Crab Gloats After Winning To Discourage Rematches

After a win, mangrove crabs (Perisesarma eumolpe) will gloat to keep opponents from going for round two. Photo Credit: Marut Sayannikroth/Shutterstock From touchdown dances to victory laps, we all love to bask in the glory after a big win. So do mangrove crabs. After a fierce physical altercation, victorious male crabs sometimes stridulate, planting one claw into the ground and rubbing it vigorously with the other to both visibly and audibly revel in their triumph. But the purpose of this gloating was unclear, as little research has examined the consequences of such victory displays. Now, a new paper in Ethology may have an explanation: rejoicing discourages the losing crabs from attempting a rematch. Battles pretty much always involve lots of communication. That's because fights can be extremely costly. Duels can be to the death. And even in species where battles have lower stakes, injuries are still a concern, and the physical costs associated with fighting can be expensive. So many species try to signal their superiority, using ostentatious ornaments like antlers and horns, or through behaviors that highlight size or dominance. But sometimes, a fight is inevitable. If the tussle isn't lethal, then there's an opportunity for continued communication post-contest. And it's becoming increasingly apparent that fight-related signals don't end when a winner is declared. Victory displays are likely common in groups like birds and amphibians. We don't really know how common, because they're rarely looked for. Why rub it in when you win? One of the prevailing hypothesis is that gloating helps discourage a second fight. Victory displays could either be used as an advertisement, to warn any possible competitors that watched your fight to steer clear, or to browbeat your opponent into submission, to ensure they don't even think about a rematch.