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1.
We experimentally studied the relative importance of plumage, dominance status, and courtship behavior in determining male pairing success in the northern pintail Anas acuta and assessed whether these traits function in female choice, male-male competition or both. In an experiment (experiment IA) that eliminated the confounding effects of male-male competition and social courtship, females chose males with pure white breasts and colorful scapular feathers. When the same group of birds were free to interact (experiment 1B), male behavior was more important: females chose males that courted them intensely and were attentive to them, although preferred males again had whiter breasts and more colorful scapulars. In a second experiment (experiment 2), testing the effect of age on pairing success, females showed a significant preference for 2-year-old males over yearlings: 2-year-old males courted more and were more attentive to the female than yearlings; they were also more colorful than yearlings in a number of plumage measurements. Although males (in both experiments 1B and 2) were aggressive to one another while courting the female and dominant males were sometimes able to exclude subordinates from social courtship, contrary to expectation, we found no relationship between initial dominance rank and pairing success or dominance rank and age. In addition, dominance was not correlated with any of the morphological traits measured. Once chosen, however, subordinate males typically initiated fights with the higher-ranked male(s) and quickly achieved dominance. These results suggest that (1) females choose males based on a suite of morphological and behavioral characteristics, (2) male dominance relationships do not constrain active female choice, (3) a male's position in a dominance hierarchy is largely a result rather than a cause of female choice, and (4) female choice plays a more significant role than male-male competition in the evolution of several secondary sexual traits in male northern pintails. 相似文献
2.
Sexual conflict in the snake den 总被引:3,自引:0,他引:3
Red-sided garter snakes (Thamnophis sirtalis parietalis) court and mate in spring, soon after they emerge from large communal overwintering dens in south-central Manitoba. Because
of a massive bias in the operational sex ratio, every female attracts intense courtship from dozens to hundreds of males.
We suggest that this courtship constitutes significant ”harassment,” because it delays the females’ dispersal from the den
and hence increases their vulnerability to predation. Small females may face the greatest costs, because they are less able
to escape from amorous males (who court all females, even juvenile animals). Our measurements show that males are stronger
and faster than females. Experimental trials confirm that the locomotor ability of females (especially small females) is greatly
reduced by the weight of a courting male. Arena trials show that intense courtship stimulates females to attempt to escape.
Remarkably, some females that are too small to produce offspring may nonetheless copulate. This precocious sexual receptivity
may benefit juvenile females because copulation renders them unattractive to males, and thus allows them to escape more easily
from the den. Female ”tactics” to escape male harassment may explain other puzzling aspects of garter snake biology including
size-assortative mating, temporal patterns in dispersal from the den, avoidance of communal dens by young-of-the-year snakes,
and female mimicry. Hence, sexual conflict may have influenced important features of the mating system and behavioral ecology
of these animals.
Received: 8 May 2000 / Revised: 28 July 2000 / Accepted: 30 July 2000 相似文献
3.
Males of the brush-legged wolf spider, Schizocosa ocreata (Araneae: Lycosidae), possess a conspicuous male secondary sexual character: dark pigmentation and tufts of bristles on the
tibiae of their forelegs. We tested several hypotheses relating to the role of this conspicuous trait in sexual selection.
Triad mating experiments suggest that the tufts do not play an obvious role in the operation of sexual selection by either
male competition or female choice, as there were no significant differences in the mating success of intact and experimentally
shaved males. However, females mated more often with males that initiated courtship first, suggesting that capture of a female’s
attention by male signalling may play a critical role. In behavioral experiments that paired a single male with a female in
arenas that allowed both visual and vibratory signal transmission during courtship, female receptivity did not vary significantly
with the presence or absence of tufts. However, experiments that isolated the visual component of communication (by eliminating
vibratory communication) revealed a significant effect of the presence of tufts: females showed receptivity less often to
males with tufts removed. Female response to visual signals was much greater in S. ocreata than in its sibling congener, Schizocosa rovneri, which lacks male tufts. We hypothesize that the tufts serve to increase the efficacy of visual displays of S. ocreata, as vibratory communication is constrained by the complex leaf litter habitat of some populations. Such environmental constraints
may make visual signalling over distance a critical factor for effective courtship communication, which may in turn strongly
influence male fitness.
Received: 30 September 1994/Accepted after revision: 4 August 1995 相似文献
4.
