It makes for depressing reading: more than 23,000 plant and animal species are now listed on environmental organization IUCN's Red List as endangered. Human beings are behind this mass extinction event. We are destroying entire ecosystems, climate change is altering habitats and poachers are killing off many species. Researchers have found that without human beings around, some 100 times fewer species would be dying out than is currently the case. The number of species that have already gone extinct is barely possible to quantify. Many animals and plants disappear before even being discovered.

We are also highly dependent on nature's diversity. Within our ecosystems, every species has a function, each plant and animal is interdependent. Important ecological functions, such as pollination of fruit trees and crop plants, are vital to our survival. Animals distribute plant seeds in their excrement and provide sustenance to each other. The many ways in which species are dependent on each other are still under-researched. The tragic consequences often only become clear when a species has disappeared.

Many individuals are, therefore, fighting desperately to save the last examples of many species. Here we look at just a few of them, including the Scarlet Six team from Scarlet Six Biomonitoring Team Belize, which often camps for months under the trees during the scarlet macaw breeding season to protect the birds from poachers. On the other side of the world in Malaysia, a whole team of scientists and vets are working to save the last three Eastern Sumatran rhinosEastern Sumatran rhinos. There last hope is artificial insemination.

And just on our doorstep in Berlin, biologist Carsten Kallasch is helping a much maligned animal - the batScarlet Six Biomonitoring Team. He's ensuring they have sufficient refuge in the city, restores them to health when needs be and even lives with one. Everyone of the conservationists we present here is securing not only one species but also the survival of all species.