As with many "very short" English words the concept of "ape" is
typically just fingerspelled.

If you are telling a story (particularly to children) you very well
may choose to thump on your chest a couple of times as if you were
an ape.
The sign for "gorilla" tends to just use the chest thumping
movement.
If you need to distinguish between an "ape" and a "gorilla" you have
a couple of options:
1. Fingerspell A-P-E and sign "gorilla" by thumping your
chest.
2. Thump your chest a couple times with "A" hands (palm-side
facing toward your chest) to mean "ape." Thump your chest a
couple of times with "S" hands to mean "gorilla."
GORILLA or APE:




Note: On first usage, if it is important to be specific about
whether your are signing "ape" or "gorilla" it is a good practice to
"fingerspell" either concept at least once for clarification.
Also see:
MONKEY
Also see: GORILLA
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American Sign Language (ASL) online at American Sign Language University ™
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