The management of invasive grey squirrels for red squirrel conservation creates a profound welfare-conservation dilemma that is among the most discussed in UK wildlife management.
The welfare-conservation tension is genuine: red squirrel conservation requires grey squirrel population management; the methods available cause individual suffering to hundreds of thousands of animals. Grey squirrels are themselves cognitively complex, curious animals capable of learning and problem-solving. Fertility control through species-specific oral vaccines currently in development offers a potential resolution that achieves population management without lethal harm.