62 



SCIENCE 



[N. S. Vol. XXVIII. No. 706 



driven back and forth from the islands of one 

 g^oup to those of the other. 



The merit of a system of rotation depends 

 on leaving the iirds unmolested for periods 

 of years, the longer the period the tetter. 

 For example, it would be an incalculable gain 

 if the alcatrases, which are now using the 

 westward island of the Lobos de Afuera, 

 could be left undisturbed on their grounds 

 for the next four or five years, say until the 

 extraction of old guano from Lobos de Tierra 

 is concluded. Then, in turn, the latter island 

 would be left to the birds for another period 

 of five years, whether the Lobos de Afuera 

 was exhausted in one year or in four years. 

 In other parts of the coast, according to the 

 conditions, certain islands would be opened 

 each year, but in accordance with a plan 

 which would permit the birds to remain un- 

 disturbed for periods of years. 



In stating that the main hope of the guano 

 industry consists in leaving the fowls unmo- 

 lested for periods of years, I speak from my 

 own observations on the habits of the birds 

 and on the disturbing effect caused by the 

 presence of even a single visitor. At the 

 same time, it is not a new idea, and the intel- 

 ligent men of long experience in the industry 

 will insist upon the same principle. I wish 

 to add this: the idea of a systematic closure 

 of islands, if adopted, must be followed reso- 

 lutely. It may sometimes mean the suffering 

 of national agriculture or of the export trade 

 for want of necessary fertilizer, but the suf- 

 fering should be accepted rather than break 

 the protective measures. It is fair to choose 

 between two courses, either to plan for the 

 future of the guano industry, adhering to 

 reasonable protective measures, even if pres- 

 ent sacrifice is necessary in order to reap the 

 future benefit, or else, continually to cater 

 to present wants and caprices and let the 

 future look out for itself. 



IV. CLOSED SEASON 



It was a most wise action of the govern- 

 ment in establishing a closed season of five 

 months (November to March), when all of 

 the islands were worked each year. Too much 

 dependence, however, can be placed upon this 



measure. With a proper system of rotation 

 and closure of islands for years, the closed 

 season for the summer months becomes a 

 matter of secondary importance. There is no 

 season of the year when the birds may be dis- 

 turbed without harm. In the middle of June 

 last year there were numbers of birds in the 

 Chinchas Islands which were still being fed 

 from mouth to mouth by their parents. At 

 the same time the process of pairing for the 

 next season had begun and by July 29 hun- 

 dreds of eggs had been laid, as the beginning 

 of the next season's brood of young. During 

 what months, then, could work have been 

 conducted on this island without injurious 

 molestation of the birds? The fostering of 

 the birds will be accomplished only by leaving 

 them unmolested for the entire year and for 

 several years in succession. If an island is 

 to be opened it is not of vital importance 

 whether it be opened in April or in June. 



I believe it to be more harmful to open too 

 late than too early. To illustrate this, let us 

 make an imaginary ease of the south island 

 of the Chinchas. If it be possible to do with- 

 out this island, it will be most beneficial if 

 the island may remain closed until April or 

 May, 1909. Suppose that it is now decided 

 to keep this island closed, and that later, about 

 August, it is found that the supply of guano 

 from other sources is inadequate and the de- 

 mands of national agriculture are such that 

 it is deemed necessary to extract guano from 

 this island. The island is opened early in 

 August — with what result ? Just at the stage 

 when the majority of the birds have mated 

 for the season, when a large number of eggs 

 are newly laid, and when the females are 

 laden with eggs ready to be deposited in the 

 prepared nests — just at this critical time, the 

 birds are frightened from the island. The 

 new-laid eggs are abandoned, and other eggs 

 laid during this time of change may be lost 

 as the birds chance to stop upon the neighbor- 

 ing rocks or islands. For the change of home 

 is not accomplished in a day ; it requires many 

 days or weeks for the birds to realize that the 

 old home must be abandoned, to settle them- 

 selves in a new place, and to recover from the 

 demoralization attending the forced change. 



