Abstract
As Bradbury & Verhencamp (1998) nicely said, communication is “the glue that holds animal societies” as it mediates many social behaviours in most species. Burrowing petrels offer a remarkable opportunity to study vocal communication in an environment that at a first glance seems unfavourable. Indeed, these seabirds gather in dense colonies during the breeding season. In spite of strong winds, vocal interferences from other birds, and presence of acoustically-oriented predators, calls are at the heart of sexual and territorial interactions. In this thesis, I studied two burrowing petrel species phylogenetically close: the blue petrel Halobaena caerulea and the Antarctic prion Pachyptila desolata, already known for their developed olfactory abilities. In spite of the climatic constraints and predation pressure, and in addition to olfactory communication, vocal communication should provide benefits, unknown so far. Using playback and attractiveness experiments on the birds’ breeding ground in Kerguelen, I aimed to investigate the determinisms and implications of male calls in female mate choice. The results of this thesis reports (i) the coding of static (caller morphology and individual identity) and dynamic (motivation) information coded in both spectral and temporal parameters of male calls, (ii) how detectability of male calls, but mostly their informative content, influence females mate choice, and (iii) the role played by the burrow in call propagation and female mate choice. Both studied species show similarities in their vocal coding and strategies, suggesting that the same environmental constraints on long-range signalling have shaped similarly vocal signals. Considerable insight has been gained concerning the communication strategies in constraining environments and in burrow-nester seabirds, still under-studied.