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Context-dependent effects of yolk androgens on nestling performance

Context-dependent effects of yolk androgens on nestling performance

Maternal effects have a great influence on offspring phenotype. In oviparous species, females can adjust offspring development by changing the levels of certain components of the egg (like yolk hormones, particularly androgens), thus buffering the impacts of environmental heterogeneity on the performance of their descendants. Several studies have reported short term benefits of high yolk androgen levels, but such high hormone levels can also entail some costs, particularly those associated to decreased immunocompetence. In this research article it is shown that the resolution of this conflict is context-dependent. Thus, it was found that the effects of androgens on growth, immune function and survival of spotless starling chicks vary depending on the environment in which they develop. Overall, a positive effect of increased androgen levels was found in early clutches, whereas a negative balance (i.e. decreased immunocompetence and increased mortality) was found in clutches laid later in the season, when environmental conditions are harsher. The contrasted environmental conditions that the different broods of the species experience within the same breeding season determines why females should accurately and adaptively adjust their androgen allocation to egg yolks. informacion[at]ebd.csic.es: Muriel et al (2015) Context-dependent effects of yolk androgens on nestling growth and immune function in a multibrooded passerine J Evol Biol 28 ( 2 0 15 ) 1476–1488 doi: 10.1111/jeb.12668


http://onlinelibrary.wiley.com/doi/10.1111/jeb.12668/abstract