Domestication is accompanied by marked changes in the phenotype of the domesticated form of a species relative to its wild ancestor. The domestic dog and its wild ancestor, the wolf, are a widely used model system to study the effects of domestication on cognition and behaviour. There is a general trend for a reduction in overall brain size as well as the size of sensory brain structures in the domesticated forms relative to their wild ancestors which is thought to have led to a decrease in sensory capabilities.

Despite the presumed importance of blood odours for predator/prey relationships, surprisingly little is known about the volatiles that comprise the odour of blood in mammals and about the constituents of blood odour that elicit behavioural responses in predators. A recent study found that one substance, trans-4,5-epoxy-(E)-2-decenal, evokes a typical “metallic, blood-like” odour quality in humans. This component was further found to be as attractive as real blood to several different carnivore species.

1. to compare the behavioural responses of wolves and of domestic dogs to the odour of mammalian blood and a blood odour component,
2. to compare their behavioural responses to a plant-derived control odour and a near-odourless control,
3. to compare the behavioural responses of the wolves and dogs to those observed in other carnivore species tested previously with the same odour stimuli