Do females invest more into eggs when males sing more attractively? Postmating sexual selection strategies in a monogamous reed passerine.
Maternal investment can play an important role for offspring fitness, especially in birds, as females have to provide their eggs with all the necessary nutrients for the development of the embryo. It is known that this type of maternal investment can be influenced by the quality of the male partner. In this study, we first verify that male song is important in the mate choice of female Eurasian reed warblers, as males mate faster when their singing is more complex. Furthermore, female egg investment varies in relation to male song characteristics. Interestingly, clutch size, egg weight, or size, which can be considered as an high-cost investment, is not influenced by male song characteristics, whereas comparably low-cost investment types like investment into diverse egg components are adjusted to male song characteristics. In line with this, our results suggest that female allocation rules depend on investment type as well as song characteristics. For example, egg white lysozyme is positively correlated with male song complexity. In contrast, a negative correlation exists between-song speed and syllable repetitiveness and egg yolk weight as well as egg yolk testosterone concentration. Thus, our results suggest that female egg investment is related to male song performance in several aspects, but female investment patterns regarding various egg compounds are not simply correlated.
Institute of Zoology, Slovak Academy of Sciences Dúbravská cesta 9, Bratislava, 84506, Slovakia.
Ján
J
Krištofík
Institute of Zoology, Slovak Academy of Sciences Dúbravská cesta 9, Bratislava, 84506, Slovakia.
Alžbeta
A
Darolová
Institute of Zoology, Slovak Academy of Sciences Dúbravská cesta 9, Bratislava, 84506, Slovakia ; Department of Microbiology, Faculty of Medicine, Slovak Medical University Limbová 12, 833 03, Bratislava, Slovakia.
Juraj
J
Majtan
Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University Mlynská dolina, 842 15, Bratislava, Slovak Republic.
Monika
M
Okuliarová
Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University Mlynská dolina, 842 15, Bratislava, Slovak Republic.
Michal
M
Zeman
Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna Savoyenstr. 1a, Vienna, A - 1160, Austria.
Herbert
H
Hoi
Acrocephalus scirpaceus; egg yolk testosterone; lysozyme; male quality; song