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Along
with its world-class showcase of biology, evolution,
geology, and astronomy, Hawaii has also gained the
regrettable reputation as the endangered species
capital of the world. Conservationists consider
Hawaii to be at the forefront of the global extinction
crisis. A short trip around the Big Island will
take you past habitats of some of the rarest plants
and animals on earth. Predation, disease, invasive
species, and deforestation are all continuing threats
to the native Hawaii biota. Hawaii has turned into
one of the best places to study extinction process
and Conservation Biology. Because of Hawaii’s isolation and unique
evolution, the species that evolved here were poorly
equipped to compete and defend against the thousands
of species brought here by man over the last few
hundred years.
Rats
were first brought to Hawaii by the Polynesians
and later by Westerners. They have come to play
a disastrous role in native ecosystems. They impact
both native birds and endemic vegetation by predation.
Native
Hawaiian plants have few defenses against hoofed
browsers, grazers or rooters. Cattle, while an important economic component
of modern Hawaii continue to impact native plant
habitat, as do sheep, goats, and deer.
Wild
Pigs can devastate native forest destroying native
plants by their extensive “rooting”. Compare the
full forest growth on the left side of the barbwire
fence with the damage to the forest floor created
by pig activity on the right side of the fence.
Though
not as obvious, the impact of wild pigs on native
birds is tremendous. By making wallows in the forest
floor and by eating the tuberous centers of tree
ferns pigs create pools of stagnant water throughout
the rainforest. Mosquitoes, not native to Hawaii,
breed within these pools. The mosquitoes then spread
avian blood diseases such as pox and malaria by
biting the birds such as the young honeycreeper,
Apapane, in the photo below. Lacking genetic defenses
against these diseases the native birds weaken and
die. Research has drawn direct correlations between
the number of pigs in a forest and the level of
disease in the forest bird population.
Invasive
species such as the Blackberry are able to compete
and replace native flora. The island has literally
thousands of acres of once diverse native forest
overgrown with species such as Christmasberry, Guava
and numerous exotic grasses. Millions of dollars
are spent each year to combat, eradicate, and prevent
new plant and animal introductions into the islands.
Add
to these threats the continuing deforestation by
logging, urban development, and fire. The state of Hawaii’s native habitat
is in dire shape.
From 1970 to 1995 Hawaii’s population grew
61%. At
the same time, the land in forest decreased by 52%.
In
many instances species of plants and birds have
been reduced in population to a single or a few
individuals. Shown below is a native Hibiscus once
near extinction. Its beautiful blossom led to its
cultivation for landscaping. One wild population
was found on the island with less than a handful
of individuals. The population was fenced off from
animals and today there are dozens of plants in
the enclosure. The battle to save the endemic Hawaii
is being fought from many angles. With education
and awareness we can slow the loss of our native
Hawaii.
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