Prey scarcity cycles drive intense selection pressure on predator hunting weapons

Evidence

Snowshoe hare populations fluctuate wildly in number, with over forty times more animals in “boom” years than in “bust” ones. These population cycles mean that every eight to ten years lynx experience drastic shortages in their food supply and, in these lean years, starvation is rampant. Kitten survival plummets from 75 percent in years with abundant hares to 0 percent when hares are scarce. The difficulty of catching prey and the periodic shortages in abundance of prey together result in intense selection for improvements in the lynx’s hunting performance, placing a premium on the weapons necessary for successful hunts. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 69

Categorization

• XREF: Connects to the red queen / arms race dynamics in earlier chapters on weapon evolution, and to boom-bust population dynamics laid out in previous chapters of the book. — connects to: Ambush predation releases predators from chasing speed, allowing extreme weapon evolution.; Predator diversity is best explained by weapon adaptation to habitat and prey — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 70; Loss of pursuit hunting drives evolution toward heavier jaws and teeth — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 112

Related

• Predator diversity is best explained by weapon adaptation to habitat and prey (similarity 0.86)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.84)
• Lynx fail to catch hare in three of every four chases (similarity 0.83)
• Ambush predators evolve large weapons because they strike rather than chase prey (similarity 0.81)
• Loss of pursuit hunting drives evolution toward heavier jaws and teeth (similarity 0.81)
• Predator weapons stay small because larger ones hinder hunting (similarity 0.80)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.80)
• Specific ecological circumstances must align before weapon arms races begin (similarity 0.80)
• Ambush predation releases predators from chasing speed, allowing extreme weapon evolution. (similarity 0.79)
• Weapons shrink when predator pressure falls and armor gets costly. (similarity 0.79)
• Ambush predators depend on appendage speed more than body speed (similarity 0.79)
• Predation risk is a near-universal cost of elaborate weapons (similarity 0.79)
• Dueling plus competition and defensibility is the general rule for extreme weapons (similarity 0.79)
• Each weapon-size increase resets the competitive baseline, ratcheting populations upward (similarity 0.78)
• Species with huge weapons often show weak current selection on them. (similarity 0.78)

Broader Connections

• Loss of pursuit hunting drives evolution toward heavier jaws and teeth #exemplifies (0.40) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 112
• Predator diversity is best explained by weapon adaptation to habitat and prey #qualifies (0.30) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 70