Chemical profiles reflect heterozygosity and seasonality in a tropical lekking passerine bird

Abstract

Many lekking systems exhibit highly skewed male reproductive success, but traits preferred by females are not always evident. In the lance-tailed manakin, Chiroxiphia lanceolata, male reproductive success is correlated with age, experience and heterozygosity, but mechanisms by which females might detect these qualities are unknown. Avian chemical signals, such as volatile compounds present in preen oil secreted by the uropygial gland, have been shown to predict reproductive success, correlate with genetic diversity and indicate body condition and immune function in temperate passerines. Here we tested whether preen oil volatile compounds contain information about individual characteristics related to mate choice in male and female lance-tailed manakins, including social and breeding status, heterozygosity and age. In males, preen oil volatile profiles reflected heterozygosity but not social status or age. In females, we found a relationship between volatile profiles and age but not breeding status or heterozygosity. Volatile compounds covaried with sampling date in both sexes. The information reflected in manakin volatile profiles suggests that they have the potential to serve as mate assessment cues in this species.