IN TOUCH WITH NATURE

Otago Witness, Issue 3618, 17 July 1923, Page 5

IN TOUCH WITH NATURE

GREAT GLACIERS. By J. Drummond, F.L.S., F.Z.S. The largest pile of glacial deposit in New Zealand forms a low range of hills that bound the east side of the Taieri Plain, Otago. It extends from Allanton, about 15 miles out of Dunedin, to the southern end of Mount Misery, in the C'lutha Valley, a distance of about 27 miles. It may be traced from Mount Misery along the north side of an ancient Olut'ha glacial valley to the Blue Spur, near Lawrence, where it has been worked for gold. Professor J. Bark states that the Taieri moraine was formed by a great sheet of ice that descended the Clutha A alley, overspread the Barewood Plateau, and passed over and around Mount Maungatua into the upper end of the Taieri Basin. The main flow of the ice was south towards the lower end of the basin, but the ice also flowed over the site of the present coastal range to the sea. One of the best examples of a moraine piled up by a glacier at its terminus is on the sea beach a few miles south of Ross. Westland. In the- early days of prospecting and digging, miners passed the cliffed front of this moraine, which rises almost sheer 250 ft, and they named it Bold Head, a name it bears on all maps. It consists principally of a deposit of clay, sand, and gravel formed by means of water from the melting glaciers; but embedded in its face, like gigantic pimples, are many blocks, of many shapes and sizes, carried from the Alpine ranges by the glaciers that flowed down the Mikonui and W aitaha Valleys. A few chains in front of the cliff, aoout half-way along the three-mile stretch of beach, there is a good sample of an erratic block carried bodily by the glaciers and stranded there when the ice began to melt and retreat. Ibis erratic, which is covered with shunted flax bushes and shrubs, is as big as a shepherd s but with two storeys An ancient glacier that occupied the Hokitika * alley left a moraine close to the sea. In hummocky hills in Kanieri township, and around the charming Lake Kanieri. glaciers have left evidence of their power to remove great pieces of material ine Teremakau and Arahura Valleys had their glaciers, and a glacier came down to the present northern shore of Lake Brunner, where the pretty lake-side village of Moan a has been built.

The present glaciers in the Canterbury section of the Southern Alps are amongst the largest in the world, except those in Polar regions, but Professor Park describes them as ‘’but. shrunken stumps of glaciers that descended to the present coast line on the eastern side of the South Island, per; haps even beyond.” There is evidence ot gigantic glaciers all over the South Island, from the Bluff to Cook Strait, and in the North Island as far north as a line from New Plymouth to Maliia Peninsula. They were present in places where now there are neither permanent nor seasonal snowlields, and whore the rainfall is not more than 12 inches a year. In the watershed of the Rangitikei River there is a great moraine composed of blocks that glaciers tore from the higher slopes of Mount Ruapehu and carried across the Rangitikei divide into the Lower Hautapu Valley. Occupying an area from two to three miles wide, and more than 20 miles long, and forming a chain of hummocky ridges that run from Maunga-nui-a-tea to the Upper Wanganui Valley, there is a crescent moraine deposited bv confluent glaciers that came down from the western sides of Ruapehu, Ngauruhoe. and Tongariro.

Several millions of years probably have passed since those glaciers were at their maximum, but Professor Park gives them quite a recent date in •geological history. He places them in the Pleistocene —Most Recent —Period of the Tertiary Era, at the threshhold of the present area. Evidence he has collected from rocks and boulders, mountain tarns, ice-worn surfaces, and terraces on valley sides, high above present rivers, has led him to believe that New Zealand had two phases of Pleistocene glaciation. The first phase was at a time of continuous ice-sheets or ice-caps. These are seen now in Polar regions only; the largest is in the Antarctic. In New Zealand, later in the Pleistocene Period, they gave way to valley glaciers of the same discontinuous type as the present glaciers. That was the second phase of Pleistocene glaciation. At that time the great glaciers began to decay. ‘‘ln some cases,” Professor Park writes, “the decadence was arrested. and there were short-lived increases of cold. In those intervals the glaciers entrenched themselves behind their piled-up moraines, across which they made a few feeble sorties; but recession began again, and the period of progressive decadence reached down to the present time.”

In the Epsom district, Auckland, some years ago,. Mr J. B. Allen, Hobsonville, sa\v §, shining cuckoo rise from a patch of maize and fly over a road to a hawthorn hedge, passing close to him. It was followed almost immediately by three other shining cuckoos, evidently young ones. He comments on the incident: ‘‘ls it possible that shining cuckoos occasionaljv forsake their parasitica! habits and allow the mother instinct to prevail? Or is it merely that a young cuckoo, after leaving its fosterparents, finds an adult member of its own species to supply its wants?”

The incident is unusual, but not unique. Individuals of several species of cuckoos have been known to revert to the instinct of feeding the young, even to the instinct of nest-building, instincts which, it is believed, cuckoos once shared with other birds. A correspondent in Nelson supplied Dr R. Fulton, Dunedin, with notable observations of this atavism on the Wautui River, Nelson, 15 years ago. A pair of shining cuckoos were seen with five young, which they fed and taught to fly. The family was under observation for about three weeks. The feeding was systematic, “ihe five young birds sat on a branch side by side, and would not change from their positions for quite a long time, the adults continually feeding them, hut never the same one twice in succession,” the correspondent wrote. An American species of cuckoo which usually builds its own nest and rears its young, occasionally departs from that good habit, and, like almost all species of the Cuculidae, places its eggs in other birds’ nests.

Writing from St. Felix College, Suva, Fiji, Master W. Suowsill warns New Zea^

landers about the bulbul bird, which somebody, apparently, has suggested should be introduced to this dominion. He reports that it is prominent on account of its destruction of fruit, particularly paw-paws, sometimes destroying a whole crop. It is not clear whether the bulbul Master Snowsill condemns is a native of Fiji or is one of a group of birds of the same name that have their homes in most parts ob Africa and Asia. Some members of the group are plentiful in the Indian region. Ornithologically, they are the Ixidas. Master Snowsill places the bulbul next to the flying fox —probably the large fruit-eating bat of the Indian Peninsula, if not a native of Fiji—in respect to destructiveness; “and I know what I am writing about,” he adds.