Habits and economic relations of the guano birds of Peru

Abstract

and fishery industries appeared in the Proceedings of the Fourth International Congress meeting in Washington in 1908.* Various circumstances unnecessary to be detailed in this place combined to delay, first, the compilation of the observations relating to the habits of the birds, and, second, the publication of the manuscript after it was completed. During the past few years other investigators have studied the guano industry, but, so far as the writer is aware, no report has been issued to cover the ground of the present paper.^Its publication even at this time seems therefore desirable. It does not seem inappropriate to indicate briefly, or at least to suggest, some of the conditions under which the studies were pursued, for, had more favorable circumstances prevailed, mvestigations covering a period of like duration might have been productive of more extensive and valuable results. Travel was sometimes accomplished by taking a steamer from one port to another, whence small sailing skiffs were used to visit islands that were 10 to 50 miles from port and upon which temporary camps could be established if desired. At other times trips of 100 to 500 miles were made in a balandra, or small cargo sloop. In a few instances travel could most conveniently be made by pack over the desert. As one may have inferred, the studies were primarily economic and directed at two related industries.^In such a case the primary needs could be met only by securing accurate knowledge of the natm*al forms upon which the industries are based and recording the methods of operation as well as the precise conditions under which they were conducted. With only unskilled assistance available, it was necessary for the investigator to devote much time personally to the collection and preservation of specunens, to the mevitable routme of record keeping, and to the preparation of reports describing the existing comm.ercial operations. It win be understood that the conditions both of work and of travel were not favorable to the preservation of so many skins of birds as it would have been desirable to save. I am glad, however, to acknowledge the cordial aid rendered by Mr. Robert Gunner, of Callao, who, having started with me as interpreter, acquired some facility in the preparation of bird skins and in other services. In all, about 80 skms were saved and 30 lots of eggs. With the permission of the Peruvian Government, and by its direction, this small col-» Coker, R. E.: The fisheries and the guano industry of Peru. Bulletin of the Bureau of Fisheries for

The Ecology of Tick Parasitism on Densely Nesting Peruvian Seabirds

“…Vultures, and until recently, condors were shot on sight by the guards on the islands. The original accounts of their causing desertions are all second-hand (Coker 1920, Murphy 1925, Vogt 1942. Kelp and Band-tailed Gulls were never seen to attack nests defended by adults.…”

Oceanographic and climatic factors influencing breeding and colony attendance patterns of Humboldt penguins Spheniscus humboldti in central Chile

“…The breeding pattern of the Humboldt penguin appears to have evolved in response to the oceanographic and climatic conditions of Perú, where it was more abundant in the past (Coker 1920, Murphy 1925, 1936. But why do Humboldt penguins still follow the 'Peruvian' strategy in Central Chile and why have they not evolved to seasonal breeders?…”

Current Ornithology

“…A breeding pair has to chose a nest site initially, regardless of whether they use it only once or return to it for years. Selection of a suitable nest site may occur at random (e.g., Guanay Cormorant, Leucocarbo bougainvillii: Coker, 1919), adjacent to some feature of the microhabitat (Section 5.1), or the process may be more complex and involve density-dependent factors (Section 4.1).…”