The Northern shoveler, known simply in Britain as the shoveler, is a common and widespread duck. This bird is unmistakable in the northern hemisphere due to its large spatulate bill. The breeding drake (male) has an iridescent dark green head, white breast and chestnut belly, and flanks. In flight, pale blue forewing feathers are revealed, separated from the green speculum by a white border. In early fall the male will have a white crescent on each side of the face. In non-breeding (eclipse) plumage, the drake resembles the female. The female is a drab mottled brown like other dabblers but easily distinguished by the long broad bill, which is gray tinged with orange on cutting edge and lower mandible. The female's forewing is gray.
Northern shovelers breed in wide areas across Eurasia, western North America, and the Great Lakes region of the United States. They are strongly migratory and winter in southern Europe, Africa, the Indian Subcontinent, the Caribbean, northern South America, Malay Archipelago, Japan, and other areas. In North America, they winter south of a line from Washington to Idaho and from New Mexico east to Kentucky, also along the Eastern Seaboard as far north as Massachusetts. Northern shovelers are birds of open wetlands, such as wet grassland or marshes with some emergent vegetation. Preferred feeding areas include lakes, estuaries, coastal shorelines, saltmarshes, flooded fields, and agricultural ponds.
Northern shovelers are social ducks that live in small flocks and coexist peacefully with many other species. They feed by day by dabbling for plant food, often by swinging their bill from side to side and using the bill to strain food from the water. Their wide-flat bill is equipped with well-developed lamellae; these are small, comb-like structures on the edge of the bill that act like sieves, allowing the birds to skim crustaceans and plankton from the water's surface. This adaptation gives them an advantage over other puddle ducks, with which they do not have to compete for food resources during most of the year. Thus, mud-bottomed marshes rich in invertebrate life are their habitat of choices. During the midday heat, the birds usually rest on land near the water. Northern shovelers are fairly quiet and communicate with each other only in certain situations; males have a low clunking call, whereas females have a light Mallard-like quack.
Northern shovelers are carnivores and use their highly specialized bill to forage for aquatic invertebrates such as mollusks, insects, crustaceans, small minnows, and sometimes small fish. In winter they consume mainly seeds and aquatic plants.
Northern shovelers are serially monogamous and form pairs that last only during one breeding season. The birds breed from April to June and prefer to nest in grassy areas away from open water. Their nest is a shallow depression on the ground, lined with plant material and down. The drakes are very territorial during the breeding season and will defend their territory and partners from competing males. Drakes also engage in elaborate courtship behaviors, both on the water and in the air; it is not uncommon for a dozen or more males to pursue a single female. Females typically lay about 9 eggs and incubate them for about 25 days. The ducklings are precocial; they are born fully-developed and begin to walk a few hours after hatching and follow their mother to the water. After 40 to 45 days, the young begin to fly and become independent from their parents.
Northern shovelers are not considered globally threatened at present; however, their population is decreasing due to habitat loss, changes in climate, and nest predation.
According to the IUCN Red List, the total Northern shoveler population size is around 6,500,000-7,000,000 individuals which roughly equates to 4,300,000-4,700,000 mature individuals. The European population consists of 170,000-233,000 pairs, which equates to 340,000-466,000 mature individuals. Overall, currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.