Rutting stag health collapses from the cost of weapons and mating

Evidence

Darting them with sedatives lets biologists have access to each male for an hour or so to measure their height, weight, and age (determined from the teeth), as well as count external parasites and sample blood to measure internal parasites and infections. Collecting this information before the breeding season—the rut—and then again after this season, and comparing these values, can shed light on just how expensive this whole mating process is to a male. In fact, rutting stags lose a stunning amount of body weight, and their physical condition plummets during the rut. Weapons, and the stamina, testosterone, and aggression that necessarily go with them, can be devastating to the health of a male. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 309

Categorization

• XREF: connects to: Arms races inevitably stall as weapon costs neutralize reproductive benefits — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 432; Male combat for mating access frequently causes serious wounds and sometimes death; Weapons evolve only when reproductive benefits exceed costs — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199 (+5 more)

Related

• Lifetime tracking of 318 stag males quantifies weapons’ fitness costs (similarity 0.92)
• Male combat for mating access frequently causes serious wounds and sometimes death (similarity 0.85)
• Arms-race weapon growth makes resource trade-offs drastically impair body functions (similarity 0.85)
• Arms races inevitably stall as weapon costs neutralize reproductive benefits (similarity 0.85)
• Extreme skew in mating success drives arms-race escalation in weaponry (similarity 0.83)
• Weapons evolve only when reproductive benefits exceed costs (similarity 0.82)
• Weapon size should track resource availability more than any mandatory body part (similarity 0.81)
• Big weapons only benefit males with the reserves to wield them effectively (similarity 0.81)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.81)
• Weapon costliness keeps signals honest by excluding weaker males (similarity 0.81)
• Growing large weapons diverts resources and stunts other body parts (similarity 0.81)
• Weapon-bearing male deer pay extreme costs and most never mate (similarity 0.81)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.81)
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races (similarity 0.81)
• Sexual selection can be far stronger than natural selection and drives weapon extremes (similarity 0.80)

Broader Connections

• Growing large weapons diverts resources and stunts other body parts #expands (0.80) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295
• Arms-race weapon growth makes resource trade-offs drastically impair body functions #expands (0.75) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 296
• Weapons evolve only when reproductive benefits exceed costs #expands (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199
• Weapon escalation ends when costs outweigh benefits and cheaters invade #complicates (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 457
• Sexual selection can be far stronger than natural selection and drives weapon extremes #qualifies (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 177