the size of a large duck, to which they are unrelated. Their plumage is largely grey or black, and they have spear-shaped bills. Loons swim well and fly adequately, but are almost hopeless on land, because their legs are placed towards the rear of the body. Red-throated loon, Gavia stellata Pacific loon, Gavia pacifica Common loon, Gavia immer Yellow-billed loon, Gavia adamsii Northern storm-petrels Order: ProcellariiformesFamily: Hydrobatidae The storm-petrels are the smallest seabirds, relatives of the petrels, feeding on planktonic crustaceans and small fish picked from the surface, typically while hovering. The flight is fluttering and sometimes bat-like. Fork-tailed storm-petrel, Hydrobates furcatus (A) Shearwaters and petrels Order: ProcellariiformesFamily: Procellariidae The procellariids are the main group of medium-sized "true petrels", characterized by united nostrils with medium septum and a long outer functional primary. Short-tailed shearwater, Ardenna tenuirostris (A) Cormorants and shags Order: SuliformesFamily: Phalacrocoracidae Cormorants are medium-to-large aquatic birds, usually with mainly dark plumage and areas of coloured skin on the face. The bill is long, thin, and sharply hooked. Their feet are four-toed and webbed. Pelagic cormorant, Urile pelagicus (A) Double-crested cormorant, Nannopterum auritum (A) Pelicans Order: PelecaniformesFamily: Pelecanidae Pelicans are very large water birds with a distinctive pouch under their beak. Like other birds in the order Pelecaniformes, they have four webbed toes. American white pelican, Pelecanus erythrorhynchos (A) Herons, egrets, and bitterns Order: PelecaniformesFamily: Ardeidae The family Ardeidae contains the herons, egrets, and bitterns. Herons and egrets are medium to large wading birds with long necks and legs. Bitterns tend to be shorter necked and more secretive. Members of Ardeidae fly with their necks retracted, unlike other long-necked birds such as storks, ibises, and spoonbills. American bittern, Botaurus lentiginosus (A) Great blue heron, Ardea herodias (C) Great egret, Ardea alba (A) New World vultures Order: CathartiformesFamily: Cathartidae The New World vultures are not closely related to Old World vultures, but superficially resemble them because of convergent evolution. Like the Old World vultures, they are scavengers. However, unlike Old World vultures, which find carcasses by sight, New World vultures have a good sense of smell with which they locate carcasses. Black vulture, Coragyps atratus (A) Turkey vulture, Cathartes aura (C) Osprey Order: AccipitriformesFamily: Pandionidae Pandionidae is a family of fish-eating birds of prey possessing a very large, powerful hooked beak for tearing flesh from their prey, strong legs, powerful talons, and keen eyesight. The family is monotypic. Osprey, Pandion