We are currently in the midst of a massive extinction crisis, with species all around the world disappearing at an unprecedented rate. They are calling it the sixth mass extinction, with at least 30-50% of all species at risk of going extinct by mid-century.

One individual who is helping to shine a light on this pressing issue is wildlife photographer Tim Flach. In his book, Endangered, Tim documented some of the amazing animals across the world that are currently threatened.

We’ve gathered 50 of the best ones for our slideshow, but the whole collection can be found on Tim Flach’s website. Once you see the images, you’ll understand how truly important this is. The time to start fighting for these species is now. Losing these incredible animals would be a giant tragedy.