A pilot study of hierarchy, agonism and aggression in a group of domestic cats while feeding

In a stable cat group, interactions such as territorial defence or resource competition may be dynamic or variable. Simultaneous feeding can promote the emergence of aggression when defending or claiming food and represents a useful context to identify changes in hierarchy in pets. The aim of this study was to explore the identification of hierarchical positions occupied by individuals within a group of domestic cats by evaluating the frequency of aggressions performed and received during food offering. Four cats (three females and one male), all neutered and aged between 3 and 6 years, were included. To avoid bias due to modifications in feeding habits, the study was conducted in the home, and behavioural observations were performed by a person already familiar with the cats. Observations were carried out for 14 consecutive days at a fixed schedule for 10 minutes, during which the frequencies of agonistic and aggressive behaviours performed and received by each cat were recorded. Individual aggression indexes were estimated as follows: Aggressions Performed / (Aggressions Performed + Aggressions Received). In addition, aggression frequencies were analysed using the chi-square test. The frequency of aggressions performed and received differed between cats (P < 0.0001), with two cats identified as the main aggressors and one receiving the highest number of aggressions. The cats ranked by aggression index were: youngest female (3 years old) > male (6 years old) > older female (5 years old) > oldest female (6 years old), with an index nearly ten times lower. These results should be interpreted with caution due to the small sample size. We conclude that identifying a high frequency of aggressive behaviours enables the identification of the dominant individual within the group and the lower-ranking animal in the hierarchy, which may present a welfare concern due to reduced control over food access.