REGIONAL VARIATION IN THE DISTRACTION DISPLAYS OF THE OYSTER-CATCHER.

The Oyster-catcher Haematopus astralegus populations of western Europe (Holland, South Britain, Fair Isle, Unst and Faeroe Islands) differ very little morphologicallv, but show interesting variations in their distraction displays.
These displays, comprising (1) aggressive flight, (2) a furtive run, (3) false-brooding, (4) pseudo-sleeping, and (5) lure display, are described, with comments on their regional importance. Aggressive flight, false-brooding and lure display are more strongly developed in Faeroe than elsewhere. At Fair Isle (and to a less extent at Unst) displacement " butterfly-flight" replaces lure display.
It is shown that the lure display has evolved as a terrestrial modification of displacement " butterfly-flight", which has proceeded furthest in the Faeroe population, hardly at all in the more southerly populations, and to an intermediate degree among the birds of Unst.
The Oyster-catcher's extension to the Faeroe Islands—probably from the British area, in Comparatively recent times—involved colonization of an atypical moorland habitat. The distraction displays appear to have been perfected in the absence of terrestrial predators other than men and dogs, which have been present for about 1000 years.
The remarkable development of these display patterns is probably due to hereditan differences, affecting ethological attributes, which have arisen between the Faeroe and the more southerly populations. It is suggested that their evolution has been stimulated by the psychological effect of frequent disturbance of the brooding urge by man, during the attempt to colonize a new and unsympathetic environment.     

THE BREEDING BEHAVIOUR OF THE WHITE BOOBY SULA DACTYLATRA*

The aim of this paper is to describe the form and interpret the motivation, function and derivation of breeding behaviour in the White Booby. Attention is paid to adaptive aspects and an effort made to correlate behaviour with environment? particularly colony density and associated degree of competitive behaviour. The absence, simplicity or complexity of certain displays can be correlated with the extent to which highly developed social and /or pair interaction are needed. Throughout I have tried to place White Booby behaviour in the framework of behaviour in the Sulidae as a group and particularly to compare it with Gannet behaviour, since the latter nest more densely than other sulids and show more extreme aggression and greater ritualization of behaviour patterns used in interpair and wider social communications. The White Booby provides an interesting contrast. After a brief account of morphology and voice the points are made that White Booby colonies are generally smaller and much less dense than those of the Gannet or Peruvian Booby and also that White Boobies breed in a wide variety of habitats. Site establishment, pair formation, later pair relations, social interactions, body maintenance behaviour, incubation and care of young are described and an account of behaviour in the young is given. The male establishes the site and shows yes /no headshaking as an aggressive, site-ownership display, often performed after landing. He attracts the female with a sky-pointing display which is homologous with sky-pointing in the Gannet, where, however, it subserves a different and, it is argued, phylogenetically older function, signalling that a bird is about to leave the site rather than serving as an advertizing display. In the White Booby it is thus a good example of a motivationally and functionally emancipated display. When the pair meet, mutual jabbing, a hostile-looking and relatively undifferentiated meeting ceremony, and bill-touching occur. Symbolic nest building plays an important part in White Booby pair behaviour, though the nest is structurally negligible. Nest building is associated with copulation, in which the female is not gripped. Bill-up-face-away is a bill-averting posture used when a booby moves away from its mate. It is probably an appeasement posture and, so far as the situation “I am about to move” is concerned, seems to have taken the place of Gannet sky-pointing, the latter having become the booby's advertizing. Wing rattle is a movement probably partly functional in preparing feathers for flight, but is also used as signal behaviour prior to take-off, particularly during the frequent flights around the breeding area that White Boobies show early in the season. Wing flapping, sometimes with rotary headshaking, is mainly feather maintenance behaviour. The forms of headshaking and head flinging are described. Reciprocal allo-preening occurs; it is suggested that it can do so without disadvantage since White Boobies possess mutual jabbing—an interaction which can accommodate any aggression engendered by the pair pointing bills at each other, as required for reciprocal allo-preening. The average incubation spell in the male is 30 hours and in the female 25 hours; all sulid males show this tendency to spend longer on the site. Seasonally, too, there is a marked sex-difference in site attendance and this is depicted in graphs for different categories of White Boobies. The young are left unguarded from about four weeks of age and move off the site. They are fed about 1.4 times per day. They respond to adult investigation or attack by beak-hiding—an effective appeasement posture. Soon, they perform aggressive territorial behaviour and dispel other young and adults. They return to the site to be fed for around 50 to 60 days after they become free-flying and show all forms of territorial behaviour. The discussion is mainly concerned with the correlation between nesting density, aggression and associated appeasement behaviour. It is concluded that, overall, the White Booby's ritualized postures and displays are less well differentiated than those of the Gannet, though individual behaviour patterns may be more complex. The pair relationship in the White Booby approximates more closely to that normally found in birds, where the male is not outstandingly aggressive to his mate.     

