About Thalassarche chrysostoma (J.R.Forster, 1785)
Thalassarche chrysostoma, commonly known as the grey-headed albatross, has an average body length of 81 cm (32 in) and an average wingspan of 2.2 m (7.2 ft). Its weight ranges from 2.8 to 4.4 kg (6.2 to 9.7 lb), with an average mass of 3.65 kg (8.0 lb). Adults have a dark ashy-grey head, throat, and upper neck; their upper wings, mantle, and tail are almost black. They have a white rump, white underparts, and a white crescent-shaped marking behind each eye. Their bill is black, with bright yellow ridges along both the upper and lower parts that fade to pink-orange at the tip. Their underwings are white, with extensive black coloring on the leading edge and less black on the trailing edge. Juveniles have a black bill and black head, with a darker nape than adults. The white eye crescent is indistinct in juveniles, and their underwings are almost completely dark. Grey-headed albatrosses nest in colonies on several islands in the Southern Ocean. Large breeding colonies are found on South Georgia in the South Atlantic, and smaller colonies are located on Islas Diego Ramírez, the Kerguelen Islands, the Crozet Islands, Marion Island, and Prince Edward Islands in the Indian Ocean, Campbell Island and Macquarie Island south of New Zealand, and Chile. When breeding, grey-headed albatrosses forage for food within or south of the Antarctic Polar Frontal Zone. Individuals that roost in the Marion Island area forage in the sub-tropical zone. Juveniles and non-breeding adults fly freely across all southern oceans, ranging as far north as 35°S. For reproduction, this albatross lays a single egg in a large nest that is typically built on steep slopes or cliffs covered in tussock grass. The egg is incubated for 72 days. Studies conducted on South Georgia's Bird Island show that growing chicks are fed an average of 616 g (21.7 oz) of food every 1.2 days, and reach a peak weight of around 4,900 g (170 oz). Chicks typically lose weight before fledging, which occurs 141 days after hatching. After fledging, young grey-headed albatrosses generally do not return to the colony for 6 to 7 years, and do not breed for the first time until several more years after returning. If a breeding pair successfully raises a chick, they will not breed in the following year, taking a full year off from breeding. During their time away from the colony, these albatrosses can travel great distances, often circling the globe multiple times.