The social spider Anelosimus studiosus exhibits a behavioral polymorphism where colony members express either a passive, tolerant behavioral tendency (social) or
an aggressive, intolerant behavioral tendency (asocial). Here we test whether asocial individuals act as colony defenders
by deflecting the suite of foreign (i.e., heterospecific) spider species that commonly exploit multi-female colonies. We (1)
determined whether the phenotypic composition of colonies is associated with foreign spider abundance, (2) tested whether
heterospecific spider abundance and diversity affect colony survival in the field, and (3) performed staged encounters between
groups of A. studiosus and their colony-level predator Agelenopsis emertoni (A. emertoni)to determine whether asocial females exhibit more defensive behavior. We found that larger colonies harbor more foreign spiders,
and the number of asocial colony members was negatively associated with foreign spider abundance. Additionally, colony persistence
was negatively associated with the abundance and diversity of foreign spiders within colonies. In encounters with a colony-level
predator, asocial females were more likely to exhibit escalatory behavior, and this might explain the negative association
between the frequency of asocial females and the presence of foreign spider associates. Together, our results indicate that
foreign spiders are detrimental to colony survival, and that asocial females play a defensive role in multi-female colonies. 相似文献
5.
Jonathan N. Pruitt Susan E. Riechert David J. Harris 《Behavioral ecology and sociobiology》2011,65(10):1957-1966
Relatively few investigations explicitly test for concordant versus conflicting selection pressures from intrasexual versus
intersexual selection. Here, we examine the effects of male body mass and behavioral type (BT) on reproductive success in
the spider Anelosimus studiosus, with emphasis placed on the potential interaction between intrasexual and intersexual selection influences. Female A. studiosus exhibit either an aggressive-active or docile-passive BT, both of which co-occur in multifemale colonies. Males, in contrast, exhibit a more continuous distribution of
behavioral tendencies. We investigated the male traits favored by females in five trial types: one docile female, one aggressive
female, four docile females, four aggressive females, and two docile and two aggressive females. Male reproductive success
was estimated by the number eggs produced by females following staged mating trials. In previous work, it was established
that large aggressive males are favored in male–male contests, an intrasexual effect. However, large aggressive males were
not universally favored here. We failed to detect an effect of male body mass or aggressiveness on reproductive success in
trials with all docile females; however, in situations involving aggressive females, large aggressive males experienced diminished
reproductive success relative to small docile males. Large, aggressive males were also more likely to be attacked and killed
by aggressive females in the first 20 min of staged encounters and were more likely to be found dead after 72 h of unobserved
interactions. Taken together, our data suggest that the reproductive consequences of male traits differ based on (1) the aspect
of sexual selection being considered (intrasexual versus intersexual) and (2) the BT of their prospective mates: large aggressive
males enjoy advantages in intrasexual selection and when courting docile females and small docile males experience reduced
risk of cannibalism and increased reproductive success with aggressive females. 相似文献
6.
Vikram K. Iyengar 《Behavioral ecology and sociobiology》2009,63(6):847-855
Determining the factors that affect male mating success is essential to understanding how sexual selection operates, including
explanations of the adaptive value of female preferences and how variation in male traits is maintained in a population. Although
females may appear to choose males based on a single parameter, female mate choice is often a complex series of assessments
of male quality that can only be revealed through manipulation of multiple male traits. In the moth Utetheisa ornatrix (Lepidoptera: Arctiidae), females have been shown to judge males primarily on their production of a courtship pheromone,
hydroxydanaidal, derived from defensive chemicals acquired as larvae. Recent work, however, suggested that other factors,
including prior mating experience by males, may also influence the outcome of precopulatory interactions with females. I ran
mating trials with one female and two males to determine whether there were any differences in male mating success based on
their prior exposure to females, mating experience, and time between matings. Previously mated males were favored over virgins
when both males lacked the pheromone, but courting experience and mating interval did not explain these differences in male
mating success. Furthermore, multiply mated males lacking the pheromone were favored over virgin males that produced the pheromone,
thus reversing the commonly observed trend of female precopulatory bias towards males with higher levels of the pheromone.
These results demonstrate that males with mating experience can secure copulations despite deficiencies in the pheromone,
and I provide possible mechanisms and discuss their implications regarding sexual selection. 相似文献
7.
