Domestication effects on aggressiveness: Comparison of biting motivation and bite force between wild and domesticated finches

• Published in: Behavioural processes Vol. 193; p. 104503
• Main Authors: Suzuki, Kenta, Okanoya, Kazuo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-12-2021
• Subjects: Aggression; Aggressiveness; Animals; Bengalese finch; Bite Force; Biting behaviour; Domestication; Finches; Humans; Motivation; Songbird; Vocalization, Animal; Bite force; Domestication; Bengalese finch; Songbird; Biting behaviour; Aggressiveness
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2021.104503

Domesticated animals evolve unique traits, known as the domestication phenotypes or the domestication syndrome, due to their adaptation to a captive environment and changes in selection pressures. After being tamed, the Bengalese finch (Lonchura striata var. domestica) has undergone behavioural and physiological trait changes that differ from those of its wild ancestor, the white-rumped munia (Lonchura striata). The Bengalese finch has complex songs, lower fear response, and lower corticosterone levels than those in the white-rumped munia. We hypothesised that domesticated finches would exert less effort to maintain survival fitness for wild conditions because they are no longer subjected to natural selection pressures. Instead, they have been artificially selected by humans. Bite performance, denoting aggression affects survival rates, and is an indicator of adaptability in the wild. Furthermore, aggression is important as a behavioural trait influenced by domestication. Therefore, we compared the aggressiveness and biting force of white-rumped munias with those of Bengalese finches to explore the evolutionary mechanisms of behavioural changes due to domestication. Bengalese finches had decreased bite motivation and force compared to white-rumped munias. Domestication may have reduced aggression in Bengalese finches by eliminating the need to cope with predators and because of artificial selection by humans.
•We examined the differences in aggressiveness between wild and domesticated finches.•Aggressiveness was measured by the number of biting responses and bite force.•Incidence of aggressive biting birds was significantly higher in wild than domesticated finches.•Mean and maximal bite force was also stronger in the wild white-rumped munias.•These results suggest that aggressiveness has decreased due to domestication.