If it is a mallard, and not toe punched (hole in between toes, or missing last part of one toe) done and showed healed from when hatched, you could be prosicuted for having it captive if it cannot come and go. maybe clippied wing would be enough to say was a pet. anyone asks later if you keep say you bought from fea market as roun duck ect..
That said, if found in street could be from escaped ethnic cooking, dumped duck, or more likely wild mallard that got separated maybe bumped by car (they'd come into major city in middle of downtown to forage and beg for food so much they got used to being played with and held even. when id call my rollers and parlors ect in to get main meal, they learned somehow that there maybe more food in my apt, and started just waddling or flying in when id open my back door or window (no screen, as manager was dead beat). I thought of bringin with when moved out to country on pond and spring fed streams ect on three acres, but someone decided to let their dogs tear them apart before moved even.
peas, mealworms, nightcrawlers, crickets, minnows, ect (basically anything small easily found for fishing bait), lettuce/ leafy greens (dandilions are best for, lettuce worst for), should work. Stay away from bait stores especially, as they use chemicals and bait critters full of parisites and disease generally, though never heard of bothering ducks.. get it a female friend or two as soon as possible, as they feel much more secure then. use small guage hardware wire for cage, as chicken wire worthless for keeping preds and pests that would hurt your duck/s out. make sure your duck has enough water to put whole head in and shake around or will eventually choke/suffocate and die (they need to clean out nose mouth and eyes that food and debris build up in. don't use cedar as can be toxic. I find a grate, or at least grated container (litter box or bigger) under about middle of water (some say use water jugs with hole cut in to stop ducks from getting most water around), to work best for my flock of scovys. also ACV (apple cider vinager), seems to help make my ducks happy and healthy. have fun with it and keep us posted.
