Pacific and Atlantic walruses are increasingly crowded onto terrestrial haul-out sites as sea ice retreats, creating dangerous stampede conditions with significant welfare costs.
Trampling deaths during stampedes cause acute traumatic injury, particularly to calves. Crowded terrestrial haul-outs prevent wallowing behaviour, expose animals to elevated disease transmission and increase thermal stress in warm conditions. The chronic stress of overcrowding suppresses reproduction and immune function. Individual welfare impacts are multiplied across tens of thousands of animals simultaneously at major haul-out sites.