We studied female guppies from two populations (Trinidad and Jemez Springs, New Mexico) to determine their mating preferences,
the degree of consensus among females for particular male phenotypes, and the variation among females for the types of traits
they prefer. We recorded the visual responses of 68 Trinidad and 10 Jemez females in paired male trials. The three sexually-selected
male traits quantified were the area of orange color and iridescence on the body, and display behavior. Females from the Trinidad
population agreed in their choice of males in three of the eight replicates, and this agreement was based on display rate
rather than male color patterns. Females from the Jemez population showed no agreement in their preferences of males. Mating
preferences of females varied both between populations and among females of a population. In both populations, female preferences
were based primarily on courtship intensity and only secondarily on color pattern. However, females from both populations
differed in the relative importance of orange color and iridescence. The fact that females differ in criteria for evaluating
males has important implications for selection and maintenance of color polymorphisms and for the interactions among multiple
secondary sexual traits of males in the guppy.
Received: 5 December 1995/Accepted after revision: 7 June 1996 相似文献
8.
Effects of male dominance and courtship display on female choice in the ring-necked pheasant 总被引:7,自引:0,他引:7
Male traits and behaviours acting in mate choice and intrasexual competition are expected to be congruent. When studying
their evolution, this often makes it difficult to differentiate between these two components of sexual selection. Studies
are therefore needed on mate choice in conjunction with the role of displays and dominance. We present the results from two
experiments conducted to investigate the effects of male dominance and courtship displays on female choice in the ring-necked
pheasant, Phasianus colchicus, controlling for differences in morphological male traits. We found: (1) different courtship behaviours had different effects
on female choice: females were mainly attracted by the feeding courtship behaviour, while another courtship display (the lateral
display) was effective in producing the copulation-acceptance response by the females; (2) subordinate males performed the
courtship behaviour before females less frequently than dominant males, and females reinforced intrasexual selection by choosing
dominant males, and (3) subordinate males in visual contact with a dominant became less attractive to females. The results
support the idea (armament-ornament model) that female pheasants may benefit from using traits selected in male-male competition
as clues for mate choice.
Received: 23 October 1997 / Accepted after revision: 7 October 1998 相似文献
9.
Fluctuating asymmetry (FA) can indicate developmental instability in bilaterally symmetric organisms, and studies have shown
that the degree of asymmetry in male secondary sexual characters influences female mate choice in a number of taxa. In male
Schizocosa ocreata wolf spiders, conspicuous tufts of bristles on the forelegs are a critical component of visual courtship signals, which appear
to play a role in female mate choice. Previous studies have shown that females exhibit reduced receptivity to males with regenerative
asymmetry, a consequence of leg loss and regeneration that causes males to be grossly asymmetric with respect to this important
signaling character. We provide data on the occurrence of FA in the tufts of S. ocreata, and examine further the influence of asymmetry on female mate choice. The distribution of tuft area asymmetry values from
a sample of field-collected males was normal, with a mean value of zero, indicating true FA. For a subset of males measured
directly after field collection and prior to feeding, tuft asymmetry was significantly negatively correlated with measures
of body size (body length) and condition (abdomen volume/cephalothorax width). Receptivity responses of females to visual
signals from live males of similar size varied with the degree of asymmetry in male tufts. Since FA covaries with male body
size and condition, which may also influence behavioral vigor, we used video image manipulation to alter the degree of asymmetry
in tufts of a courting male while holding size and condition constant. Asymmetry treatments represented values within the
range of natural FA variation as well as more extreme values characteristic of regenerative asymmetry. With the confounding
effects of male size, condition, and behavior held constant, female spiders exhibited reduced receptivity responses to all
experimental asymmetric video images relative to a control video stimulus. There were no differences in the frequency of female
receptivity among the various asymmetry treatments, suggesting that discrimination against asymmetry in conspecific male signal
characters is not simply a rejection of extreme phenotypes. Results suggest that asymmetry in a key male secondary character
used in visual signaling, independent of any concomitant behavioral or size factor, is an important criterion in mate choice.
Received: 26 February 1998 / Accepted after revision: 12 September 1998 相似文献
10.
