PERU CURRENT 



Another interesting by-product of the Peru Current is the un- 

 usual nitrate wealth of the north Chile desert. Nitrate beds are found 

 on the upland plain behind the coastal range between latitudes 19° S. 

 and 26° S. One theory is that the substance owes its origin to ancient 

 huge deposits of the guano of sea birds; later to be acted upon by 

 water and sun in the presence of quantities of sea weed. Some of 

 these beds are still the breeding grounds of many sea birds. Numer- 

 ous petrel mummies are unearthed during present day mining opera- 

 tions. Geologic changes in the history of this unstable coast could 

 well account for the present location of these inland beds far above the 

 sea. Regardless of their origin the nitrate fields are the basis for an 

 important industry in Chile. An average income of over twenty mil- 

 lion dollars gold has been realized by Chile in export taxes alone from 

 this source. For many years the nitrate trade accounted for half the 

 total value of the export trade. 



The foregoing is but a short description of the peculiar conditions 

 found on this strange coast, with its odd interrelations of industry and 

 nature, where a mountainous desert borders the ocean for 2,000 miles. 

 Here rain threatens but never falls. Here the ocean current is cold 

 and mostly vertically disposed. Here birds (penguins) fly under water 

 instead of in the air. 



The bird life and some of its spectacular features in this area have 

 been aptly described by the talented Dr. Chapman as follows: 



"As for the birds, who can describe them in their incalculable 

 myriads? Visible link in the chain of life that begins with dia- 

 toms nourished by the cool, highly oxygenized waters of the 

 Humboldt Current, they animate both the air and the sea. 

 No other coastline of similar extent can show an avian popu- 

 lation equalling that of the waters off Peru. 

 "Whichever way one looked from our anchorage at Salaverry, 

 birds could be seen in countless numbers fishing in dense, ex- 

 cited flocks, passing in endless files from one fishing ground to 

 another, or massed in great rafts on the sea. Toward the shore 

 long, waving whip-like streamers and banners passed in end- 

 less undulating lines sharply silhouetted against the coast range. 

 "Seaward, like aerial serpents, sinuous files crawled through the 

 air in repeated curves lost in the distance, while low over the 

 water processions passed rapidly, steadily, hour after hour, 

 with rarely a break in their ranks during the entire day. At 

 times the flocks were composed of Cormorants with, at inter- 

 vals, a white-bodied, brown-winged Booby. At others, they 

 were composed of Boobies accented, here and there, by a Cor- 

 morant. 



"When the birds stopped to feed, the scene commanded the 

 untiring and often excited attention of every passenger aboard 

 the ship. The Cormorants fished from the surface in a sea of 

 small fry. Swimming and diving they gobbled voraciously 

 until their storage capacity was reached. Then they floated 

 in dense, black masses waiting for the processes of digestion 

 to give space for further gorging. 



"The Boobies fished from the air, plunging into the water with 

 great force from an average height of 50 feet, to disappear in a 

 jet of spurting spray as they hit the surface. In endless cata- 

 racts they poured into the sea. It was a curtain of spearheads, 

 a barrage of birds. The water bacame a mass of foam from 

 which hundreds of fishers took wing at a low angle to return 

 to the throng above and dive again; or their hunger satisfied, 

 they flew by thousands to some distant resting place. It is 

 difficult to understand why the birds near the surface were not 

 impaled by their plunging comrades. 



"But the most amazing maneuver in all this astounding spec- 

 tacle was the instantaneous disappearance from the air of flocks 

 of 500 to 1,000 Boobies that chanced to pass over a school of 

 fish. Then as one bird, they plunged seaward and the sky, 

 which a moment before seemed full of rapidly flying birds, was. 

 left without a feather. This evolution, the most surprising I 

 have ever seen in bird-life, was witnessed repeatedly during the 

 day. When we left [Salaverry] late in the afternoon there was 

 no apparent decrease in the numbers or activities of the winged 

 fishers; but I could look at them no longer without a feeling 

 of confusion and dizziness; for the first time in my life I had 

 seen too many birds in one day!" 



Sources of information include the following: 



Ocean Birds of South America, 1936, Robert Cushman Murphy. 



The Oceans, 1942, Sverdrup, Johnson and Fleming. 



Variations in Behaviour of the Peru Coastal Current — with an 



Historical Introduction, 1936, E. R. Gunther, The Geographical 



Journal. 



Notes on the Findings of the "William Scoresby" in the Peru 



Coastal Current, 1937, R.C. Murphy, The Geographical Review. 



BLUE-FOOTED BOOBIE. Sulo nebouxji, "Camay , on ungainly bird we/ghing 

 obouf 4 pounds, of brown and white somewhat streaked appearance, wi(h white underbody, 

 dull blue bill and bright blue legs ond feet This bird dives and glides to great depths in the 

 woter, IS a bufioonish sort, curious and unafraid, and is the least important of the guano producers 



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