Ducks are unusual among our wild neighbors in that almost nobody sees them as a nuisance. The harm that comes to them here comes mostly from affection rather than hostility, which makes understanding how they actually live the most useful thing we can do for them.

What they look like

The mallard is the duck on nearly every Montclair pond. Males have an iridescent green head, a yellow bill, and a narrow white collar; females are mottled brown with an orange bill, camouflage that keeps them hidden on the nest. Both show a patch of blue on the wing edge. The loud quack everyone imitates belongs to the female — the male’s call is a quieter, raspier sound.

A few others turn up. The American black duck is a native species, darker and more uniformly sooty than a female mallard, with a paler head and violet on the wing; it is most likely here in the colder months, and its numbers have declined regionally, partly because it interbreeds with mallards. The wood duck is the most striking of them — the male patterned in iridescent green, chestnut, and white — and unusually for a duck it nests in tree cavities near water. In winter you may also see hooded mergansers, small diving ducks with a fan-shaped crest the male raises and lowers, and a narrow serrated bill for catching fish rather than the flat bill of the others.

All-white or patchy birds that look heavier than the rest and can barely fly are not wild ducks at all. They are former pets, which is a problem in its own right.

Family life

Pairs form over the winter, well before nesting, and the courtship displays that go with it — head bobbing, sudden whistles, males swimming in tight circles around a female — are part of why ponds get noisy in late winter. The bond usually lasts only until the eggs are laid; the male takes no part in raising the young.

The hen chooses the nest site alone and often surprisingly far from water — in a flowerbed, a courtyard, under a shrub against a house. She lines a shallow scrape with down plucked from her own breast and lays around eight to twelve eggs, incubating them for roughly four weeks while sitting motionless and almost invisible.

Ducklings hatch ready to walk, swim, and feed themselves within hours, which is why the hen leads them to water so soon after hatching — sometimes on a long overland walk. Wood duck ducklings do something more remarkable still: the day after hatching, they climb to the mouth of the tree cavity and jump, sometimes from thirty feet, bouncing unhurt on the ground below and following their mother to the nearest water.

Daily habits

Mallards, black ducks, and wood ducks are dabblers rather than divers. They feed at the surface or upend themselves, tails in the air, to reach plants, seeds, snails, and insect larvae a foot or so down. Mergansers are the exception, diving and swimming underwater after small fish.

A great deal of a duck’s day goes into preening. Oil from a gland near the tail is worked through every feather, and that waterproofing is what allows a bird to sit on cold water without becoming soaked and chilled. A duck that looks bedraggled and low in the water is often a duck in trouble.

They rest through the middle of the day, frequently on one leg with the bill tucked back into the feathers, and feed most actively around dawn and dusk.

Through the year

Some of our ducks stay year-round and others move through. What surprises most people is the summer molt: after breeding, males shed their bright plumage for a drab “eclipse” pattern that makes them look like females, and for a few weeks in mid to late summer they lose all their flight feathers at once and cannot fly at all. Birds in that state hide in vegetation and are extremely vulnerable — a good reason to keep dogs leashed near the water in July and August.

Winter concentrates ducks on whatever water stays open, which is when a small pond can suddenly hold a lot of birds.

What else to watch for

• Never release a pet duck at a pond. Domestic breeds are bred too heavy to fly, so they cannot migrate or escape a predator, and they often cannot survive a hard winter. Abandoning a domestic animal is illegal in New Jersey. If you can no longer care for a pet duck, a farm sanctuary or rescue can help.
• Take fishing line home. Discarded monofilament wraps around legs and bills and tightens as a bird struggles, and swallowed hooks and lead sinkers are often fatal. See our Q&A on pond fishing.
• Give ducklings room, and watch the roads. Because hens nest away from water, broods crossing streets or slipping into storm drains are a regular spring occurrence. Keep back and let a hen lead her brood rather than herding them.
• Keep dogs leashed near the water. A loose dog scatters resting birds, separates hens from ducklings, and is a serious danger to flightless birds during the summer molt.
• Keep the water clean. Runoff, lawn fertilizer, and uneaten food all feed the algae blooms that degrade the habitat ducks depend on.