By Jan TenBruggencate
Advertiser Columnist

The kakerori of Takitumu has one of the most impressive success stories in Pacific conservation.

This endangered Cook Islands flycatcher in 1989 had dropped to 29 birds on its home island of Rarotonga, the capital island of the Cooks. That made it one of the 10 rarest birds in the world. The Cook Islands lie directly south of Hawai'i, and Rarotonga is about as far south as Kaua'i is north of the Equator. The environments are not identical, but they are similar.

Scientists concluded that rats were the major threat facing the birds, and in 1988 they launched a rat control program during the nesting season. That program targets both black rats and Norwegian rats. Rat bait is placed inside plastic tubes so birds and other wildlife won't get to it.

During the next 16 years, the population of the kakerori increased tenfold — enough for wildlife folks to transplanted 30 birds to the neighboring island of Atiu, where they form a backup population in case something happens to the Rarotonga birds.

The kakerori, which is orange as a youngster and gray as an adult, has a cousin in the Hawaiian Islands, the 'elepaio. Both are monarch flycatchers. Both are attractive, agile birds a little bigger than a sparrow.

The O'ahu 'elepaio's population has plummeted during the past two decades. Researcher Eric VanderWerf, who conducted much of the crucial research into the O'ahu 'elepaio, was able to document that rats are a primary problem here, as they were for the kakerori.

Cook Islands naturalist Ian Karika said the same behavior was hitting the kakerori before the rat control began. Today, the kakerori population continues to grow, but birds that spill over from rat control areas into adjacent lands tend not to establish successful colonies, because the rats still attack them there, he said.

The kakerori conservation program is managed not by government, but by private landowners — representatives of three families that own three adjacent valleys on the south side of Rarotonga. They formed the Takitumu Conservation Area in 1996.

They offer tours for a fee, control weeds, control rats during the breeding season, and invite student groups to the site for educational programs and work parties. There are some government grants involved in the operations, but much of the cost of the program comes from tour fees.

If you have an issue, question or concern about the Hawai'i environment, drop a note to Jan TenBruggencate, The Advertiser's Kaua'i Bureau chief and science and environment writer. Reach him at jant@honoluluadvertiser.com, (808) 245-3074 or P.O. Box 524, Lihu'e, HI 96766.