Thesis: Significance of olfaction in the social behaviours of Procellarriform seabirds: Personal odours and individual recognition in two petrel species.
For many centuries, an anthropocentric view of sensory biology has seen olfaction (i.e. smell) dismissed as ‘primitive and unimportant’ by most scientists. Yet, ecological research of the last few decades has proven that chemical signals are broadly used in communication systems in both vertebrates and invertebrates. Individual odours in particular are commonly used by many animals as cues to assess the physiological and genetic characteristics of the surrounding individuals.
Personal odours can be used not only for individual recognition but also to assess the quality of a sexual partner and its compatibility with your own set of genes. This kind of unconscious sensory process has been recently revealed in humans whose preferences, in terms of body odours, are correlated with genetic characteristics of the bearer. Similar mate choice processes, through the effect of personal odours, have also been reported in fish, reptiles and other mammals. However, little is known of birds for which chemical signals have rarely been examined.
Seabirds and nocturnal petrels in particular have very good olfactory capabilities. Indeed, it has been found that these birds rely mainly on their smell to forage in the ocean and locate their nest on land. Recent experiments by our team on Antarctic prions (Pachyptila desolata) and blue petrels (Halobaena caerulea) have revealed their capacity to discriminate between individual odours. These results brought the first experimental support to the hypothesis that petrels’ odorous signals may be related to some genetic characteristics and contributing to mate choice. If true, each individual petrel should exhibit a consistent and specific personal odour, i.e. a ‘personal olfactory signature’. This is the focus of my PhD research which examines in Antarctic prions and blue petrels, the existence and composition of such ‘personal olfactory signature’ and its role in individual recognition and mate choice.
Why my research is important
In terms of conservation, understanding the mechanisms controlling breeding success in these marine birds will improve the efficiency of the conservation efforts for these polar species directly threatened by climate change. At the biological and experimental level, this project will clarify the nature of olfactory signatures in birds. It is the first study of its kind and should therefore constitute a methodological basis for future studies on avian olfaction. Finally, from an evolutionary perspective, this project contributes to a better understanding of how olfaction and odours are related to attraction and mate choice. Although this project considers petrels as the model organism, the same research theme is currently being investigated in mice, and also in humans, by other research teams. And after all, smelly birds matter in their own right.....don’t they?