How to describe and identify a chimp?

In this project, we want to identify individual chimpanzees. Identifying (i.e., matching) chimpanzees means here determining whether a chimp in two different situations is the same chimp or not only from the video material available.

Start with finding a video with a good view of a chimp. 

Check whether there is already a discussion that links to this video, if not, start a new discussion. The video will link to the discussion automatically.

Try to describe the chimp in question in all aspects that you can see and that might help to find it again. Don't worry about the things you can't see or you aren't sure about. This is a discussion and others will contribute, too. No correct “scientific” terms are needed. We will probably know what you mean when describing “that strange bump on her left eyebrow”.

Every distinctive feature can be seen as a trait and support the match. All traits should be permanent, although temporary wounds might be recognizable a few days or even weeks and can support a match in this time span.

Determine your chimp’s age and sex.

Age class: Juvenile or Adult?

Infants (up to age 4), juveniles (up to age 10), and adolescents (up to age 14) are annotated as “youth”. Infants are mostly carried by their mothers and stay very close to her. Chimps are born with light-colored faces that darken with age, so light face color is a good indicator for youth, too. A special mark of infant and juveniles is the white anal tuft. But without a direct size comparison to an adult, it is often not easy to point out the juveniles.

Sex: Female or male?

If a chimp is carrying an infant it is usually a female. The presence of a carried infant (ventrally or dorsally) and/or of a juvenile always traveling with a female is an important observation for any matching discussion.

Female chimps have a (cyclically changing) sexual swelling that is visible as a pinkish skin folding at their backsides. If a female is swollen, she is definitely an adult. One can also often see elongated breast nipples in females.

The sexual swelling of a female looks distinctive and can be used for matching - but its inflation depends on the cycling phase, so you need to check the timestamps. For the cycling stages, you can imagine a balloon in different phases of air inflation. During maximum tumescence (the stage of a maximal swelling) the swelling does not have any wrinkles and should be tagged with #max_swelling. If the female has only a partially or fully deflated swelling, no hashtag will be used.

Male chimps have usually a more robust body build than females. The testicles are often seen, at least from behind. Sometimes you can see the penis too. In general the rear or “butt view” are excellent for matching, but we will not confirm a match without any face view of the chimp in question.

Here are some examples for female swellings and their body build

female swellings

Here are some examples for males, their body builds, and rear views

Example Alt Text

Other body traits

Next check for missing limbs, ears, fingers, or any obvious injury or health issue.

For the hair (fur) you can look at color and density. For matching is the presence of a gray back and/or legs of special interest.

Facial features

The most important part is to describe the chimp’s face.

examples for eyebrows

examples for balding pattern

Ears can be regular, big, small, presenting cuts, folds etc. They can stick out or be missing.

You can post additional images from the linked screenshots or make your own screenshots, if you want to highlight a feature of your chimp. The discussions will be easier with clear images.

Once you posted your chimp, check back to this discussion and see what others think about your chimp and discuss with them.

Matching to a known or prospective chimp

In this video tutorial “How to Recognize Chimpanzee Faces” by Kristeena Sigler, you’ll learn a step-by-step technique that shows you what to look for and how to compare individuals to find a match. It’s loosely based on a concept used by sketch artists and facial recognition software, and is simple enough for anyone to follow and put to use.

How to Recognize Chimpanzee Faces (14 mins., English)

 

If you suggest a match right away, please let us know why you think this might be a match and post images from this other chimp and - most importantly - the video where this other chimp is seen. This match proposal can be another video you found or a known or prospective chimp from the list.

Please keep in mind that we assume that each site has its own community. Make sure to check the correct list!

A match is called when three persons agree on a proposal. A science moderator will facilitate the discussion and will finally agree (or disagree) to a match proposal.

And now: Name a chimp!

Once an individual chimp is identified, a volunteer who has participated in the matching discussion will be asked to propose a name for this chimpanzee.