Predators evolve counter-tactics that exploit weapon-costly prey

Evidence

In my favorite example, John Christy and his colleagues, including Patricia Backwell and Tsunenori Koga, studied a natural population of the fiddler crab Uca beebei on mudflats along the Pacific coast of Panama. They found that fiddlers were heavily preyed upon by great-tailed grackles, and that these birds had a quirky strategy for catching the crabs. Grackles often employed a “feinting reverse lunge” as they chased a crab. Instead of charging directly at a crab, they would charge to the side of the target crab, seemingly passing it by. As soon as they’d passed, they would whirl and lunge backward in a surprise diagonal feint that often caught the crab unaware. Grackles that did this were twice as effective at catching crabs as birds who simply ran straight at a crab and, remarkably, when birds employed the reverse-feint method, they caught almost exclusively males. Male crabs, by virtue of their distorted major claws, were more conspicuous targets to the lunging bird. The result: in this population, male fiddlers suffered dramatically higher predation than females. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 306

Categorization

• XREF: Parallel to arms-race predator-prey dynamics and military ruses like feinting maneuvers in human warfare. — connects to: Successful cheaters can reverse selection so big weapons collapse; Fortification-artillery escalation mirrors predator-prey arms races, not rival contests; Ambush predation releases predators from chasing speed, allowing extreme weapon evolution. (+4 more)

Related

• Ambush predation releases predators from chasing speed, allowing extreme weapon evolution. (similarity 0.86)
• Predator diversity is best explained by weapon adaptation to habitat and prey (similarity 0.80)
• Wolves evolved dual-purpose teeth and pack tactics to subdue oversized prey (similarity 0.80)
• Fiddler crabs assess rival claw size and only approach equally-matched opponents. (similarity 0.80)
• Fiddler crabs use their oversized claws far more as signals than as weapons (similarity 0.79)
• Predation risk is a near-universal cost of elaborate weapons (similarity 0.79)
• Sexual weapons sometimes protect rather than burden their bearers from predators (similarity 0.79)

Broader Connections

• Wolves evolved dual-purpose teeth and pack tactics to subdue oversized prey #exemplifies (0.65) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 74