Male fitness is often determined by the ability of the male to gain access to multiple mates, although in species that exhibit
sexual cannibalism, males might increase their likelihood of being cannibalized with each encounter. This risk should create
selection for males who are able to perceive potential risks associated with mating encounters. We studied male Schizocosa ocreata wolf spiders to determine whether they use female chemotactile cues (silk, excreta) as indicators of potential risks and
how these cues affected subsequent male courtship behaviors. Female treatments included satiated females vs. starved females,
as well as a treatment where females had recently cannibalized a male S. ocreata. We performed experiments to assess (1) if males use female chemotactile cues to determine potential risks associated with
differing female feeding treatments and alter courtship investment, and 2) how male experience with female chemotactile cues
affected courtship investment in subsequent female encounters. At first encounter, males do not vary courtship investment
(number of bouts, duration, and vigor) with different female feeding treatments. However, male behaviors during subsequent
encounters with female chemotactile cues varied in complex ways, depending on female feeding treatment and male first encounter
experience. These data suggest that male experience impacts perception of female chemical cues and offers the male opportunity
to avoid sexual cannibalism in high-risk situations. 相似文献
11.
Male seahorses (genus Hippocampus) provide all post-fertilization parental care, yet despite high levels of paternal investment, these species have long been
thought to have conventional sex roles, with female mate choice and male–male competition. Recent studies of the pot-bellied
seahorse (Hippocampus abdominalis) have shown that sex-role reversal occurs in high-density female-biased populations, indicating that male mating preferences
may lead to sexual selection on females in this species. Egg size, egg number, and offspring size all correlate positively
with female body size in Hippocampus, and by choosing large mating partners, male seahorses may increase their reproductive success. While male brood size is
also positively correlated with body size, small H. abdominalis males can carry exceptionally large broods, suggesting that the fecundity benefits of female preference for large partners
may be limited. We investigated the importance of body size in reproductive decisions of H. abdominalis, presenting focal individuals of both sexes with potential mating partners of different sizes. Mating preferences were quantified
in terms of time spent courting each potential partner. Male seahorses were highly active throughout the mate-choice trials
and showed a clear behavioral preference for large partners, while females showed significantly lower levels of activity and
equivocal mating preferences. The strong male preferences for large females demonstrated here suggest that sexual selection
may act strongly on female body size in wild populations of H. abdominalis, consistent with predictions on the importance of female body size for reproductive output in this species.
An erratum to this article can be found at 相似文献
12.
Male mosquitofish are very persistent in their sexual activity and harass any female they encounter. Gravid females pay a
large tribute to this intense male sexual activity in terms of reduced foraging efficiency. Previous observations have demonstrated
that gravid females, when chased by a male, dilute male harassment by moving closer to other females to form shoals. They
also approach other males to promote male competition, and when males differ in size, they preferentially target large males,
whose harassment is less intense. In this study, we tested whether the modulation of females’ social preferences in response
to male harassment is innate or learned. We tested social preference in three groups of females that differed in experience
of sexual harassment and in the factors affecting it. Females of the first group were reared without any sexual experience,
and pregnancy was induced through artificial insemination. The second group was composed of naive females kept singly with
a male; these females experienced sexual harassment but were prevented from experiencing the effects of male–male competition
and shoaling on the amount of male sexual harassment. In the third group (controls), females were reared in multi-male, multi-female
groups and could experience the modulating effects of social interactions on sexual harassment. When exposed to a harassing
male, females of the three groups immediately reduced their distance from another female, approached a group of males or moved
toward the larger of two available males. Moreover, the results for these three groups of females were similar to those obtained
in wild-caught females that were tested in the same three tests in a previous study (Dadda et al. An. Behav., 70:463–471, 2005). This suggests that the strategies adopted by females in response to male sexual harassment do not need to be learned through
specific experience of the social contexts. 相似文献
13.
Jérémie H. Cornuau Margaux Rat Dirk S. Schmeller Adeline Loyau 《Behavioral ecology and sociobiology》2012,66(7):1045-1055
There is increasing evidence that female mate choice is often based on the assessment of multiple male traits, involving both morphology and behavior. We investigated female mate choice for multiple male traits in the palmate newt, Lissotriton helveticus, including male tail filament length, hind foot web size, crest development, body size, ventral coloration, and courtship display activity. Observations of courtship display in the field revealed that females spent more time in front of males with longer tail filaments. Laboratory experiments revealed a more detailed relationship between filament length and courtship display. We found that females took more sperm masses from males with both longer filaments and greater display activity. Experimental shortening of the tail filament length substantially decreased the number of male sperm masses transferred. However, when we experimentally reversed relative filament length between two males in mating trials, male mating success was explained by courtship activity and not by filament length. Our results show that female palmate newts value multiple traits during mate choice, including both morphological ornaments and reproductive behaviors in males. Our results further suggest that, when filament length is below a certain threshold, females may value the information content of courtship activity over that of filament length. 相似文献
14.
