68 Gross, The Yellow-hilled Tropic-hird. [jan' 



The young birds flopped their wings \igorously, as if attempting 

 to fly, but were never able to rise from the water during the time 

 I observed them. Such an event created considerable excitement 

 among the adult Tropic-birds, which assembled to witness the 

 affair. The young bird while thus floating on the water may be 

 fed by the adults, but more probably depends on its stored fat 

 until it gains enough strength to fly and fish for itself. 



IV. EXPLANATION OF PLATES. 



Plate III. 



Fig. 1. One-Rock Island, a typical island of Great Sound nearly 

 covered with second growth cedars, a few palmettos, and cactuses. Five 

 of the cavities on this side of the island were occupied by nesting birds. 



Fig. 2. A close view of one of the cliffs on the outer shore of Morgan's 

 Island, Ely's Harbor. The lower n(>st is 6 feet above high water mark. 



Plate IV. 



Fig. 3. Adult Tropic-bird in the act of leaving her nest at One-Rock 

 Island. This view shows how the wings may be used in- locomotion on 

 land, especially on rough uneven surfaces. 



Fig. 4. Adult Tropic-bird on her nest at Tucker's Town. The nest 

 was excavated, probably by the birds themselves, in the side of one of the 

 high sand dunes which run along the shore. The long tail feather is 

 bent over the back of the bird. 



Plate V. 



Fig. 5. Adult Tropic-bird resting in a natural cavity of the cliffs at 

 Bethel's Island. 



Fig. 6. Adult Tropic-bird on her nest and egg at Morgan's Island. 

 This nest is made in a thick mat of sargassum which was deposited by the 

 waves. 



Plate VI. 



Fig. 7. Nest and egg of the Tropic-bird at Tucker's To^\Ta. Same nest 

 as shown in Plate IV, fig. 4. The egg gave the following measurements: 

 longest diameter 4.9 cm., shortest diameter 3.6 cm., w^eight 37 grams. 

 The markings on this egg are distributed with comparative uniformity. 



Fig. 8. Egg of the Tropic-bird at Two-Rock Island. The measurements 



