Knowing Me, Knowing You: Anal Gland Secretion of European Badgers (Meles meles) Codes for Individuality, Sex and Social Group Membership

Michael J Noonan,Carsten T Müller,Christina D Buesching,Frank Rosell,Helga V Tinnesand,David W Macdonald

doi:10.1007/s10886-019-01113-0

Abstract

European badgers, Meles meles, are group-living in the UK, and demarcate their ranges with shared latrines. As carnivores, badgers possess paired anal glands, but olfactory information on the content of badger anal gland secretion (AGS) is largely uninvestigated. Here, we examined the volatile organic compounds (VOCs) of AGS samples from 57 free-living badgers using solid-phase microextraction (SPME) and gas chromatography—mass spectrometry. AGS was rich in alkanes (C7–C15, 14.3% of identified compounds), aldehydes (C5–C14, 9.7%), phenols (C6–C15, 9.5%), alcohols (C5–C10, 7.3%), aromatic hydrocarbons (C6–C13, 6.8%), ketones (C6–C13, 6.3%) and carboxylic acids (C3–C12, 5.6%) and contained a variety of esters, sulfurous and nitrogenous compounds, and ethers. The number of VOCs per profile ranged from 20 to 111 (mean = 65.4; ± 22.7 SD), but no compound was unique for any of the biological categories. After normalization of the raw data using Probabilistic Quotient Normalization, we produced a resemblance matrix by calculating the Euclidian distances between all sample pairs. PERMANOVA revealed that AGS composition differs between social groups, and concentration and complexity in terms of number of measurable VOCs varies between seasons and years. AGS VOC profiles encode individual identity, sex and vary with female reproductive state, indicating an important function in intraspecific communication. Because AGS is excreted together with fecal deposits, we conclude that chemical complexity of AGS enables particularly latrine-using species, such as badgers, to advertise more complex individual-specific information than in feces alone.

Highlights

The environmental persistence of olfactory cues ensures their efficiency in indirect communication, where the signaler is not required to encounter other individuals directly to convey information (Johnston 2008)
Olfactory communication plays a central role in badger socio-spatial organization (Buesching and Macdonald 2001; Delahay et al 2000; Tinnesand et al 2015), a mechanistic understanding of how information at latrines is conveyed between individuals has remained a hitherto under-investigated topic
Our results evidence that badger anal gland secretion (AGS) odor profiles are more diverse and encode more individual-specific information than previously concluded (Davies et al 1988; Gorman et al 1984)

Summary

Introduction

The environmental persistence of olfactory cues ensures their efficiency in indirect communication, where the signaler is not required to encounter other individuals directly to convey information (Johnston 2008). Many mammals use their feces as a means of intra-specific communication in the context of individual advertisement, Michael J.

Objectives

Methods

Results

Conclusion