Table 2.

Definitions of the 19 referential gestures observed in cross-species domestic dog communication

Gesture	Definition
Roll over	Rolling onto one side of the body and exposing the chest, stomach and groin
Head under	Plunge headfirst underneath an object or human
Head forward	Move the head forwards and up to direct a human’s appendage to a specific location on the body
Hind leg stand	Lift front paws off the ground and stand on hind legs, front paws are not resting on anything
Head turn	Head is turned from side to side on the horizontal axis usually between a human and an apparent object of interest
Shuffle	Shuffle whole body along the ground in short movements, performed whilst in roll over position
Back leg up	Lifting of a single back leg whilst lay on one side of the body
Paw hover	Hold one paw in mid-air whilst in a sitting position
Crawl under	Move entire or part of body underneath an object or a human’s appendage
Flick toy	Hold toy in the mouth and throw it forwards, usually in the direction of a human
Jump	Jump up and down off the ground, human or an object, usually while staying in one location
Paw reach	Placing a single paw or both paws underneath another object to retrieve an object of apparent interest
Nose	Pressing nose (or face) against an object or human
Lick	Licking an object or human once or repetitively
Front paws on	Lifting both paws off the ground and resting them on an object or human
Paw rest	Lifting a single front paw and resting it on an object or human
Head rub	Involves rubbing the head against an object or human on which the signaller is leaning on
Chomp	Involves opening the mouth and placing it over the arm of a human whilst repeatedly and gently biting down on the arm
Paw	Lifting of a single front paw to briefly touch an object or human