Grey squirrels are an introduced species from North America that threaten red squirrels and woodland ecology through competition and disease transmission. Their management raises significant welfare questions.
Lethal trapping using spring traps can cause non-target captures and protracted deaths if traps are not checked frequently. Drowning of cage-trapped squirrels, while technically legal in some contexts, causes distress and slow death. Shooting causes immediate death when carried out accurately but causes suffering when animals are only wounded. The development of immunocontraceptive approaches would allow population management with significantly lower welfare costs than current lethal methods while achieving conservation objectives.