Displays of the Honeyeater Manorina melanocephala

Investigated displays of Noisy Miners, Manorina melanocephala, in Australia. This unusual bird lives in colonies and many ♂♂ care for the offspring of each ♀ flight displays, 11 non-flight displays, and several components of facial displays (including a variable eye patch) are described. The eye patch provides a large yellow and black augmented eye, important in intimidation. No stereotyped sequence of courtship behaviour precedes copulation. Displays are used to advertise nest locations. A greeting display, the corrohoree, is extremely common. The possibility of the evolution of submissive display from threat is discussed. Special vocalisations of ♂♂ and ♀♀ are use in a duet. The maintenance of bonds among many individuals in a colony may be more important than strong pair bonds. Group cohesion is probably maintained by flight display, nest display, mobbing, and other communal activities. High interspecific aggression results in few resident species in colonies. This level of interspecific aggression might be maintained by incorporating much intraspecific mimetic display and ritualised submissive behaviour.     

The displays of the White-throated Manakin Corapipo gutturalis in Suriname

The courtship displays of the White-throated Manakin Corapipo gutturalis (Pipridae) were observed in the Brownsberg Nature Preserve, Suriname, for over 50 h on 17 days between 17 October and 17 December 1982, and the display elements and calls are described. Males perform displays from perches in trees, in flight and on mossy fallen logs. The perch displays are performed as preliminaries to the log-approach displays which are given while in flight towards the log. The log-approach displays vary in length and complexity from a short flight from a nearby perch down to the log, to a dramatic flight above the canopy and back to the log. As males land, they perform a series of aerial manoeuvres and give a complex vocal and mechanical display call. Males may also perform a slower silent moth-flight log approach. The log displays are the culminating elements of courtship and copulation is known to take place there (Davis, T.A.W. 1949. Ibis 91: 146–147). All the courtship displays can be performed either solitarily by a single male or by a group of up to seven males which compete simultaneously for access to single display sites at a series of different logs. Fourteen display logs were located dispersed in two areas 250 m wide which were separated by 350 m, but it was not determined whether these areas constituted separate leks with different pools of possible mates. The behaviour of C. gutturalis is compared with that of the White-ruffed Manakin Corapipo leucorrhoa and other manakins. Male Corapipo appear to have abandoned defence of exclusive advertisement territories in favour of simultaneous competition for a series of different display sites. This detached or mobile form of lek is unique among known manakins and a mechanism for its evolution through female choice is discussed.     

Discrimination of conspecific individuals via cuticular pheromones by males of the cricket Gryllus bimaculatus

Cuticular substances on the body surface of crickets serve as pheromones that elicit a variety of different behaviors in male crickets. Antennal contact between males and females resulted in courtship behavior, and that between two males resulted in aggressive displays. As a first step in elucidating how crickets recognize and discriminate individuals, behavioral responses of male individuals to cuticular substances of conspecific males or females were investigated. The behavioral responses of males to antennal or palpal stimulation with an isolated antenna from a male or a female were recorded. To both antennal and palpal stimulation with female antennae, the majority of males responded with courtship behavior; to stimulation with male antennae, males responded with aggressive displays. To gain insight into the chemical nature of the behaviorally relevant components, isolated antennae were washed in either n-hexane, acetone or ethanol before behavior assays. Washed antennae no longer elicited courtship or aggressive responses in males. Next, polypropylene fibers were smeared with substances from the body surface of females and used for antennal stimulation. This experiment showed that the quality and quantity of cuticular substances appear to be highly age-dependent. Significantly more males responded with courtship behavior to cuticular substances from younger females. Isolated males generally showed higher levels of aggression than males reared in groups. Grouped males also were more likely to display courtship behavior towards antennae from younger females, and aggressive behavior towards antennae from older females. These results suggest that male discrimination of mating partners depends on the nature of female cuticular substances.     

