Rebecca J Safran

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Paternity in male animals can be influenced by their phenotypic signals of quality. Accordingly, the behavior underlying patterns of paternity should be flexible as signals of quality change. To evaluate the dynamics of paternity allocation, we analyzed paternity before and after manipulating plumage coloration, a known signal of quality, in male barn(More)
Sexual adornments often vary markedly across a species’ range, which presumably is owing to differences in local environmental conditions and the associated selection pressures, such as natural versus sexual selection or the relative signaling value of different ornamental traits. However, there are only a few reported examples in which the information(More)
The cosmopolitan Barn Swallow complex (Hirundo rustica and related Hirundo species) provides a model system for studies of mate choice, sexual selection, and related topics in behavioral ecology, but the phylogenetic and phylogeographic relationships within this group are not yet completely resolved. We reconstructed the phylogeny of all 14 species of(More)
Recently, evidence is mounting that females can adaptively engineer the quality of their offspring via the deposition of yolk compounds, including carotenoids and androgens. In this study, we simultaneously consider how both carotenoids and androgens in egg yolk relate to parental quality in barn swallows (Hirundo rustica erythrogaster). First, we found no(More)
Animal coloration is a powerful model for studying the genetic mechanisms that determine phenotype. Genetic crosses of laboratory mice have provided extensive information about the patterns of inheritance and pleiotropic effects of loci involved in pigmentation. Recently, the study of pigmentation genes and their functions has extended into wild(More)
A prevailing view in sexual selection theory is that costly physiological processes underlie the development, maintenance and expression of sexual signals, and that the costs of these signals enforce their honesty [1,2]. However, this unidirectional view of how physiology governs signal expression is narrow, because many of the putative physiological(More)
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(More)
Recent studies of several species have reported a latitudinal cline in the circadian clock gene, Clock, which influences rhythms in both physiology and behavior. Latitudinal variation in this gene may hence reflect local adaptation to seasonal variation. In some bird populations, there is also an among-individual association between Clock poly-Q genotype(More)
Acoustic signals mediate mate choice, resource defense, and species recognition in a broad range of taxa. It has been proposed, therefore, that divergence in acoustic signals plays a key role in speciation. Nonetheless, the processes driving divergence of acoustic traits and their consequences in terms of speciation are poorly understood. A review of(More)