Northern rockhopper penguin
|Northern Rockhopper Penguin
|480,600 (2018 est.)
The northern, or Moseley's rockhopper penguin (Eudyptes moseleyi) is a species of penguin of the family Spheniscidae, and found in the South Atlantic Ocean. It was named for British naturalist Henry Nottidge Moseley, a member of the HMS Challenger expedition of 1872-76.
The northern rockhopper penguin is medium-sized, standing 17.7 to 24.5 inches tall, and weighs up to 8.6 pounds. The weight varies considerably over the course of a year, with their heaviest weights just before moulting. Females are slightly smaller than males. Adult birds have a narrow yellow streak of feathers over the eyes, which become elongated behind the eyes and protrude; further to the back of the head these feathers are striped yellow-black in the longitudinal direction and form a loosely fitting crest there. The eyes are red, the short, strong and bulging beak is reddish-brown, the feet and legs are pink, with the soles. The head and face are otherwise black. The top of the body is dark slate gray. New plumage after the moult has a bluish shimmer. Worn plumage just before moulting has a brownish tint. The underside of the body is white, with the wings blue-black on the top and white underneath. Chicks are completely black with a gray chin and throat, with a small, dull-colored beak; immature birds can be recognized by a matt yellow line above the eye and a reddish brown beak, but lacking a crest.
Range and habitat
The northern rockhopper penguin is found in the South Atlantic and Indian oceans; breeding sites are divided into roughly 85% located at the Tristan da Cunha archipelago and Gough Island in the South Atlantic, with the remaining 15% on Amsterdam and St Paul islands in the Indian Ocean. After the moulting period the birds spend six months at sea, usually within an area approximately 21°S and 15°E (South African shelf), westward to 42°W (southeastern South American shelf) and south to 51°S (Antarctic convergence). Vagrants have been sighted on the Falkland Islands, South Africa, and Australia.
In the late 19th century the estimated number of northern rockhopper penguins was in the millions; today they are less than 500,000, with the majority of breeding pairs at Tristan de Cunha. Harvesting the birds for oil, feathers, and eggs during the first half of the 20th century may or may not have affected its population; this was discontinued in 1955. The birds have also been used as bait in crab pots, and have appeared as bycatch in lobster and gillnet fishing.
Yet, a severe reduction in numbers has been blamed on several factors: illegal gillnet fishing within the foraging range of the penguins, in which bycatch has not been reported; a change in the surface temperature of the water due to climate change, which affects the available food supply; and the threat of oil spillage from ships, demonstrated by the wreck of MV Oliva in March, 2011, releasing 1,500 tons of fuel oil, coating more than 10,000 birds, of which less than 10% could be saved.