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Breeding synchrony and extrapair fertilizations in two populations of red-winged blackbirds 总被引:7,自引:5,他引:2
We tested the relationship between synchrony of breeding andthe frequency of extrapair fertilizations (EPFs) in two populationsof red-winged blackbirds known to differ in female extrapairbehavior. We found no association between the number of simultaneouslyfertilizable females (temporal neighbors) and EPF rate in eitherpopulation, although a significant difference between populationsin the direction of this relationship (positive where femalesinitiated extrapair copulations and negative where males initiatedthem) suggested a modest difference in the influence of synchrony.Males losing offspring to EPFs tended to have more fertilizablefemales at that time than the actual sires in some analysesbut not in others. We also tested several assumptions underlyingtwo competing hypotheses for the effects of synchrony. We foundno evidence that females pursued extrapair copulations moreoften when other females were synchronous. Rather, females weremore likely to gain EFFs with exirapatr males whose social mateswere not yet building their nests. Synchrony also did not consistentlyaffect male pursuit of exirapair copulations or achievementof EPFs. These results suggest that timing of breeding has someeffects on extrapair activity, but that those effects are bothrelatively weak and influenced by other factors that vary betweenyears or populations. 相似文献
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The function of extrapair paternity in blue tits and great tits: good genes or fertility insurance? 总被引:11,自引:7,他引:4
DNA fingerprinting of an island population of blue tits andgreat tits in southeast Norway revealed that extrapair paternityaccounted for 36% (17/47) and 27% (15/55) of broods and for7% (31/466) and 8% (33/408) of young in the two species, respectively.Cuckolded males did not differ from noncuckolded males withrespect to morphology, age, or survival. There was no seasonalpattern in the frequency of extrapair paternity, and males showedno individual consistency in paternity loss over multiple broods.Extrapair offspring did not grow faster, they did not fledgewith a higher body mass, and they did not show a higher localsurvival rate than their half siblings. Hence, there was noevidence of any association between extrapair paternity andmale phenotypic or genotypic quality. Extrapair offspring wererandomly distributed among broods, with the only exceptionsof one blue tit and two great tit broods in which all young(six to nine) were sired by an extrapair male. This patternis best explained by a small proportion of males (2%4%)being infertile and by most females performing a few extrapaircopulations as insurance against laying infertile eggs. We concludethat the results suggest a role for fertility insurance butthat alternative functional explanations to extrapair paternityin these populations cannot yet be ruled out. 相似文献
114.
Female-solicited extrapair matings in Humboldt penguins fail to produce extrapair fertilizations 总被引:4,自引:2,他引:2
Schwartz Michael K.; Boness Daryl J.; Schaeff Catherine M.; Majluf Patricia; Perry Elizabeth A.; Fleischer Robert C. 《Behavioral ecology》1999,10(3):242-250
The study reported in this paper demonstrated that Humboldtpenguins at
Punta San Juan, Peru, despite forming pair-bonds,are not strictly monogamous
in their mating behavior: 19.2%of the study males and 30.7% of the study
females (21 nests)engaged in extrapair copulations. The total number of
completedmatings observed during the course of this study was 106, ofwhich
17.9% were extrapair copulations. Using DNA fingerprintingwe demonstrated
that none of these extrapair copulations resultedin extrapair fertilizations;
all 49 offspring were attributedto the putative father. Location of
copulations suggested thatfemales solicited these extrapair copulations
because 89.2%of Humboldt penguin within-pair copulations occurred at thehome
burrow, yet extrapair copulations took place at a differentlocation based on
the sex of the penguin. Extrapair copulationsby males occurred at their nest,
whereas females conducted 92%of their extrapair copulations away from the
nest. These resultsare most consistent with mate-appraisal and epiphenomenal
hypotheses. 相似文献
115.
Several hypotheses have been proposed to explain why femalebirds either
copulate repeatedly with a single mate or copulatewith multiple partners even
though only a single copulationmay be sufficient to fertilize an entire
clutch. We hypothesizethat females may directly benefit from high frequencies
of copulationand multiple copulation partners if they receive a cloacal
inoculationof beneficial sexually transmitted microbes (STMs) that caneither
protect them against future encounters with pathogensand/or serve as therapy
against present infections. Experimentsin domestic animal production,
wildlife rehabilitation, andclinical medicine indicate that inoculations of
beneficial microbesderived from the indigenous microflora of hosts can lead
tonutritional benefits, resistance to colonization by pathogens,the
elimination of infection, and improved immune system functioningin
recipients. Our hypothesis predicts greater copulatory rateswhen the
probability of the transmission of beneficial microbesexceeds that of
pathogens and when the positive effects of beneficialmicrobes on host fitness
exceed the negative effects of pathogens.Patterns of copulatory behavior in
birds suggest the potentialutility of our hypothesis. We discuss our
hypothesis in thecontext of observed patterns of copulation in birds and
proposesome ways to directly test our hypothesis. Information on the
probabilitiesof transmission during copulation of beneficial and pathogenic
microbesand their relative potencies in birds are needed to directlytest the
predictions of our hypothesis. 相似文献
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Jan T. Lifjeld Jostein Gohli Arild Johnsen 《Evolution; international journal of organic evolution》2013,67(10):3073-3074
We recently reported a positive association between female promiscuity and genetic diversity across passerine birds, and launched the hypothesis that female promiscuity acts as a balancing selection, pressure maintaining genetic diversity in populations (Gohli et al. 2013 ). Spurgin ( 2013 ) questions both our analyses and interpretations. While we agree that the hypothesis needs more comprehensive empirical testing, we find his specific points of criticism unjustified. In a more general perspective, we call for a more explicit recognition of female mating preferences as mechanisms of selection in population genetics theory. 相似文献
119.
Handicapped males and extrapair paternity in pied flycatchers: a study using microsatellite markers 总被引:7,自引:0,他引:7
We report an attempt to induce extrapair copulations and fertilizations in a species with a low intensity of sperm competition, the pied flycatcher Ficedula hypoleuca. Shortly after pair formation males were made less attractive to females by removing certain wing and tail feathers. Earlier research has shown that this manipulation reduces a male's pairing success. The idea was to test whether females mated to such males (N= 9) were more likely to obtain extrapair fertilizations than females mated to unmanipulated controls (N= 9). Paternity testing was carried out on all 98 young in the 18 broods, using a set of six microsatellite markers isolated from the species. Extrapair fertilizations were revealed in only three (17%) broods; two broods of handicapped males and one of a control male. A total of seven (7%) offspring were not genetically related to their putative father, a level which agrees well with results of other studies of this and other populations. We conclude that there was no evidence to suggest that the fertilization pattern was altered by the experimental manipulation. One reason for the lack of response could be that female mate choice in this species is based on male phenotypic, and not genotypic, quality. 相似文献