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1.
Models of parasite-mediated sexual selection have thus far overlooked the potential effects of parasites of females on their
hosts’ ability to choose mates. A set of models addressing this issue is developed, each building on the previous one to add
complexity and realism to the framework. The selection coefficient for parasite immunity and brightness is estimated using
the ratio of the fitness of susceptible males to the fitness of immune males. Parasite-induced reduction in female choosiness
can substantially relax the selection for bright, immune males, especially when: (1) immunity to parasites is rare in the
population, (2) parasites are not highly aggregated within the host population, (3) parasites are abundant, and (4) the effects
of parasites on male brightness or female choosiness are severe. Parasite-induced variability in male brightness is most likely
to occur in populations in which parasites are abundant and not aggregated; if females in those populations show a reduced
preference for bright males, sexual selection for brightness (and parasite immunity) will still operate but exert a weaker
selective pressure.
Received: 4 November 1994/Accepted after revision: 9 September 1995 相似文献
2.
Female choice for parasite-free male satin bowerbirds and the evolution of bright male plumage 总被引:5,自引:1,他引:5
Summary Hamilton and Zuk proposed that bright male plumage may have evolved in males of polygynous species as a result of female preferences for males that are able to demonstrate their resistance to disease. They predicted an inverse correlation between female mating preferences and the level of parasitic infection of males. We found such a correlation between the level of infection by a common ectoparasite (Myrsidea ptilonorhynchi: Menoponidae) and mating success of male satin bowerbirds (Ptilonorhynchus violaceus). In addition, we tested and were able to confirm three other predictions derived from their model: that (1) older males had fewer parasites than their younger counterparts, (2) levels of individual parasitic infection are highly correlated between years, and (3) that individuals resighted in successive years are less parasitized than those that fail to return. These results support the bright male model, but they are also consistent with two other hypotheses that may explain plumage dimorphism based on the level of parasitic infection. The correlated infection model suggests that females choose males with few ectoparasites because of a correlation between the level of ectoparasitic infection and heritable resistance to internal infections. In the parasite avoidance model, females favor parasitefree males because it lowers their own prospects for parasitic infection. Our data did not show the predicted relationship between parasite numbers with plumage quality that is needed to support the bright male hypothesis, nor did it show the inverse correlation between male condition and parasite numbers that is predicted by both the bright male and correlated infection hypotheses. Our results are most consistent with the parasite avoidance hypothesis. 相似文献
3.
The effects of parasites on male ornaments and female choice in the lek-breeding black grouse (Tetrao tetrix) 总被引:1,自引:0,他引:1
Summary We describe the results of two studies of parasitic infection in the black grouse (Tetrao tetrix). The first deals with our own observations of lekking black grouse in which the parasite levels of two blood parasites, the protozoan Leucocytozoon lovati and microfilaria, probably produced by a nematode worm Splendidofilaria tuvensis, were scored. We also obtained measures of age, survival, number of copulations, body mass and length of the ornamental tail feathers (the lyre) of the lekking males. The second study analysed the data from Lund (1954) which involved eight gut parasites obtained from birds which were killed. In the first study we found higher levels of infection of Leucocytozoon in adults relative to young birds. Parasites had no effect on male survival and there was no correlation in infection between the two types of parasites. Birds infected with microfilaria had shorter tail ornaments. There was no relationship between parasitic infection and mating success. However, the data indicated that such a trend indeed may exist for Leucocytozoon and the most successful males on the leks were less often infected by Leucocytozoon than other males. Results of the second study showed a negative relationship between parasite load (a combined measure of all parasites) and both ornamental tail feather length and body mass. These observations are compatible with, but not conclusive evidence for, the hypothesis of Hamilton and Zuk (1982) on the evolution of secondary sexual characters, where females choose to mate with genetically resistant males which show their resistance by expressing larger and more showy secondary sexual characters. Alternative explanations for the observed patterns are: females avoid infected males for some immediate benefit; and/or parasite loads are indicators of general stress rather than genetical resistance. Under the latter hypothesis females could mate with more vigorous males for reasons unrelated to parasite resistance. 相似文献
4.
