...Chloe Peneaux; Gabriel E. Machovsky-Capuska; John A. Endler; Andrea S. Griffin ABSTRACT Producing colored signals often requires consuming dietary carotenoid pigments. Evidence that food deprivation can reduce coloration, however, raises the question of whether other dietary nutrients contribute...

...Ismael Galván; Khaled Murtada; Alberto Jorge; Ángel Ríos; Mohammed Zougagh ABSTRACT Pigments are largely responsible for the appearance of organisms. Most biological pigments derive from the metabolism of shikimic acid (melanins), mevalonic acid (carotenoids) or levulinic acid (porphyrins), which...

... expression of ornamental traits (darkened bills and red back feathers) is positively associated with age and circulating androgen titres, (2) females have the capacity to express most male-typical traits in response to exogenous T, including carotenoid-pigmented body plumage, shorter feathers, darkened bill...

...Viviana Marri; Heinz Richner Oxidative stress is the imbalance between the production of reactive species and antioxidants, which causes damage to lipids, proteins and DNA. Antioxidants, like vitamins and carotenoids, can limit oxidative damage and can therefore regulate the trade-off between...

... stage (e.g. entering the adult reproduction stage), we must carefully examine the degree to which developmental versus adult conditions shape performance of the immune system. We investigated how variation in dietary access to carotenoid pigments – a class of molecules with immunostimulatory properties...

...Peeter Hõrak; Elin Sild; Ursel Soomets; Tuul Sepp; Kalle Kilk SUMMARY Carotenoid and melanin pigments in the plumage of birds are hypothesized to be sensitive to oxidative stress. We manipulated oxidative status of captive greenfinches ( Carduelis chloris L.) by the administration of buthionine...

... greater for low-quality than for high-quality individuals. Given the physiological functions of carotenoids, carotenoid-based ornaments could indicate individual immunocompetence, and possibly the ability to mount an immune response at a lower cost. We evaluated whether the red carotenoid-based coloration...

...% carbohydrate and 20% fat( Pierce and McWilliams, 2005 ). The E diet contained 41% protein, 0.25% lutein, 2% vitamin, 15% carbohydrate and 15% fat. This diet was a novel dietary formulation that was designed to simulate an insect diet in protein content, contained higher vitamin and antioxidant (carotenoid...

...Geoffrey E. Hill; Wendy R. Hood; Kristal Huggins SUMMARY It has been well established that carotenoid and melanin pigmentation are often condition-dependent traits in vertebrates. Expression of carotenoid coloration in birds has been shown to reflect pigment intake, food access and parasite load...

... that there was no effect of dietary antioxidant intake on escape time. In contrast, Blount and Matheson reported that zebra finches Taeniopygia guttata , a small passerine bird, receiving a carotenoid-enhanced diet flew faster than controls ( Blount and Matheson, 2006 ). In their study oxidative stress was not measured...

...Mats Olsson; Mark Wilson; Caroline Isaksson; Tobias Uller; Beth Mott SUMMARY We performed experiments on male Australian painted dragon lizards( Ctenophorus pictus ) to test the hypothesis that carotenoids can scavenge reactive oxygen species (ROS), protecting the organism from oxidative stress...

... the health properties of carotenoid pigments, carotenoid-based ornaments offer a relevant context in which to investigate the effect of environmental stress, such as ambient temperature, on the production and maintenance of secondary sexual traits and, also, to explore the proximate mechanisms shaping...

...Sophie Bertrand; Bruno Faivre; Gabriele Sorci SUMMARY Carotenoid-based signals are thought to be indicators of male quality because they must be obtained from the diet and might thus indicate the ability of individuals to gather high-quality food. However, carotenoids are also known to have...