Abstract
Despite research in several biologically-relevant contexts, including orientation and resource acquisition, olfaction studies in free-ranging reproducing bird populations are rare. This, inter alia, hampers the quantitative study of fitness- consequences of olfaction. Here we provide a brief review of the use of avian smell in the context of reproduction, focusing on a model system, the blue tit. Corsican blue tits (Parus caeruleus ogliastrae) incorporate into their nests small fragments of aromatic plants that deliver high levels of volatile compounds easily perceived by a human observer. Blue tits use olfactory cues to anticipate the changes of the aromatic environment in their nests by repeatedly delivering fresh plant material with high concentrations of volatile compounds. A chemical approach will enable measurement of volatile compound concentrations, the identification of the volatile compounds involved, and ultimately the study of the functional meaning and fitness consequences of olfaction in free-living populations of birds.