| the evolution of carotenoid coloration in estrildid finches: a biochemical analysis. | the estrildid finches (aves: passeriformes: estrildidae) of africa, asia, and australia have been the focus of several recent tests of sexual selection theory. many estrildids display bright red, orange, or yellow colors in the beak or plumage, which typically are generated by the presence of carotenoid pigments. in this study, we used high-performance liquid chromatography to investigate the carotenoid content of feathers and other colorful tissues in seven species of estrildids. star finches ( ... | 2004 | 15364287 |
| low survival of parasite chicks may result from their imperfect adaptation to hosts rather than expression of defenses against parasitism. | host parents exhibit a variety of behaviors toward avian brood parasites, but not all of their actions have necessarily evolved in response to costs imposed by parasites. to investigate whether common waxbills (estrilda astrild) have evolved defenses specifically against parasitic pin-tailed whydahs (vidua macroura), i studied the specificity and flexibility of host behaviors toward nestlings at two sites that differed significantly in parasitism rates and intensities. i focused on documenting n ... | 2005 | 16261738 |