郑州地区夜鹭的求偶行为

2003年及2004年3~6月在河南郑州市区对夜鹭(Nycticorax nycticorax)的求偶行为进行了观察。结果表明,3月中旬至5月底雄性夜鹭表现出占区及固定的仪式化求偶行为,主要包括伸展炫耀、扬举炫耀、炫耀羽毛和配偶形成后的相互爱抚4个方面,其中前两种行为是夜鹭主要的求偶行为。在营巢地,求偶行为从早上日出之前夜鹭觅食归来开始,一直持续至日落前后。夜鹭的配偶选择包括雄性之间对巢区的竞争、雄鹭与雌鹭的相互选择等一系列过程。     

THE BURROW-EXCAVATION PHASE IN THE BREEDING CYCLE OF THE SAND MARTIN RIPARIA RIPARIA

Observations were carried out at a Sand Martin colony in a working sand-pit, where fresh burrows have to be dug each year. Sand Martins arrive at the breeding pit from migration unpaired, and their social organization is then at its lowest. Burrow excavation occurs only as the climax to a form of group display. Digging is communal in character, and the number of holes dug is roughly equal to the number of individual birds present. The mounting excitement and mutual stimulation of the display period induces a climax at which the birds begin to build nests and lay. This period of display produces close synchronization which seems to be a necessary condition for the communal behaviour of the birds during the rest of the breeding cycle.     

Growth and development in six species of African mole-rats (Rodentia: Bathyergidae)

The bathyergid mole-rats provide a unique example of a family of subterranean rodents exhibiting a broad spectrum of sociality. Three genera comprise solitary, strongly territorial individuals whereas two genera are social. This sociality culminates in the eusocial naked mole-rat, Heterocephalus glaber . The pups of solitary mole-rats disperse, establish and thereafter defend their own burrow systems when approximately two months old, whereas those of social genera join an established natal colony. This paper examines whether these different lifestyles are reflected in the early development and rate of growth of pups of mole-rats.
Although the trends are not clear-cut, it is apparent that the pups of solitary genera grow and mature more rapidly than those from social genera. Thus, the growth rate constant ( K ) for the first70–80 days of postnatal growth (using the Gompertz equation) for the solitary genera was between 0.042 and 0.052 day⁻¹, whereas that of the social mole-rats was considerably lower (0.01 5 day⁻¹). Similarly the mean growth rates of solitary genera ranged between 3.3 and 1.227g/day while those of the social mole-rats were 0.229-0.233 g/day.
The pattern of development and the rates of growth in solitary bathyergids are similar to those of other solitary subterranean rodents. One interesting feature common to all the social genera studied to date was that the first pups recruited to a 'new colony', consisting of a reproductive pair of adult mole-rats, grew at a significantly faster rate than pups born to an established colony.     

