490 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



the Tortugas ; that is, from July 19 until the end of the month. There 

 were at least two dozen birds varying in plumage from the adult 

 blacks through the checkered of the adolescent to the immature of 

 the year. Their occurrence at this time seems to almost indicate that 

 they might have bred here, but I greatly doubt that this could have 

 been the case, for we have no record of black terns breeding any- 

 where nearly as far south as this. I also failed to find any signs of 

 nests, which I am sure I should have been able to locate had they 

 been present, for I am thoroughly familiar with their nesting habits 

 in the North. 



THE ROYAL TERN {TJialasseus maximus). 



A few royal terns are always to be found about the Tortugas 

 during the spring and summer months, but we have no record of their 

 breeding here. A bunch of 14 frequented the northern hook of Log- 

 gerhead Key on fair days where they would preen and doze for hours 

 at a time, usually during the warmer parts of the day, in which occu- 

 pation they were frequently joined by an even larger number of 

 least terns. Plate 37, figure B, shows the birds in this place in char- 

 acteristic poses. 



THE MAN-O'-WAR BIRD (Fregata magrtificens rothschttdi). 



Until the young noddy and sooty have slipped from their shell, 

 man-o'-war birds are not especially abundant about the Tortugas. It 

 is true, Fort Jefferson, some old stakes and pieces of wreckage on Bird 

 Key, and on the outer reef, furnish desirable resting places for them, 

 and the abundance of fish likewise an adequate food supply, so that 

 there may be a few more birds here at all times than one would see 

 along the rest of the keys, excepting, of course, their roosting place, 

 the little island near New Found Harbor Key and Ke} T West, whose 

 refuse furnishes a never failing food supply. 



However, when the young terns begin to appear on the ground, the 

 man-o'-war birds increase in numbers until four to five hundred will 

 be found crowding all the available wreckage on Bird Key (pi. 3G), 

 where they augment their finny diet by occasionally swallowing a 

 young tern. I have seen them pick up and fly away with an almost 

 fledged bird. We will, therefore, have to consider the man-o-'war 

 bird an enemy of the tern. 



If you come to dislike the man-o'-war bird for his pilfering on 

 the tern rookeries, you soon lose your dislike when you see him on 

 wing, for there is no bird in existence that equals him when it comes 

 to soaring, a feat for which every airman who sees him envies him. 



Fort Jefferson, on Garden Key, is an ideal place from which to 

 study his powers of wing. The high wall that circles the structure 

 catches the slightest breeze that may ripple the sea and causes the 



