Olfactory cues of mate quality in mammals: inflammatory response is higher in males of long-nosed bats with odorous dorsal patch

Abstract

Bats use olfactory signals to provide information of species and individual identity and quality. Males of two species of long-nosed bats, Leptonycteris curasoae and L. yerbabuenae, display an odoriferous dorsal patch during the mating season that is involved in mate choice. The dorsal patch is documented to serve as an indicator of male quality; for instance, males with dorsal patch present larger testes and lower ectoparasite loads. We evaluated the role of the dorsal patch in males of L. curasoae and L. yerbabuenae as an indicator of inflammatory response 6 and 12 h after being injected with phytohemagglutinin (PHA). We found that the inflammatory response of males of both species was not different between reproductively active bats with or without dorsal patch 6 h after PHA injection, but the response was higher in bats with dorsal patch 12 h after the injection. Our study adds to the evidence that the dorsal patch exhibited by males of long-nosed bats indicates their immune quality for mating females. Further work including other branches of the immune system and the potential role of microbiota in the strength of the inflammatory response is warranted.