Successful introduction for Maïsha
The introduction process of our new female gorilla has started just a few days after her arrival at the zoo.
In the wild, females leave their natal group when they reach sexual maturity (at about 7/8 years old), generally during intergroup encounters. In zoos, females are transferred at the same age (Maïsha will turn 8 soon) and even if it's a tricky phase both for the individual who is moved and for the group that will have to integrate her, it is necessary: such movements help to maintain genetic variability and replicate the natural emigration of wild individuals.
The first video ("Introduction d'une nouvelle femelle gorille - Phase 1") shows the first full introduction of Maïsha to the group. Although it is rough, this kind of confrontation with the silverback is normal. Maïsha adopts a submissive posture by crouching on the ground while Nyuki bites (superficially) her back, showing that he's the dominant. The footage is very impressive because of their size difference and the screams of the female, but this kind of spectacular display is part of the social functioning of gorillas. Our role is to attentively monitor what's going on, in order to react quickly if we think the stress level or the risk of injury is too high. It is important to keep a cool head to take the right decision and not interrupting a contact to early, or too late.
After a few minutes, we introduced the three remaining individuals (Ybana the adult female, Bangui and Miley, the juveniles). Ybana and Bangui immediately charged Maïsha, while Miley tried to approach her. These positive contacts between the two young females had already been observed during the protected contact in the night rooms.
In the wild, the female hierarchy depends on the order on which they are acquired by the silverback. In captivity the addition of a new female is generally not well tolerated by the resident female(s), which explains why Ybana is charging and displaying at Maïsha. The young male Bangui also intimidates Maïsha, a very usual behaviour from a juvenile.
When these changes occur in a group, the silverback plays an essential role: as a dominant, he protects the group and resolves conflicts its members. During an introduction, he has to accept the new female to being able to regulate the intimidation displays carried out by the others against the newcomer.
After about an hour of full contact and Maïsha having decided to go back to her night room, we kept her separated from the others (but still in visual contact) to reduce the global stress level.
We then resumed the contact only between Maïsha and Nyuki, in order to strengthen their relationship. 48 hours later, we put all the individuals together again (second video "Introduction d'une nouvelle femelle gorille - Phase 2") and there was a striking difference! The intensity level of the intimidations dropped considerably and Nyuki plays a more active role in regulating the tensions. Another noticeable progress: Maïsha started to accept some proximity with Miley who played a key role during the process as expected.
All the individuals are now together. Not much tension is observed during feeding times and all the gorillas seem to have calmed down, even if displays still occur. The stabilization of the small troop will take several weeks but things are well underway. Welcome Maïsha!