Hawaii - Jeff Campbell [47]
Most likely the descendants of domestic pigs brought by early European explorers, feral pigs in fact cause such complete and widespread devastation to native wet forests that Mardy Lane, a ranger at Hawai′i Volcanoes National Park, says, ‘Pigs are public enemy number one.’ Despite the park’s ongoing eradication and fencing program, thousands still live within its boundaries. Asked if feral pigs will ever be eliminated, Lane shrugs in frustration: ‘I don’t know.’
Outside of federal lands, eradication efforts are few, and one estimate is that there may be one feral pig for every 20 state residents.
Pigs trample and kill native fauna, destroy the forest understory and spread far and wide the seeds of invasive plants. They love native tree-fern stems, knocking them over and eating the plants’ tender insides and the bowl-like cavities left behind catch rainwater and create ideal breeding pools for mosquitoes.
These common mosquitoes – presumed to have arrived in water casks in 1826 – pick up avian malaria and avian pox (also introduced from the European continent) and spread it to native birds, particularly honeycreepers, who lost their natural immunity to these diseases as they evolved.
Even in wet forests, water typically drains into the porous volcanic soil, and mosquitoes have trouble breeding. It’s a simple equation: no feral pigs, far fewer mosquitoes, far less avian malaria and far more honeycreepers.
Lane is not alone in her feelings. As the eminent historian Gavan Daws wrote: ‘To the Hawaiian forest, the pig is death.’
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MARINE MAMMALS
Up to 10,000 migrating North Pacific humpback whales come to Hawaiian waters for calving each winter (January through March), and whale watching (p80) is a major highlight. The fifth largest of the great whales, the endangered humpback can reach lengths of 45ft and weigh up to 45 tons. Other whales (such as rarely seen blue and fin whales) migrate through, and Hawaii is home to a number of dolphins, the most notable of which is the intelligent spinner dolphin, so named for its acrobatic leaps from the water.
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No one knows why spinner dolphins spin, but one likely explanation is that they are simply having fun, and this friendly play enhances group cohesion.
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Hawaii’s other endemic mammal, the Hawaiian monk seal, breeds primarily in the remote Northwestern Hawaiian Islands. Adults are 7ft and 600lb of tough, some with the scars to prove they can withstand tiger shark attacks. Once nearly driven to extinction, monk seals number around 1300, and they have recently been appearing more regularly on Waikiki and Big Island beaches.
FISH
Hawaii’s coral reefs constitute 84% of all US reefs, and they are home to over 500 species, of which 30% are endemic. However, the contrast between the variety and numbers of fish in the main Hawaiian Islands and the protected Northwestern Hawaiian Islands (Click here) is stunning. For instance, the weight of fish per acre in the Northwestern Hawaiian Islands is 2000lb, but it’s 600lb in the main islands, and only 250lb on O′ahu; meanwhile, predators like sharks, jacks and parrotfish are 15 times as numerous in the Northwestern Hawaiian Islands’ shallow reefs, where they dominate life.
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Hawaiian monk seals migrated to the Hawaiian islands over 10 million years ago, evolving into a unique species that’s been called a ‘living fossil.’
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That said, protected main-island coral reefs – such as at Hanauma Bay (Click here) and Kealakekua Bay (Click here) – teem with vast numbers of tropical fish: bright yellow tangs, striped butterflyfish and moorish idols, silver needlefish, and gape-mouthed moray eels. Neon-colored wrasse have more species (43) than any other Hawaiian reef fish. The saucy wrasse mate daily and change sex (and color) as they mature; most start female and become male.
Plants
Mile for mile, Hawaii has the highest concentration