We are in an unprecedented crisis of biodiversity in human history. All evidence suggests that the current rates of extinctions vastly exceed the estimated background extinction rate. The major difference with the previous mass extinctions is that humans are simultaneously responsible for it, threatened by it, and able to stop it. More than 900 species across all taxa have been documented to go extinct since 1500, with probably as many as 400 bird species alone in prehistoric times1. For the scientific community, five main global threats are typically considered responsible of these losses: habitat destruction, over-exploitation, biological invasions, climate change, and pollution2, although many more local perturbations and stressors are also important.
