The Eurasian teal is a common and widespread duck which breeds in Eurasia and migrates south in winter. It is often called simply the teal due to being the only one of these small dabbling ducks in much of its range. The bird gives its name to the blue-green color teal.
Eurasian teal breed across the Palearctic and mostly winter well south of their breeding range. However, in the milder climate of temperate Europe, the summer and winter ranges overlap. These ducks are commonly found in sheltered wetlands with dense fringing vegetation, such as taiga bogs or small lakes and ponds with extensive reedbeds. In winter, they are often seen in brackish waters and even in sheltered inlets and lagoons along the seashore.
Eurasian teal are highly gregarious ducks outside the breeding season and can form large flocks. In flight, the fast, twisting flocks resemble waders. Despite their short legs, Eurasian teal are also rather nimble on the ground by ducks' standards. Diurnal throughout the breeding season, in winter they are often crepuscular or even nocturnal feeders. They usually feed by dabbling, upending, or grazing; they may submerge their head and on occasion even dive to reach food. Eurasian teal are quite noisy. The males whistle 'cryc' or 'creelycc', not loud but very clear and far-carrying. The females have a feeble 'keh' or 'neeh' quack.
Eurasian teal are herbivores (granivores) and carnivores (insectivores). In the breeding season, they eat mainly aquatic invertebrates, such as crustaceans, insects and their larvae, mollusks and worms. In winter, they shift to a largely granivorous diet, feeding on seeds of aquatic plants and grasses, including sedges and grains.
Eurasian teal are serially monogamous and form pair bonds that last only during one breeding season. Pairs form in the winter quarters and arrive on the breeding grounds together, starting about March. The breeding starts some weeks thereafter, not until May in the most northernly locations. The birds nest on the ground, near water and undercover. The nest is a deep hollow lined with dry leaves and down feathers, built in dense vegetation near water. After the females have started laying, the males leave them and move away for shorter or longer distances, assembling in flocks on particular lakes where they molt into eclipse plumage; they will usually encounter their offspring only in winter quarters. The clutch may consist of 5-16 eggs, but usually numbers 8-11; they are incubated for 21-23 days. The ducklings leave the nest soon after hatching and are attended by the mother for about 25-30 days, after which they fledge. The males and the females with young generally move to the winter quarters separately. After the first winter, the young molt into adult plumage.
Eurasian teal are threatened by habitat loss mainly due to drainage and pollution of wetlands. They are also often hunted in the wintering areas and suffer from human disturbance.
According to the IUCN Red List, the total population size of the Eurasian teal is 6,600,000-7,700,000 individuals. The European population consists of 557,000-915,000 pairs, which equates to 1,110,000-1,830,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.