If you live in an area with seagulls they can easily be caught by fishing for them. They will catch food in the air if you throw it up to them. Do that a few times then throw a baited hook on line up and you have yourself a seagull.
I've also read about catching birds with guard feathers (such as quail) by baiting a plastic cup, etc. They put their heads in and the guard feathers catch the cup keeping the cup on their heads. Not being too bright they assume it's dark and go to sleep so you can just pick them up. I've never seen it in real life though, and don't know anyone who has.
For survival purposes I would cook all food in a soup to preserve the fat and nutrients. Use the organs too, as nasty as they taste to me. Boil for a while and crack open the bones to get out the marrow. Eat the bland meat and drink the soup to get the most bang for your buck. Of course having some spices or hot sauce with you or knowing some wild veggies always helps with the taste.