THE SOUTHERN SKUA

Forest and Bird, Issue 44, 1 May 1937, Page 2

THE SOUTHERN SKUA

By R. A. Falla.

(Megalestris antarctica).

JUST as there are birds of nrey on land, so some families of seabirds obtain their living by preying upon other species. The most rapacious of these in southern seas is the southern skua, locally known as the “sea hen” or “sea hawk” at Stewart Island and along the south coast generally. Its range elsewhere is subantarctic throughout the southern ocean, and its habits are everywhere the same. This skua is a member of the gull family, but is larger and heavier than other gulls, and may be distinguished by its build, dark colour, and the whitish bar in the wings. The prejudice against all birds of prey has resulted in some hard things being said about the skua, and an idea prevails generally that smaller birds are benefited when skuas are destroyed. It cannot be emphasised too often, however, that, whether we like it or not, most species reproduce more of their kind than the natural food supply will support, and that the sudden death of many to support another species is preferable to slow starvation of many more. In the case of the petrels, upon which skuas mainly feed, tens of thousands die annually over and above the toll taken by skuas. There is, in any case, a rigid natural check on the increase in skuas, provided by the fact that their “savage” disposition includes fierce jealousy among themselves, and one finds strictly only one pair in possession of an island where there may be food supply for a dozen. These birds nest on exposed headlands, and the nest itself may be only a depression in the rock lined with grass, or the flattened top of a

trampled tussock. Two olive brown, darkblotched eggs are laid, and in about three weeks the chicks hatch. Sturdy legs and bright beady eyes are the main features of these cinnamon-coloured downy younsters, and from the day of hatching they commence to roam, only returning to the

nest in obedience to the parents’ call. Early morning and late evening are the chief hunting times, when small petrels are leaving their burrows .

for the sea or returning to them at dusk. Sometimes, too, the old skuas kill petrels at sea in broad daylight. For their own supply the adults swallow small petrels whole, and eat all but the wings of the larger ones. The chicks begin with “insides” and later learn to pick a carcase. Even at an early age the instinctive spirit of rivalry begins to assert itself, and the stronger of a pair of chickens has been known to kill and devour his nest-mate. There is no bird more courageous in defence of nest and young than the southern skua. Both male and female join in bold attack on any intruder and swoop down upon him repeatedly with defiant cries. This courage and their strong mutual attachment are things which should be recorded to the skua’s credit when its acts of bloodshed are being chronicled. Male and female are equally fearless in defence of home and young, and only the death of one of them will terminate the alliance— even death, indeed, for I have seen a male skua perish in a subantactric blizzard while standing guard over his dead mate. Much interesting information about the domestic life of the skua may be obtained from the writings of H. Guthrie-Smith and E. F. Stead, and good photographic illustrations accompany their published work. ©