The Eurasian teal (Anas crecca ), common teal, or Eurasian green-winged teal is a common and widespread duck which breeds in temperate Eurosiberia and migrates south in winter. The Eurasian teal 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 colour teal. It is a highly gregarious duck outside the breeding season and can form large flocks. It is commonly found in sheltered wetlands and feeds on seeds and aquatic invertebrates. The North American green-winged teal (A. carolinensis ) was formerly (and sometimes is still) considered a subspecies of A. crecca.
The Eurasian teal is a relatively small duck, with a body length of about 12 to 15 inches (30 to 38 centimeters). It has a compact and rounded body, with a relatively short neck and a distinctive, pointed tail. During the breeding season, the male Eurasian teal exhibits vibrant and striking colors. The head is adorned with a chestnut-brown cap that extends down to the eyes, contrasting with a bright emerald-green eye stripe. The chest and sides are chestnut-brown, with small white spots, while the back is finely vermiculated in black and white. The wings are primarily dark with a noticeable iridescent green patch (speculum), bordered by white at the front and black at the back. The speculum is a key identifying feature when the duck is in flight. The rest of the body is a mix of intricate patterns and colors, including a buff-colored breast and a whitish belly. Female Eurasian teals, in contrast, have a more subdued and mottled appearance. They typically have a brownish overall plumage with darker streaks, providing excellent camouflage in their natural habitats. Like the males, females also have the distinctive speculum on their wings, but it is usually less vibrant. The bill of the Eurasian teal is dark and relatively small, proportionate to its body size. Legs are short and set towards the rear of the body, which is characteristic of dabbling ducks. These adaptations make them well-suited for shallow water foraging. Outside of the breeding season, males molt into a more subdued plumage resembling that of females. This change in appearance helps them blend in with their surroundings and avoid detection while vulnerable during the molting period.
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.