THE BREEDING BEHAVIOUR OF THE RED-FOOTED BOOBY SULA SULA

The breeding behaviour of the Red-footed Booby on Tower Island, Galapagos, is described. A connection is traced between the arboreal nesting habit and the type and degree of ritualised behaviour; in general territories are large, movement relatively restricted, and territorial and intra -pair displays relatively few and undifferentiated when compared, for example, with the North Atlantic Gannet, in which the opposite conditions (dense nesting and maximal inter- and intra-pair contacts) occur. On Tower Island, 96% of the Red-footed Boobies are either brown or partly brown forms and 4% are full white forms. The adaptive significance of the polymorphism is discussed, and it is tentatively suggested that the brown form may be more nocturnal than the white. The average nest density was 0–009 pairs and the maximum density 0'053 pairs per square yard. Behaviour is considered under the headings: non-display behaviour (sunning, sleeping, etc.); behaviour with some signal value (Feather Ruffing, Wing Flicking, etc.); behaviour concerned with site establishment (fighting, agonistic displays); pair relationship (mutual displays); incubation and parental care and behaviour of the chick. Before flying from their territory Red-foots Wing Flick, a signal action which they have developed to a greater extent than other sulids. Other ritualised wing movements are rarer, possibly because they are associated largely with locomotion preceding flight, which is impracticable for the arboreal Red-foot. Sideways Headshaking, a frequent dirt-dispelling movement in the Gannet, is much reduced in the Red-foot. Correspondingly, it is much less used in Red-foot displays, whereas the Gannet incorporates it into many. Territorial fighting is relatively rare. Territorial behaviour includes Flight Circuiting over the breeding area, Wing Flailing, Jabbing, non-ritualised Menacing and Forward Head Waving (a ritualised, aggressive, site-ownership display). Appeasement displays are poorly developed, being confined in the adult to a fleeting Facing-away movement. The chick lacks Beak-hiding and the implication of this for the derivation of allied adult postures is discussed. Sky-pointing or Advertising is used by the male to attract a female (occasionally vice versa); it is also a mutual display cementing the pair bond and stimulating co-operation in coition and nest building. This unusually wide range of functions, compared with other sulids, is perhaps necessitated by this species' lack of a ritualised meeting ceremony. There is little interaction between mates and their aggressiveness to each other remains overt. A noticeable sign of fear on meeting is a marked tremoring of head and neck. One to three weeks elapsed between starting the nest and laying the egg. Nest-building movements occur commonly as conflict behaviour during sexual and agonistic encounters. Incubation (tints are lengthy (male average 58-4, female 60-7 hours, maximum 199) over the 46-day incubation period; nest relief is without ceremony. Feeding of the young, by incomplete regurgitation, averages slightly less than once per day after the young are more than a month old. Young beg distinctively and frenziedly. Parents do not at first discriminate between their own and other young, but do so vigorously when their young can fly. Similarly, young Red-foots only become hostile to other young when both are well grown and capable of intruding and stealing feeds. Flight is attained gradually by progressive wing exercising and local sallies. Free-flying young return regularly (usually daily) to the nest and are fed. Later they congregate in “clubs” and show most of the adult patterns of agonistic behaviour. The post-fledging care of the young shown by the Red-foot (and other boobies) is contrasted with the lack of it in the Gannet, and a hypothesis is suggested for this important divergence within the Sulidae.     

Triggers of the Postural Display of Courtship in <Emphasis Type="Italic">Drosophila persimilis</Emphasis> Flies

D. persimilis courtship shows some flexibility and courting males sometimes perform an elaborate postural display in addition to the standard courtship behaviours shared by most Drosophila species. This postural display includes the acrobatic contortion and tremulation of their abdomen, accompanied by the generation of substrate-borne vibrations, and they proffer a nutritional droplet to the female. Here, we use courtship and choice assays to ask what triggers this display and what advantages males may gain from it during courtship. In pair assays, we found no differences in the courtship duration and copulation success between displaying and non-displaying males. In trio assays, however, the female always mated with the male who performed the display. To investigate what promotes the male display, we varied the level of receptivity of the female and studied the impact of a second male. We found that rejection by the female does not induce the male to display, contrary to what was previously suggested. We present evidence that the male display is in fact promoted by the presence of an attentive and sexually receptive female and the absence of male competition, with the greatest exhibition rate obtained if the courted female is starved. These findings provide valuable information about the social ecology of flies, and how internal and external cues influence sexual behaviours and mate choice.     

Modification of the courtship song by visual stimuli in the grasshopper Gomphocerus rufus (Acrididae)

ABSTRACT. Males of Gomphocerus rufus L. perform a courtship song consisting of repetitive units, each of which is composed of three subunits (S1, S2, S3). S1 is characterized mainly by slow and fast head rolling; S2 and S3 are distinguished by different types of leg-stridulation. These movements and the associated sounds were recorded during presentation of visual stimuli, either linear displacement of a living female or optomotor stimuli generated by a striped drum. Females moved artificially through the binocular visual field of a courting male with a velocity of 1 cm/s or more are mounted by the male from any subunit S1, S2 or S3, although under natural conditions mounting occurs only from S2. Thus above a critical velocity the courtship programme can be modified. Rotation of a striped drum about the yaw axis of the male during the slow S1 induces asymmetrical leg position, following movements of the head, and prolongation of S1. During S2 the male is especially sensitive to optomotor stimuli and responds with marked changes in body position. In S3 the intensity of the song is reduced, and its duration shortened. Fast drum movements interrupt the courtship programme. Rotation of the drum about the roll axis elicits optomotor head turning that interferes with the head rolling of S1. The fast phase of S1 and the frequency of head-rolling during S1 cannot be modified by optomotor stimulation. The results can be interpreted by assuming certain interactions between three central nervous elements: a calling-song generator, a head-rolling generator, and an optomotor centre.     

