with males that harassed them are unlikely to lay fertilized eggs

Results of previous studies of courtship and mating in Japanese quail (Coturnix japonica) suggest that females avoid conspecific males because, while courting and mating, males engage in behaviors that are potentially injurious to females. However, prior experiments provided no direct evidence that females avoided harassing males. Here the authors show that a female quail choosing between a previous sex partner and an unfamiliar male avoids the former if he engaged in relatively many potentially injurious acts while courting and mating, (Experiments 1 and 2) and that males behaving aggressively toward mates are less likely than are gentler males to fertilize the females' eggs (Experiment 3). Male sexual harassment appears to be a tactic both aversive to female quail and relatively ineffective in fertilizing them.     

Modulation of aggression toward an intruder during the reproductive cycle of white king pigeons (columba livia)

For three of four mated male pigeons, intrusion of a still, two-dimensional image of a conspecific into the reproductive situation initiated aggressive behavior over months of daily testing with little habituation. There was a transient increase in aggressive contacts against the head of the target within two days prior to or following the occurrence of the second egg. Such an increase did not occur with extended daily testing of the male alone and was more closely synchronized to egg laying than time since the introduction of the female. The results are consistent with previous studies of reproductive and schedule-induced aggression in birds.     

Counting Chicks Before They Hatch: Female Cowbirds Can Time Readiness of a Host Nest for Parasitism

ABSTRACT— Here we show that demands associated with brood parasitism have favored sophisticated cognitive abilities in female brown-headed cowbirds. We discovered that cowbirds can use the rate at which eggs are added to a nest across days to assess the readiness of the nest for incubation, which would allow them to synchronize laying with the host and avoid nests where incubation has most likely commenced. In three experiments, cowbirds investigated and laid eggs in artificial nests that differed in the number of eggs they contained. Across days, we added eggs to nests at different rates to simulate differences in the timing of reproduction of the hosts. Cowbirds avoided a nest if the number of eggs that had been added was less than the number of days that had elapsed. The ability of females to remember egg number and compare changes in egg number across days allows them to select nests most suitable for parasitism.     

Note on social behavior of long-term captive female orangutans (Pongo pygmaeus abellii)

Some observations of social behavior of two aging female orangutans with a younger male son of one were made in an outdoor and in an indoor enclosure during the day. These included social distance, grooming, and locomotion plus wrestling and genital stimulation. As noted 15 years earlier, the two old females were never in contact with each other. Each showed contact and noncontact with the younger male. No clear social relation between the females was evident. Careful study of aging zoo populations could be useful.     

Differences in affiliative behavior, pair bonding, and vaginal cytology in two species of vole (Microtus ochrogaster and M. montanus)

Prairie voles (Microtus ochrogaster) and montane voles (M. montanus) display marked differences in social organization in the field. Trios of 1 male and 2 females were studied in a large enclosure for a 10-day period. Prairie voles spent 59% of the observation time in side-by-side contact, whereas montane voles spent only 7% of the time in contact. Vaginal smears indicated female-female suppression of estrus in prairie voles; female montane voles appeared to cycle in the presence of males. Male prairie voles preferentially paired and nested with 1 of the females, and vaginal estrus generally followed pair formation by 2 days. Male montane voles did not spend time preferentially with either female, even after mating. These results suggest that the contrasting mating systems of these species result from differences in the propensity for affiliative behavior and social bonding rather than from mate availability or female receptivity.     

Sexual Pavlovian conditioned approach behavior in male Japanese quail (Coturnix coturnix japonica)

A localized visual stimulus presented immediately prior to access to a female conspecific stimulated approach behavior in male Japanese quail after several conditioning trials. Development of this conditioned approach behavior was observed with two different types of signal lights, 10-s and 30-s signal durations, large and small experimental chambers, and with male birds housed continually in the conditioning chambers or only placed in the chamber for brief daily sessions. Conditioning also resulted in shorter latencies to initiate copulation in males given access to a female following the signal light, in comparison with males that received access to a female unannounced by the light. Although some aspects of the conditioning experience were retained over a 6-week interval, some loss of the behavior was also observed. The conditioned behavior also decreased with repeated extinction trials, during which the signal light was presented in the absence of access to a female conspecific. The results are discussed in relation to other aspects of the social behavior of Japanese quail and other studies of sexual conditioning.     

Contextual conditioning and the control of copulatory behavior by species-specific sign stimuli in male Japanese quail

Three experiments were conducted to identify species-specific sign stimuli sufficient to elicit copulatory behavior in male Japanese quail and to determine how learning is involved in the control of behavior by these sign stimuli. In Experiment 1, sexually experienced subjects were tested for copulatory behavior with a live female quail and with a model consisting of a female quail's head and neck mounted in front of a foam pad. Comparable levels of copulatory behavior were observed in the two tests, indicating that static visual cues provided by a female quail's head and neck are sufficient to elicit copulatory behavior in this species. Experiment 2 showed that male birds that previously received numerous opportunities to copulate with a live female quail in the test situation were significantly more likely to copulate with the head + neck model than were sexually inexperienced subjects. Experiment 3 showed that prior sexual experience with live quail facilitated responding to the head + neck model only if the sexual experience was provided in the same place where subjects were later tested with the model. This last finding suggests that sexual experience facilitates control of copulatory behavior by species-specific sign stimuli through contextual conditioning. Contextual conditioning may lower the threshold for sexual behavior with the result that a stimulus as impoverished as an immobile model containing only the head and neck of a female quail becomes sufficient to elicit normal levels of copulatory behavior. The results are also discussed as an example of conditioned stimulus facilitation of responding to an unconditioned stimulus.     

