Page 67 - Environment: The Science Behind the Stories

CeNtRal CasE stUdy

saving Hawaii’s Native Forest Birds

KAUA`I
O`AHU
MAUI Hakalau “When an entire island avifauna . . . is dev-
Forest NWR
astated almost overnight because of human
meddling, it is, quite simply, a tragedy.”
Pacific
Ocean — H. douglas Pratt, ornithologist and expert on
HAWAI`I
Hawaiian birds
Mauna Kea
Hilo “To keep every cog and wheel is the first
precaution of intelligent tinkering.”
HAWAI`I
—aldo Leopold

Mauna Loa

Jack Jeffrey stopped in his tracks. “I hear one!” he said. “Over mating preferences, diets, and bill shapes. Bills in some species
there in those trees!” became short and straight, allowing birds to glean insects from
Jeffrey quickly led his group of ecotourists through a leaf surfaces. In other species, bills became long and down-
misty woodland of ferns, grasses, koa trees, and red-flowering curved, enabling birds to probe into flowers to sip nectar. The
‘o¯ hi‘a-lehua trees toward an emphatic chirping sound that car- bills of still other species became thick and strong for cracking
ried farther than the other bird songs in the forest. At last they seeds. Some bills became highly specialized: The aki uses the
spotted the bird—an ‘akiapo¯la¯ ‘au, one of fewer than 1500 of short, straight lower half of its bill to peck, woodpecker-style,
its kind left alive in the world. into dead twigs and branches of koa trees to find beetle grubs,
The ‘akiapo¯la¯‘au (or “aki” for short) is a sparrow-sized and then uses the long, downcurved upper half to reach in and
wonder of nature—one of many exquisite birds that evolved extract the grubs.
on the Hawaiian Islands and exists only here. For millions of Hawaii’s honeycreepers thrived for several million years in
years, this chain of islands in the middle of the Pacific Ocean the island’s forests, amid a unique community of plants. The
has acted as a cradle of evolution, generating an abundance stately ‘o¯ hi‘a, a slow-growing tree that can live for 2000 years,
of new and unique species. Yet in recent years, many of these spreads twisting gnarled limbs covered with moss and lichens
species have gone from cradle to grave. Half of Hawaii’s native through the misty air, and offers up bright red flowers that provide
bird species (70 of 140) have gone extinct in recent times, and nectar and pollen to birds and insects. The koa thrives here too,
the percentage of species that teeter on the brink of extinction a fast-growing acacia tree with twigs that the aki snaps off in its
here today is higher than anywhere else in the world. search for grubs. A multitude of shrubs, herbs, and vines found
The aki is one of 30 species of endangered birds remaining nowhere else in the world used to fill out the forest understory.
on the Hawaiian Islands. It is a type of Hawaiian honeycreeper, Today native Hawaiian forests are under siege. The crisis
a group of birds numbering 18 living species (and at least 38 began 750 or more years ago when Polynesian settlers col-
species recently extinct), all of which originated from individu- onized the islands, cutting down trees and introducing non-
als of a single ancestral species that reached Hawai‘i several native animals. Europeans arrived in the 1800s and did more
million years ago. As new volcanic islands emerged from the of the same. Pigs, goats, and cattle ate their way through the
ocean and then eroded away, and as forests expanded and native plants, transforming lush forests into ragged grasslands.
contracted over the millennia, populations were split many Rats, cats, dogs, and mongooses destroyed the eggs and
times, and new honeycreeper species evolved. young of native ground-nesting birds. Foreign plants from Asia,
As honeycreeper species diverged from one another, they Europe, and America, whose seeds accompanied the people
66 evolved different colors, sizes, body shapes, feeding behaviors, and animals, spread across the altered landscape.

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