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Sexual signaling systems often explain conspicuous male ornaments (Andersson 1994; Johnstone 1997). In sexual signaling systems, female receivers may use information extracted from male signals as the basis for choosing mates. Females can overcome deceptive male interests by preferring signal characters that impose costs to the signaling male (Zahavi 1975;(More)
Why females mate with multiple males, particularly in socially monogamous species, is one of the central unanswered questions in sexual selection and behavioural ecology. Recent theory suggests that socially monogamous females may improve the genetic quality of their offspring by mating with extrapair males with whom they are more genetically dissimilar(More)
Interest in female ornamentation has burgeoned recently, and evidence suggests that carotenoid-based female coloration may function as a mate-choice signal. However, the possibility that females may signal status with coloration has been all but ignored. Bill coloration of female American goldfinches (Spinus tristis) changes seasonally, from dull gray in(More)
Many socially monogamous species paradoxically show signs of strong sexual selection, suggesting cryptic sources of sexual competition among males. Darwin argued that sexual selection could operate in monogamous systems if breeding sex ratios are biased or if some males attract highly fecund females. Alternatively, sexual selection might result from(More)
Michael S. Webster, Keith A. Tarvin, Elaina M. Tuttle, and Stephen Pruett-Jones School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, WA 99164-4236, USA, Department of Biology, Oberlin College, Oberlin, OH 44074, USA, Department of Life Sciences, Indiana State University, Terre Haute, IN 47809, USA, and(More)
Ornamental bill color is postulated to function as a condition-dependent signal of individual quality in a variety of taxonomically distant bird families. Most red, orange, and yellow bill colors are derived from carotenoid pigments, and carotenoid deposition in ornamentation may trade off with their use as immunostimulants and antioxidants or with other(More)
Conspicuous ornamentation has been linked to immunological and physiological condition in males of many species. In species where both sexes are ornamented, it is unclear whether the signal content of ornaments differs between males and females. We examined the immunological and physiological correlates of carotenoid-based bill and plumage ornamentation in(More)
West Nile virus (WNV) was first detected in North America in New York City in 1999 and rapidly moved westward. Understanding the mechanisms by which the amplification cycle is reinitiated each year increases our ability to predict epizootics and geographic expansion of the disease. Such understanding is enhanced by knowledge of the patterns of infection in(More)
We examined the prevalence of antibodies to three mosquito-borne arboviruses in blue jays, Cyanocitta cristata, and Florida scrub-jays, Aphelocoma coerulescens, to identify the effects on host survival, the influence of sex and age on infection, and the temporal patterns of antibody prevalence. Blood samples from 306 blue jays and 219 Florida scrub-jays(More)
—Nesting success of birds often is influenced by habitat features surrounding nests. However, few studies have investigated habitat influences at multiple levels and spatial scales. We examined the relationship between Blue Jay (Cyanocitta cristata) nesting success and habitat at three levels (macrohabitat, microhabitat, and nest site) and at three(More)