Development of an ethogram of dogs’ predatory behaviour.

Hunting behavior is an important part of dog’s behavioral repertoire, being a trait of selection and a target of training. It can also be a threat to wildlife, livestock, pets, and humans. Developing a detailed descriptive characterization of dogs’ predatory behavior. We selected 60 videos showing unambiguously predatory acts by dogs belonging to the Pointing Dogs, Scent Hounds, and Sight Hounds breed groups, hunting birds, hares. Two observers described every video, split into each of the 4 presumptive phases (search, approach, chase, bite). Systematic comparisons of descriptions resulted in the definition of an ethogram for each phase and dog type, which was organized in different levels. An excerpt of the ethogram of Pointing dogs’ search phase. Function: Identify the presumed location of the prey. General description: exploratory and dynamic phase, the dog moves quickly with changing/unprecise direction. When the dog apparently detects a sensory cue of the prey, the next phase starts. This transition can happen suddenly, or gradually, with a clearer directionality of the movements and a gradual decrease in pace until a complete halt. Body postures and movements: Initially, the dog moves with running gaits, displaying zigzag patterns of direction. The head initiates direction changes, followed by the rest of the body. The dog presents a centered barycenter and extended limbs. The trunk is straight and parallel to the ground. The position of the head in relation to the trunk line varies according to where the olfactory cue is located, i.e., the dog’s sniffing area ranges from the ground to up in air. The tail is held along, under or above the trunk line, generally with very rapid and shallow wag; rarely not wagging. Perceptual features: clear visual and olfactory exploration of the environment, with lateral, upward and downward head movements accompanied by sniffing activity, sometimes visible by nostril movements. Ears are still neutral, while towards the end of the phase, they can begin to be held forward. Phase-function consistencies between groups of dogs were found, as well as behavioral within-phase consistencies between subjects of the same group. However, differences were found between group of dogs in relation to behaviors within phase, as well as to the structure of the sequence. This ethogram represents the first systematic description of predatory behavior and sequence in dogs, and could serve as a model for further investigation on other groups of dogs, as well as on factors possibly affecting its expression.