IN TOUCH WITH NATURE

Otago Daily Times, Issue 19697, 26 January 1926, Page 2

IN TOUCH WITH NATURE

THE CANADIAN" GOOSE, BY J. DRUMMOND, P.D.S., P.Z.S. Large, honking birds, grey, with black heads and necks, seen by a visitor to Lake Hawea, Otago, flying in V-shaped flocks, with a heavy and laboured flight, are Canadian geese. Although introduced to New Zealand by acclimatisation societies as game birds, they will be found very interesting to Now Zealand naturalists who like birds for their own sake. As they have established themselves in parts of Otago and Canterbury, and in a few other districts in the Dominion they may, when they increase in numbers, be interesting to farmers also, as in their native country they often take a toll of sprouting grain and growing grasses. They seem to live on different kinds of food at different seasons, but they show a marked preference for the green-leaf diet where it is available. They sometimes feed in flocks by night as well as by day. They resort to the same feeding grounds day after day, and prefer to feed for a few hours in the early morning and for an hour or two before sunset. They are called Canadian geese because, probably, they were first made known from Canada, but the whole of North America, from the Arctic Coast to the Gulf of Mexico, is their domain. They are, in fact, more widely distributed than any other North American wild fowl. They are regarded by some Americans as the grandest of them all. They are harbingers of spring, the earliest of the water fowl to migrate at that season. Those that winter furthest south are the first to feel the mysterious migratory impulse. They start about a mouth earlier than some of the others, moving slowly at first, but gradually increasing their speed. Beginning with an average speed of only nine miles a day between the lowest degree of latitude, the rate is increased from stage to stage of the migration until the last part of the journey is done at 30 miles a day. The migration.in parts of the country follows close upon the heels of retreating snow and ice. Geese in the south first began to feel the restless impulse when the days lengthen and sun’s rays become warmer. Gathering in flocks,, they evidence their uneasiness by honking and gabbling, and by preening and oiling their feathers. A few flocks, mounting into the air, start northward. They arc led by the older and stronger and more experienced birds. Flock after flock joins the aerial procession until the winter home is deserted and still. They follow no coastline, no mountain chain, no river valley. They travel an unwavering course to their summer homes, over hill and valley, lake and river, forest and plain, town and country district. Flying by day or by night, they stop only to rest and to feed in places the leaders know are suitable and safe. They may be confused by a thick fog, or turned back by a heavy snowstorm, but they form ranks again ana press on. Flying low in the early stages of the migration, they show consternation when they pass into a bank of fog or fly over a city or an arm of the sea in which there is much shipping. Crowding together confusedly, they wheel irregularly and make a noise like that of a disconcerted mob of humans. A flock separating, some of its members go in a direction opposite to the one they were following. . They sail to the ground and alight so stupefied that they may bo knocked over with sticks. In snowstorms, in the day, they sometimes dash against beacons and lighthouses, and crash their heads against the walls. Attracted by the lights at night, a whole flock of them may be caught. In spite of all this, they hide cunningly, and often effectively, eluding even what is known as the hunter’s eye, developed by sportsmen. Lying flat, they so closely resemble water-worn driftwood that the most experienced eye does not see them until they take, to the wing. After an intruder has gone several hundred yards, they slowly raise their heads an inch or two at a time, and finally rise to their feet. They do this on the ice, as well as on river-beds, boulders, and sandbars, and in the grass. The Canadian goose is a true goose, but so far from exemplifying the proverbial goose, it has got wisdom and understanding. The note sounded while on the wing in a trumpet-like honk. This is uttered, more frequently, and querulously, in a fog. To other waterfowl Canadian geese- seem to be haughtily disdainful. They often share feeding-grounds and resorts with ducks and other species, but never mingle with them socially, or allow them to join the flocks. They are surprisingly sagacious in distinguishing between harmless friends and dangerous enemies amongst men and other animals. If an enemy pursues them into the water the males utter loud cries and the geese arrange themselves in close ranks, rise together in a few seconds, and fly off complacently. Shortening days and sharp frosts in the autumn warn them that they must prepare to go south again. Their leaders summon them to gather together in the air. Travelling high and straight they at frequent intervals answer the leaders’ clarion call. Sighting some wellknown lake, the weary migrants may ghicily answer the call of a clansman below. Sotting their wings they glide down in a long incline, circle the lake for a place to alight, and answer their friends with loud calls. Too often they discover that their friends are false traitors domesticated members of their own species, trained to lure thorn within range of hidden guns. A female giant yellow-banded ichneumon fly was watebed by Mr Stuart Lindsay, Wellington, while she performed the interesting operation of depositing her eggs in a beech’ tree. It was in a beech forest on Mount Grey, Canterbury. Standing a few yards off. and using a small telescope, Mr Lindsay saw the insect circle the tree several times and then alight at a place she evidently felt was suitable for her eggs. After feeling around with her antennae, kept in rapid motion, she arched her abdomen high over her thorax and began to bore into the tree with her long, slender, hairlike ovipositor, which streams out from the end of her body. At the base of the ovipositor there was seen a semi-trans-parent bladder or sac, which was protruded from the abdomen and was made to pulsate at intervals. Mr Lindsay was unaole to follow the operation further, as the insect flow away, but he suggests that the bladder may bo used for injecting liquid through the ovipositor in order to soft in the wood in which a hole is made. Mr Lindsay and Mr G. V. Hughes, another Wellington entomologist, have found this giant ichneumon in association with a strange, jumping, burrowing weevil. Rhynsodes ursus, which has a boat-shaped lx>dy The ichneumon ho saw may have been penetrating the bark and skin of the beech tree to reach a burrow and to deposit an egg in the weevil s grab inside the burrow On hatching, the parasitic ichneumon would devour the grub. Entomologists are surprised at the .penetrating powers of ichneumons ovipositors. Although very thin and flexible, they are thrust into‘hard wood so far, sometimes, that pressure must bo exerted to withdraw them The insoot Mr Lindsay saw belongs to a well-known group of ichneumons, the rliyesa; its particular name is Rhyssa >ractinervis. ________