In no area in the world have native birds fared more poorly than in
Hawaii during the past century. The causes of the decimation of numbers
and species are probably multiple; certainly no single factor alone can
be cited. Possibly some of the most specialized forms had already begun
a decline in numbers before the arrival of Western man. It is unlikely
that feather gathering for leis as practiced by the ancient Hawaiians
had much to do with the decline. On the other hand, the clearing of
land, which began early in the 1800’s, must have had a devastating
effect on those birds that had become so specialized—they simply were
forced into new environments and were unable to adapt. The introduction
of new plants, especially grasses, and the establishment of feral
mammals (goats, sheep, and pigs), and insects played a subtle but
possibly even more destructive role in altering the over-all
environment.
Introduction of exotic birds must have been the final blow to many of
the native species. Unfortunately until recently there was no adequate
control over importing and releasing new birds in Hawaii. The delicate
balance of nature was rudely upset when some of the more aggressive
exotic birds were released indiscriminately on the islands. Exotic birds
such as the white-eye became so plentiful that direct competition for
food with the natives must have occurred. Furthermore, bird diseases new
to Hawaii, such as avian malaria (probably brought to the islands with
some introduced bird from the Orient), would have been a great killer.
With a few exceptions, however, it does seem that the remaining Hawaiian
native birds are now holding their own.