BIRDS OF LOWER CALIFORNIA. 263 



noticeable, probably because most of them were covered by 

 birds. They were composed of small sticks and branches, 

 and occasionally a bit of sea-weed or marsh weed laid any- 

 where on the mangrove branches that would bear the 

 required weight with that of the sitting bird. Nests which 

 had apparently been in use for more than one rearing werp 

 usually considerably thicker and some were heavily 

 incrusted with guano, making the surface so smooth that it 

 did not seem as though the egg would remain on if in the 

 least disturbed. A single egg is laid which is chalky white 

 in color, shaped much like eggs of the Laridce but perhaps 

 a trifle more pointed at the small end. The average meas- 

 urement of twenty specimens is 68.7 x 46.9, the largest and 

 smallest examples measure 73.5 x 47; 72.5 x 49; 64.5 x 46; 

 67 X 45 millimetres respectively. 



Eggs were collected for food by the Mexicans during the 

 latter part of December, and owing to repeatedly taking 

 them, some were found February 13, 1888, which were in 

 different degrees of incubation, others were quite fresh. The 

 Mexicans had fresh eggs April 27 which they had recently 

 taken. 



The first young were seen in the middle of February; 

 they had been hatched sometime earlier, for although some 

 were nearly naked, others had a full covering of snowy 

 down and the dark scapular pin feathers. They cling- 

 tightly to any object that touches their feet, and in this way 

 are probably enabled to keep upon the nest when agitated 

 by a high wind. A downy young which I took away alive 

 would not take food held to it, but had to be fed by crowd- 

 ing the food so far down its throat that it had to swallow it. 

 The little thing was very lielpless and kept up an almost 

 continual complaining from the time that it left the nest. 



The food of this species as far as was observed, consisted 

 wholly of fish. Disgorged masses of fish were found upon 

 some of the nests, and upon the ground below I sometimes 

 saw small fish entire. Once a full grown bird, when I 



