Gray squirrels have been caught in the crossfire of public debate in the UK for decades. A new plan calls for the use of contraceptives to control their numbers.

Welfare expectancy can serve as a framework for weighing up the different levels of well-being animals might experience over the course of their lives, helping to model the welfare consequences of interventions and natural pressures, such as predation, that may disproportionately affect animals of particular ages.

Uncertainty about fundamental ethics is a significant roadblock to large-scale intervention for wild animal welfare. There is also plenty of uncertainty on more empirical questions. Fortunately, these questions seem much more tractable, and answers to some may reveal actions we can take that are robustly good under a range of ethics.