FURTHER NOTES ON PAIRING AND SUBMISSIVE BEHAVIOUR OF THE RED-LEGGED PARTRIDGE ALECTORIS RUFA

1. The submissive display is described. It is sometimes given when the bird appears to be simultaneously frightened and attracted by a fellow member of the species.
2. The pairing behaviour of some individual captive birds is described. Some degree of mutual fear and hostility seems to be a necessary correlate of sexual attraction in this species. Birds that know and are at ease with one another do not pair.
3. A young male showed (in autumn) behaviour similar to that of a female ready to pair when introduced to an old and aggressive male. A possible biological function of such behaviour is suggested.     

Changes in the sexual tendency accompanying selection for aggressiveness in the three-spined stickleback,Gasterosteus aculeatus L.*

Independent selection experiments for reduced juvenile and reduced territorial aggression levels in male three-spined sticklebacks both resulted in reduced courtship aggression levels. In the low juvenile aggression line this is accompanied by an enhanced sexual activity, but in the low territorial aggression line males display a reduced sexual activity. These results are consistent with a mutually inhibitory relationship between the aggressive and sexual tendencies, if selection for juvenile aggressiveness has only affected the aggressive tendency while selection for territorial aggressiveness has simultaneously affected the aggressive and sexual tendencies in the same direction. This is in agreement with the hormonal changes (pituitary-gonadal axis) suggested by the selection studies.     

Mating Behavior of Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae) and the Effect of Female Mating Frequency on Offspring Production

The courtship behavior of Cephalonomia tarsalis, a solitary semiectoparasitoid of Oryzaephilus surinamensis, was investigated in the laboratory. Courtship behavior includes a series of stereotypic movements. Males play the most active role, executing the majority of courtship action, and females respond with relatively limited observable behaviors. Males typically keep antennae still during encounters with females prior to mounting, which may be correlated with recognition of the female's sexual status. After mounting, males display a series of movements on females, such as antennae touching female's antennae, antennae or mouth touching female's head or thorax, and walking around on female, which may serve to stimulate females towards increased receptivity. Females signal receptivity by assuming a stereotypical posture of remaining stationary, with head down, and antennae still in front of the body. The male then inserts his aedeagus and the pair copulates. After an average of 40.4 s of copulation, females signal the end of copulation by waving the antennae and moving away from the copulation site. Males continue copulating for a short time after females start moving but dismount soon thereafter. After dismounting, the two wasps move away from each other immediately, and they typically begin grooming. Neither males nor females exhibit mating preference based on mate's mating status in both choice and no-choice tests. The male is polygynous and the mated female can mate multiple times within the first 3 days after starting oviposition. However, female mating frequency does not affect the production of female progeny.     

Aggression versus courtship in threespine sticklebacks and the role of habituation to neighbours

Interaction of courtship and territorial aggression in male threespine sticklebacks, Gasterosteus aculeatus, was investigated by presenting dummy females to subjects nesting alone (solitary situation) and in view of males nesting in adjacent tanks (rival situation). During dummy presentation subjects engaged in more courtship and nest activity when solitary than when in the rival situation. Behaviour of subjects in the latter situation was dominated by threats and attempts to bite rivals during dummy presentation. Thus, rivals can interfere with another male's courtship by competing for the time during which he could court a female or by eliciting in him an aggressive state that is incompatible with sexual behaviour. Subjects in the rival situation gradually decreased the time spent with rivals but increased the time spent courting the dummy and tending the nest during presentations. This decrease in aggression towards neighbouring males is presumed to result from habituation. Thus, habituation can play an important role in mitigating the aggressive response to familiar rivals, allowing males to devote more time and energy to courtship and nest activities while still forming breeding aggregations in which members may mutually benefit.     

It Takes Two to Tango: Relative Influence of Male and Female Identity and Morphology on Complex Courtship Display in a Newt Species

Consistency in behaviour is currently receiving a renewed interest. Although courtship display is generally consistent in terms of behavioural sequence and structure, there is also commonly important variation in the intensity of courtship display between and within males of a given species. Indeed, not all males have the same ability to perform courtship display (variation between males), and each male can potentially adjust his courtship effort in response to the environment (variation within a male). Although the study of male courtship display has received considerable attention in recent years, it is still unclear which part of the variation can be explained by male ability or motivation. We investigated this issue on two phases of the complex courtship display of the palmate newt Lissotriton helveticus. Overall, we found that both male and female identities affected courtship behaviour, but the relative influence of each sex depended on the courtship phase. Male identity explained variation in fan and creep‐quiver display, whereas female identity explained variation in creep‐quiver only. Interestingly, we did not find any link between the expression of courtship display and male or female morphological traits. Our study showed consistency of male courtship display in newts and successfully dissects the different sources of variation that can affect behavioural repeatability/consistency of courtship display.     

