DEPARTMENT OF MARINE BIOLOGY. 145 



birds would be captured and marked and put into one cage. Under these 

 conditions they injured themselves seriously by climbing over one another. 

 Furthermore, some of the birds are shyer than others and will not feed un- 

 less individual attention is given. Late in the season it was found that if the 

 large cage is divided into individual compartments the birds could be easily 

 shipped. Minnows, too, are indispensable for keeping the birds in good con- 

 dition. On some occasions it was found impossible to get minnows for the 

 trip in Key West and large fish had to be carried and then chopped up at 

 feeding-time. These precautions in shipping and in caring for the birds 

 were not taken in the experiments made at New York, Galveston, and Mobile. 

 Releases were made in all these harbors. The birds were invariably found 

 in poor condition upon arrival — many of them dying en route. Furthermore, 

 after every release the birds had to contend against cold weather and strong 

 adverse winds. No birds returned from these ports. 



a. Notwithstanding the failure to get returns from the above ports several 

 important returns were obtained from intermediate points : Four sooties were 

 carried from Bird Key and placed on a Mallory boat bound for New York. 

 They were released at night (7 h 30 111 p. m.) 365 miles from Bird Key. One 

 bird returned at the end of 4 days. A second one, according to Mr. Wilson 

 (a reliable employee of the laboratory), returned after my departure from 

 the island — at the end of about 5 weeks. 



b. Two noddies out of three returned from a distance of 460 miles due 

 west of Bird Key. The time required was 3 days. This is probably the 

 most important record ever obtained in the homing work. The journey was 

 made entirely over water (the place of release was about midway between 

 Galveston and Key West), with no possible object to serve as a visual land- 

 mark. Four sooties released with the noddies did not return. (See /.) 



c. Twenty-four noddies and sooties were released at Key West, 65.25 

 miles from Bird Key. Twenty-two returned — twelve out of twelve noddies 

 and ten out of twelve sooties. The time of the noddies varied from 17.5 

 hours to 2 days 15 hours. Three of the sooties returned at the end of 17.5 

 hours ; two required 1 day 20.5 hours, while the remaining ones required 

 5, 6, 8, 9, and 11 days respectively. This flight is of interest in showing such 

 a large percentage of returns and the varying times of those returns. It is 

 of further interest in showing that the nest mate and nest locality are recog- 

 nized and claimed after an interval of several days. 



d. An attempt was made to determine the speed of flight. Three noddies 

 which had already been over the route to Bird Key from Key West were 

 again shipped to Key West and released at i h 30 m p. m. All three returned 

 to the island at 5 h 45 m p. m. of the same day. They returned just as the other 

 birds were coming in from the feeding-grounds for the night. It is probable 

 that the three birds flew back until familiar waters were reached and then 

 stopped to feed. 



e. Cyon's well-known hypothesis of a special nasal sense was tested. The 

 anterior nares of two birds were tightly plugged with wax and then coated 

 heavily with asphaltum. They were released at Key West at i h 30™ p. m. 

 Both were on the nest at daylight of the following morning. Examination 

 showed that the nostrils were still tightly closed. The asphaltum had not 

 even been scratched. The birds were in very good condition. This entirely 

 upsets Cyon's theory so far as the terns are concerned. 



/. Exhaustive experiments were made upon the water-habits of the birds. 

 Both species can swim in, rest on, and fly up from the water. If the two spe- 

 cies are confined in a large cage partially sunk in the water, it is found that 



10 — YB 