A. Peters L. B. Astheimer C. R. J. Boland A. Cockburn 《Behavioral ecology and sociobiology》2000,47(6):438-445
Testosterone has been proposed as a physiological link between the level of sexual signalling and male condition. Bright plumage
is one of the most noticeable sexual signals and is often used by females as a basis for mate choice. Yet bright male plumage
is not necessarily testosterone dependent. We investigated the role of testosterone in the moult into seasonal nuptial plumage
in male superb fairy-wrens. Early pre-nuptial moult is under intense intersexual selection and males can acquire the bright
plumage any time between autumn and the next spring. Testosterone was always undetectable or very low in males in dull eclipse
plumage. During the pre-nuptial moult, both the number of males with detectable testosterone and average testosterone levels
increased sharply. High testosterone was more correlated with nuptial plumage than with presence of the cloacal protuberance
(indicative of sperm storage). Subcutaneous testosterone implants always induced the pre-nuptial moult within 2–3 weeks after
implantation, even well outside the natural time range of moulting. Moreover, removal of the implants before the nuptial plumage
was completed, arrested the moult process. The evidence suggests that development of the nuptial plumage is testosterone dependent,
although we cannot exclude that testosterone exerts its action after conversion to a metabolite such as oestrogen. Once the
nuptial plumage was completed, all males maintained substantially elevated testosterone, sometimes months before the onset
of breeding. These high levels could be necessary to maintain the plumage, and/or are involved in courtship displays. The
results are discussed with respect to potential costs involved in acquiring and maintaining the nuptial plumage.
Received: 17 January 2000 / Received in revised form: 24 February 2000 / Accepted: 25 February 2000 相似文献
5.
Summary Despite a tendency for males of polygynous bird species to show bright or elaborate plumage, comparative analyses have failed to show any consistent relationship between male brightness or plumage dimorphism and the form of breeding systems. Here we argue that this may be partly because the opportunity for sexual selection varies between species showing serial or seasonal monogamy and life-long monogamy. In waterfowl, both the brightness of male plumage and sexual dimorphism in colouration vary between these categories of monogamy. Other ecological factors related to male brightness or plumage dimorphism include male assistance in protecting young, latitude and an index of parasite sharing. The adaptive significance of these trends is discussed.
Offprint requests to: D.K. Scott 相似文献
6.
Female mallard mating preferences for multiple male ornaments 总被引:3,自引:1,他引:3
K. E. Omland 《Behavioral ecology and sociobiology》1996,39(6):353-360
Mating preferences were studied in captive wild-stock female mallards. Independent observers scored ornament brightness for
the bill and eight plumage areas of male mallards on a scale of 1 to 6. Ornament scores were generally positively correlated
with each other as indicated by univariate correlations and principal component analysis. Males with higher bill scores were
significantly more likely to obtain pairings. None of eight individual plumage ornaments were significant predictors of pairing
success, but males with higher average plumage scores had significantly higher pairing success. Males that completed the molt
first were also significantly more likely to be paired. Thus females may have paid some attention to plumage brightness. Stepwise
multiple regression produced a model that included only bill and molt, both of which contributed a similar degree (r
2 = 0.39); plumage ornaments and size measurements did not enter the model. These results are interpreted in light of hypotheses
for the evolution of multiple ornaments, and phylogenetic plumage patterns in dabbling ducks.
Received: 18 December 1995 / Accepted after revision: 22 September 1996 相似文献
7.
Joel W. McGlothlin Deborah L. Duffy Jessica L. Henry-Freeman Ellen D. Ketterson 《Behavioral ecology and sociobiology》2007,61(9):1391-1399
Sexually selected traits that act as signals of quality often display some degree of condition dependence. In birds, condition
dependence of ornamental plumage is often mediated by production costs related to acquisition or allocation of dietary resources.
White plumage ornaments, however, have often been assumed to be inexpensive because their production requires neither pigment
nor specialized feather structure. In male dark-eyed juncos (Junco hyemalis), the size of a white patch on the tail contributes to attractiveness and mating success. Using captive males, we examined
the effects of diet quality on the size and brightness of the tail-white patch. After removing four tail feathers to induce
replacement, we maintained subjects on a subsistence (low-protein) or enriched (high-protein) diet while induced feathers
grew. Birds that received an enriched diet grew their feathers more quickly and grew larger, brighter white patches. Feather
growth rate was positively correlated with the increase in the size of the tail-white patch, a relationship that was stronger
in the subsistence diet group. However, within diet treatments, faster-grown feathers were slightly duller. Taken together,
these results suggest that variation in diet quality may lead to condition-dependent expression of tail white and that condition
dependence may be stronger in more stressful environments. We suggest a mechanism by which increased feather growth rate may
lead to an increase in the size of the tail-white patch and discuss potential trade-offs between signal size and brightness. 相似文献
8.
