460 BIRDS OF THE GALAPAGOS ARCHIPELAGO— RIDGWAY. vol.xix. 



phases; in fact, many are known only from a few specimens in female 

 or immature dress. No observations liave been made " upon tlie atti- 

 tu«le the different species of Geoxpiui^ maintain toward one another 

 tending to show how far the differences observable, or thought to be 

 obsorvabh'. in dried specimens indicate the actual grouping in species 

 of living individuals."- Tlic anomaly of individuals adult as to plum- 

 age but with bills suggesting immaturity, and of others which show 

 exactly the reverse, remains to be explained; and there are other (pics- 

 tions which only protracted held studies by a competent investigator 

 can decide. Until all these present mysteries are solved, theories and 

 generalizations are necessarily futile. 



An effort to obtain the unknown data should not be too long delayed. 

 As Mr. Salvin truly says : ^ 



The advent of in:in to islands previonsly uninhabited is of the highest importance 

 to the existence of the indigenous fauna and tiora. ... It may safely be said 

 that tliese islands have bt'on visited from time to time for more than three centuries, 

 so that duriuji this jieriod man's intlucnce has been more or less felt by the indij^e- 

 nous products. This inlliieuce is manifested in all similar cases by the capture and 

 destruction for food of all animals fit to eat ; and in order to establish a supply of fresh 

 food for vessels in need of it, pigs and goats are usually turned out in such ]>laces. 

 The vegetation chietly suHera from the latter, while upon such animals as easily fall 

 a prey to the former theeHect is generally very speedily marked. Cats often abound 

 on such islands, and rats and mice escape 1 from some ves.sel calling for wood and 

 water. All these prove enemies to some previously unmolested species. Fires, too, 

 either wantonly or carelessly lighted, sometimes work great destruction. 



So far as the birds of the Galapagos Islands are concerned the effect produced by 

 the visits of ships, chieHy whalers, and the attempts at colonization do not seem to 

 have lessened their numbers at present. .Judging i'rom the records of the various 

 authors 1 have been able to consult, 1 should say that birds are about as numerous 

 now as they were two centuries ago. How long this will remain so is uncertain. 

 All the species are able to <ly, and thus protect themselves from the wild pigs and 

 cats, their most oi)en enemies. The effect upon the vegetation produced by the 

 cattle, horses, and goats may eventually lessen the number of birds, if not erad- 

 icate some of the species; but as so many of the species resort to the seashore for 

 food, the destruction of the vegetation will be of less importance than it otherwise 

 might. With a lessened vegetation, however, less rain would fall, and in consequence 

 the increased difficulty in procuring water will operate against the birds maintaining 

 their numbers. On the whole, it seems evident that the avifauna of these singular 

 islands is menaced not only by open enemies, but also is in danger of serious injury 

 should any further disturbances of the ((uiditious of life supervene. 



Since the preceding paragraphs were published it has been ascer- 

 tained that at least one of the indigenous birds of the Galapagos has 

 apparently become extinct, the larger mockingbird of Charles Island 

 {Xesomimus trij'asciati(.s) having been fruitlessly searched for by the 

 naturalists of the Albatross and by Messrs. Baur and Adams. Others 

 appear to have become extinct on the islands where they were origi 



'Also those of Camnrhiinchiis, of which also there are sometimes several forms found 

 on a single island. 



^Salvin, Trans. Zool. Soe. Lond., IX, I't. ix, 1876. p. 469. 

 ^Ibid, p. 455. 



