It's one thing to see still images of extinct animals, but it's quite another to see them alive and moving. The sight of the heath hens in a field and the thylacine sniffing around in an enclosure allows us to see how these now extinct creatures moved and behaved.

The footage is eye-opening reminder of how important wildlife conservation efforts are. According to the latest Living Planet Report from the Zoological Society of London (ZSL) and the World Wildlife Fund, overall wildlife populations around the world have declined by 58 percent since 1970. Poaching, habitat loss and other factors are driving populations to critical levels.

There is still time, however. As Robin Freeman, head of ZSL's Indicators & Assessments Unit told the BBC, "[...] one of the things I think is most important about these stats, these trends are declines in the number of animals in wildlife populations — they are not extinctions. By and large they are not vanishing, and that presents us with an opportunity to do something about it."

And that something is supporting conservation efforts so that, in 100 years, elephants and sharks aren't added to a video like the one above.