Delayed plumage maturation in Lazuli buntings: tests of the female mimicry and status signalling hypotheses 总被引:1,自引:0,他引:1
Vincent R. Muehter Erick Greene Laurene Ratcliffe 《Behavioral ecology and sociobiology》1997,41(4):281-290
The evolutionary importance of delayed plumage maturation (DPM) in passerines, the condition when more than 1 year is required
to achieve adult-like coloration, remains highly contentious. Adaptive hypotheses propose that aggression from after 2nd-year
(ASY) males or predation favors DPM in 2nd-year (SY) males, thereby increasing SY male survivorship or reproductive success.
However, each hypothesis suggests a distinct selective mechanism explaining “how” this is accomplished. Alternatively, DPM
may be a consequence of a nonadaptive molt constraint. We tested the female mimicry and status signalling hypotheses in territorial
ASY male lazuli buntings (Passerinaamoena) using three sets of model presentation experiments. The female mimicry hypothesis proposes that dull SY male plumage deceptively
mimics female plumage, and predicts that ASY males can not distinguish SY male from female plumage. The status signalling
hypothesis proposes that dull SY male plumage honestly signals low competitive threat, and predicts that ASY males respond
less aggressively to dull versus bright, ASY-like plumage. Contrary to the female mimicry hypothesis, ASY males distinguished
between SY male and female plumage, as they were aggressive to SY male models exclusively and attempted to copulate with female
models. Supporting the status signalling hypothesis, ASY males were significantly less aggressive to SY versus ASY male plumage.
While DPM may result from a physiological constraint on bright SY male plumage, our results support the idea that dull plumage
in an SY male's first breeding season may be maintained by selection to reduce aggression from ASY males, serving as a signal
of competitive status.
Received: 21 February 1997 / Accepted after revision: 16 June 1997 相似文献
9.
Mate choice games, context-dependent good genes, and genetic cycles in the side-blotched lizard, Uta stansburiana 总被引:4,自引:0,他引:4
According to mate choice models, a female should prefer males with traits that are reliable indicators of genetic quality
which the sire can pass on to their progeny. However, good genes may depend on the social environment, and female choice for
good genes should be context dependent. The side-blotched lizard, Uta stansburiana, exhibits genetically based throat colors (orange, blue, or yellow) that could be used as a sexually selected signal since
they reliably predict the genetic quality of mates. The frequencies of male and female morphs cycle between years, and both
male and female morphs have an advantage when rare; thus genetic quality will depend on morph frequency. A female should choose
a sire that maximizes the reproductive success of both male and female progeny. We examine a game theoretical model that predicts
female mate choice as a function of morph frequency and population density. The model predicts the following flexible mate
choice rule: both female morphs should prefer rare males in ’boom years’ of the female cycle (e.g., ’rarest-of-N rule’), but
prefer orange males in ’crash years’ of the female cycle (’orange-male rule’). Cues from the current social environment should
be used by females to choose a mate that maximizes the future reproductive success of progeny, given the social environment
of the next generation. We predict that the cue is the density of aggressive orange females. In the side-blotched lizard,
cycling mate choice games and context-dependent mate choice are predicted to maintain genetic variation in the presence of
choice for good genes.
Received: 8 March 2000 / Revised: 26 August 2000 / Accepted: 4 September 2000 相似文献
10.
The Hamilton-Zuk hypothesis states that females choosing males with more developed secondary sexual traits, i.e. brighter males, achieve greater fitness if variability in brightness reflects heritable variation in resistance to parasites. However, several factors will affect the likelihood that parasites play a role in sexual selection in given species. Here, using simple models, we show that because of parasite aggregation on a few hosts, only few breeding males would suffer from reductions in brightness due to parasites. Only in cases where parasites are abundant and show low levels of aggregation among their hosts would there be sufficient variability in brightness among breeding males for female choice of bright, resistant males to evolve. In addition, sufficient parasite-induced variability in brightness among breeding males will only occur in host-parasite systems where pathology is linearly related to the number of parasites per host. The presence of males that are uninfected and bright but genetically susceptible to parasites will also influence the fitness advantages obtained by females choosing bright males. If genetic immunity against parasites is rare in the host population, females can probably only benefit from choosing bright males if parasites are common and little aggregated among males. These results greatly limit the generality of the Hamilton-Zuk hypothesis, and suggest that only a small fraction of host-parasite associations could promote the evolution of host mate choice for resistance based on brightness.
