188 



AVIFAUNA OF LAYSAN, ETC. 



local and rare, and seems to be confined to the highest forest on Haleakala, at an elevation 

 of some 5000 feet above sea-level. Being very tame and apparently unwilling to fly far, 

 1 had on several occasions excellent opportunities to learn something of its habits, and 

 especially of the use of its curiously formed and exceedingly powerful beak. The bird has 

 an evident predilection for the koa trees (Acacia falcata\ and it is from these that it mainly 

 gets its food. This consists of the larvae of a highly peculiar endemic genns of Longicorn 

 beetles (Clytarlus), of which there are in the islands a considerable number of species, nearly 

 all of them attached to the different species of acacias. The larger ones usually burrow in 

 the main trunks, the smaller in the limbs and twigs above. It is on the larva} of the latter 

 that Pseudonestor feeds, and in procuring them has developed the large hooked beak, the 

 powerful jaw-muscles, and heavy skull, which constitute its chief peculiarities. It may be 

 observed that the twigs in which the Qlytarli have their burrows are not generally rotten, 

 but dry, and of excessive hardness, often surpassing in this respect the still living and 

 unaffected branches. The bird is sluggish, in its movements parrot-like in the extreme, 

 especially in the varied hanging attitudes that it assumes, while the similarity is still further 

 increased by the shape of its beak. 



"Those that I saw in the act of feeding were generally clinging to the under sides of the 

 thin branches or twigs, the head raised above the upper surface; the point of the curved 

 maxilla was thrust into the burrow, the short mandible opposed thereto, and pressed against 

 the side or under surface of the twig, and the burrow opened out by sheer strength. All 

 that I shot contained larvae of these beetles, as many as 20 or 30 being found in the 

 stomach of a single bird. No less than four species of Clytarlus were found on the acacias 

 in the actual haunts of Pscndoncstor ; these, too, like the bird, are all of species peculiar to 

 the same island. When alarmed the bird gave utterance to a short squeakin°* cry ■ it has 

 besides a decided song, which reminded me much of that of the green TUmationc. Once 

 I heard it sing on the wing as it crossed a gulch. 



"The unpleasant scent of Pseudonestor, like that of many Drepanididaj and other 

 Hawaiian Finches, is very noticeable. 



"Looking at the Hawaiian Finches as a whole, it may be noticed how wonderfully the 

 structure of each of them has been specially developed according to the nature of its own 

 particular and most important article of food. Thus Pscudonestor, as above mentioned, has 

 an enormous development of beak and skull and muscles attached thereto, for splitting the 

 koa twigs; Chloridops has a huge beak and still heavier skull and muscles, which enable it 

 to crack the hard nuts of the bastard sandal (Myoporum) ; then there is the strong cutting- 

 beak of Bhodacanthis for dividing up the koa beans, and a large development of the 

 abdominal portion of the body, in accordance with the large fragments that it swallows; the 

 shorter bill of Toxoides, which deftly cuts oil' the bean of the mamane acacia (Sophora), 

 while the bird holding it in position with its foot opens the pod and devours the seeds ; and, 

 lastly, the hooked bill of Psittacirostra, with which it digs out the separate components of 

 the ileshy inflorescence of the 'icie' {Freycinetia), for this is certainly its natural food, though 

 it has now come to teed largely on various introduced fruits— guavas, oranges, and the like. 

 Besides their special foods all the Einches vary their diet at times with the larva' of 

 Lepidoptera." 



These notes were of course written before it had been recognized that Pseudonestor 

 was a Drepanine and not a Fringilline bird. 



