First let me put in the disclaimer, I believe bird hunting with a fishing line and hooks is probably illegal in all 50 states. The only conditions under which I would ever recommend that you do this would be if you are in a life and death situation.
But if the situation is desperate, here is a way to catch ducks, geese, swans, seagulls and many other birds. If you are hunting ducks first determine what kind you have. Diving ducks and sea ducks dive deep underwater to get food. Dabbling ducks feed on land or on the surface of the water. First of all, watch the ducks and see if they are diving ducks or dabbling ducks.
Most common waterfowl feed on a diet of grasses, aquatic plants, small fish, insects, worms, small amphibians (frogs and toads) and small mollusks. Dabbling ducks or waterfowl that feed on land or the surface of the water are the easiest to catch. All you need is a good fishing, strong line (10 Lbs test) and a small treble hook. A treble hook works the best, but others will do. Bait the hook (bread works well) cast out near the ducks and wait. When the duck bits give him time to swallow the hook and pull him in.
This can also work with seagulls and other shorebirds; if they are used to being fed, you can often just cast the line into the air. I have had both seagulls and pelicans grab my bait when fishing.
Using corn, bread or bugs, you can catch many different types of birds including doves, pheasant and quail. This technique will sometimes even work for getting a squirrel or two. You want to have a large cloth or something to wrap the birds in when you drag them to you. This makes them easier to control until you can dispatch them.
Whenever I mention eating seagulls, someone always says I heard they taste horrible. Now to be truthful I have never eaten a seagull. However many cultures in different parts of the world have consumed them during periods of need. Some have even learned to cook them into what became popular dishes. My only advice about cooking birds would be if the birds are meat eaters or scavengers, cook them well.
Again I repeat this type of bird hunting is only something you should ever consider doing if your life depends on it.