Fight winner

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Fig. 13.3 Influence of familiarity on duration of repeated fights between crayfish (a) and American lobsters (b). Familiar denotes that the same pair of size-matched animals fights on two consecutive days first and second fight. Unfamiliar denotes that the loser of the first day fights an unknown winner drawn from a separate fight on the second day. White bars denote first fights, black bars denote second fights. In crayfish, but not in lobsters, unfamiliar treatments leads to a decrease in fight duration on the second day. This indicates that crayfish recognize the winner-status of their oponent, but not the identity of a familiar oponent. (a) Drawn from data in Breithaupt and Eger 2002 (b) modified after Karavanich and Atema (1998)...

There is contradictory evidence from different crustacean species as to whether the chemical signals mediate individual identity or social rank of combatants. Experiments on American lobsters and hermit crabs indicate that dominance is maintained by the loser recognizing the individual scent of the familiar opponent it has lost to (Fig. 13.3b Karavanich and Atema 1998 Gherardi and Tricarico, Chap. 15). Previous losers surrender early on in a fight when paired with a familiar winner. Unfamiliar winners, however, are challenged and these subsequent fights last as... 

Characteristic results are shown in Figure 2. One day after the interaction phase, males that lost fights spent more time in the base of the Y-maze, near the start box, than in either of the arms of the Y and they spent very little time near the male that had beaten them in the series of three encounters. In contrast, males that did not fight or those that were tested with an unfamiliar winner spent less time in the base of the Y and much more time near the stimulus male. Males that lost also took much longer to approach the end of the Y containing the familiar winner than the clean arm of the maze. Similarly, the latency to approach a stimulus male was much greater for males tested with a familiar winner versus those tested with an unfamiliar winner. Similar results were found when we tested males 30 min, 1 day, 3 days or 7 days after the three brief encounters (Lai and Johnston, 2002). 

Figure 2. The behavior of male hamsters in a Y-maze subjects had either fought and lost and were tested in a Y-maze or were exposed to an arena and were tested in a Y maze. Males that fought and lost (fight side) spent most of their time in the start box (top right) and took a long time to approach the familiar winner (bottom right). Males that were just exposed to a clean arena spent most time near the unfiuniliar winner (top left) and approached this male more quickly than the clean arm of the Y (bottom left). ( - p < O.OS Lai and Johnston, 2002)...

Rutting bull elks fighting for social dominance. The reward for the winner is more food, and more mates, and increased serotonin levels ... 

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