In a Discord channel I am in, someone linked this video: https://www.youtube.com/watch?v=jmys2abx4co
In it, a Professor Toshitaka Suzuki is described as having proven that animals, specifically the Japanese Tit (Parus minor), can use complex language skills like sentences and words which refer to the external world.
He discovered this by running several experiments related to bird calls made in the presence of other predators, including rearranging the bird call and using mental misidentification.
Through observation and experiments, he discovered several words, like ones that mean "gather", "snake", and "danger".
This was a major discovery in the field of Animal Linguistics, which is the study of the use of language by animals.
Looking up the professor's name brings up a few websites which have papers and summaries that seem to cover the facts covered in the video:
Although, it appears that Toshitaka Suzuki is an Associate Professor, not just a Professor.
So, I think the video is covering legitimate events.