Bright colours of male birds have often been shown to be the target of sexual selection through female choice, yet few studies have looked at the role of colour expressed after pairing on female motivation and behaviour. Here we analyse the role of an integumentary colour in the spectral range of 400–700 nm, the foot colour in male blue-footed boobies, Sula nebouxii, which is prominently displayed during pair courtship. Measurements early in the breeding season showed that foot colour of courting males is pale (high values of brightness) and has an aqua-blue chroma, and females in better body condition were mated to males with brighter feet. We carried out an experimental manipulation which modified the foot colour of males in courtship, making it closer to the foot colour of males in low nutritional state. We found that females paired to experimental males courted less and were less likely to copulate than females in the control group. Male behaviour was apparently unaffected by the manipulation; thus the change in female behaviour can be attributed exclusively to foot colour manipulation. These results strongly support the hypothesis of female preference for an integumentary colour and suggest that this dynamic trait is used as a male ornament after pairing.Communicated by J. Graves 相似文献
15.
Life-history theory predicts that individuals should increase their reproductive effort when the fitness return from reproduction is high. Females mated with high-quality males are therefore expected to have higher investment than females mated with low-quality males, which could bias estimates of paternal effects. Investigating the traits females use in their allocation decisions and the aspects of reproduction that are altered is essential for understanding how sexual selection is affected. We studied the potential for differential female allocation in a captive population of a precocial bird, the Chinese quail, Coturnix chinensis. Females paired with males with large sexual ornaments laid larger, but not more, eggs than females paired with males with small sexual ornaments. Furthermore, female egg mass was also significantly positively affected by male testis size, probably via some unknown effect of testis size on male phenotype. Testis size and ornament size were not correlated. Thus, both primary and secondary male sexual traits could be important components of female allocation decisions. Experimental manipulation of hormone levels during embryonic development showed that both male and female traits influencing female egg size were sensitive to early hormone exposure. Differences in prenatal hormone exposure as a result of maternal steroid allocation to eggs may explain some of the variation in reproductive success among individuals, with important implications for non-genetic transgenerational effects in sexual selection.Communicated by C. Brown 相似文献
16.
Effect of female molt stage and sex ratio on courtship behavior of the blue crab Callinectes sapidus
In many species, males and females actively participate in courtship, and the outcome of pre-mating interactions influences
the mating success of both sexes. Female blue crabs, Callinectes sapidus, mate soon after their final molt to maturity; thus female molt stage dictates the timing of mating. In a field experiment,
we manipulated female molt stage and sex ratio to test their effects on the courtship behavior of both sexes, if female behavior
influences the behavior and pairing success of males, and if male courtship influences male pairing-success. Early-molt-stage
females avoided males during courtship, whereas late-molt-stage females sought out males. As a result, males had to pursue
and capture early-molt-stage females whereas males displayed to late-molt-stage females and more easily physically controlled
them. Males sometimes abandoned late-molt-stage females, but this occurred more often when females were abundant. The rate
at which females avoided males was positively correlated with that of males abandoning females, and males that were unsuccessful
at pairing met with higher rates of female resistance than successful males, suggesting that female behavior influences male
pairing-success. Unlike unsuccessful males, successful males more often made the transition between display and maintaining
physical control of the female. At high male sex ratios, males initiated courtship more readily; thus both sexual competition
and female behavior influence male courtship in this species.
Received: 7 July 1996 / Accepted: 10 January 1998 相似文献
17.
Magne Friberg Namphung Vongvanich Anna-Karin Borg-Karlson Darrell J Kemp Sami Merilaita Christer Wiklund 《Behavioral ecology and sociobiology》2008,62(6):873-886
Animal courtship rituals are important for species recognition, and a variety of cues might be utilized to recognize conspecific
mates. In this paper, we investigate different species-recognition mechanisms between two sympatric butterfly sister species:
the wood white (Leptidea sinapis) and Real’s wood white (Leptidea reali). We show that males of both species frequently court heterospecific females both under laboratory and field conditions.
