Costs of injury for scent signalling in a strepsirrhine primate

Abstract

Honesty is crucial in animal communication when signallers are conveying information about their condition. Condition dependence implies a cost to signal production; yet, evidence of such cost is scarce. We examined the effects of naturally occurring injury on the quality and salience of olfactory signals in ring-tailed lemurs (Lemur catta). Over a decade, we collected genital secretions from 23 (13 male, 10 female) adults across 34 unique injuries, owing primarily to intra-group fights. Using gas chromatography-mass spectrometry, we tested for differences in the chemical composition of secretions across pre-injury, injury and recovery, in animals that did and did not receive antibiotics. Lemur genital secretions were significantly dampened and altered during injury, with patterns of change varying by sex, season and antibiotics. Using behavioural bioassays (excluding odorants from antibiotic-treated animals), we showed that male ‘recipients’ discriminated injury status based on scent alone, directing more competitive counter marking towards odorants from injured vs. uninjured male ‘signallers.’ That injured animals could not maintain their normal signatures provides rare evidence of the energetic cost to signal production. That conspecifics detected olfactory-encoded ‘weakness’ suggests added behavioural costs: By influencing the likelihood of intra- or inter-sexual conflict, condition-dependent signals could have important implications for socio-reproductive behaviour.

Anthropogenic injuries disrupt social associations of common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida

“…However, it may also be that dolphins interpret injury as a sign of weakness and are less likely to associate with an injured animal repeatedly, thereby increasing the variety of associates for the injured animal. While this is not confirmed in marine mammals, other species such as the ring‐tailed lemur ( Lemur catta ) distinguish weaker individuals through changes in their pheromones and adapt their behavior accordingly (Harris et al, 2018).…”

Sex differences in scent‐marking in captive red‐ruffed lemurs

“…In particular, olfactory communication is exhibited by several mammal species (reviewed in Scordato & Drea, ), such as rodents (e.g., Hurst, Robertson, Tolladay, & Beynon, ; Roberts, ), but also by reptiles (e.g., Müller‐Schwarze, ) and birds (e.g., Leclaire, Strandh, Mardon, Westerdahl, & Bonadonna, ). Odor secretions are directly linked to the physiological conditions of senders (Harris, Boulet, Grogan, & Drea, ) and can be costly to produce (Scordato & Drea, ), thus they are expected to deliver a more honest signal compared to other forms of communication (Hasson, ).…”

Design, delivery and perception of condition-dependent chemical signals in strepsirrhine primates: implications for human olfactory communication

“…With regard to health or wellness, we also uncovered salient effects of injury on signal composition in male and female L. catta [111]. Over the course of a decade, we amassed a set of genital scent samples from naturally 'injured' animals, that were or were not treated with antibiotics, and a set of seasonally matched samples from 'healthy' animals (both at baseline, prior to injury and following recovery).…”