NATURE NOTES

Evening Post, Volume CV, Issue 129, 2 June 1928, Page 17

NATURE NOTES

BIRDS OF ROSS DEPENDENCY FURTHER OBSERVATIONS (By It. H. D. Slidolph, U.A.0.U.) Mr. 11. T. Terrar, in his, article on the "Birds of. lloss. Dependency," in a recent issuo-.of ■ the, ."New Zealand Journal of Science. <vnd Technology," goes on to refer..to tho' presence" of llocks of tern,, .seen . flying over and alighting upon, .pieces- oi loose packice. The spocies. >was. not definitely identified, but he states that there ia ample evidence that these birds are to ~ be found in large numbers in the« South Polar regions. Two species of skuas occur in' the area. One, the Antarctic skua; is abundant in New Zealand territory and may often, Mr. Ferrar states, be seen- chasing gulls- in the wake of steamers crossing the Tasman Sea. Farther south, he states,'.^' Coruiick's skua domineers all other* birds. Its range is limited to the icy portions of the South Polar regions. It is gregarious, and breeds on ilat, stony areas along (ho coast of South Victoria Land b.etwtH'u Capo Aclare and Capo Armitage. Some of these birds remain far south until tho month of May, when 'the sun disappears below the, horizon, and they begin to return again; in September, shortly, after the reappearance of the sun. M'Cormiek's skua: is ' a predatory and aggressive bird. It lives on fish, usually second-hand, on the refuse of seals' breeding-places, and on. young penguins. It obtains its" fish by forcing other birds to disgorge, and it will also eat its, own dead young, ancl sometimes 'carry off . its .neighbours' living chicks. ' Probably tho most. notable bird inhabitants of the Polar regions are the penguins. .Mr. Ferrar states that .only two species—the Adelie and tho Emperor penguin's—properly belong to Ross Dependency, though the king penguin, which breeds on Macquario jsla.nd, should also bo included. Mr. Ferrar's observations, on the emperor penguin are worthy of quotation. He states: "Tho emperor penguin arrives on South Victoria Land from, the southern seas abo\it mid-winter (Juno), and make 3 its home as far south as it possibly can. One po^iguinry' is known at Capo Crozier, and possibly there is another near Edward VII. Land, at the- east end of the Great Ice Barrier.' Each season the emperor penguin lays an. egg, which it incubates against its abdomen, in the same manner as that of its nearest relative, the king penguin. The emperor, however, is not particular as to the parentage of the egg en-1 gaging 'his or her attention at tlfe moment, for ail disengaged, birds, will scramble for any egg, or 'even for', a' living or dead chick that may be temporarily exposed to the cold. Eggs are laid on tho ice about the first .week of July, tho darkest month of the year, and the clucks hatch out in August, the coldest month of the year. The newly-hatched chicks are covered in white down . except for their heads, ■which are black. About mid-October mature birds and unfledged chicks allow themselves to be ferried.northwards on rafts of ice, but the chicks do not tako to the water before shedding their down. Infant mortality is. therefore very high—probably 77 per cent.'; and from Wilson's rough census of the Cape Crozier peiiguinry.it has been computed that the average life of-the .emperor penguin must bo. 34 1-3 years, to keep ■its numbers stationary. , First-year birds differ in colour and in markings from adult Mrds. The latter moult during January, and the'old feathers coma away in patches, dropping, off; the ends of new feathers in a way that' suggests, but does not resemble,, the scaling of reptiles. Adult birds stand about 3ft ■" high, and are GOlb^.to 301b in weight, being about half the.size of their-.6ft eocene relative." The Adelie penguin, states Mr. Ferrar, is the most numerous Bird on tho coarfts of Ross Dependency. • He states that it arrives from the southern seas by thousands; some time about.the beginning of October, and departs .for the belt t of pack-ice towards, the end of February. It nests in huge colonies at such places as Cape Adare, the Pos- '"■ session Islands, Beaufort Island, Granite Harbour, Cape Koyds, and Cape Crozier. The "nest—a heap of stones —contains two eggs, ■which areMneubated ,in turn by either parent. The chicks are covered in brown down and are fed by both parents, in the manner of pigeons. Mr. Forra'r proceeds to give some interesting observations on the habits of penguins. These birds, he states, travel beneath the surface of the sea by using their flipper-like wings in'the same way as ordinary flying birds do when flying through the air. : They thus fly, he states, through the water at a speed that exceeds that of most of their marine enemies, and resemble a shoal of porpoises as they neatly dive through the air to tako breath at intervals. On leaving the water they emerge,,like a and land feet first on icefloes sometimes six feet above. On tho snow they cither walk upright or slide along on their breasts, using their feet and their flippers as .a means of propulsion. They sleep either in. a prone position or upright," in the latter case they often tuck their bills under their flippers after the manner .of other birds. ' . ■ .