IN TOUCH WITH NATURE

Otago Witness, Issue 3993, 23 September 1930, Page 9

IN TOUCH WITH NATURE

STRANGE MATES.

By J. Drummond, F.L.S., F.Z.S.

The notorious Portuguese men-of-war, their floats tilled with gas, as clear as glass, but tinged with blue, purple, and pink, occasionally sail New Zealand seas, the flotillas looking very beautiful as the miniature vessels are driven by the winds like the old-time galleons of romance under full sail. They recall pictures ot the brave old fleets sent forth by Spain and Portugal, and they retain the popular name sailors gave them. Less picturesquenly, men of science christened them Physalia, meaning sea-bladder. The Portuguese man-of-war certainly is beautiful, even amongst the most exquisite jellyfishes—it is one of them—but its notoriety comes from its viciousness. Its beauty delights, but its sting is regarded as the sharpest given by any creature pf the sea. People who have suffered state that in immediate painfulness, and in the, after-effects, the Portuguese man-pf-war’s sting is comparable to the manifold stings of bees, wasps, or scorpions.

The. latest elaborate examination ot this creature’s deadly weapons shows that they are equipments in the trailing tresess that hang below the floats. They look like small swellings. Each swelling holds multitudes of microscopical dishes. Each dish contains poison, and in each there is a twisted filament. When the pkin of a fish or of a human being comes into contact with a stinging organ, thousands of the filaments shoot out and penetrate the skin. Each filament is a tube. Poison gushes out of a dish, runs down the tubes, and enters the skin. Each filament and the attached dish combined haye been described as a microscopic hypodermic syringe. '. After it has been inserted under the skin “it may ’ continue to inject poison into the creature whose misery or death it may bring about.”

The tentacles are almost transparent, and take on the blueness of the water. A fish, swimming along gaily, strikes a tentacle. Batteries of poison dishes are discharged. The fish is not only poisoned instantly, but also adheres to the tentacle. By its struggles it causes the tentacle to fhorten itself. The fish is drawn nearer to the cluster of sucking mouths. Its movements cause contact with other tentacles, more poison is poured into it, and it is gripped more firmly. Completely overcome and benumbed by the poison the many mouths spread their lips over it. The juices and pieces of the partlydigested fish are sucked in and consumed. Portuguese men-of-war sometimes are found with the remains of several partly-digested fishes held to the lower surface of the floats. These are cast off, as creature catches more fishes than it needs for food.

In spite of all this splendid equipment for success in life, and of the poisons and suckers and all, there are small fishes, Nomens, which go in and out amongst the tentacles apparently witr impunity. Further than this, they often are found in association with the Portuguese men-of-war. These fishes, with a Strange weakness for the men-of-war, are only about four inches long. The readiest way to obtain individuals of Nomeus. in parts of the Indian and Atlantic Oceans at least, is to dip up, with a large net, a man-of-war. . Several of the small fishes, probably, will be found beneath. Nomeus, strangely enough, loves to spend a’most all its life in one of the deadliest places in the spacious ocean, a place that is death to all other small fp’ies—the area swept by the man-of-war’s tentacles.

Mr G. H. Parker, director of the zoological laboratory at Harvard University, is puzzled to account for the mutual relations between the man-of-war and Nomeus. He believes that the presence of Nomeus amongst the tentacles induces other small fishes to enter the deadly area. In this way, Nomeus helps to provide the men-of-war with an abundant supply of food. Some of this, partly digested, falls to the share of Nomeus. which gathers the crumbs from the rich man’s table, after having helped at the harvest. Apart from this, Nomeus has advantage of the exclusive use of a territory in the open sea. No other fish can trespass there without danger. These conjectures are interesting, but they do not explain how Nomeus succeeds when all others fail. There is nothing at present to show if Nomeus is immune from the poison, or if its skin contains a substance that prevents the poison-holding dishes from discharging their contents. Nomens has been reported from New Zealand waters, but little seems to be known of its habits here, and it is not mentioned as benig associated with the Portuguese man-of-war in New Zealand. A pretty Nomeus caught at the Bay of Islands was honey yellow, marbled and spotted with blackish-brown and dotted with white.