The Elaborate Postural Display of Courting <Emphasis Type="Italic">Drosophila persimilis</Emphasis> Flies Produces Substrate-Borne Vibratory Signals

Sexual selection has led to the evolution of extraordinary and elaborate male courtship behaviors across taxa, including mammals and birds, as well as some species of flies. Drosophila persimilis flies perform complex courtship behaviors found in most Drosophila species, which consist of visual, air-borne, gustatory and olfactory cues. In addition, Drosophila persimilis courting males also perform an elaborate postural display that is not found in most other Drosophila species. This postural display includes an upwards contortion of their abdomen, specialized movements of the head and forelegs, raising both wings into a “wing-posture” and, most remarkably, the males proffer the female a regurgitated droplet. Here, we use high-resolution imaging, laser vibrometry and air-borne acoustic recordings to analyse this postural display to ask which signals may promote copulation. Surprisingly, we find that no air-borne signals are generated during the display. We show, however, that the abdomen tremulates to generate substrate-borne vibratory signals, which correlate with the female’s immobility before she feeds onto the droplet and accepts copulation.     

NEST PARASITISM AND DISPLAY OF CHESTNUT SPARROWS IN A COLONY OF GREY-CAPPED SOCIAL WEAVERS

Chestnut Sparrows Passer eminibey near Magadi, Kenya, built no nests of their own but usurped nests newly built by Grey-capped Social Weavers Pseudonigrita arnaudi. The sparrows laid eggs and raised their own young in the appropriated nests. The sparrows were synchronized in their breeding with the social weavers but appeared to have a slightly later peak of breeding. Breeding of the sparrows may be stimulated by the sight of breeding activity of the social weavers. Breeding occurred in May and June at the end of a rainy season.
Male Chestnut Sparrows display at the nests with the wings raised. The display is given for several hours each day. Examination of nests built by the social weavers is an element of courtship display by the male sparrow.
In the subfamily Passerinae there is a greater difference in the form of the courtship display between the Chestnut Sparrow and other species of Passer than between nest-building species of Passer and other genera. The display of Chestnut Sparrows is derived from the nest-advertisement display of nest-building Passer. Its exaggerated form may be an adaptation related to pair formation and intrapair sexual stimulation in the absence of male nest-building behaviour.     

Co-option of male courtship signals from aggressive display in bowerbirds

The pre-existing trait hypothesis suggests that females evolve a mating preference for an already existing male trait. This hypothesis poses a simple resolution to Darwin's long-standing question of how elaborate, male display traits evolve. The frequently observed convergence of aggressive and courtship displays across a wide array of species provides the only current support for this hypothesis. Here we provide much more detailed supporting evidence from bowerbird skrraa calls used in aggression and courtship. Consistent with the pre-existing trait hypothesis we show that (i) putatively co-opted skrraa calls used in courtship and aggression are homologous, (ii) skrraa calls were used in aggression in bowerbirds before being used in courtship, (iii) historically, intense, aggressive-like courtship calls were present near the time of co-option, and (iv) bower types contemporaneous with co-option emphasize design features that provide females protection from the adverse effects of intense courtship displays. These results, plus evidence for a female preference for males with intense aggressive-like courtship skrraa calls, suggest that aggressive skrraa calls have been co-opted for use in male courtship display     

Behavioral stimulation of ovarian growth

The present study was conducted to test the following hypothesis: male courtship induced egg-laying behavior in the female ring dove is mediated by the female's nest-coo display which feeds back to stimulate her ovarian system through the mechanisms of audio- and proprioceptive feedback. In Experiment I, females were exposed to 24 hr male courtship and then received playback of different nest-coos in the absence of their mates. All playback was effective in inducing the females to perform nest-coo displays, but none as effective as presence of the courting males. A specified level of the female's nest-coo display determined whether there would be changes in follicular diameter. The females which received no playback after 24 hr pairing with the male (control) did not show any change in the follicular diameter. In Experiment II, females were deafened by removal of cochleae and upon recovery paired with males. Half of those deafened females performed nest-coo displays and subsequently laid clutches. The others failed to perform the display and did not lay. We conclude that both proprioceptive feedback and audio-feedback must be involved to yield maximal stimulation of follicular growth by the female's nest-coo display.