Hawaii - Jeff Campbell [46]
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Even visiting Midway might not provide as intimate a portrait of the Northwestern Hawaiian Islands as Archipelago by David Liittschwager and Susan Middleton. Island denizens pose for close-ups while the authors share tales of their adventures.
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So-called alien or nonnative species refer to those introduced after late-18th-century Western contact. They include relatively benign crops and ornamental plants, as well as notoriously invasive and devastating pests – such as cattle, ants, fountaingrass and ivy gourd. Delicately balanced ecosystems have been decimated by even a single invader (for instance, rabbits on Laysan Island, Click here). Today, over two-thirds of known birds, over half of known snails and about 10% of endemic plant species are extinct.
Progress reports can make depressing reading, but success stories do occur, proving that with sufficient effort and the right conditions, nature can rehabilitate itself. In many ways, the Hawaiian Islands are a unique laboratory in the global effort to discover ‘sustainable’ methods of conservation – preserving diversity, and by extension our own skins.
Animals
Prior to the arrival of humans, the islands were home primarily to birds, snails, insects and spiders.
BIRDS
Many of Hawaii’s birds are spectacular examples of adaptive radiation. For instance, all 57 species of endemic Hawaiian honeycreepers most likely evolved from a single finch ancestor. Today, over half of those bright-colored species – along with two-thirds of all native Hawaiian birds – are extinct, the victims of more aggressive, nonnative birds, predatory feral animals (like mongooses) and infectious avian diseases against which they have no immunity (see the boxed text, below). Over 30 bird species remain endangered.
The endangered nene, Hawaii’s state bird, is a long-lost cousin of the Canada goose. Nene usually nest in sparse vegetation on rugged lava flows, to which their feet adapted by losing most of their webbing. While eight other species of Hawaiian geese (now extinct) became flightless, nene remain strong flyers. Nene once numbered as many as 25,000 on all the islands, but by the 1950s there were only 30 left. Intensive breeding programs have raised their numbers to around 2000 on Hawai′i, Maui, Kaua′i and Moloka‘i.
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The Hawaii Audubon Society (www.hawaiiaudubon.com) publishes the best bird guide and its website has bird-viewing suggestions for each island, and a good image gallery.
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The only hawk native to Hawaii, the ′io was a symbol of royalty and often an ′aumakua (protective deity). They breed only on the Big Island; their numbers have held steady at over 3000 for the last decade, and in 2008 the ′io was proposed for delisting from the endangered species list.
LAND MAMMALS
In modern times, nearly every animal introduction – whether rabbits, goats, sheep, pigs or horses – has led to devastating environmental damage. Some, like Maui axis deer and Big Island cattle, were sent as ‘gifts’ to Hawaiian kings that spun off out-of-control feral populations. The ubiquitous mongoose was originally introduced to control sugarcane rats, but have become a worse plague than the rats. Today, feral animals are the most destructive force in Hawaii, and getting rid of them is central to reestablishing native landscapes and saving certain endangered species.
The endangered ′ope′ape′a (Hawaiian hoary bat), one of Hawaii’s two endemic mammals, has reddish-gray, white-tinged fur, making it appear ‘hoary’ (grayed by age). With a foot-wide wingspan, these tree-dwellers exist predominantly around forests on the leeward sides of the Big Island, Maui and Kaua′i.
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OF PIGS, MOSQUITOES & HONEYCREEPERS
How delicately interdependent are Hawaiian ecosystems?