In Dawkins' sense of the word, memes are 'units of cultural inheritance'. So melodic movements in bird song, that birds teach each other, could be considered memes.
Any other place you might find cultural inheritance, you could describe it in terms of memes. Memes were simply meant to be a cultural analogy to genes.
What species aside from Homo Sapiens use memes?
In Dawkins' sense of the word, memes are 'units of cultural inheritance'. So melodic movements in bird song, that birds teach each other, could be considered memes. Any other place you might find cultural inheritance, you could describe it in terms of memes. Memes were simply meant to be a cultural analogy to genes.