Weapon-bearing male deer pay extreme costs and most never mate

Evidence

Fallow deer and moose pay exorbitantly for their weapons, and for the stamina and energy needed to win fights during the rut, suffering gashes, infections, and depleted energy reserves. Above: Three-quarters of fallow deer bucks die without ever succeeding in defending territories, and 90 percent fail to mate even once in their lifetime. Below: Bull moose double their daily energetic demands while growing antlers, and a third die from injuries sustained during combat. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 963 (#corroborates, via linked claim)

Nature is the ultimate economizer, relentlessly culling individuals who allocate resources poorly. Over time, we expect that populations will evolve to become increasingly efficient in their use of resources, investing in the growth of large structures such as weapons only when the benefits of having them outweigh any associated costs—that is, when they are cost-effective. By any measure, weapons are costly. They are expensive to produce, and they are expensive to use. Males incur risks when they fight, and fighting requires time and energy that could be expended on feeding and other life tasks. However, males with the largest weapons may derive significant reproductive benefits if these weapons help them secure access to females and keep rival males away. When the reproductive rewards are high enough, even extravagant weapons can be cost-effective. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199 (#qualifies, via linked claim)

Categorization

• XREF: connects to: Most male ungulates never reproduce because weapon costs are so extreme — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 963; Weapons evolve only when reproductive benefits exceed costs — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199; Some elaborate animal weapons are astonishingly cheap to produce and carry (+1 more)

Related

• Most male ungulates never reproduce because weapon costs are so extreme (similarity 0.96)
• Some elaborate animal weapons are astonishingly cheap to produce and carry (similarity 0.89)
• Predation risk is a near-universal cost of elaborate weapons (similarity 0.88)
• Weapons evolve only when reproductive benefits exceed costs (similarity 0.85)
• Weapon costliness keeps signals honest by excluding weaker males (similarity 0.85)
• Big weapons only benefit males with the reserves to wield them effectively (similarity 0.84)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.84)
• Only a minority of males can afford to build full-size weapons (similarity 0.84)
• Cheating males erode the reproductive payoff of weapons, capping their evolution (similarity 0.84)
• Poor-quality males pay steeper costs for large weapons and so invest less (similarity 0.84)
• Weapon expense is what keeps signals of fighting ability honest (similarity 0.84)
• Weapon growth widens the gap between the best- and worst-armed males. (similarity 0.83)
• Deterrence amplifies the evolutionary payoff of extreme weapon size. (similarity 0.83)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.83)
• Bigger weapons usually fail because their costs outweigh their benefits (similarity 0.82)

Broader Connections

• Most male ungulates never reproduce because weapon costs are so extreme #corroborates (0.85) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 963
• Weapons evolve only when reproductive benefits exceed costs #qualifies (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199
• Some elaborate animal weapons are astonishingly cheap to produce and carry #contradicts (0.60)
• Predation risk is a near-universal cost of elaborate weapons #expands (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 307