Notes from a Traveler in the Tropics 89 



dance. There is doubtless no area of equal extent in the world with a larger 

 sea-bird population than the waters off this coast. Throughout its entire 

 length of some 1,200 miles, birds are always present in large numbers, and when 

 some unknown cause induces the small fish on which they feed to appear in a 

 comparatively restricted area in incalculable myriads, there is a corresponding 

 concentration of the feathered forms which prey upon them. 



On November 20, when we were anchored ofY the port of Salaverry, it was 

 obvious that we were in the center of such a gathering. Whether one looked 

 north, east, south or west, birds could be seen in countless numbers passing 

 in endless files, fishing in dense, excited flocks or massed in dark islands on 

 the sea. If one looked toward the shore, where the bare, blazing sand-dunes 

 smothered in smooth banks the base of coastal hills rising dark and desolate 

 behind them, to be in turn overtopped by the distant Andes, long, waving, 

 whip-like streamers and banners of birds passed in endless, undulating tiles 

 sharply silhouetted against the atmospheric mountains. 



Seaward, like aerial serpents, sinuous lines crawled through the air in re- 

 peated curves which lost themselves in the distance, or processions streaked the 

 sky or water in rapidly-passing, endless files, flowing steadily by, hour after 

 hour, during the entire day without ceasing, and with but slight breaks in the 

 line. At times the flocks were composed of Cormorants, with, at intervals, 

 an occasional white-bodied, brown-winged Booby. At others, they would be 

 made up almost wholly of Boobies, accented here and there by a Cormorant, 

 while for an hour or more Cormorants were passing northward some forty feet 

 above the sea, and below them, low over the water. Boobies were flying south- 

 ward, the head and tail of each procession being beyond the limit of vision. 

 The Booby formation was less regular than that of the Cormorants, three or 

 four birds often traveling abreast, and they passed at an average of three 

 hundred per minute. It was not possible, however, to estimate from such 

 observations the number of birds which passed a given point during the day, 

 since the direction of flight was at times reversed as the birds sought new fish- 

 ing-grounds. 



These were near the shore, and the focal {joints toward which sooner or 

 later, the birds converged, resulted in a scene to which no description can do 

 justice. There was not a passenger aboard the shij) who did not express his 

 lively interest in it, and throughout the day it commanded untiring and often 

 excited attention. 



The Cormorants fished from the surface where they were e\idently sur- 

 rounded by a sea of the small fry, which, with much plunging and diving, 

 they gobbled voraciously, until, their storage capacity reached, they rested in 

 great black rafts on the water, waiting for the processes of digestion to give 

 both excuse and space for further gorging. 



The Boobies fished from the air, i)lunging headlong and with great force 

 from an average height of lifty feet into tlie water almost directly. Like 



