A have a few of the Frank & Ernest strips in my archive. I'd probably have more except that I find a lot of them ... well, not all that funny. Here is an old one from February 10, 1998 that has an intellectual component to it ... it is the only one of a series from back then called "avian grammar" that I saved. (I can go back and find more if I get requests for these, otherwise this is the only one you get.)
Mutts from March 17, 2011. I agree with the last panel's comment.
Free Range from July 10, 2013 offers another variation on "Polly want a cracker".
Dan Piraro turns another cliché on its side in this Bizarro from July 20, 2013:
This look just makes me laugh. Who says birds can't have facial expressions? From Cheezburger, January 9, 2014.
The comic strip Lio has only once (to the best of my knowledge) had a bird-themed strip, and this is it: July 28, 2014, as Lio gets his comeuppance from a bird that doesn't want to be watched:
We haven't seen anything of Monty since I introduced that strip some five weeks ago, so here is one from March 11, 2010 in which Pilsner fails as a feathered GPS device:
Speed Bump from May 2, 2014. Self-explanatory.
This is the oldest Mutts strip I have a copy of. It was never made available online, so it is a scan of the one I clipped out of the newspaper on September 10, 1994. It is also one of only two Mutts strips in the comic's entire history to feature a budgie.
We move along in my limited archive of Peanuts strips into the 1960s ... Snoopy has now taken on the more familiar appearance, but birds still do things that exasperate him. From August 22, 1964: