The Brown teal is a species of dabbling duck native to New Zealand. Common in the early years of European colonization, the "brown duck" (as it had been often referred to) was heavily harvested as a food source. Its numbers quickly fell, especially in the South Island, and in 1921 they became fully protected. There are no distinctive differences between a male, female, and a juvenile Brown teal during the non-mating season. They all have a white ring around their eyes as well as a mottled brown color on their heads and throat. During the breeding season, the male will begin to change color, now having a green colored head, chestnut-colored breast, and a white stripe on each side of their body. They will sometimes also have a white clerical neckband. This does vary as some males do tend to be more colorful than others.
Brown teal occur on northern North Island (Northland, Great Barrier, and Little Barrier Islands and the Coromandel Peninsula) but also in predator-proof sanctuaries on the mainland such as Tawharanui Regional Park. These birds were once found in forested areas but now they inhabit wetlands, coastal streams, ponds, estuaries, and agricultural areas.
Brown teal are nocturnal ducks; during the day they usually stay hidden in the grass and overhanging vegetation, and at night forage in fields for worms and insects, or hunt small shellfish swimming in bodies of water. Brown teal belong to the family of dabbling ducks because they feed mainly at the water surface rather than by diving. Their legs are placed more towards the center of their bodies and they walk well on land. Brown teal are gregarious and communicate with each other using various calls; males produce soft whistles and pops, and females emit low quacks and growls.
Brown teal are omnivores. They feed mainly on aquatic invertebrates like insects and their larvae, or crustaceans and are quite fond of mollusks. Their diet also includes seeds of sedges, clover leaves, and leaves of various wetland plants.
Brown teal are monogamous and highly territorial. Pairs generally nest in late winter from July to September; however, breeding may occur throughout the year. Their nests are built in thick vegetation near water or under the shelter of large sedge, heavily lined with down. The female lays a clutch of 4 to 8 creamy-brown eggs and incubates them for 27-30 days. The male stays in his territory as a guard, aggressive to all other waterfowl. The ducklings fledge at 50-55 days after hatching but remain with their parents until the following breeding season.
The Brown teal was once widespread on the New Zealand mainland, but it disappeared there due to introduced predators like cats, dogs, and rats, which easily preyed on this unwary, weakly flying bird. Other serious factors that caused its population decline include habitat loss, hunting, roadkill, droughts, and starvation.
According to the IUCN Red List, the total Brown teal population size is around 1,500-2,500 individuals. Currently, this species is classified as Near Threatened (NT) on the IUCN Red List but its numbers today are increasing.