Behaviour 2019
Aggressive behaviors and dominance hierarchies in captive tree sparrow (Passer montanus) flock
Ju Hyun Lee1, Wan Hee Nam1, Dong Yun Lee1, Ha Cheol Sung2. 1School of Biological sciences and Biotechnology, Gwangju, N/A, South Korea; 2Department of Biology , Gwangju, N/A, South Korea

In animal social flock, individuals face the competition or cooperation over shared resources. Group-foraging individuals often interact aggressively against conspecifics, including threat displays and physical attacks for acquiring food. In that case, intraspecific plumage variability represents functions to signal individual’s social status. Here, we investigated social interactions in the captive tree sparrow (Passer montanus) flock members forming dominance hierarchies, and identified the correlation between the social status signaling and the morphological traits. In this study, we recorded aggressive behaviors (attacking and threating) of two groups of captive tree sparrow. We examined the tree sparrow’s dominance structure, and recorded 1,051 aggressive interactions among 19 individuals observed at a feeder. As a result, the number of aggressive behaviors were significantly higher in males than in females, and the dominance rank positively correlated with badge size and wing length. These results suggest that social signals closely relate with morphological traits to form dominance hierarchies in tree sparrow society.