Duck is the common name for some 100 species of waterfowl.1 Usually found lingering around marshes, oceans, rivers, ponds, and lakes, ducks live wherever there's water, on every continent except Antarctica. They belong to the same family (Anatidae) as swans and geese and demonstrate vast interspecies variety. Some stand out due to their spectacular plumage, oddly shaped bills, or unique calls.

Knob-billed Duck: The Knob-billed Duck, also known as Comb Duck, is a unique species because of its large black knob on the bill from the male birds. The species are found in tropical wetlands in Sub-Saharan Africa, Madagascar and south Asia. They are one of the largest species of waterfowl. The adult ducks have white head freckled with dark flanks. The neck and the underparts are white. The upper parts are glossy blue-black with bluish and greenish iridescence.

Hooded Merganser: The hooded merganser is known for its extraordinary black and white crest. They are the second smallest species of merganser and is the only native habitat that can be found in North America. The adult male hooded merganser has yellow eyes, white chest with two black stripes and a white fan-shaped crest on its head. The female hooded merganser has brown eyes, reddish-brown crest and greyish-brown body.

King Eider: The King Eiders are the largest sea ducks that live in the Northern Hemisphere. The duck gets its name from the distinctive yellow knob on its head, since the knob almost resembles a crown. The duck species resides on the Arctic coast of Alaska, Canada, Greenland, Svalbard and Russia. The male eiders have black body, creamy white chest, bluish grey neck and head, and red bill. The female eiders' appearances are overall warm brown with black bill.

White-headed duck: The beautiful white-headed duck is one of the rarest water birds in the world. Both male and female ducks are approximately 45 centimeters long or 19 inches. The males are characterized by their small size, stunning white head, its thick blue bills and stiff tail features. The females have a darker head, grey-brown body and darker brown bill.

Long-tailed Duck: The long-tailed duck is a medium-sized sea duck that possess a small bill and two long and slender tail feathers. The duck was once known as the Oldsquaw in the United States. The plumage of the male duck changes into different color during the seasons of winter and summer. In summer, the white features on the head of the male changes into black. The diving duck prefers to reside in the ocean or on saltwater in winter and artic tundra pools, ponds and streams in summer.

Surf Scoter: The surf scoter is an unusual duck that can be found in the coastal waters of the pacific and Atlantic during winter. The sea duck is native in North America. Because of its striking head pattern, the male sea duck is nicknamed "skunk-headed coot." The male surf scoters are distinguished by their velvety black plumage, white patches on the forehead and at back of the neck and their colorful bills. The females have lighter black body and white patches on the cheek and their bills are greenish-black.

Mandarin Duck: The mandarin duck is regarded as one of the most beautiful duck in the world. This duck species is native and was introduced from East Asia. Today, Mandarin Ducks can be found in several parts of the world including Russia, Korea, England, Ireland and California. The exotic ducks are usually seen on lakes and perch in trees. The male Mandarins have an array of beautiful colors while the female mandarins are dull brown. Both male mandarin duck and female mandarin duck can easily be determined.

Ruddy Duck: The ruddy duck stands out for its brilliant bright blue bill and is of the stiff-tailed ducks from North America. They are often seen with their stiffed-tailed features that are cocked up in the air. During the winter season, their chestnut bodies as well as their bright blue bill fades to dull gray. In the summer, both male and female ruddy ducks have similar appearance. Their food mainly consists of aquatic crustaceans and plants.

Smew Duck: The Smew duck is famous for its black and white plumage. The duck is one of the merganser species that can be found in North America, Europe and Asia. They are regarded as one of the most beautiful ducks in the world. The male smew ducks have white body with striking black marking on its head, back and breast. The wings are dark with large white patches and the eyes are black. The females have a chestnut head, white throat and dark brown eyes. The breast is light grey while the rest of the body is dark grey. Both genders have gray feet.

Pink-eared duck (Malacorhynchus membranaceus): The pink-eared duck is a species of duck found in Australia. It has a large spatulate bill like the shovelers. Its vernacular name refers to a pink spot in the corner formed by the black head pattern; it is only noticeable at close distance however. Widely distributed throughout Australia and highly mobile, these ducks can appear anywhere there is standing water, especially in dry inland regions, where annual rainfall rarely exceeds 15 inches.

Magellanic steamer duck (Tachyeres pteneres): This flightless species can be found on the Pacific coast of South America from south-central Chile to Tierra del Fuego. The Magelannic steamer duck frequents rocky coastlines and can be found several miles offshore. It dives in shallow waters among kelp beds, with a diet of aquatic molluscs, crutaceans and sometimes fish. Foraging occurs mostly during the high tide.

Spectacled Eider Duck: The spectacled eider is a beautiful sea duck found in the coasts of Alaska and northeastern Siberia. It is a medium-sized sea duck which is approximately 52.8 centimeters long for males and 49.8 centimeters long for females. The male spectacled eider is characterized by its white back, yellow-green head, black body with white patches around the eyes while the female spectacled eider is identified by its rich brown color with lighter brown patch of features around its eyes. During the season of late summer and fall, the males are entirely mottled brown.