I don't think so. In fact I've never seen the statistics on which zoo hosts the largest bird collection on the East Coast, but I feel that Bronx (and maybe even Washington) Zoo has more bird species and exhibits than Philadelphia... And I think that between it's two parks San Diego easily beats anything we have here on the East Coast. Philadelphia does have a very nice collection though and the new Bird House is in my opinion quite good.
Philly doesn't have that large of a bird collection as there are very few outside of this relatively small building. I agree that the Bronx probably has the best collection as far as I know at least. DC had a very good collection too.
The McNeil Aviary Center is my favorite bird experience though.