The amazing numbers of eggs laid by oysters has been demonstrated by Mr D. G. Stead, of New South Wales. He found young oysters -only three-quarters of an inch in diameter producing eggs. An oyster three inches long may produce many millions in one season. _ If destruction of the eggs was not in proportion to their numbers, he believes, the progeny of a single pair of oysters soon would cover an area equal to New South Wales. 310,000 square miles. There are millions of unfertile eggs, great numbers fail because they are produced in unsuitable waters, and untold numbers fair to hatch on account of unsuitable catchment. Eggs and young are the prey of many microscopical animals. Fishes, molluscs, sea worms, starfish, and other creatures take a toll, and passive resisters like sponges and marine growths envelope oysters and stop their growth.

"Wandering through the bush not far from Oxford,” a correspondent wrote some weeks ago, “ I was surprised to note how native bird* l have increased there. In one tree there were no fewer chan four Pests with young bellbirds in them. Furthere in, there were a good number of willow-wrens; we counted 12 of them. I counted no fewer than nine wood pigeons.

They are lovely birds and fairly tame, merely flying to adjacent trees when we went close. Other native birds were present, but not in numbers. There were a few riflemen wren and tom-tits. The birds’ greatest enemies' are the weasels and the stoats. The weasels frequent places where the birds congregate. Many birds would be required to satisfy them for only a day. On the ground in many places may be seen bunches of feathers left by weasels. Four of these have been caught, three in the middle of the township. It is unfortunate that they were ever introduced. They have cleaned up all the wekas and Californian quail.”

The white-eye. the tui, the bellbird, and the stitch bird are New Zealand's only members of the Meliphagidae, the honey-eaters, characterised by protactile tongue, furnished at the tip with a bunch of stiff fibres. The honey-eaters do not live by honey alone, but observations by Mr J. Turner, Domain road, Mount Albert, Auckland, show that honey is the white-eyes’ favourite dish, if they can ge't it. He caught several white-eyes some months ago, and has kept them ever since in an old shed, which he converted into an aviary. “ They are eager to eat honey,” he writes, “ but they are wise, and do not eat too much at a time, coming back for more at frequent intervals. While honey seems to be their particular dainty, their main food is all sorts of fruit and bread. They are so tame that they eat from my hand. About the last week in August they paired off, and in the evening, when preparing to sleep in some brush, I provided for them, there were many fights, as each pair had its own little roosting-place, and considered the space for a radius of about a foot as its own particular territory.”

In the sarrje way the bellbird, although it takes berries and insects, is true to tne family of honey-eaters, preferring above everything else the nectar of the flax plant. It obtains this delicious liquor by thrusting its bushy, highly specialised tongue into the flowers. It is stated that the planting of acacia trees greatly helps the bellbird. through the late winter months and the early spring. The flowers of these trees supply the bellbird with food of which it is not deprived by the blackbird and other introduced species. At Governor’s Bay, Lyttelton Harbour, years ago, several varieties of acacia were planted specially for the belllnrds. This consideration was rewarded by constant melody through the following winters. At Mr W. Napier’s residence, Waimate, cups of honey are set out in the trees and shrubs for the bellbirds, which show their appreciation by attending regularly, especially at sundown, and singing their evening songs with gladness.

Mr H. J. Hills. Papakura. believes that the skylark in New Zealand is losing some of the qualities that have made it famous and the theme of poets. He writes: " I think that it is losing its faculty for soaring and singing. Looking back some 40 years, when I lived near Wellington, I remember that it was quite common to see skylarks soar until they were mere specks in the sky. hardly visible to the naked eye. How beautifully they sang! I never see them soar now. If they do soar, it is in a half-hearted way; and their songs are short. Perhaps other readers of your column have noticed what I mention. I am interested to know if any have.’’

A Wanganui lady has asked where the oyster-catchers go to 'about this time, after having been present on the coasts in large numbers all through the winter. The answer is that they retire to the river beds and other places, sometimes far into the mountains, to make their nests and rear their families. The oystercatcher is restless and noisy, but wary, and in its nesting season it is almost human in its wariness. When a sitting bird is alarmed, it slides off its nest quietly, takes advantage of any broken ground that helps to conceal its movements. and makes a long detour. From an effective hiding-place, it peers out, carefully watching every movement of the intruder.