In richer countries, the socio-economic impact of invasive species can be tackled through technology or adaptive behaviour. But this isn't the case in poor countries.
Giraffe populations have declined by more than a third over the past 30 years. Two wildlife law experts explain the protections that would come with including them on a US list of endangered species.
Historical evidence shows African elephants are endangered by the ivory trade, despite any attempt at regulating the market. A total ban is the only hope for the world's largest living land animal.