The long-lasting elaborate courtships impose energetic costs, since the second courtship of males that were introduced to
two subsequent conspecific females lasted on average only one fourth as long as the first courtship. In this paper, we demonstrate
that premating reproductive isolation is dependent on female unwillingness to accept heterospecific mates. We studied female
and male courtship behavior, chemical signaling, and the morphology of the sexually dimorphic antennae, one of the few male
traits visible for females during courtship. We found no differences in ultraviolet (UV) reflectance and only small differences
in longer wavelengths and brightness, significant between-species differences, but strongly overlapping distributions of male
L. sinapis and L. reali antennal morphology and chemical signals and minor differences in courtship behavior. The lack of clear-cut between-species
differences further explains the lack of male species recognition, and the overall similarity might have caused the long-lasting
elaborate courtships, if females need prolonged male courtships to distinguish between con- and heterospecific suitors. 相似文献
18.
Female choice of multiple male criteria in guppies: interacting effects of dominance,coloration and courtship 总被引:9,自引:0,他引:9
Astrid Kodrie-Brown 《Behavioral ecology and sociobiology》1993,32(6):415-420
Summary I experimentally examined the relative importance of social dominance, color patterns, and courtship behavior in male mating and reproductive success in the guppy Poecilia reticulata. Female choice of males is based on a complex set of behavioral and morphological traits. The results of 59 paired-male one-female visual choice and mating trials showed that male mating success was positively correlated with dominance, courtship intensity, and male coloration. Only dominant males engaged in full copoulations, and they sired two-thirds of the broods. An analysis of the paternity of broods and results of mating trials showed that a female's visual response when the sexes are separated by a glass partition is a good predictor of a male's reproductive success when the partition is removed and they are allowed to mate. A canonical correlation analysis of male behavioral and morphological traits indicated that female visual response and male mating success were positively correlated with male courtship and with agonistic behavior. However, the relative importance of color varied. Carotenoid and iridescent spots were important both in attracting the female's attention and in enhancing male mating success. Melanins were not correlated with either mating success or female response. There was a relatively low correlation (48%) between male behavioral and morphological variables and female response variables (full copulation and female visual response). These results suggest that female choice is subtle, and is based on a complex suite of male behavioral and morphological traits as well as on competitive interactions among males. 相似文献
19.
Reproductive isolation and speciation can result from female choice for particular males. Isolation can also result, however, from male mating preferences or from aggressive encounters which then influence mating decisions. In this study, we use laboratory discrimination trials to study the behavioral mechanisms of population discrimination in sagebrush lizards (Sceloporus graciosus). We specifically ask three questions about population-level discrimination: (1) Does it vary in strength in relation to the geographic distance between the populations? (2) Is it more apparent in inter- or intra-sexual interactions? (3) Does it take the form of attraction or avoidance? We ran 890 trials that tested the ability of male and female sagebrush lizards from one population to discriminate their own population from four other populations. In addition, we utilized both sequential and simultaneous-choice designs, which enabled us to distinguish between attraction and avoidance. We found that most population-level discrimination was exhibited by male lizards preferring to associate with particular types of females, as well as female avoidance of particular types of males. The strength and direction of both discriminations depended on the populations compared and on whether the tests were conducted as sequential- or simultaneous-choice tests, producing a complex relationship between geographic distance and behavioral discrimination. Our results suggest that there are roles for male attraction and female avoidance in population discrimination, reproductive isolation, and speciation. 相似文献
20.
Vocalisations of many songbirds, anurans, and insects are shaped by sexual selection. Males acoustically compete for territories, and females choose their mates by means of male courtship songs. In courtship, richness and complexity of elements are often favoured characters. Only a few examples of complex songs are known in mammals. Males of the harem-polygynous sac-winged bat (Saccopteryx bilineata, Emballonuridae) have an uncommonly complex vocal repertoire, and different song types of males are used in the context of territorial defence and in courting females. We classified the daytime vocalisations of 16 male S. bilineata from a colony in Costa Rica, both on the basis of their acoustical properties and the social context in which they occurred. Seven vocalisation types were differentiated: echolocation pulses, barks, chatter, whistles, screeches, territorial songs and courtship songs. Territorial songs were short, rather stereotyped and not obviously directed towards a certain conspecific. They appear to be of importance in male competition for harem territories, in which females roost during the day. Courtship songs were exclusively observed when males displayed towards a female; they were long and complex, and consisted of highly variable elements (calls). We classified the calls in courtship songs of six males into call types, based on acoustical properties, mainly spectral purity and duration. Four call types are described in detail: trills, noise-bursts, short tonal calls, and quasi constant frequency calls. Twelve parameter values were extracted from the most common call type, the trill. Discriminant function analysis of trills showed that different males had different repertoires. This could allow females to use trill parameters for recognition of individual males and thus for mate choice.Communicated by G. Wilkinson 相似文献