Effects on Sexual Conditioning of Devaluing the US through Satiation

Male Japanese quail were conditioned to approach a visual CS that predicted an opportunity to copulate with a female quail. Subsequently the subjects were tested in both non-reinforced and reinforced test trials while sexually satiated and sexually deprived. In the satiation condition the sexual US was devalued by allowing the male subjects to copulate repeatedly with female birds just prior to testing; in the deprivation condition, the males were not allowed to copulate for a day prior to testing. The subjects displayed significantly less approach to the CS when sexually satiated than when sexually deprived. These results are compatible with a mechanism in which performance of Pavlovian sexual approach conditioning is mediated by activation of a memorial representation of the US.     

CLASSICAL CONDITIONING OF COURTING BEHAVIOR IN THE JAPANESE QUAIL,COTURNIX COTURNIX JAPONICA1

Male Japanese quail were classically conditioned to display courting behavior at the sound of a buzzer, a previously neutral stimulus. The buzzer (conditioned stimulus) was paired with the presentation of a female quail (unconditioned stimulus) for a number of trials. The courting display, invariably elicited from the male by the presentation of the female, began to appear in part to the conditioned stimulus as early as the fifth pairing. All components of the display were elicited from all birds by the conditioned stimulus alone within 32 pairings of the conditioned and unconditioned stimuli.     

Learning to discriminate the sex of conspecifics in male Japanese quail (Coturnix coturnix japonica): tests of "biological constraints"

Male Japanese quail learn to approach and remain near female, but not male, quail if they are allowed to copulate with female quail and receive noncopulatory exposures to males. The generality of the mechanisms involved in this type of discrimination learning was investigated in the present study. In Experiment 1, Ss learned to spend more time near initially unfamiliar blonde quail than familiar brown female or male quail as a result of being allowed to copulate with the blonde, but not the brown, quail. In Experiment 2, Ss learned to respond more to nonreproductive male as compared with female quail as a result of being allowed to copulate with the males, but not with the females. The experiments provided some evidence of a bias favoring responding to females independent of copulatory reinforcement contingencies. However, the results also indicated remarkable plasticity of discrimination learning about species-specific sexual stimuli.     

Avoidance of relatively aggressive male Japanese Quail (Coturnix japonica) by sexually experienced conspecific females

Sexually experienced female Japanese quail (Coturnix japonica) that are offered a choice between 2 conspecific males previously observed engaging in an aggressive encounter prefer to affiliate with the less aggressive male. The authors determined whether this apparent preference for less aggressive males results from females approaching less aggressive individuals or avoiding more aggressive individuals. The authors found that females that had seen 2 males fight before choosing, in counterbalanced order, between each of them and a neutral stimulus were indifferent to less aggressive males but avoided more aggressive males. The results are consistent with the view that in species in which male courtship and mating are potentially harmful to females, females keep away from relatively aggressive males in order to avoid the physical punishment that can result from contact with them.     

The structure of social relationships among captive female giraffe (Giraffa camelopardalis)

Giraffe herds have been characterized as random associations of individuals, but recent evidence suggests giraffe have a more complex social structure. The authors formulated 3 hypotheses designed to evaluate whether a herd of captive giraffe (Giraffa camelopardalis) associated randomly or patterned their behavior and proximity in a manner indicative of social relationships. Affiliative interaction, proximity, and nearest neighbors for 6 captive female giraffe living in a large outdoor enclosure were analyzed, and all three measures were nonrandomly distributed, indicating female giraffe had social preferences. Furthermore, preferences were consistent across measures and time, suggesting that adult female giraffe maintain relationships. Mother-daughter pairs and pairs with large age differences between members interacted and associated most often. The social structure of this captive herd is influenced by social relationships between individual adult females, and the social behavior of individual females should be examined more closely in the wild.     

Pair-bonded humans conform to sexual stereotypes in web-based advertisements for extra-marital partners

Partners advertisements provide advertisers with access to a large pool of prospective mates, and have proven useful in documenting sex differences in human mating preferences. We coded data from an Internet site (AshleyMadison.com) catering to advertisers engaged in existing pair-bonded relationships. While we predicted that pair-bonding may liberate advertisers from conforming to sexual stereotypes of male promiscuity and female choosiness, our results are uniformly consistent with those stereotypes. Our findings thus provide further evidence that human mating behavior is highly constrained by fundamental biological differences between males and females.     

Extinction of conditioned sexual responses in male Japanese quail (Coturnix japonica): role of species-typical cues

The authors examined how a conditioned stimulus (CS) that included species-typical cues affected the acquisition and extinction of conditioned sexual responses in male quail (Coturnix japonica). Some subjects were conditioned with a CS that supported sexual responses and included a taxidermic head of a female quail. Others were conditioned with a similar CS that lacked species-typical cues. Pairing the CSs with access to live females increased CS-directed behavior, with the head CS eliciting significantly more responding than the no-head CS. Responding to the head CS persisted during the 42-day, 126-trial extinction phase; responses to the no-head CS extinguished. Responding declined when the cues were removed or the subjects were sexually satiated. Possible functions and mechanisms of these effects are discussed.