Parental investment and egg yolk lipid composition in gulls

Abstract

1. Within‐clutch variation in parental investment of yolk lipid (including essential fatty acid composition and fat‐soluble vitamin content) was investigated in whole clutches of three eggs of Lesser Black‐backed Gulls, Larus fuscus. 2. Although there were no significant differences between years in egg size or yolk mass among eggs of the same laying order, eggs collected in 1996 had significantly lower lipid content than those collected in 1997. 3. In both years third‐laid c‐eggs were smaller, had a smaller mass of yolk and had significantly lower yolk lipid mass compared with earlier laid (a‐ and b‐) eggs. 4. Despite this lower lipid mass of c‐eggs, of the different lipid fractions only cholesterol content of c‐eggs was significantly lower than that of a‐ or b‐eggs. 5. Earlier laid eggs had greater amounts of arachidonic acid in the phospholipid and cholesterol ester fractions of yolk lipid, and considerably greater quantities of vitamin E and carotenoids. 6. Conversely, levels of linoleic acid and vitamin A were equalized among eggs of different laying sequence as both these essential nutrients have primarily systemic roles. 7. The probable effect of increased antioxidant (vitamin E and carotenoid) content of earlier‐laid eggs is to enhance embryonic and neonatal growth and development, reduce susceptibility to pathogens and increase the ability of the embryo to withstand the oxidative stress associated with hatching. 8. The results suggest that there is maternal bias of essential nutrients to offspring with the highest reproductive value in order to maximize reproductive success.

Genetics, local environment and health as factors influencing plasma carotenoids in wild American kestrels (Falco sparverius)

“…Carotenoid concentrations found in nestlings in our study are also correlated with plasma levels of other nutrients, including vitamins A and E (P. Surai and G. R. Bortolotti, unpublished data). Recently Royle et al (1999) proposed that variation in carotenoid levels in eggs within clutches of lesser black-backed gulls (Larus fuscus) may impact on nestling growth and survival. Similarly, immunocompetence and other health-related functions of may be in£uenced by carotenoids in eggs (Haq et al 1996;Pastoret et al 1998;Surai & Speake 1998;Tella et al 2000a).…”

Carotenoids in Avian Nutrition and Embryonic Development. 2. Antioxident Properties and Discrimination in Embryonic Tissues.

“…Carotenoids together with other antioxidants (vitamin E, ascorbic acid, reduced glutathione or antioxidant enzymes) build an effective antioxidant system responsible for maintaining protection against damaging effects of free radicals and products of their metabolism (Surai, 1999). Therefore the antioxidant effect of carotenoids in embryonic tissues could be expressed directly or indirectly via antioxidant interactions but in both cases antioxidant protection could be the major advantage for the chick liveability and survival in postnatal development.…”

“…For example, this was the case in chick embryo brain where a very low vitamin E concentration in combination with a high ascorbic acid content is able to prevent lipid peroxidation in physiological conditions (Surai et al, 1996). Vitamin E recycling is ultimately dependant on the reducing power of NADPH generated by the pentose phosphate cycle of carbohydrate metabolism (Surai, 1999). In this case, as a result of the antioxidant action of vitamin E, the tocopheroxyl radical is formed.…”

“…Since carotenoids are not accumulated in the body to any great extent (Surai et al, 2000), it is important for the female to transfer them effectively to the egg yolk. For example, in the lesser black-backed gull the second and third eggs of a clutch usually contain less carotenoids than the first egg laid (Royle et al, 1999).…”

Heritable Variation in Maternal Yolk Hormone Transfer in a Wild Bird Population

“…Indeed, maternal investment into the egg (i.e., egg size and composition) has been found to critically influence offspring development in a variety of taxa, including birds, amphibians, reptiles, and fish (e.g., McCormick 1999; Royle et al 1999;Nager et al 2000;Wade 2001, 2003;Blount et al 2002;Saino et al 2002;Räsänen et al 2005;Warne and Charnov 2008;Dziminski et al 2009). In particular, androgens of maternal origin, such as testosterone (T) and its precursor androstenedione (A4), which accumulate in the egg yolk during follicle maturation (Schwabl 1993;Schwabl et al 1997), are an important component of egg quality.…”