Whether it’s blackbirds in Sweden, moths in Borneo, or mice in California, animals around the world are on the move thanks to climate change. Species are shifting higher up mountains and closer to the poles as global temperatures rise, following the climate conditions to which they’re adapted. Their futures depend not only on their changing natural environment but the countries in which they happen to live. As conservation scientists, we need to know how species will move between countries to understand how they’re likely to fare. National borders define where the authority of laws and policies begins and ends, so a species living on one side of a border can sometimes expect very different levels of protection – and very different threats – compared to one living on the other side.