Correspondence to: R. Poulin 相似文献
11.
Testis size variation in the greenfinch Carduelis chloris : relevance for some recent models of sexual selection 总被引:3,自引:0,他引:3
Interspecific evidence that testis size responds to selection caused by sperm competition has been obtained from many taxa. However, little is known about the sources of intraspecific variation in testis size, although such variation may have functional significance. Variation in testis size and asymmetry was studied within and between eight geographically separated (and genetically differentiated) populations of greenfinches Carduelis chloris. The relationships between testis size and plumage brightness (degree of yellowness) and the prevalence of haematozoan infections were also investigated in three of these populations, as they related to the predictions of the immunocompetence handicap hypothesis, and Møller's hypothesis relating directional testis asymmetry to phenotypic quality. There were large differences between populations in testis size, with males from northern populations having larger testes than those from southern populations. Within populations, large testes were associated with larger body size and greater age. When the influence of these factors was removed statistically, males with large testes were more likely to be infected with haematozoan parasites, and had brighter yellow plumage. No evidence was found that directional asymmetry in testis size was related to either of these measures of phenotypic quality. These results are consistent with the hypothesis that males with large testes, while signalling higher phenotypic quality as revealed by increased plumage brightness, also pay a cost in terms of reduced immunocompetence, revealed by the increased probability of infection in these males. That these patterns were similar in three different populations adds further strength to these conclusions. Our results suggest that studying the sources of variation in testis size among individuals can reveal interesting processes in sexual selection. 相似文献
12.
The haploid state of males in eusocial Hymenoptera—the ants, bees, and wasps—has been proposed as a driving force in the evolution of social behavior under the assumption that haploidy results in higher susceptibility to pathogens. In this study, we present the first test of the assumptions of the “haploid male susceptibility hypothesis”. We challenged males and workers of the bumblebee Bombus terrestris with its parasite Crithidia bombi but found no differences in either initial susceptibility or the intensity of infection between haploid males and diploid females. We reviewed observational studies on parasitism in haplodiploid insects and found that in 15 out of 26 cases, haploid males had lower parasite prevalence. However, the majority of available data related to nontransmissible parasites and thus any general statements about haploid susceptibility remain unclear. Using a simulation model, we studied how diverse genetic mechanisms could affect the values for resistance; results suggest that only a phenomenon that renders workers effectively haploid, e.g., imprinting, could explain our experimental results. A more likely explanation is that, in eusocial Hymenoptera with predominantly female populations, parasites may simply become more adapted to the more common female hosts and, thus, male haploid susceptibility may be hidden due to parasite adaptation. Our results do not support the idea that the haploid susceptibility hypothesis explains the origin or maintenance of social systems in the eusocial Hymenoptera. 相似文献
13.
L. W. Simmons 《Behavioral ecology and sociobiology》1990,26(6):403-407
Summary A recent model in sexual selection has proposed a role for parasites in maintaining heritable fitness variation. Females are envisaged as benefitting from preferentially mating with males that show resistance to infection. The post-copulatory guarding behaviour characteristic of many species of field cricket, has been envisaged as a means by which females assess male health and vigour. This hypothesis was tested in a field cricket, G. bimaculatus, which harbours a protozoan gut parasite. In enclosed arena trials, no direct correlations between female behaviours and levels of infection in males were found. However, there were significant correlations between the intensity of male guarding and the number of parasites found in the gut; infected males guarded more intensely in order to maintain contact with the female. In a second experiment simulating open field conditions, females left heavily parasitized males sooner than mildly or uninfected individuals. These data are discussed in relation to female choice for male health and vigour. 相似文献
14.
Several experimental studies have shown that female birds use ornamental melanin and carotenoid plumage coloration as criteria
in mate choice. Whether females choose mates based on natural variation in structural coloration, however, has not been well
established. Male eastern bluebirds (Sialia sialis) display brilliant ultraviolet (UV)-blue plumage coloration on their head, back, wings, and tail, which is positively correlated
with condition, reproductive effort, and reproductive success. We experimentally tested the hypothesis that female eastern
bluebirds prefer as mates males that display brighter structural coloration by presenting breeding-condition females with
males of variable coloration. We conducted two types of mate-choice experiments. First, females chose between males whose
coloration was manipulated within the natural range of variation in the population; feathers were either brightened with violet
marker or dulled with black marker. Second, females chose between males with naturally dull or bright plumage coloration.
