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Bird - Lore 



very interesting discussion of relationships 

 and throughout valuable matter on plum- 

 age changes. Little-known, far northern 

 forms have been the subject of special 

 investigation, and the author has taken 

 pains to gather first-hand information 

 concerning them from others. 



The work will perhaps serve, primarily, 

 as a textbook of nests and eggs and of 

 general habits, as opposed to the more 

 comprehensive and detailed study of 

 particular habits which will likely be made 

 in the future. We think of it as rounding 

 out an epoch in the science of ornithology 

 and making the same more firm as a basis 

 for future research, and are pleased that 

 the tone is conventional throughout as in 

 the use of the possessive case in such names 

 as Briinnich's Murre. Most students will 

 know some things about the diving birds 

 not set forth in these life-histories, from 

 which, for instance, one could scarcely 

 gather that the Dovekie and the Red- 

 throated Loon are more pelagic on their 

 winter grounds than the Common Loon, 

 but every student will find here a book well 

 worth referring to. — J. T. N. 



Habits and Economic Relations of the 

 Guano Birds of Peru. By Robert 

 E. Coker, in Chicago Scientific Inquiry, 

 United States Bureau of Fisheries. 

 Proc. U. S. Nat. Mus., 56, 1919, pages 

 449-511, plates 55-69. 



From December, 1906, to August, 1908, 

 the author of this paper conducted an 

 economic study of the guano and fishery 

 industries of Peru for the Peruvian govern- 

 ment. The more purely economic results 

 of his labors were published some years 

 ago, and we have here a report upon the 

 habits of the birds, observed with more 

 especial reference to the part they play as 

 producers of the vast deposits of guano 

 which have proved so important a source 

 of revenue to the Peruvian government. 

 In letters written to Bird-Lore while 

 cruising down the coast of Peru, the writer 

 of this review has mentioned the funda- 

 mental factors underlying the formation 

 of these guano deposits. Briefly, they are 

 birds, fish, islands, and absence of rain. 

 Mr. Coker here fills in the details of the 



picture by observations made on nearly 

 every bird-inhabited island on the coast of 

 Peru. He describes the general features of 

 the coast, the part played by the cold 

 Humboldt current in affecting the climate 

 as well as the fauna, and treats at length 

 of the status and habits of the various 

 birds which came under his observation. 



We are, for example, accustomed to 

 think of the Penguin as restricted to the 

 Antarctic region, but the low average tem- 

 perature (about 62° Fahr.) of the waters 

 off the coast of Peru causes, as it were, an 

 arm of the Antarctic to stretch northward 

 along the west coast of North America, 

 and as a result we actually find Penguins 

 {Spheniscus humholdti) nesting within eight 

 degrees of the Equator. 



The principal guano-producing birds 

 are Cormorants, Pelicans, and Gannets. 

 In a preceding issue of Bird-Lore (March- 

 April, 19 19) we reproduced a photograph 

 by Mr. Coker, showing acres of Chilean 

 Brown Pelicans (Pelecanus thagus) on 

 the island of Lobos Afuera, and through 

 his courtesy we here present an even more 

 astounding picture of Cormorants {Phal- 

 acrocorax hougainvillei) taken on South 

 Chincha Island, June 15, 1907. This 

 species, the 'Guanay' of the natives, is 

 economically the most important of the 

 guano birds. It inhabits chiefly the 

 Chincha Islands from which, between 

 1850 and 1872, there were removed nearly 

 11,000,000 tons of guano, having a value 

 of about three-quarters of a billion dollars. 



The photograph which we here repro- 

 duce shows a colony of Guanays which Mr. 

 Coker estimated to contain about 360,000 

 adult birds, with about an equal number 

 of young, or over 700,000 individuals. A 

 month later the colony was believed to 

 have increased 50 per cent. While the 

 original supply of guano was long ago 

 exhausted, the annual deposit is so large 

 that it forms an important source of 

 revenue, but the eagerness of conces- 

 sionaires to remove it so disturbed the 

 birds that islands which they had occupied 

 for years were deserted and the guano 

 industry was thereby imperiled. It was 

 one of the objects of Mr. Coker's studies 



