264 BULLETIN 121, UNITED STATES NATIONAL MUSEUM. 



were together. For a time most of them perched aboiit on the numerous pro- 

 jecting stones in the river, preening their plumage and sunning themselves ; 

 others swam idly in the slow current about the rapids. At such times the bril- 

 liantly green masses of foliage bordering and often overhanging the water, the 

 swift dark stream broken by jutting rocks on which were the numerous, black, 

 sharply outlined forms of the cormorants, and overhead the crystalline depths 

 of the morning sky of the rainy season made a wonderfully beautiful picture. 



When a considerable number of cormorants had congregated they seemed to 

 become suddenly animated by a common purpose and followed one another in 

 swift flight to the foot of the rapids. There most of the assembled birds 

 alighted and formed a line across a considerable section of the river. Then 

 with flapping wings, beating the surface of the water into foam, the black line 

 moved up stream, the birds showing much excitement, but keeping their places 

 very well. The surface of the water was churned to spray by the strokes of 

 so many powerful wings and feet, yet in the midst of the apparent confusion the 

 birds could be seen darting to one side or the other, or spurting a few feet ahead 

 on the line, and sometimes disappearing for a moment below the surface, but 

 nearly always securing a fish. When they reached the head of the rapids the 

 birds flew heavily to their perching stones, or swam slowly up the quiet surface 

 of the river. After a short rest the line would reform and again beat up the 

 rapids and this was repeated imtil the birds had satisfied their hunger. 



The cormorants evidently fully appreciated the advantages of thus working 

 in company, so that a fish trying to escape from one bird would almost certainly 

 become the prey of another. The purpose of beating the surface of the water 

 with their wings was evidently in order to alarm and confuse the fish so that 

 they would dart blindly about and become more easily captured. I have seen 

 parties of gannets doing the same thing in the midst of fishes off the Tres Marias 

 Islands. 



When the cormorants were gorged they deserted the fishing ground for the 

 day and streamed back down the river to the lagoons, where they perched 

 motionless for hours in large mangroves or other trees along the edge of the 

 water. 



The west coast lagoons are long lakelike bodies of brackish water vai-ying 

 greatly in size and proportion but nearly always fringed by a more or less 

 dense growth of mangroves. These are low, rarely rising over twenty-five 

 or thirty feet, and as the leafage begins at the water's edge they present a 

 solid wall of dark green, back of which often rises the larger growth of scat- 

 tered forests. Here and there among the mangroves occur dead and weathered 

 trees, or, lacking these, wide branching living trees which project over the 

 water. These are favorite congregating places for the Mexican cormorants 

 which, with their somewhat grotesque outlines, form a conspicuous figure 

 of the bird life in such localities. These birds are not considered game by 

 the Mexicans and this combined with the high price of ammunition, is sufficient 

 to protect them from wanton killing so that they are not often disturbed 

 and will permit a canoe to approach within easy gunshot before they clumsily 

 take flight. They are heavy-bodied and awkward and frequently fall from the 

 perch into the water and try to escape by swimming in preference to flight. 

 When driven to take wing from such a perch they commonly make a broad 

 circuit and returning pass near the canoe and turn their heads in evident 

 curiosity to examine the cause of the alarm. Their flight like that of other 

 cormorants is steady and rather labored, and as they circle about an intruder 

 they often glide for some distance on outspread wings, turning their long out- 

 stretched necks toward the object of their curiosity and presenting almost 

 as grotesque an appearance as the snake-bird." 



