Chimpanzee Interaction: Eric And Alice

This is Chimpanzee Eric and Alice on the right from Chester Zoo in the UK. Eric is holding her head while moving about, and Alice looks like she has a big grin on her face. However, in chimpanzee language their facial expressions are crucial in determining the meaning behind this action. Here are some possible interpretations:
Aggression or Threat Display: When a chimpanzee shows its teeth with a tense face and a loud vocalisation, it may be displaying aggression or dominance.
Fear or Submission: If the teeth are shown in a more relaxed, open-mouth grimace with no vocalisation, it could indicate fear or submission.
Greeting or Bonding: Sometimes, showing teeth can be a part of greeting rituals, especially if accompanied by other friendly gestures.
Alice, who experiences partial baldness, exhibits notable perineal swelling. It's a common question whether this is typical, and Staff assures that it is indeed so. This swelling, also referred to as sexual swelling, is influenced by hormonal fluctuations. Alice seems to have this swelling consistently, which is a natural part of her reproductive cycle. It becomes more prominent during fertile periods, playing a role in signalling readiness for reproduction and influencing social dynamics within the chimpanzee community.

Alice has a daughter named Annie.
Tragically Alice lost her baby recently (about May 2024, born in December 2023). It has been confirmed by Chester Zoo staff when questioned, but no reason given and no public announcement was made as far as I know.
Alice with her baby:    • In the Heart of Chester Zoo: Chimp Al...