I noted several videos tagged with "playface" but I'm not sure what it stands for. May somebody pls. explain? And is it only used for infants and juveniles?
Another hashtag l do not understand is "wadging" I've seen merely @jwidness using it. All the dictionaries I asked for help ar not giving me any answer. But I'm sure you will. 😄
I'm curious about how to recognize playface, also. And is it a chimp-only thing?
For wadging, you could view the wadging collection, which states "fruits are not immediately swallowed but are eaten by 'wadging' the fruit pulp in the mouth." You can see example clips in the collection.
Chimps make lots of facial expressions, just like humans. One that they commonly use during play (both youngsters and adults) is called a "play face", or sometimes "open-mouth play face". The bottom jaw is relaxed and the mouth is open, usually with the bottom teeth showing. They also make a grin, sometimes called a fear-grimace or bared-teeth display, which is not used during play, rather (as the name suggests), it's used during fear or distress. Unfortunately, many photos of chimps "smiling" that you might see on greeting cards or advertisements, are actually chimps making fear grins. 😕 Here's a chart showing some chimp faces and their analogous human faces:
The paper the photos come from talks a little more about facial expressions across various species -- many primates have similar expressions, but they're not always used in quite the same contexts.
Wadge: Extract juice by chewing and compressing sticky fruits, their seeds and skin with leaves, or meat with leaves "between the lower lip and teeth", or "between tongue and palate". Honey, eggs and even semen may be wadged. After juice is extracted, the remaining inedible parts are spat out. Fruits frequently wadged at Mahale include Canthium crassum, Harungana madagascariensis, Parinari curatellifolia, Pseudospondias microcarpa, Psychotria peduncularis, Syzigium guineense, Uapaca kirkiana, and Uapaca nitida.
Basically, they suck out the tasty part of the food and leave behind the not so good parts. Sometimes they do eventually eat the material they wadge -- I knew captive chimps that wadged their dry "biscuits" with water for a while before eating them.
You guys are amazing - you dont even need the science team anymore!!
A small addition to what wadging is, after they chew, smash and suck the fruits dry, they often also dip the wadge in water many times, resoacking and resucking the wadge before discarding the wadge and starting again with new fruits.
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Boleyn
moderator
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ksigler
moderator
in response to Boleyn's comment.
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jwidness
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MimiA
scientist, moderator