Honest signalling through chemicals by elephants with applications for care and conservation

Chemical signals are difficult to fake because they are often directly associated with phenotype and physiological condition, and hence likely to be honest signals for intraspecific communication. Chemical signals may be modified after release by the sender or by the environment. The proximate and ultimate signal meanings are dependent not only on the condition of the sender, but also on the physiological status of the receiver. Understanding the relationships and linkage among signal modality, signal function and receiver response is an essential first step before using natural signals for animal care and conservation. Our studies on chemical communication in Asian and African elephants combine observational and experimental work in captive and wild settings to further this understanding. Recent discoveries of pheromones in Asian elephants and the biochemistry of these compounds provide strong evidence that such chemical signals are honest indicators of reproductive status. Chemically identifying the signals and verifying their functional context with statistically robust behavioural studies are essential aspects for understanding the communication system. Additionally, the investigative process of discovering, identifying and verifying the function of chemical signals among captive elephants offers safe and stimulating enrichments. The knowledge garnered from such studies has potential conservation benefits for managing wild elephant populations. A firm foundation of scientific information is required for successful behavioural investigations and applied conservation and enrichment components.