In both manipulated and unmanipulated coloration trials, female choice did not differ significantly from random with respect
to structural coloration. We found no support for the hypothesis that the UV–blue coloration of male eastern bluebirds functions
as a criterion in female mate choice. 相似文献
15.
Maternal investment in rhesus macaques (Macaca mulatta): reproductive costs and consequences of raising sons 总被引:1,自引:0,他引:1
Maternal investment in offspring is expected to vary according to offspring sex when the reproductive success of the progeny
is a function of differential levels of parental expenditure. We conducted a longitudinal investigation of rhesus macaques
to determine whether variation in male progeny production, measured with both DNA fingerprinting and short tandem repeat marker
typing, could be traced back to patterns of maternal investment. Males weigh significantly more than females at birth, despite
an absence of sex differences in gestation length. Size dimorphism increases during infancy, with maternal rank associated
with son’s, but not daughter’s, weight at the end of the period of maternal investment. Son’s, but not daughter’s, weight
at 1 year of age is significantly correlated with adult weight, and male, but not female, weight accounts for a portion of
the variance in reproductive success. Variance in annual offspring output was three- to fourfold higher in males than in females.
We suggest that energetic costs of rearing sons could be buffered by fetal delivery of testosterone to the mother, which is
aromatized to estrogen and fosters fat accumulation during gestation. We conclude that maternal investment is only slightly
greater in sons than in daughters, with mothers endowing sons with extra resources because son, but not daughter, mass has
ramifications for offspring sirehood. However, male reproductive tactics supersede maternal investment patterns as fundamental
regulators of male fitness.
Received: 23 July 1999 / Received in revised form: 23 February 2000 / Accepted: 13 March 2000 相似文献
16.
D. J. Green H. L. Osmond M. C. Double A. Cockburn 《Behavioral ecology and sociobiology》2000,48(6):438-446
Empirical and theoretical studies have only recently begun to examine how females use complex multi-component displays when
selecting mates. Superb fairy-wrens are well suited to the study of female choice because females have control over extra-group
paternity and cuckold their mates at high rates, while males possess a variety of sexually selected traits. Available evidence
suggests that females base their extra-group mate choice on the timing of male moult into breeding plumage or the onset of
display. However, males continue to perform elaborate displays throughout the season, and direct most displays to females
during their fertile period. We therefore conducted focal observations on fertile females to quantify the frequency of male
display and used microsatellite genotyping to compare the role of display rate during the breeding season and the timing of
male moult on female mate choice. We show that the addition of data on male display rate does not improve our ability to predict
which males obtain extra-group paternity. The timing of male moult into breeding plumage remains the only predictor of male
extra-group reproductive success. Nevertheless, we found that males displayed more to females that were unable to select extra-group
mates on the basis of the timing of moult or the onset of display. This raises the possibility that there are circumstances
when females use display rate to discriminate between potential extra-group sires. Overall this study supports the theoretical
prediction that females are more likely to base their mate choice on reliable indicators of male quality such as fixed morphological
traits and displays of endurance, in this case an early moult into breeding plumage and the performance of an elaborate display
during the winter, than a flexible behavioural trait such as display rate during the breeding season.
Received: 26 January 2000 / Revised: 1 August 2000 / Accepted: 26 August 2000 相似文献
17.
Parental investment, adult sex ratios, and sexual selection in a socially monogamous seabird 总被引:7,自引:0,他引:7
Although most birds are monogamous, theory predicts that greater female parental investment and female-biased adult sex ratios
will lower the polygyny threshold. This should result in polygynous mating, unless obligate biparental care or the spatial
and temporal distribution of fertilizable females constrains a male’s ability to take advantage of a lowered polygyny threshold.
Here we present data on the extent of male sexually dimorphic plumage, adult sex ratios and breeding season synchrony in three
populations of a socially monogamous seabird, the brown booby Sula leucogaster. For one of these populations, San Pedro Mártir Island, we also present data on differences in male and female parental investment,
mortality and probability of pairing. The extent of plumage dimorphism varied among populations. Sex ratios were female biased in all populations. On San Pedro
Mártir Island, parental investment was female biased, females failed more often than males to find a mate, but there was no
polygyny. We suggest that on San Pedro Mártir: (1) a period of obligate biparental care coupled with a relatively synchronous
breeding season constrained the ability of males to take advantage of a high environmental polygamy potential and (2) the
resulting socially monogamous mating system, in combination with the female-biased adult sex ratio, caused females to be limited
by the availability of males despite their greater parental investment.
