MIGRATORY BIRDS

Hokitika Guardian, 4 March 1933, Page 3

MIGRATORY BIRDS

NEW ZE ALA N'T) PLIGHTS. .ADDRESS BY AUt. .EDGAR STEAD. CHRISTCHURCH, March 2., . The ends served, the cause or or.gin of me custom, tli e infmiediat e .stimuli on the individual in, migration of New .Zealand birds .were dealt with in an iate.resi-.ng manner by Mr. E. F. Stead, iu an address to- the first meeting of the 1933 session of the Philosophical /Institute of Canterbury ; l'a-s-t night. ■ The lecture r quoted from many , authorities .and stated that there were many mysteries connected with migration that had not yet-been definitely explained. So far they were merely .subjects of theory. Birds migrated principally in the Northern Hemisphere for the reason ( that large area s of land- were open for the greater part of the year, fm said'. Indeed, migrating birds enjoyed a perpetual Gummer. Certain weather conditions caused the birds to move according to researches, 'but they had to be in a proper physical condition to start off before th e urge wag effective. The birds rarely followed a straight -course, and they flew at heights of from a- few yards to 8500 feet. Birds met with above 'SOOO feet were the exception, and not the rule. They did not hesitate to cross mountain' ranges ; for instance thousands crossed the Himalayas. In speed they ranged from 25 to 50 miles: an hour, but there , were known cages of much higher ’ speeds.

THE LINE OF FLIGHTS. Many theories had been put forward as 'to how the birds kept to the right path*. Vision pi yed a- part, .for birds ■sometimes became lost in foggy weather; on tf;e other hand vast numbers were able to proceed Gafely.and surely when it was impossible- to see what wag below. It was quit e possible’ that the birds possessed some .special faculty of vision denied to the human. The homing of pigeons seemed to demonstrate that 'sight played an iim ! port.iiit part in erection-finding, at least in that species. However, the homing' of pigeons could not be rej gar-ded as a parallel to th e actions of migrating birds .generally. I Foni e migrations might well be of sudden growth, said Mr Stead. The blight birds of Southland were the only migratory birds -of New Zealand in. the :tru e gebs e of the would. Considerable of the New Zealand dottrel migrated to Australia, taking a route via Auckland, Norfolk Fiend, Lord Howe Island, south Queensland,, New South Wales, and along the south cOa s .t. Thjs seemed to indicate that theiearly j ancestors found that- route easiest in. the qlayg when New Zealand was a pan of Australia. ’ ' f ACTIVITIES OF THE YOUNG. Godwit s arrived on their breeding grounds at the end of May and left i’.i : Airg'UOj. Some of;.,their.- young" were only .17 days’, old wlien they began their 1 migration-. It was not unusual for. .birds-: to‘lie blown off their course; "The shining cuckoo wintered in the Solomc u Islands, according to orif. authority. It wa,s cert.: in that .few remained in New iZealond for the winter.

Penguins, Mr said, spent- many months in the s ea. They were peculiarly adapted to an aquatic life, anu they were able to retain thc’r bveediner grounds after -having been hundreds of miles away. ... •. AN INHERITfED MEMORY. ' Young, birds definitely possessed an inherited memory of some ,sort. . It might he an instinct-, but it -accounted fo r ILie , fact that, birds were able to fly over' a* course that had been; covered by their . .parents-. Eyen this, how- . ever, could 1 not account for the exact minuteness of the penguin’s sense of djrecttion,. As to the , petrel family,, mutton birds had 'been “ringed'” by the light-keeper aV Puyse-gur Point and subi sequently. they .were: found in northern California.. They, wintered -in the: far north of the Pacific and' returned in the spring. Moreover,, theygfqilfid' their way aei’oso- ;w'ide. stretches .of ocean far better, than wel4-traihed=' navigators. , , .Mr 'Stead concluded his address by stating that the general' lack of data was so great that it was impossible even- to theoi’is e on the migration ofthe bii-ds of New Zealand. .