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791.
Bob?B.?M.?WongEmail author Michael?D.?Jennions J.?Scott?Keogh 《Behavioral ecology and sociobiology》2004,56(3):253-256
Mate choice is not just a female preoccupation. Under some circumstances, males may also be choosy. However, studies of male mate choice have generally been confined to situations where males can make direct comparisons between potential partners. In contrast, sequential male mate choice has largely been overlooked despite its biologically importance, especially if current investment in mate attraction diminishes a males future mating opportunities. Using the Pacific blue-eye fish Pseudomugil signifer, we show that males are capable of exercising sequential mate choice. When presented sequentially with large and small females, males spent more effort courting the former. However, males did not appear to modify the time spent courting a given female based on the size of the female encountered previously. We suggest that greater attention to the sequential choice problem in males may help illuminate similarities and differences between the sexes when it comes to mating decisions.Communicated by T. Czeschlik 相似文献
792.
Females across many taxa commonly use multiple or complex traits to choose mates. However, the functional significance of
multiple or complex signals remains controversial and largely unknown. Different elements of multiple or complex signals may
convey independent pieces of information about different aspects of a prospective mate (the “multiple messages” hypothesis).
Alternatively, multiple or complex signals could provide redundant information about the same aspect of a prospective mate
(the “redundant” or “back-up” signal hypothesis). We investigated these alternatives using spadefoot toads, Scaphiopus couchii. Spadefoot toads primarily use calls to attract their mates, but males also exhibit sexually dimorphic coloration. We investigated
whether male coloration is indicative of male size, condition, or infection status by a socially transmitted monogenean flatworm.
We found that male coloration and dorsal patterning predicts male size and condition but not infection status. Moreover, when
we presented females with a choice between a bright male model and a dark male model, we found that females preferred the
bright model. Because aspects of males’ calls are also associated with male size and condition, we conclude that coloration
is a potentially redundant indicator of male phenotype. We suggest that coloration could enhance mate choice in conjunction
with male calling behavior by providing females with a long distance cue that could enable them to identify prospective mates
in a noisy chorus environment where the discrimination of individual calls is often difficult. Generally, such redundant signals
may facilitate mate choice by enhancing the quality and accuracy of information females receive regarding prospective mates. 相似文献
793.
According to indicator models of sexual selection, mates may obtain indirect, i.e. genetic, benefits from choosing partners indicating high overall genetic quality by honest signals. In the scorpionfly Panorpa vulgaris, both sexes show mating preferences on the basis of the condition of the potential partners. Females prefer males that produce nuptial gifts (i.e. salivary secretions) during copulation, while males invest more nuptial gifts in females of high nutritional status. Both characters, males' ability to produce nuptial gifts and high nutritional status of females, are known to be reliable indicators of foraging ability. Thus, besides possible direct benefits, both sexes might also obtain indirect benefits in terms of “good foraging genes” by their choice and thereby increase the fitness of their offspring. A prerequisite for this possibility is the heritability of the respective trait. In the present study, we estimated the repeatability and the heritability of foraging ability. Our results indicate (1) a significant repeatability of individual foraging efficiencies in males and females and (2) a heritable component of this trait by a significant parent–offspring regression. These findings suggest that genetic benefits in terms of increased offspring foraging ability might contribute to selection for mating preferences in both sexes. 相似文献
794.
