Size communication in domestic dog, Canis familiaris, growls

Size Communication in Dogs

A.M. Taylor, D. Reby, K. McComb

Size communication in domestic dog, Canis familiaris, growls

Animal Behaviour, Volume 79, Issue 1, January 2010, Pages 205–210

ABSTRACT

In many species, body size is a key determinant of the outcome of agonistic interactions, and receivers are expected to attend to size cues when assessing competitors' signals. Several mammal vocalizations, including domestic dog growls, encode reliable information about caller body size in the dispersion of formant frequencies. To test whether adult domestic dogs attend to formant dispersion when presented with the growls of their conspecifics, we played recordings of resynthesized growls where the size-related variation in formant frequency spacing was manipulated independently of all other parameters. Subjects from three different size groups (small, medium and large dogs) were presented with playbacks of growls where formant frequencies had been rescaled to correspond to a dog 30% smaller or 30% larger than themselves. While large dogs systematically displayed more motivation to interact when growls simulated a smaller intruder, small dogs did not respond differentially to the playback conditions. However, the small dogs responded significantly less than all other size groups to both playback conditions. Our results suggest that domestic dogs are able to perceive size-related information in growls, and more specifically that they are able to adapt their behavioural response as a function of the perceived intruder's size relative to their own.

‘The bone is mine’: affective and referential aspects of dog growls

Tamás Faragó, Péter Pongrácz, Friederike Range, Zsófia Virányi, Ádám Miklósi

‘The bone is mine’: affective and referential aspects of dog growls

Animal Behaviour, Volume 79, Issue 4, April 2010, Pages 917–925

Abstract

A number of species are considered to use functionally referential signals such as alarm calls or food-related vocalizations. However, this particular function of communicative interaction has not previously been found in canids. We provide the first experimental indication that domestic dogs, Canis familiaris, rely on context-dependent signals during interspecific agonistic encounters. We recorded several sequences of growls from dogs in three different contexts: during play, guarding a bone from another dog, and reacting to a threatening stranger. We analysed the acoustic structure of the growls and additionally performed playback tests in a seminatural food-guarding situation. We found that play growls differed acoustically from the other two (agonistic) types of growls, mainly in their fundamental frequencies and formant dispersions. Results of the playback experiment showed that food-guarding growls deterred other dogs from taking away a seemingly unattended bone more effectively than growls recorded in the threatening stranger situation. We ruled out an effect of the signaller's body weight on the subjects' responses. These results provide the first evidence of context specificity of agonistic vocalizations in the dog. We discuss the possible aspects of honesty and deception through acoustic modulation of growls.