Scientists say that a fifth of the world's animals are under threat of dying out. But numbers of some species such as these Asian crested ibis are slowly improving.
Groups of these vicunas, relatives of llamas, are now back in South America thanks to lots of work by conservationists.
This wild black-footed ferret of America was once extinct in the wild, but it was bred in captivity and has now been returned to it's natural habitat.
Thanks to other conservation projects, this Przewalski's horse has also made a return to the wild in Mongolia, a country in Asia.
And numbers of humpback whales have increased quickly after people were banned from killing them to make money from their meat.
There's still a way to go for these Kihansi spray toads who are slowly being reintroduced into the wild.
These midwife toads also have a bright future, but despite these success stories, more than 50 species move closer to extinction each year.