Meeting Abstract
Animal contests dictate access to territories, mates, and other resources that influence fitness. This study examined how animals integrate contest behaviors (signals) and structures (weapons) to resolve contests. Both sexes of the mantis shrimp Neogonodactylus bredini use enlarged raptorial appendages as weapons in territorial contests, presenting visual displays and sparring by exchanging potentially deadly, high-force strikes with competitors that coil their telson (tailplate) in a defensive posture. We tested if telson sparring is a signal used in escalated contests by comparing behavioral sequences of competitors in 28 body length-matched and 35 randomly-matched unique dyadic contests (126 total individuals). Behavioral theory states that body length-matched contests should be more escalated than randomly-matched contests. Therefore, we predicted that if sparring is a signal used in escalated contests, then body length-matched competitors should show a greater reliance on sparring than randomly-matched competitors. Sparring behaviors comprised 66% of all behaviors in body length-matched contests, compared to 38% of all behaviors in randomly-matched contests. Additionally, one sparring behavior (defensive telson coil) predicted the loser’s retreat in both contest types. Given that sparring is more common in body length-matched contests that are predicted to be more highly escalated than randomly-matched contests, and that the defensive telson coil that occurs during sparring predicts a loser’s retreat, we conclude that N. bredini use sparring as a signal during escalated contests and that this signal may resolve contests. Sparring integrates lethal weaponry with contest-resolving behavioral signaling, offering insights into the critical balance of intraspecific aggression and resolution.
