フロリダの旅

抄録

After the I. O. C at Ithaca, 1962, the writer accompanied Dr. O. L. Austin, Jr. to his home in Gainesville, Florida and had a rare privilege to take part in his Sooty Tern banding project on the Dry Tortugas Is. which was made in cooperation with the Florida Audubon Society (Mr. C. R. Mason) and Evergrades National Park (Dr. W. C. Robinson, Jr.), July 11-15. Observations of birds in Florida and a special note on this tern banding are given.
The chicks were gathered to the end of wire net trap and the adult birds were easily caught (especially in the evening when they feed the young) by Japanese mist nets. Thus 3, 941 adults and 8, 700 chicks of the Sooty Tern, 84 adults and 189 juvenals of the Noddy and one Anous tenuirostris (said new to U. S. A) were banded by 17 persons. Dr. Robinson's later analysis showed that 7 birds of more than 18 years old (total of 85 such old birds so far recovered) were included, and 11 birds were first recovered this year after they were banded in 1959.
A possible effect of this mass banding to chick mortality by disturbing parent-chick relation (which is rigid) is briefly considered based on a behavior observation and counts of dead chicks. A particular adult bird circled over the colony three or more times, each time returning to a particular spot but not finding the chick. Whithin a 20 × 10m square 16 small chicks (dead before banding) and 16 larger chicks, of which 4 were newly dead and other 3 were almost dying. In a 20 × 5m square 43 unhatched eggs were found (not the effect of banding). These are of course just a temporary observation.
Sea-water drinking on the wing and touching the water with feet and breast observed similarly in the Sooty Terns and Noddies when they fly from the island, are possibly related to the thirsty and over-heating while resting on the island. During incubation period the breast touching may be effective for giving moisture to their egg.
The writer wish to express deepest thanks to Dr. and Mrs. Austin, Mr. Mason, Dr. Robinson and others of the Tortugas party for their kindness and for giving him a rare and valuable oppotunity of this experience.