- When gorillas see you every day, that's when the trust has started to kick in.

(birds tweeting) (foliage rustling) And then all of a sudden, through the habituation, you became part of the group.

(foliage rustling) And then they start doing things naturally.

And that's the moment, that's the moment when you start getting the best out of their behavior.

(researchers speaking in a foreign language) (birds tweeting) (researchers speaking in a foreign language) (hands thumping chest) - I am literally 10 meters from the baby and the mother.

They're just sitting there and looking at us.

(birds tweeting) Females become sexually mature around seven or eight.

Once a female begins to breed, she will give a birth to one baby every four to six years.

That is a cutie.

This low rate of reproduction is what partly makes it difficult for the gorillas to recover from population decline.

And knowing that really emphasizes the importance of what we're doing here.

(birds tweeting) Oh, oh, she's feeding, she's feeding.

Oh, she was feeding.

(laughs joyfully) Look at her face, just look at her.

I've never seen a mother gorilla feeding a baby.

(birds tweeting)