Red squirrels have been almost eliminated from England and Wales by the grey squirrel — disease, competition, and habitat loss combine to create a welfare and conservation crisis.
Red squirrel welfare is inextricably linked to grey squirrel management. Squirrelpox causes prolonged death in affected red squirrels — scabbing, lesions, and neurological symptoms over 15 days before death. This disease-mediated welfare harm operates at population scale wherever grey squirrels are present. Conservation management creates a secondary welfare consideration: the lethal control of grey squirrels that causes individual animal suffering in service of red squirrel population protection. Development of humane alternatives — fertility control — addresses this welfare trade-off.