Catching birds while lost at sea can be very beneficial because you can use many parts of their bodies to help you survive. Birds are harder to catch but catching them should be a thing to try.
All birds are edible. Eat any birds you can catch. Sometimes birds may land on your raft, but usually they are cautious. You may be able to attract some birds by towing a bright piece of metal behind the raft. This will bring the bird within shooting range, provided you have a firearm.
If a bird lands within your reach, you may be able to catch it. If the birds do not land close enough or land on the other end of the raft, you may be able to catch them with a bird noose. Bait the center of the noose and wait for the bird to land. When the bird’s feet are in the center of the noose, pull it tight.
Use all parts of the bird. Use the feathers for insulation, the entrails and feet for bait, and so on. Use your imagination.