22 research outputs found
Model-based analysis of photoinitiated coating degradation under artificial exposure conditions
Induction of apoptosis in A549 pulmonary cells by two Paracoccidioides brasiliensis samples
The effects of different diets on the growth, sexual maturation and reproductive performance of achatina fulica
No Abstract. Journal of the Ghana Science Association Vol. 1 (1) 1999: pp.88-9
Computing Resonant Inelastic X-Ray Scattering Spectra Using The Density Matrix Renormalization Group Method
Assessing the cost of living with elephants (Loxodonta africana) in areas adjacent to Meru National Park, Kenya
Covariation between eumelanic pigmentation and body mass only under specific conditions.
Identifying the factors that mediate covariation between an ornament and other phenotypic attributes is important to determine the signaling function of ornaments. Sign and magnitude of a covariation may vary across environments if the expression of the ornament or of its linked genes regulating correlated phenotypes is condition-dependent. I investigated in the barn owl Tyto alba whether sign and magnitude of covariation between body mass and two heritable melanin-based plumage ornaments change with food supply, along the reproductive cycle and from the morning to the evening. Using a dataset of 1,848 measurements of body mass in 336 breeding females, I found that females displaying large black spots were heavier than conspecifics with smaller spots in the afternoon (i.e., a long time after the last feeding) but not in the morning (i.e., a short time after the last feeding). This is consistent with the recently proposed hypothesis that eumelanin-based ornaments are associated with the ability to maintain energy balance between food intake and energy expenditure. Thus, covariation between melanin-based coloration and body mass can be detected only under specific conditions potentially explaining why it has been reported in only ten out of 28 vertebrate species. The proposition that ornamented individuals achieve a higher fitness than drab conspecifics only in specific environments should be tested for other ornaments