Where does Pixar get their Ideas for Short Films ?

I've just seen this film the other day, it's from UPA
and it's been directed by John Hubley in 1949,
I'm merely suggesting that Pixar, or at least their
Short Films Department, seen this film and got
influenced by it.
I don't think that the Pixar Directors consciously stole
ideas from some old UPA cartoon, but the similarities
are more than just coincidences. 



now, besides the fun in this movie, they're couple of things that ring a bell
here, first the Crow takes a magic wand that makes bunnies appear
everywhere, if it doesn't sounds familiar yet, so the name of the original
owner of the wand, the magician "Presto", ring a bell ?
(check out the in-film poster on the wall "Presto")

And if that's not enough, at the end when the Fox can't conduct his band

anymore and realize he has to give up his fame, the Crow comes helping

him wearing his All-in-One musical instruments suit, that kinda looks

familiar, don't you think ?