Received: 18 November 1999 / Accepted: 24 January 2000 相似文献
18.
Lifjeld JT Kleven O Jacobsen F McGraw KJ Safran RJ Robertson RJ 《Behavioral ecology and sociobiology》2011,65(9):1687-1697
When males become more ornamented and reproduce more successfully as they grow older, phenotypic correlations between ornament
exaggeration and reproductive success can be confounded with age effects in cross-sectional studies, and thus say relatively
little about sexual selection on these traits. This is exemplified here in a correlative study of male fertilization success
in a large colony of American barn swallows (Hirundo rustica erythrogaster). Previous studies of this species have indicated that two sexually dimorphic traits, tail length and ventral plumage coloration,
are positively correlated with male fertilization success, and a mechanism of sexual selection by female choice has been invoked.
However, these studies did not control for potential age-related variation in trait expression. Here, we show that male fertilization
success was positively correlated with male tail length but not with plumage coloration. We also show that 1-year-old males
had shorter tails and lower fertilization success than older males. This age effect accounted for much of the covariance between
tail length and fertilization success. Still, there was a positive relationship between tail length and fertilization success
among older males. But as this group consisted of males from different age classes, an age effect may be hidden in this relationship
as well. Our data also revealed a longitudinal increase in both tail length and fertilization success for individual males.
We argue that age-dependent ornament expression and reproductive performance in males complicate inferences about female preferences
and sexual selection. 相似文献
19.
Matthew B. Toomey Michael W. Butler Melissa G. Meadows Lisa A. Taylor H. Bobby Fokidis Kevin J. McGraw 《Behavioral ecology and sociobiology》2010,64(6):1047-1055
The glossy sheen of healthy hair is an ideal of human beauty; however, glossiness has never been quantified in the context
of non-human animal signaling. Glossiness, the specular reflectance characteristic of polished surfaces, has the potential
to act as a signal of quality because it depends upon material integrity and cleanliness. Here, we undertook two studies of
glossiness in avian plumage to determine (a) the repeatability of a recently developed measure of glossiness, (b) the relationship
between glossiness and conventional measures of coloration, and (c) how glossiness is associated with quality signaling. Using
museum specimens of three North American bird species with glossy plumage (red-winged blackbird, Agelaius phoeniceus; great-tailed grackle, Quiscalus mexicanus; Chihuahuan raven, Corvus cryptoleucus), we found that the glossiness measure was highly repeatable for all species and was significantly correlated with plumage
coloration (e.g., chroma, brightness) in male great-tailed grackles. We then used wild-caught grackles to examine sexual dimorphism
in plumage glossiness and its correlation to a potentially sexually selected trait in this species, male tail length. We found
that males were significantly glossier than females and that male, but not female, glossiness correlated positively with tail
length. This study provides a repeatable method to measure glossiness and highlights its potential as a signal of individual
quality in animals. 相似文献
20.
Nadia Silva Jesús M. Avilés Etiénne Danchin Deseada Parejo 《Behavioral ecology and sociobiology》2008,62(12):1969-1979
Animals may assess the quality of other individuals by using information that different ornaments may provide. The European
Roller (Coracias garrulus) is a socially monogamous species in which males and females display highly conspicuous plumage colouration. According to
the mutual selection hypothesis, we predicted that, in this species, plumage coloration could signal individual quality in
both sexes because both female and male rollers invest a considerable amount of time caring for their offspring. We used spectrophotometric
measurements to investigate the information content of multiple plumage colour traits. We found that the roller is actually
a sexually dimorphic and dichromatic species. Different plumage colours from different origins were correlated within individual.
Head and back brightness correlated with body condition in both sexes, and in males, head brightness correlated with the number
of fledglings in successful nests, while head green-yellow saturation correlated with parental provisioning. Meanwhile, in
females, back brightness was related to the number of fledglings in successful nests and to parental provisioning rate. In
addition, there was a positive assortative mating in relation to weight, body condition, head green-yellow saturation and
back brightness. Finally, we found a positive correlation between parent and offspring coloration. Altogether, these results
suggest that multiple colour traits may act as quality indicators in the roller and that they may be used by the two sexes
to assess potential mate quality. 相似文献