IN TOUCH WITH NATURE

Otago Witness, Issue 3996, 14 October 1930, Page 75

IN TOUCH WITH NATURE

A SEA ROBBER?

By

J. Drummond. F.L.S. F.Z.S.

From now on through the summer New Zealanders will have opportunities to observe the reprehensible practices of one of the most interesting sea birds in the world. It has two phases of colour, one light brown, the other sooty brown, looks like a gull, and is called the Arctic skua gull or parasitic jaeger, which means hunter. It is credited with all the agiliry and grace of the hunting birds, the hawks, but is regarded more as a robber than a hunter. The inoffensive lovely whitefronted tern, often called sea swallow, an absolute dream of grace and beauty, is marked out by the jaeger for its baleful attentions in New Zealand, but any species of tern, any species of the smaller sea birds or shore birds, in fact, seems to be robbed by this parasite.

For reasons that still puzzle ornithologists, the parasitic jaegar, whose circumpolar home is in Siberia, Greenland, North America, and Northern Europe, visits New Zealand regularly every summer, not in flocks, but singly, and not in great numbers. Like other visitors from the Far North,. it does not nest here. Nobody has noted its courtship. In Kotzebue Sound, Alaska, its nest i*> in a slight depression like a saucer, on a low mossy hummock on the tundra. Sometimes the nest is lined scantily with a few withered leaves, grasses, and lichens. In Northern Siberia the usual site is a dry place in a swamp. Each nest has two oval eggs, about two inches and a-quarter long, as dainty and dazzling as large gems, as beautiful as any thing of the same kind in Nature. Their ground colour is dull olive, green, grey, buff, or brown. This is embellished with lines, spots, and blotches of sepia, wine colour, umber, and drab, dark chocolate, distributed uniformly over all the egg or wreathed over the larger end.

This is what New Zealanders may see on their shores when a jaeger is near: “ The presence of the hunter amongst a flock of terns causes loud cries of anger. The terns scatter to right and left. The hunter, singling out an individual, chases it with great energy. No matter how skilfully aud rapidly the victim twists and turns, now up, now down, now co one side, now to the other, sooner or later, with few exceptions, it acknowledges defeat by dropping its fish or by disgorging the contents of its gullet. The jaeger, with much skill, catches these in mid-air and swallows them at once, or carries them hanging from its bill for a short distance. It sometimes, more to enjoy its meal, alights on the water. It is so gluttonous that it at times swallows too much, and must disgorge some before it can fly again.”

The tern can do nothing but protest in a loud voice. The jaeger does not always hit the mark. _ Its victim may escape. After chasing a tern for almiist a mile in a straight lint, a jaeger relinquished the chase. Two jaegers chased a tern that had caught a fish. One 4 the jaegers caught the tern and took the fish, but was pursued and dispossessed by the other jaeger. Two jaegers chased a tern, which twisted in sharp angles and small circles over a beach. The tern dropped its fish, which one of the jaegers adroitly caught in mid-air. In fairness, it should be stated that the jaeger does not live by robbery alone. It eats putrid fish and other animal substances thrown up by the sea, shell fishes, dragonflies, beetles, and other insects, small fishes, shrews, mice, even curlew berries, on which curlews fatten in countless numbers.

In Greenland, it is indicted on two counts. The first is robbery of other birds’ food, the second robbery of eggs and young. In a day’s tramp in Greenland there were found two nests of eiderducks and the nest of a ring-necked plover that a jaeger had despoiled. The pierced egg-shells were scattered about the nests as if the jaeger, like a common human burglar, delighted in mischief as well as injury. In Greenland, terns and small gulls, knots and sandpipers, join in a common and bitter hatred of the jaeger. 1 rotecting their nests and young, those birds often valiantly attack a jaeger, and drive it off, but it usually pursues them vindictively until they yield. Heartily opposed, the jaeger is cowardly. Terns sometimes unite in face of the common enemy and compel it to retreat. Along the coasts, and even in harbours, jaegers may be seen in New Zealand from October until April, when they leave for their northern homes. They nest and lay there in May, June, and July.

