I believe that canonically the tunnel painting is made by the coyote, the problem is that because it's a cartoon the bird can run into the non-existent tunnel anyway and the coyote cannot because that's funnier.

It is interesting that e.g. "Coyote time" was copied into platform games but in real life if you're not stood on solid ground you fall immediately 'cos Mother Nature doesn't give a shit what's more fun.

Mother Nature isn't in charge of gravity. That's Papa Physics' job.

>Birds chase coyotes

Does the bird ever even acknowledges the coyote?

It does beep at it.