Snowshoe hares undergo dramatic 10-year population cycles across the boreal forest, driven by predator-prey dynamics. Understanding these cycles illuminates the welfare implications of population crashes for millions of individual animals.
Wild population cycles involve enormous numbers of individual animals experiencing suffering during crashes. Hares in declining populations face increasing predation, food scarcity, and chronic stress. The chronic stress hypothesis suggests that prolonged predator exposure suppresses hare immune function and reproduction even before direct mortality occurs. Climate change adds a new welfare threat: hares that change coat color based on day length rather than snow cover become conspicuous white against brown ground, dramatically increasing predation. These are systemic welfare harms affecting millions of animals across the boreal zone.