Jan.
On this coast, as far as I know, the adults of the Eskimo Curlew (Numenius borealis) arrive first. I merely mention it, as this bird is very closely allied to the Whimbrel (Numenius phœopus) (see Gätke, page 460). This is also the case with the Hudsonian Curlew.
Judging from the twenty-five years' shooting experience of one of my friends at one of the larger fresh water ponds in Massachusetts, where the shooting of Canada Geese (Branta canadensis) has been made a specialty, it appears that they migrate in broods. It makes little difference how many birds may be travelling in company, for on alighting in the pond (unless in very stormy weather) they separate, each gander and goose with their young keeping together, the gander leading.
My observations in relation to rate of speed and length of flight lead me to believe that under very favorable conditions, such as flying before a very strong wind, such birds as the American Golden Plover and Eskimo Curlew for instance, will attain a speed of one hundred and fifty to two hundred miles an hour. It is consequently not inconceivable to me that under such favorable conditions they are able to reach the Argen- tine Republic or Patagonia in one flight, or with a possible rest on the ocean. Hence I cannot regard a flight, under favorable circumstances across the Atlantic ocean, as any great hardship to many of our birds.George H. Mackay, Nantucket, Mass.
CORRESPONDENCE.
The Soaring of Birds and Currents of Air.
To the Editors of 'The Auk':—
Dear Sirs,—Allow me to call the attention of ornithologists to the following question in which ornithology and meteorology join hands.
In recent years, wind vanes have been devised to indicate the vertical component of the wind's motion, and it has been shown that there is a significant variation in the strength of this component in various kinds of weather. It has long been known that the diurnal variation of wind velocity on land was due to local convectional ascending and descending currents, these varying greatly at different times and places, according to the nature of the land surface, the strength of sunshine, etc.
In recent years, attention has frequently been called to the importance of vertical currents in air movement as an aid in the flight of birds, Professor Langley's studies being perhaps the most important in this direction.
