the study of the Dreyanididsd. 579 



13. Other Causes of Extinction of Hawaiian Birds. 



Although the destruction of the lowest belt of forest over 

 by far the greater part of the islands has, in my opinion, 

 been a most efficient cause of the destruction of native birds, 

 many other causes have been at work, all of which are due 

 to the occupation of the islands by white men. Such causes 

 are the introduction of cattle and goats, which have extirpated 

 or very much thinned out great portions of the native forest; 

 of cats, foreign rats, and the mongoose (which are direct 

 enemies), as well as of the Mynali, Avhicli not only attacks 

 and drives away other birds, but also devours their eggs and 

 young. The disturbance caused by the entrance of cattle 

 into untrodden forest appears to be alone sufficient to scare 

 away some species. Thus, on a very rough lava-flow on 

 Hawaii in 1892, the "Oo" {Aa^nlocercus nobilis) was very 

 numerous, and as many as a dozen of these birds could be 

 seen in a single tree, making, with hosts of the scarlet 

 '^liwi,'^ the crimson '^ Apapane,'^ and other birds, a picture 

 never to be forgotten. A few years afterwards, on revisiting 

 the spot at the same season, although the trees were, as 

 before, one mass of flowers, hardly a single "^ Oo " was to be 

 seen. The only noticeable change was that cattle were 

 wandering over the flow and beginning to destroy the under- 

 brush, just as they had already reduced the formerly dense 

 forest bordering the flow to the condition of open park-land. 



Cats were introduced into the Hawaiian Islands at a very 

 early time, and, no doubt, increased, excessively, while, as 

 their owners moved from place to place, many strayed into the 

 woods and began to feed on mice, rats, and birds. They are 

 now found wild on all the islands, apparently only the wettest 

 portions of the forest being free from them. On Lanai, in 

 walking up a single ravine, I counted the remains of no 

 less than twenty-two native birds killed by cats, and these 

 must all have been destroyed within two days, as previously 

 the whole gulch had been washed out by a heavy flood. 

 Two cats were actually shot on this occasion as they were 

 devouring their prey, and several others seen, but, owing to 

 the fact that they are extremely shy and mostly nocturnal 



