A bird hides a bit of food in place X while another bird is watching, but pretends to hide it in place y.
A second bird pretends not to watch while the deception is going on, but actually has seen the real hiding place.
The second bird shows "mind-reading" in the sense needed here. That is, it acts according to a conception of the purposes of the first bird.
There was some lengthy research published on this someplace recently, & I think I read a report on it in Science News. But as I said, this is too sloppy but maybe it will remind someone else of a decent source with more accurate information.
Carrol