Birds have an extremely varied diet. Some birds are entirely carnivorous, eating only meat, while others are omnivorous and eat both meat and plant foods such as nuts and seeds. Ducklings are vulnerable to any larger meat-eating bird. Duck owners should always house ducklings in a protective enclosure and lock them in at night.
Birds of Prey
Falcons, hawks, eagles, harriers and kites are all birds of prey. They hunt during the day and are carnivorous. They eat all kinds of smaller animals, including the offspring of other birds, or nestlings. Owls are also birds of prey, but they hunt at night and will also eat nestlings. Owls and many other birds of prey often consume their prey whole. If a duckling is eaten by a bird of prey there may be no sign left except one or two feathers.
Crows and Ravens
Crows and ravens belong to the Corvidae family which also includes jays and magpies. Most corvids live in open areas such as grassland or open forest. They are omnivorous and eat on the ground. They will eat whatever is available, including the eggs and the young of other birds. A corvid that has killed a duckling may not eat it immediately. It may try to hide the body and return to eat it later.
Seagulls are omnivorous and many will eat small birds, including nestlings. The American herring gull, for example, is common across North America, both inland and on the coast. In some areas it comes inland only to breed or to overwinter. Other areas of the United States are on gull migration routes. Herring gulls capture their prey as it is walking or swimming, so ducklings are vulnerable to attack even in the water.
Ducklings raised away from their mother need an area protected from drafts. There should also be a heat source such as a commercial gas brooder. Place food and water near the heat source so the ducklings are encouraged to eat and drink. Spread clean, dry litter on the floor such as chopped straw or wood shavings. Allow enough room for the ducklings to move away from the heat source if they get too hot.