No, but humans didn't have writing up until pretty recently either so I don't think that is a great measure of base intellectual capability.

The interesting part is how do you research that.

Starting from what should be considered "writing" to how to identify specific artifacts as abstract words.

Some researchers spend years in the forest studying one animal to isolate one single word they're speaking. Understanding other kind of intelligences is a crazy complex task.

Researchers have taught primates to communicate using sequences of simple symbols. It's sort of like a system of writing but very primitive.

Not even close.

Some great apes can learn to use symbols for communication. Bees can use specific dances to indicate direction and distance.

I dont think any other animal even have language at all (at least not language like we use the word language)