CLOSED: Which chickadee is that?

I saw this bird in Pittsburgh PA. I believe it's either a Black-capped Chickadee or Carolina Chickadee. How do I tell the difference?

Thanks,
Cui

Don't think it's possible from this pic, unfortunately. And as far as I can find out, Pittsburgh is right on the borderline between the two species, so it could be either there, or of course a hybrid.

To distinguish: B-c tends to have a more obvious pale panel on the secondaries, a slightly longer and more rounded-tipped tail, and a larger black bib, while C has a more uniformly brown wing, slightly shorter, square-ended tail, and a smaller bib. But it isn't easy.

Resin

Interesting. I remember I have a Black-capped Chickadee identified in another thread:
http://davesgarden.com/community/forums/t/1383585/

Did you identify it based on the pale panel?

Thanks,
Cui

I will trust your intuitive guess, Resin ;)

Thanks,
Cui