A survey of mountain gorillas has revealed their numbers have gone over the last ten years.
The animals only live in two areas of East Africa.
The Uganda Wildlife Authority has found the numbers have increased.
There are 880 individuals compared to an estimated number of 786 in 2010.
Mountain gorillas are under threat from loss of habitat, disease and getting caught in hunting traps.
David Greer, WWF's African great ape programme manager, said: "Mountain gorillas are the only great ape experiencing a population increase.
"This is largely due to intensive conservation efforts and successful community engagement."