Bearing even a worse reputation is the jaeger’s somewhat distant connection, the sea hawk of the Southern Ocean. It nests in some southern parts of New Zealand, and is plentiful on the Dominion’s southern outliers. To the Maons it is hakoakoa. It is as cowardly as the jaeger, is no fighter, and feeds on young birds and sick adult birds, killing them remorselessly, and robs penguins, petrels, and gulls, compelling them to drop their fishes and often catching the fishes before they reach the water. It swallows small birds whole. Wood pigeons and kakas that fly between Stewart Island and its islets arc at treked, forced down to the sea> killed, and eaten. It frequents the

nesting places of penguins and petrels. On islands covered with scrub it searches for small birds injured on landing.

A sea hawk’s larder was inspected by Mr E. F. Stead' on a piece of bare rock on the Snares, south of Stewart Island. The sea hawks had feasted on mutton birds, whale birds, and other petrels. The skeletons were bare. The heads, can be swallowed whole, had disappeared. Only the wings were left. On Cundy Island, off Stewart Island, engaging little S.urm petrels are taken. They are swallowed whole, Mr Stead states, but the sea hawks eject from their mouths small balls of feathers, out of which stick the storm petrels long, thin legs. Mr H. Guthrie-Smith mentions a strange feature of the sea hawks’ domestic affairs. Three adults, two males and a female, always are in attendance at each nest. Each adult takes a turn at sitting on the two stone-coloured eggs blotched with brown, but the female is more eagei than the males. The trio always are present when the young are fed. A young is maneevered into the middle. One adult then disgorges food, which the young picks up and eats. On Campbell Island sea hawks follow the big gull’s horrible practice of picking the eyes out of fallen sheep.

Another membei of this interesting g.oup of sea birds, whose webbed toes are armed with large hooked claws, has been recorded in New Zealand only once. This is the Antarctic skua gull. Its dominion is the vast Antarctic continent and vaster Antarctic seas. It so loves the ice that it seldom goes far from it, but in the winter it moves north from the continent and flies over Antarctic seas. As Antarctic skuas have no ordinary gulls to rob, they rob one another or small petrels, attacking them on the wing, and compelling them to disgorge food. Their richest harvest is the eggs of the little Adelie penguins, which nest and live on the Antarctic Continent. Mr H. T. Ferrar, who was geologist in Captain Scott’s first expedition and who now is a member of the New Zealand Geological Survey, Wellington, saw a young Antarctic skua wander on to a beach. It was caught and carried out to sea by an adult skua, which was followed by a clamouring crowd of skuas, all eager to rob the robber. The only Antarctic skua recorded in New Zealand was shot in Patterson Inlet, Stewart Island, 35 years ago by a member of Lord Raufurlv’s party in the Tutanekai.

People in a country' strangely devoid of snakes and all their allies may have no direct personal interest in pythons and their ways, but they can fall under a pleasant fascination by reading a book by Mr E. W. FitzSimons, director of the museum and snake park at Point Elizabeth, South Africa. An occasional sea snake drifts across rhe Tasman Sea and is found in New Zealand waters, but these overseas visitors are not seen by many New Zealanders, whose own reptiles are restricted to harmless lizards and to shy and rare tuatara. There are pythons in our next-door neighbour, the Commonwealth. They are sun worshippers, and favour Australia, South-eastern Europe, South and Central Asia, South, Central, and Western America, the West Ind'es, and Africa

It is surprising to leara frmn Mr FitzSimons that, in spite of huge bulk and great power of constriction, pythons are inoffensive. If unmolested, they seldom or never attack human beings. There is no authenticated instance of a python in South Africa, Mr FitzSimons states, having deliberately attacked man, woman, or child without molestation, real or fancied. Mr FitzSimons saw a python constrict a Zulu, but it was in the nature of an accident or misjudgment on the python’s part.

Still, perhaps nothing in natural history is more exciting than Mr Fitz Simon’s description of an encounter in a lumber room of his residence between a python and a lady who was alone with the reptile, accidentally locked in, and no means of escape. Victor Hugo could have made better “ copy ” out of this thrilling incident that he made out of the imaginary fight between the devil fish and the man. There are many other python stories in this book, which, in a light, interesting, and intimate style, give a unique insight into pythons’ minds, habits, ’prejudices, and views of life. The book is published, with many illustrations from photographs, by Messrs J. G. Harrop and Co., London. Price, 7s 6d net.