Posted on 02/23/2009 12:27:51 PM PST by nickcarraway
Conservation authorities have started to fight back against nonnative lizards that are slowly but surely destroying the indigenous insect population on the Ogasawara island chain.
The islands, which lie 1,000 kilometers south of Tokyo, are known as the "Galapagos Islands of the Orient" because of the many species that can be found there and nowhere else. Even in winter, the temperature on the island chain exceeds 20 degrees in the daytime.
The lizards--green anoles native to the southeastern United States--seemed to have gained the upper hand, raising fears that endemic insect species could soon become extinct.
To combat the destruction of native insects, the Environment Ministry set up a sanctuary on Hahajima, one of the two main islands, last year. After protecting a part of a forest with a lizard-proof fence, researchers caught and removed about 1,000 nonendemic lizards.
The sanctuary was created inside a national park in March at a cost of 88 million yen. Government conservationists encircled about 2 hectares of forest in central Hahajima island with a 1-meter-high fence. Its total length is about 1 kilometer.
"The fence leans outward a little so the anoles can't climb it," said Fumiko Shibazaki, 43, an Environment Ministry employee stationed on the island.
Green anoles are arboreal lizards that grow to about 15 centimeters long and are frequently kept as pets.
The reptile was brought to the other main island--Chichijima--in the 1960s and arrived on Hahajima in the 1980s. The creatures are believed to have made the journey aboard freighters. Some may have been brought to the Ogasawaras as pets.
With few predators, the green anoles flourished. It is estimated that there are about 6 million green anoles on Chichijima and Hahajima.
About 1,300 insect species share the islands with the lizards. Of these, 30 percent are native and can't be found elsewhere.
However, the green anoles make no distinction, eating the native and nonnative bugs with equal gusto.
Among endemic insects whose numbers have been drastically reduced are the Ogasawara-shijimi butterfly and the Ogasawara-zemi cicada. Both are designated by the government as natural treasures.
Green anoles are now causing headaches for Ogasawara villagers, who hope to see their islands chosen as a UNESCO World Natural Heritage site.
"On Chichijima island, there used to be five kinds of native dragonflies. But all of them had become extinct by the latter half of the 1990s. The main culprits were green anoles," said Haruki Karube, a senior researcher at the Kanagawa Prefectural Museum of Natural History.
"Ideally, we would completely eliminate anoles on Chichijima and Hahajima islands. However, to do so would require an enormous amount of money and labor. And by the time we finished, native insects would be even further reduced," said Mitsuhiko Toda of the Japan Wildlife Research Center in Tokyo. The center has been commissioned by the Environment Ministry to study the issue.
Instead of declaring all-out war on the green anoles, the ministry opted for a more realistic strategy.
Inside the fenced-in sanctuary on Hahajima island, workers have set 5,000 anole traps. Made of plastic pipe, the traps are tied to tree trunks. Like roach traps, if an anole tries to crawl through a trap, its feet get stuck in adhesive lining of the pipe's walls.
Workers inspect the traps about once every three days. Last year, Takao Yamada, 62, says he snared up to 70 green anoles at a time. But lizard captures have dropped dramatically.
"I got only one green anole today," he said. "The small number is partly due to the fact that it's winter and the lizards are sluggish. But certainly, the number of green anoles within the fence is decreasing."
About 1,000 similar lizard traps have been placed around a port on Chichijima island. In addition, the same type of traps were set up last fall within a 2-hectare fenced grassy area on southern Hahajima island
"If the lizard eradication projects in the fenced-in areas work, we will expand those areas," said Ryuji Nakayama, a senior nature conservation ranger for the ministry.
A citizens group, Ogasawara-shijimi no Kai, plans to survey insects in the forest in central Hahajima to see what effect the fences have had.
Kazuhiko Uemura, chairman of the group, said: "The number of Ogasawara-shijimi butterflies has decreased so dramatically that only one or two may be seen during a daylong hike. We want to leave the island's natural resources to the next generation."
They need to have "Green Anole" as the theme ingredient on Iron Chef.
That would solve the problem ...
Payback for kudzu?
The Japanese eat kudzu ...
In this case, it would seem to make more sense to capture the native insects...breed them in isolated areas, then let the lizards eat themselves into extiction..then repopulate the islands with insects..
yeah especially those cute little Malaria, Dengue and Yellow fever mosquitoes.
criminal.
When it says “the temperature exceeds 20 degrees” they mean 68 real (Fahrenheit) degrees.
Chichijima? That’s where George HW Bush almost ended up on the dinner menu when he was shot down during WWII.
Dang Lizards are taking over!
Offer a 100 yen/each reward for catching them. School boys would welcome a way to make money.
Beautiful little animals. I used to have one when I was around 8 - spent the first week probably stressing the little guy with endless handling as I placed him on different colored surfaces to watch his skin change shade, but after I got bored with it my mom made me feed him and clean his aquarium regularly, and he actually lived for about 3 years in relative peace and quiet.
I sit on the porch steps a lot in summer, they will sit and watch for a while, and get closer. The one in the pic actually waited for me to smack yellow flies, and then he would eat them out of my fingers. He would drop from the top of the screen door and land on my shoulders, and give me a “let’s eat” look. I don’t know how you could measure their intelligence but they aren’t totally stupid.
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