No, the 13" Air has an SD card reader, one which leaves part of the card sticking out and requires a special microSD adapter to sit flush, like the one already linked on this thread: http://theniftyminidrive.com

Lots of people with 13" Airs don't realise the 11" lacks the SD card reader, so it's a common mistake to make. (It's also a pity the 11" doesn't have it - I've missed the SD card reader a lot more than the ethernet port.)