Is there an ethological description of aggressive behaviour in dogs
The short answer to this question is no. Various authors recognize the similarity between wolf and dog in the units of aggressive behaviour, and some texts provide shorter or longer lists of the behavioural units (Feddersen-Petersen 1991, Packard 2003). Importantly, behavioural analysis has been carried out at different levels of behavioural organization (see also Chapter 2, Box 2.4). For example, Feddersen-Petersen (2001a) argued for seven facial regions (muzzle posture, mouth corner, lips, nose ridge, forehead fur, eyes, ears) which play a role in the expression of aggressive inner state (see also Bolwig 1962). This coding system is based on the mimicking of wolves but can be applied to any dog.
Not surprisingly, Feddersen-Petersen found that dogs have a reduced ability for signalling in comparison to their ancestor. So far, however, there is little direct evidence that the different facial expressions have a functional value, that is, that they reflect differences in the inner state and are recognized by the others as distinct signals. Others suggest the use of a more holistic coding system which is based on overt behavioural units, such as 'avert gaze' or 'chase' (e.g. van den Berg et al. 2003, Packard 2003), and finally, Schenkel (1947) uses an intermediate variant by taking into account behavioural details (e.g. visibility of the teeth) and overall body posture (Harrington and Asa 2003).
Qualitative analyses indicate that dog breeds differ in the number of signals used, for example more wolf-like breeds (e.g. German shepherd) have at least nine threat signals in comparison to the two signals in Norfolk terriers (Goodwin et al. 1997). But there is little published information on the use of aggressive actions, or their effect on the opponent's behaviour. We do not know whether dogs rely on these signals for assessment, or whether there are qualitative and/or quantitative differences in the aggressive behaviour of different breeds towards either conspecifics or humans. No information is available on the temporal structure of aggressive behaviour in dogs (for a related study on greeting behaviour see Bradshaw and Lea 1993), or whether signalling depends on the rank differences.
Post a comment