From preen secretions to plumage: the chemical trajectory of blue petrels' Halobaena caerulea social scent

Abstract

Petrel seabirds heavily rely on their olfactory sense and are thus appropriate models for the study of avian chemical communication. The uropygial secretions of blue petrels Halobaena caerulea, for instance, have been shown to encapsulate elaborate sociochemical information including species, gender and identity. Yet, it is the plumage, and not preening secretions per se, which acts as the final substrate of avian scents. Importantly, the chemical relationship between secretions from the uropygial gland, located at the dorsal base of the tail, and plumage lipids has been considered in only a handful of studies which reported large qualitative differences. The emission process of avian scents, and the possible participation of the uropygial gland in particular, are therefore not elucidated. In the present study, we examine the early chemical trajectory of blue petrels' social chemosignals by comparing secretion and feather samples using Gas‐Chromatography Mass‐Spectrometry (GC/MS) and recently developed multivariate statistics. Our results indicate that (1) 85% of the feather lipids come from the uropygial secretions, (2) chemical differentiation between secretions and feather lipids includes qualitative and quantitative variations, which both have interesting implications for scent production, (3) the sociochemical information contained within the secretions (i.e. a sex‐specific signal and individual chemical signatures) are present in very conserved forms on the plumage. In the light of these results, it is apparent that the uropygial gland plays a critical role for chemical communication in petrels and possibly other avian groups.

The perfume of reproduction in birds: Chemosignaling in avian social life

“…Results show that mice were exploring the unknown odor significantly more often than expected by chance (Celerier et al, 2011), confirming that blue petrels have an individual odor (Mardon et al, 2010; 2011b), and showing that mice were able to perceive and discriminate this perfumed individuality. But mice also seemed able to identify kin-related individual birds.…”

“…Chemical cues have been shown to play a role in both species and sex recognitions in birds. The comparisons of the chromatographic profiles of chemical compounds coming from different bird species, populations and sexes have shown that all these levels of organization can be reliably identified (Bonadonna et al, 2007; Jacob et al, 1979; Leclaire et al, 2011; Mardon et al, 2010; 2011b; Whittaker et al, 2010; Zhang et al, 2013). For example, two subspecies of sharewaters, the Atlantic and the Mediterranean Cory’s sharewaters, have recently been shown to differ in their chemical profiles (Gabirot M., Raux L., Dell’Ariccia G., Bried J., Gonzales-Solis J., Buatois B., Crochet P.A., Bonadonna, F., unpublished data).…”

Major histocompatibility complex class II compatibility, but not class I, predicts mate choice in a bird with highly developed olfaction

“…The uropygial gland lipids, in the blue petrel, may also contain microbes that could modify these odour components to accentuate individual odours. Moreover, degradation of the gland components, which may be attributed to microbial breakdown, has been shown on the feathers of blue petrels [58]. Consequently, if the uropygial gland or feather microflora is determined by the MHC profile, it could contribute to the personal odour signature.…”

Chemical kin label in seabirds

“…More precisely, a detailed chemical examination of the uropygial secretions and feathers of Antarctic prions (Pachyptila desolata) and blue petrels (by gas chromatography) has shown that these two petrel species exhibit critical socio-ecological information, such as species, gender and individual identity, which could be involved in olfactory behaviours observed in the field (i.e. individual recognition, self-odour avoidance) [16][17][18].…”