Reproductive investment of female green toads (Bufo viridis)

Females of iteroparous species may compromise between contrasting reproductive strategies. They should balance the amount of energy devoted to reproduction against the energy saved for growth and survival, and they should compromise between the quantity versus the quality of offspring. In the present paper, we analyze these trade-offs in European Green Toads (Bufo viridis). We define reproductive investment in terms of clutch dry mass, number of eggs, and mean ovum dry mass, whereas we describe the amount of resources saved for growth and survival (somatic investment) with a fat index derived from the total body electrical conductivity (TO-BEC) of postspawning females. Our results indicate that larger individuals produce larger clutches, both in the number and size of eggs. Females with higher reproductive effort, however, also show a larger somatic investment regardless of size. We show that females of similar size invest similar proportions of resources in reproduction, so that those in good condition not only show larger reproductive effort than lower-quality females but also store larger amounts of resources for growth, survival, and future reproduction.