The influence of intrinsic factors and fighting experience on aggressive consistency

• Main Authors: Chen, Chia-Ping, 陳家平
• Other Authors: Hsu, Yu-Ying
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/n4rg5z

碩士 === 國立臺灣師範大學 === 生命科學系 === 107 === Animals fight for limited resources. Fighting behavior would be influenced by intrinsic factors like fighting ability, body size and hormonal state of the individual. Recent studies show that individuals usually behave consistently over time and in different contexts. Besides, winning and losing experience would provide information about individuals’ fighting ability and change their fighting behavior. It can also be affected by the outcomes of the individual’s previous fights: winning and losing experiences tend to increase and lower an individual’s aggressiveness and chances of winning subsequent fights, respectively (winner and loser effects). However, the importance of winning/losing experiences might depend on the intrinsic factors of individuals.Winner and loser effect would change an individual’s aggressiveness but there is no experiment has proof that whether and how winner and loser effects would influence individual’s aggressive consistency, and whether the influence of winning/losing experiences is dependet on individuals’ intrinsic factors. I used K. marmoratus as the study animal. I first divided the fish into better and worse fighters by staging size-matched contests. Then I randomly assign individuals to 3 experience treatments (winning, losing and no recent contest experience). I measure the aggressiveness of the fish, before and after the experience treatments (1 day after and 28 days after) by recording the attack behaviors that the fish deliver to their mirror images. The result showed that: (1) Better fighters behaved more aggressiveness than worse fighters; (2) Older/larger individuals attacked slower; (3) Winning (but not losing) experience affected the fish’s aggressiveness; (4) Individuals showed consistency in their aggressiveness in both one-day-period and four-week-period; (5)Winning increased individuals’ aggressiveness but didn’t influence aggressive consistency of individuals; (6) Younger and individuals at higher testosterone level showed more aggressive consistency after receving fighting experience.