12-6-2017 OLIVA MARJAL, VALENCIA - MALLARD (JUVENILE) (Anas platyrhynchos)

Mallards fly in groups called flocks. Like most migratory birds, mallards fly in the famous V formation. During winter migration, mallards fly south in search of warm weather, often resting at the same spots year after year. Migrating mallards can travel great distances, relying on rivers, coasts, and valleys to find their way.

A female mallard lays up to a dozen eggs in nests on the ground near water, often in a small depression or tree hole. She lines the nest with warm down plucked from her undercoat. Soon after birth, baby ducks, called ducklings, open their eyes. A little more than a day after hatching, ducklings can run, swim, and forage for food on their own. They stay in the nest for less than a month. A group of ducklings is called a brood. Outside the nest, the brood sticks close by the mother for safety, often following behind her in a neat, single-file line.

Mallards nest on the ground on dry land that is close to water; nests are generally concealed under overhanging grass or other vegetation. Occasionally, Mallards nest in agricultural fields, especially alfalfa but also winter wheat, barley, flax, and oats. Both urban and wild populations readily nest in artificial nesting structures. Pairs search for nest sites together, typically on evening flights circling low over the habitat. Occasionally nests are placed on floating mats of vegetation or woven into plant stems that rise out of the water.

Mallards are an abundant city and suburban park duck and because of constant feedings by park visitors, they can become very tame and approachable. In more natural settings and where Mallards are heavily hunted, they can be very wary of approaching people. They commonly associate with and may hybridize with other dabbling ducks. Mallards have a huge variety of displays that can be fascinating to watch and decipher. Most displays are ritualized versions of common motions: males may face off with a head-bob, threaten an aggressor with an open bill, or push against each other, breast to breast. Paired males defend their territories with vigorous acrobatic chases. Males court females by shaking or flicking the head side to side, looking over their shoulder, or raising up in the water and flapping their wings. Several males often gather around a female to display. A female encourages a male by nodding her head back and forth or paddling with her head held low.

The female forms a shallow depression or bowl on the ground in moist earth. She does not carry material to the nest but rather pulls vegetation she can reach toward her while sitting on nest. During egg-laying phase, she lines the nest with grasses, leaves, and twigs from nearby. She also pulls tall vegetation over to conceal herself and her nest. After incubation begins, she plucks down feathers from her breast to line the nest and cover her eggs. The finished nest is about a foot across, with a bowl for the eggs that is 1–6 inches deep and 6–9 inches across.

You'll find mallard ducks near ponds, marshes, streams, and lakes, where they feed on plants, invertebrates, fish, and insects. Mallards are dabbling, or surface-feeding, ducks because they eat by tipping underwater for food—head down, feet and tail in the air—rather than diving. Mallards also forage and graze for food on land.

The male mallard duck, called a drake, sports a glossy green head, a white ring around its neck and a rich, chestnut-brown breast. The mottled brown female mallard looks downright dull next to the male's showy feathers.

The mallard duck's outer feathers are waterproof, thanks to oil that’s secreted from a gland near the tail. Beneath this tightly packed waterproof layer of feathers lies a soft, warm layer of feathers called down. Twice a year, mallards molt, or shed, their flight feathers, temporarily grounding the birds for several weeks until the feathers grow back.