Muskox

Muskoxen demonstrate perhaps the most striking defensive prosocial behavior among ungulates. When wolves approach, adults form a tight circle or line facing outward, with calves protected behind them. This 'defensive formation' requires coordination—individuals must trust that others will hold position rather than flee. The formation works because collective defense exceeds individual flight benefits in Arctic environments.

The formation is genuinely altruistic for outer-ring adults. Those facing predators directly accept elevated risk to protect the group center. This isn't purely kin-selected—groups contain non-relatives who benefit from defense. The system may persist because participation is observed and non-participants face social costs, or because the formation's effectiveness compensates for individual risk.

Dominant bulls position themselves at formation edges. This prime defensive position is both most dangerous and most prestigious. Bulls who successfully defend against wolves gain social standing. The willingness to accept defensive risk becomes a status signal—cowards can't fake courage when wolves actually attack.

Social tolerance enables defensive coordination. Muskoxen maintain relatively peaceful herd relationships outside the rut, with low rates of within-herd aggression. This social tolerance may be necessary for defensive formation to work—you can't coordinate defense with individuals you're constantly fighting.

For organizations, muskoxen illustrate how collective defense requires social cohesion. Teams that fight internally can't coordinate against external threats. The formation's effectiveness depends on trust built through routine peaceful interaction.