Effects of carotenoid availability during laying on reproduction in the blue tit

Abstract

Carotenoids are antioxidant pigments involved in several physiological processes and signalling in animals that cannot synthesise them and therefore must acquire them from food. We experimentally investigated the effects of carotenoid availability in the diet during egg laying on antioxidant deposition in egg yolk and the related effects on nestling condition, female body condition and parental investment in the blue tit (Parus caeruleus). Carotenoid supplementation of egg-laying females resulted in a significant increase in carotenoid concentration in egg yolk, but not in vitamin E or A concentration. There was no relationship between yellow plumage colour of adult females and carotenoid deposition in eggs, and no differential effect of feeding treatment depending on female colour. Nestlings from eggs laid by carotenoid supplemented females had longer tarsi, had faster development of the immune system as reflected by leukocyte concentration in blood, and grew brighter yellow feathers than nestlings from control females. However, nestlings from the two groups did not differ significantly in body mass, plasma antioxidants or plumage colour hue. At the time of chick rearing, carotenoid-fed females had increased plasma vitamin E levels compared to controls. However, females from the two treatment groups did not differ significantly in body condition or feeding rate. These results suggest that carotenoid availability is limiting during egg laying, and that females may have to balance the benefits of investing in egg quality against the potential costs of impairing their own future antioxidant protection. In addition, there may be considerable variation in carotenoid availability not only across seasons, but also among different stages of the breeding season.

Carotenoid availability in diet and phenotype of blue and great tit nestlings

“…Hexane extracts were pooled and evaporated at 60-65°C under nitrogen flow and the residue was dissolved in 0.1·ml dichloromethane and 0.1·ml methanol. Carotenoid composition and concentration, and vitamin A and E concentration were determined using reverse phase HPLC following previously published procedures (Surai, 2000;Surai et al, 2001c) (for details see Biard et al, 2005). All nestling plasma samples of at least 20·l (blue tit N=99, great tit N=82) were analysed for total carotenoid concentration, and a random sub-sample was used for carotenoid composition and vitamin analysis (one nestling of each treatment for blue tit N=10 nests, great tit N=7 nests).…”

A window on the past: male ornamental plumage reveals the quality of their early-life environment

“…One-way ANOVAs were used to assess repeatability of the different plumage colour variables (following Lessells & Boag [48] [16,49,50], justifying the use of these colour variables. Repeated measures were averaged per individual for use in subsequent analyses.…”

“…The long-term effects of developmental nutrition on morphology, physiology and metabolism can influence adult ability to assimilate the dietary pigments necessary for pigment-based coloration [9,10], and potentially also to form feather nanostructures necessary for structural coloration [11]. A number of studies have considered the immediate effects of developmental environment on nestling plumage colour [12 -15], demonstrating, for example, the importance of maternally invested egg yolk carotenoids for yellow plumage in nestling blue tits [16]. In addition, some studies have tracked the downstream effects of developmental environment on colourful adult traits.…”

Nest-climatic factors affect the abundance of biting flies and their effects on nestling condition

“…Mass and tarsus length were not significant correlated (Simple regression: F 1,44 ¼ 2.55; p ¼ 0.12). Nestling mass was corrected by size by using tarsus length as a covariate in further analyses (see Biard et al, 2005;Suárez et al, 2005;Shapiro et al, 2006 for a similar procedure).…”