Data from: Costs of injury for scent signalling in a strepsirrhine primate

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.

当信号发出者传递自身身体状况相关信息时，诚实信号在动物通讯中至关重要。信号产生的条件依赖性意味着信号生成存在成本，但目前此类成本的实证证据仍较为匮乏。本研究以环尾狐猴（Lemur catta）为研究对象，探究了自然发生的损伤对其嗅觉信号质量与显著性的影响。研究历时十余年，我们从23只成年个体（13雄10雌）身上采集了与34处不同损伤相关的生殖器分泌物，这些损伤主要源于群体内部争斗。我们采用气相色谱-质谱联用（gas chromatography-mass spectrometry, GC-MS）技术，对比了接受抗生素治疗与未接受抗生素治疗的环尾狐猴在损伤前、损伤期及恢复期的分泌物化学成分差异。研究发现，环尾狐猴的生殖器分泌物在损伤期会显著减少且成分发生改变，其变化模式因性别、季节及抗生素使用情况而异。我们通过行为生物测定实验（排除经抗生素处理个体的气味信号）证实，雄性‘接收者’仅通过气味即可分辨雄性信号发出者的损伤状态，且会对受伤雄性信号发出者的气味表现出更多竞争性反向标记行为。受伤个体无法维持其正常的气味特征，这一发现为信号生成的能量成本提供了罕见的实证依据。同种个体能够通过嗅觉感知到这种‘弱势状态’，这表明信号生成还存在额外的行为成本：条件依赖性信号会影响同性或异性冲突发生的概率，因此对社会生殖行为具有重要的演化意义。