When the Godwits Fly

New Zealand Listener, Volume 4, Issue 94, 10 April 1941, Page 5

When the Godwits Fly

BY keeping small finches, called juncos, in cages, Professor Rowan of Canada, found that if he could close out all the light from the cages and also have electric lights fitted inside the cages he could make the day appear to be of any length he wished. With some of the finches he made the days appear to become shorter and shorter and with others he made the days appear to become longer. The birds with the shortening days became quiet, whilst the birds with lengthening days began to sing and become very restless. He then

liberated the birds. The ones which were in the cages of shortening days flew away to the warmer South, whilst the ones of lengthening days flew towards the North although it was mid-Winter in Canada and so they flew to their doom. He thus showed that birds do not think about migration, they just set off when the dgys are of a certain length and they just can-

not help it. Their ancestors have been flying along the same routes for many thousands of years, and so they possibly are flying along ocean routes where there. was once land. The godwits do not all leave New Zealand on the same day, nor do they all leave from the same place-but it is quite possible that they all begin to move north at the same time, and so those nearest to Spirits Bay, in the far north, set off first for the Arctic. Farewell Spit at the north of the South Island is also another point of departure, -("The Habits of the Godwit," by George Guy. 3YA, March 21).