Chimp seeks zoo visitors help to escape enclosure (VIDEO)
The video shows the chimp pointing its finger at a window bolt and mimicking the movement required to open it.
In one gesture, its enterlaced fingers are reminiscent of the American Sign Language representation of the word 'gate'.
Alex Bailey from Manchester, who recorded the interaction at the Welsh Mountain Zoo, interprets the signs as a direction to free the chimp.
The visitor can be heard saying: "He wants us to lift the window up."
Peter Dickinson, a worker at Welsh Mountain Zoo, has written about using sign language with animals as part of their enrichment programme and has previously observed chimpanzees at the zoo trying to communicate with visitors.
Read the full article and watch the video here.