Correlates of extra-pair fertilization success in hooded warblers 总被引:13,自引:0,他引:13
Bridget J. M. Stutchbury W. H. Piper D. L. Neudorf S. A. Tarof Judith M. Rhymer G. Fuller R. C. Fleischer 《Behavioral ecology and sociobiology》1997,40(2):119-126
We examined correlates of extra-pair fertilization (EPF) success in the hooded warbler (Wilsonia citrina), a species where females pursue extra-pair matings. The good genes hypothesis predicts that females choose extra-pair mates
with morphological or behavioral traits that reflect differences in male genetic quality. EPFs were common, as 35.3% (42/119)
of broods contained extra-pair young (EPY) and 26.7% (95/356) of nestlings were the result of EPFs. There was a strong skew
in male EPF success which increased the variance in annual male mating success 2–3 fold. However, male morphology did not
predict EPF success, as extra-pair males were not older or larger than the males they cuckolded. Likewise, there were no significant
correlations between the proportion of extra-pair young in a brood and male size or age. The good genes hypothesis predicts
that high-quality males will be consistently preferred as genetic mates, but the number of young sired by a male with his
social mate was not consistent from one year to the next. There was a significant negative correlation between female age
and proportion of EPY produced, which could result if older females obtain higher-quality social mates. We found no strong
evidence that females choose extra-pair mates for good genes, but females may use behavioral rather than morphological cues
to assess relative male quality.
Received: 31 May 1996 / Accepted after revision: 17 October 1996 相似文献
795.
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
796.
Stephen Nowicki Jeffrey Podos Frances Valdés 《Behavioral ecology and sociobiology》1994,34(5):329-335
In many songbird species, males sing a repertoire of distinct song types. Song sparrows typically are described as having repertoires of about a dozen song types, but these song types are themselves quite variable and some songs are produced that appear intermediate between two types. In this study we quantify the similarity between successive songs produced by song sparrows in order to determine if differences between song types are emphasized or deemphasized in bouts of continuous singing. In spite of the high degree of variation within song types and similarity between song types observed in this species, we show that transitions from one song type to the next are distinct as compared to transitions within sequences of the same type (Figs. 4 and 5). Variation does not accumulate across sequences of the same song type, and the average variation observed within a continuous sequence of the same song type is significantly less than is predicted from the total variation recorded for that type across many different bouts (Fig. 6). These results support the view that song sparrows include two levels of variation in their singing: differences between song types as is commonly observed in species with song repertoires, and an independent level of variation observed for songs of the same type. 相似文献
797.
在总结环境影响评价因子筛选方法的基础上,提出了"工程与环境相结合 ,定量化进行评价因子筛选"的新方法.同时,结合实践工作体会,提出了对较复杂项目, 在报告书阶段进行"环境影响因子再识别和评价因子再筛选"的思路. 相似文献
798.
危险废弃物安全填埋场的选址及安全措施 总被引:1,自引:0,他引:1
程鹏 《辽宁城乡环境科技》2006,26(1):8-10,17
在工业生产过程中,会产生大量的固体废弃物,而其中危险废弃物占有一定比例,如果对这类废弃物不适当或随意处置,则对自然环境和人体健康将产生有害影响.文中就危险废物安全填埋场的作用、选址要求、选址工作程序、建设标准、营运管理体制,以及污泥稳定化固化预处理方案等问题进行了研究和探讨。 相似文献
799.
800.
Sex linkage among genes controlling sexually selected traits 总被引:8,自引:0,他引:8
Klaus Reinhold 《Behavioral ecology and sociobiology》1998,44(1):1-7
Using literature data on reciprocal crosses I estimated the influence of sex-chromosomal genes on morphological and behavioral
traits. To determine a special role of the sex chromosomes for sexually selected traits, I compared the estimated influence
of X-chromosomal genes on sexually selected traits with their estimated influence on traits not under sexual selection. About
one-third of the phenotypic variation in sexually selected traits is caused by X-chromosomal genes. There was, in contrast,
no significant influence of X-chromosomal genes on traits that were classified as not sexually selected. Sexually selected
traits thus seem to be influenced significantly more by X-chromosomal genes than traits not under sexual selection. Though
this differential influence of X-chromosomal genes cannot readily be explained with current theoretical knowledge, it may
shed some light on X-linked hybrid sterility and on the discussion between arbitrary and good-gene models for the evolution
of female choice.
Received: 30 January 1998 / Accepted after revision: 20 June 1998 相似文献