Rare Hawai‘i: It wasn’t meant to be a barnyard

Millions of years of evolution in isolation. Thousands of plant and animal species found nowhere else in the world. Introduced pigs, goats, deer and sheep roaming freely over public lands. More than 265 extinctions and counting.

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Op-Ed Feb. 19 2009

Costs (Residents pay)

Policy and Control Outside Hawaii (Hawaii Lags)

Problem Overview

Newspaper and Magazine Articles

A Look at What We're Losing


Feral Pigs and the Death of Hawaii's Native Birds

Native Hawaiians Speak Out




Scientific Reference List

Don Chapman describes being in a Hawaiian rainforest

Edward O. Wilson on Biodiversity

Report about invasive species in Hawaii available online From The Hawaii State Legislative Reference Bureau (pdf file)

Environmental Valuation and the Hawaiian Economy takes a look at the financial and social costs of losing native Hawai`i.

USGS's Hawaii and the Pacific Islands page. Scroll down a few pages and look for Feral Pigs, followed by Feral Goats and so on.

Link to Nature out of place, Chapter 1 (pdf file)

Controlling Feral Animals (see how they do it Down Under)

Other Environmental Issues

Speak Out!

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"Scientists have come up with a new explanation for what made the Spanish flu the biggest killer of the 20th century. The deadly influenza did not jump from birds into humans, they argue, but rather was the unfortunate result of an unprecedented recombination of pig and human flu genes." New Scientist magazine article, research first reported in Science (vol 293, p 1842).

This is why professors at UH's Department of Tropical Medicine are concerned about the mix of feral chickens and feral pigs throughout Hawai'i's natural areas.

“To the Hawaiian rainforest, the pig is death: consuming ground-cover plants, churning the rich ground into foul muck, the forest dies from the bottom upward and the rains wash the soil away to smother coral reefs with silt.” From Hawaii: The Islands of Life, by Gavan Daws
Photo courtesy of Sandra von Riper and Charles von Riper III
USFWS: "Destruction of habitat by pigs, goats, and other introduced ungulates has had devastating impacts on all native habitats in Hawaii. Feral pigs have had direct impacts on native forest birds by destroying understory vegetation, spreading alien weeds, and creating mosquito breeding areas from their rooting and wallowing in wet forests. For birds such as the Poouli, which specialize in foraging in the understory, disturbance by pigs has been a major threat." [Update: The po'ouli was lost to extinction in 2004.]

Australia’s Federal Environment Minister has recognized feral pigs under Commonwealth environment legislation as a key threat to native Australian wildlife. Hawaii needs the same official recognition of the problem, followed by legislative action and funding. Pigs may be appreciated without allowing them to destroy natural resources.

Links to online information about feral pigs.

Invasive Species

Introduced game mammals--pigs, goats, deer, and sheep--are all invasive species in Hawai'i. They also help invasive plants spread into new areas.

The photo at right demonstrates how pigs and other introduced game animals help spread alien plants in the Hawaiian environment. Feral pigs range on the right side of the fence, where an alien plant species, fireweed, has taken over. The soil disturbance caused by rooting pigs is a boon to highly competitive alien species, helping them gain a foothold from which to expand their range into native ecosystems. Pig activity (see wallow below) also increases mud, silt and erosion in the watershed.

Plants compete for living space just as animals do. With introduced grazing and rooting animals in the mix, the Hawaiian plants are at a disadvantage because they evolved without the presence of such animals. For more information on invasive species in Hawaii, visit www.hear.org.

Free-roaming game mammals change the Hawaiian landscape

"The Olomao is particularly noted for its beautiful singing in the forest and sits on the tops of trees, singing loudly at dawn and dusk. With its small numbers, however, few of these bird songs are still sung today. Olomao has become a victim of avian malaria, which is transmitted by mosquitoes. The mosquitoes hatch in standing water left in wallows dug by wild pigs, which are considered a nuisance to the preservation of Molokais endangered species." Islander magazine, 1997. More information about mosquitoes and feral pigs.

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