Chemical composition of the substances from dorsal patches of males of the Curacaoan long-nosed bat, Leptonycteris curasoae (Phyllostomidae: Glossophaginae)

In the absence of visual cues, chemical signals are especially important for nocturnal mammals such as bats, because they facilitate individual recognition, communication, and mate selection. In a recent study, it was reported that adult males of the Curacaoan long-nosed bat, Leptonycteris curasoae, develop an odoriferous dorsal patch during the short mating season. It was postulated that dorsal patches signal health condition to females, and that females are preferentially attracted to the odor of males with dorsal patches. The chemical characterization of the dorsal patch is key to understanding its implications in chemical communication in a sexual context. In the present study, organic compounds collected from dorsal patches of males of L. curasoae from northwestern Venezuela were extracted using solid-phase micro-extraction (SPME) techniques and tentatively identified using GC-MS (Gas Chromatography-Mass Spectrometry). Nineteen compounds were present in 75% or more of the patches examined: 3-methyl-2-buten-1-thiol, acetic acid, 2'-aminoacetophenone, diacetyl, 2-pentanone, 2,3-dimethylpyrazine, 2-nonanone, acetamide, 2-undecanone, piperidinone, 4-methylquinazoline, 2,4-dimethylquinazoline, 3-methyl-2,5-pyrrolidinedione, 2-butanone, 2-methylfuran, 3-methyl-2-butenal, delta-valerolactone, 3-methyl-2-butenoic acid, and 2-methyl-2-butenoic acid. Although some of these compounds have been reported as important in female attraction among other male mammals during their respective breeding seasons, the actual function of these chemicals in L. curasoae remains to be determined. Some of these compounds have also been identified as natural insecticides, and this may be associated with lower ectoparasite loads reported on males with dorsal patches. These results, when considered along with previous observations, suggest that the dorsal patch in males of L. curasoae promotes the attraction of females during the mating season, and/or provides protection against ectoparasites.