Domination of olfaction over vision in explosives detection by dogs

This study examines the relative contribution of the senses of sight and smell to detection of explosives in dogs. Six sniffer dogs were required to detect explosives in a controlled (indoors) and uncontrolled (field track) environment, under both virtually dark (very low light intensity) and full light conditions. Detection percentages, search duration, and sniffing and panting frequencies were measured. Olfaction was shown to be the main sense used by the dogs for detection not only when vision was possible but difficult, in very low light intensity, but also in full light. Furthermore, neither the presence nor the virtual absence of light was demonstrated to differentially affect the dogs' detection ability. The results of the current study are of considerable importance for operational application. Many security organisations use sniffer dogs for detection of various substances. The possibility of using the same dog for both day and night operations offers a cost-effective reduction in number of dogs required as well as manpower needed to train them. Furthermore, understanding the search mechanism of security dog breeds that have not been selectively bred for odour searches, will enable more efficient training, leading to improved performances.