Does losing reduce the tendency to engage with rivals to reach mates? An experimental test

Male-male contests for access to females or breeding resources is critical in determining male reproductive success. Larger males and those with more effective weaponry are more likely to win fights. However, even after controlling for such predictors of fighting ability, studies have reported a winner-loser effect: previous winners are more likely to win subsequent contests, while losers often suffer repeated defeats. While the effect of winning-losing is well-documented for the outcome of future fights, its effect on other behaviors (e.g., mating) remains poorly investigated. Here, we test whether a winning versus losing experience influenced subsequent behaviors of male mosquitofish (Gambusia holbrooki) towards rivals and potential mates. We housed focal males with either a smaller or larger opponent for 24 hours to manipulate their fighting experience to become winners or losers, respectively. The focal males then underwent tests that required them to enter and swim through a narrow..., Here, we examined whether winners/losers changed their behavior with the time that had elapsed since their previous contest experience. To do this, each male was tested twice in encounter tests: once immediately after the contest period ended (Test I), and then again one week later (Test II). To control for any potential effects of time and/or familiarity with the aquarium setup in Test II (Fig. 2), we ran an additional pair of encounter tests with another set of males who did not initially experience staged contests. After their first encounter test, focal males were isolated in individual 1L tanks for a week. Then they experienced contests for 24 hours (as above), after which we recorded these males’ behavior during their second encounter test (Test III).
The encounter test contained a start area at one end which was connected by a corridor to a reward area at the opposite end. The focal male was introduced into a mesh cylinder in the start area. Four large females were housed in the ..., , # Data from: Does losing reduce the tendency to engage with rivals to reach mates? An experimental test

[https://doi.org/10.5061/dryad.s4mw6m9dv](https://doi.org/10.5061/dryad.s4mw6m9dv)

## Description of the data and file structure

The analysis details can be found in the corresponding R Markdown (RMD) files. Specifically, in the RMD file “Zang_C_winner_loser_effect_initiation,” we conducted paired t-tests on body size, comparing focal males in size-matched pairs, focal winners and their competitors, and focal losers and their competitors. This analysis utilized data from the file called “Fish_size”, which contains the body length of focal fish and model males used in contests and encounter tests. The columns include “Pair ID” (i.e. ID of each size matched pair of a winner and a loser), “ID” (i.e. focal fish ID), “length” (i.e. standard length of focal fish), “winner_loser” (i.e. the contest outcome: winner/loser), “length_of_competitor” (i.e. the standard length of the stimulus fis...