Common Tern

Description:

Common Tern (Sterna hirundo) - a pair in winter plumage - flying over Eco Pond, Flamingo, Everglades National Park, Florida. << The terns, family Sternidae, are small to medium-sized seabirds closely related to the gulls, skimmers and skuas. They are gull-like in appearance, but typically have a lighter build, long pointed wings (which give them a fast, buoyant flight), a deeply forked tail, slender legs, and webbed feet. Most species are grey above and white below, and have a black cap which is reduced or flecked with white in the non-breeding season. >>

Habitat:

The Common Tern (Sterna hirundo) is a seabird of the tern family Sternidae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly red with a black tip or all-black. There are a number of similar species, including the partly sympatric Arctic Tern, which can be separated on plumage details, leg and bill colour, or vocalisations. The terns, family Sternidae, are small to medium-sized seabirds closely related to the gulls, skimmers and skuas. They are gull-like in appearance, but typically have a lighter build, long pointed wings (which give them a fast, buoyant flight), a deeply forked tail, slender legs, and webbed feet. Most species are grey above and white below, and have a black cap which is reduced or flecked with white in the non-breeding season. The Common Tern's closest relatives appear to be the Antarctic Tern, followed by the Eurasian Arctic and Roseate Terns. Genetic evidence suggests that the Common Tern may have diverged from an ancestral stock earlier than its relatives. No fossils are known from North America, and those claimed in Europe are of uncertain age and species. The nominate subspecies of the Common Tern is 31–35 cm (12.2–13.8 in) long, including a 6–9 cm (2.4–3.5 in) fork in the tail, with a 77–98 cm (31–39 in) wingspan. It weighs 110–141 g (3.9–5.0 oz). Breeding adults have pale grey upperparts, very pale grey underparts, a black cap, orange-red legs, and a narrow pointed bill that can be mostly red with a black tip, or all-black, depending on the subspecies. The Common Tern's upperwings are pale grey, but as the summer wears on, the dark feather shafts of the outer flight feathers become exposed, and a grey wedge appears on the wings. The rump and tail are white, and on a standing bird the long tail extends no further than the folded wingtips, unlike the Arctic and Roseate Terns in which the tail protrudes beyond the wings. There are no significant differences between the sexes. In non-breeding adults the forehead and underparts become white, the bill is all-black or black with a red base, and the legs are dark red or black. The upperwings have an obvious dark area at the front edge of the wing, the carpal bar. Failed breeders may start moulting into non-breeding adult plumage from June, but late July is more typical, with the moult suspended during migration. There is also some geographical variation, Californian birds often being in non-breeding plumage during migration. Juvenile Common Terns have pale grey upperwings with a dark carpal bar. The crown and nape are brown, and the forehead is ginger, wearing to white by autumn. The upperparts are ginger with brown and white scaling, and the tail lacks the adult's long outer feathers. Birds in their first post-juvenile plumage, which normally remain in their wintering areas, resemble the non-breeding adult, but have a duskier crown, dark carpal bar, and often very worn plumage. By their second year, most young terns are either indistinguishable from adults, or show only minor differences such as a darker bill or white forehead. The Common Tern is an agile flyer, capable of rapid turns and swoops, hovering, and vertical take-off. When commuting with fish, it flies close to the surface in a strong head wind, but 10–30 m (30–90 ft) above the water in a following wind. Unless migrating, normally it stays below 100 m (300 ft), and averages 30 km/h (18.6 mph) in the absence of a tail wind.[4] Its average flight speed during the nocturnal migration flight is 43–54 km/h (27–33 mph). at a height of 1,000–3,000 m (3,200–9,700 ft). Most populations of the Common Tern are strongly migratory, wintering south of their temperate and subarctic Northern Hemisphere breeding ranges. First summer birds usually remain in their wintering quarters, although a few return to breeding colonies some time after the arrival of the adults. In North America, the Common Tern breeds along the Atlantic coast from Labrador to North Carolina, and inland throughout much of Canada east of the Rocky Mountains. In the United States, some breeding populations can also be found in the states bordering the Great Lakes, and locally on the Gulf coast. There are small, only partially migratory, colonies in the Caribbean; these are in The Bahamas and Cuba, and off Venezuela in the Los Roques and Las Aves archipelagos. (credit: http://en.wikipedia.org/wiki/Common_Tern...)

Notes:

Eco Pond, Flamingo, Everglades National Park, Florida. 25.139° -80.938°