79 



government has adopted a wise system of conservation, includ- 

 ing rigid protection of the birds. Thereby the greatest of all 

 modern business undertakings based on the conservation and 

 protection of wild birds, has been rapidly built up. The prin- 

 cipal guano-producing birds of these islands are a species of 

 cormorant, a pelican and two gannets. They are constantly 

 guarded and protected from their enemies, and now (1921) have 

 increased within twenty years from a miserable remnant to 

 enormous numbers. It is estimated that there were in 1913 

 5,600,000 cormorants on the central Chincha Island alone. 

 Under the present system the production of guano on these 

 islands has risen from 25,370 tons in 1909-10 to 80,898 tons in 

 1917-18. In a letter dated August 24, 1920, Senor Ballen wrote 

 that it was expected that the output for that year alone would 

 be 82,000 tons. These figures refer not to the ancient or fossil 

 guano, now entirely exhausted on these particular islands, but 

 to the recent product deposited since the policy of conservation 

 began. It is noted, also, that under this policy the average 

 nitrogen content of the guano has risen nearly 4 per cent in the 

 last five or six years. Dr. Coker estimates that the money 

 value of a single pair of cormorants (Phalacrocorax bougainvillei) 

 is not less than $15 for the guano that they produce. 



For the above facts I am largely indebted to Dr. Murphy, 

 who has recently investigated the Chincha Island guano in- 

 dustry on the spot. There are many other guano islands, but 

 those in rainless regions are of the greatest value, losing little 

 of the nitrogen content which, elsewhere, rain washes out. 

 American citizens have filed claims to about seventy-five guano 

 islands situated mainly in the Pacific or the Caribbean sea. 

 On some of them deposits have proved worthless, but guano 

 valued at more than $3,000,000 has been imported to the 

 United States from some of these islands. Citizens of other 

 countries have exploited other guano islands in various parts of 

 the world, but the Peruvian Islands, under wise management, 

 will continue to be the greatest guano-producing station in the 

 world. 



Here ends our survey of the value of birds to man from a 

 material standpoint. What follows is taken in substance from 

 "Useful Birds," with such changes as afterthought has dictated. 



