Secrets of animal life / by J. Arthur Thomson.

  • John Arthur Thomson
Date:
1919
Catalogue details

Licence: In copyright

Credit: Secrets of animal life / by J. Arthur Thomson. Source: Wellcome Collection.

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    out the first day, but two of the Noddies returned in safety to Bird Key. On 4th June eleven birds were liberated in Galveston Harbour ; on 9th June one of the observers, returning to Bird Key on the steamer, saw one of his terns (a red-marked Sooty) resting upon a piece of driftwood in the open sea about 409 statute miles east of Galveston. A heavy storm unfortunately removed all chance of its successful return. > * The authors are not prepared to offer any solution of the problem of distant orientation in birds, but they have made a distinct step in proving that un- trained birds can return successfully across the apparently trackless sea from a distance of 800 to 1000 miles. Dr. Lashley has shown that for short distances on the island itself the terns adjust them- selves to nest and mate and young on a basis largely of visual experience, helped a little by memory of movements, and sometimes by sounds. There is no whit of evidence of any unusual sensitiveness nor of the functioning of any hypothetical sense- organ. But what can be said in regard to distant orien- tation ? (1) It has been suggested that the Cape Hatteras birds followed the coast-line in the direction of greater warmth. This is possible enough, but it does not bear at all upon the flight from Galveston to Bird Key across the Gulf of Mexico. (2) It has been suggested that the Galveston birds followed a well-marked water-current which sweeps around the coast of Texas, Louisiana, Alabama, Florida,