problem Yawning (choking?) in 4 week old chick

[Oona chick]

I hatched 7 chicks and 2 have died in the last 2 weeks. I am not entirely sure why. I have noticed a few of them look like they are choking. Now we have one doing it and I don't want it to die too. I have read Storey's Guide to Raising Chickens and searched this forum but can't quite tell what might be wrong. Except would it be gapeworms? That seems like the only thing I can see. In retrospect this chick has not been eating well for the last 24 to 36 hours. I think it is a rooster as it is WAY bigger than the others and has weird feathers sticking out the top of it's head. Any suggestions out there?
Thanks in advance
Shannon