PERU'S WEALTH-PRODUCING BIRDS 



545 



guano-producer, possibly because, 

 in spite of its abundance, it is 

 less familiar than many others. 

 One may not visit a pier without 

 hearing the grunts of black cor- 

 morants, one may hardly take 

 the briefest trip on the water 

 without seeing the scarlet-foot 

 cormorant scurrying low over the 

 surface ; yet a visitor may re- 

 main in ignorance of the most 

 abundant species of cormorant, 

 the guanay, unless by chance his 

 boat pass near a cloud of thou- 

 sands or hundreds of thousands, 

 or unless the solid black crest of 

 some islet be pointed out as a 

 rookery. Not infrequently, in- 

 deed, they form small rookeries, 

 but it is typical to find them in 

 immense aggregations. 



Guanays occur on the Peruvian 

 coast from near the northern to 

 the extreme southern boundary, 

 but their preeminent home is the 

 double group of islands opposite 

 Pisco, in the south, the Chinchas, 

 and the Ballestas. 



NEARLY 14,000 NESTS IN AN AREA 

 OF 5,500 SQUARE YARDS 



When the Ballestas were visited 

 by the writer, in May, each of 

 the three islands had large flocks 

 of guanays, all of which, how- 

 ever, had been disturbed since 

 the opening of the season for 

 guano extraction. 



The smallest of the three flocks 

 had occupied the southwest cor- 

 ner of the north island on com- 

 paratively level ground beyond a bluff. 

 The main part of the rookery was bounded 

 by straight lines, being 93 yards in length, 

 with an average width of 59 yards. The 

 area was, therefore, approximately 5,500 

 square yards, within which were nearly 

 14,000 nests. 



The south island of this group is some 

 300 feet in height and difficult of ascent. 

 Its small top was nearly half covered 

 with birds in a compact rookery of be- 

 tween eleven and thirteen thousand 

 square yards. The middle island main- 

 tained a rookery of nearly equal size. In 

 all, about 150,000 birds had nested upon 



A DISTANT VIEW OP THE PIQUERO ROOKERY SHOWN 

 ON THE PRECEDING PAGE 



The foam from the surf, in the distance, is seen 

 streaming away to the north, in the Humboldt, or 

 Peruvian, Current. 



these three islands during the preceding 

 season. 



These flocks seemed large, and where 

 the casual observer immediately says 

 "millions" one is almost reluctant to ap- 

 ply the cold criteria of tape-line measure- 

 ment, nest-counting, and simple arith- 

 metic ; yet, upon visiting the Chincha 

 Islands in the following month, the rook- 

 eries hitherto observed seemed insignifi- 

 cant. 



Upon the south island of the Chinchas, 

 a small and generally triangular body of 

 land between twenty and thirty acres in 

 area, there was a rookery which for size 



