Fast-growing plant threat to habitat of Lanai petrels

LANAIHALE – For decades, researchers thought the last major colony of Hawaiian petrels in the islands nested on the slopes of Haleakala.

Then about a decade ago, wildlife biologist Fern Duvall was working on Lanai when he noticed a petrel burrow. He kept the discovery in the back of his mind for six years, until he was able to return to the island to follow up.

“We just went to see if we could detect any birds at all,” Duvall said. “It turned out that not only could we find birds – there were thousands of them. We think it’s the second-largest known concentration of Hawaiian petrels.”

Duvall suspects that the birds have thrived on the slopes of Lanaihale – Lanai’s only large mountain – because the island has so little development and few urban lights.

The night-flying birds depend on starlight to navigate and often become disoriented and crash in urbanized areas.

“Lanai disappears after dark,” Duvall said. “We think the birds cue in on this absolute darkness.”

The qualities that attracted the birds to Lanai also helped them go unnoticed for decades – and still makes it tough to get an accurate estimate of the population, said researcher Jay Penniman.

Tree plan introduces bugs

Brazilian insect could slow growth of nonnative strawberry guava tree

The state is once again seeking approval to release a Brazilian scale insect into Hawaii forests to control the spread of the popular but environmentally needy strawberry guava tree.

    Acres already densely infested
    Acres of native forest areas that could become densely infested at current rates of growth
    Acres of native forest not yet threatened

The state Department of Agriculture is expected to release an environmental assessment today, and the public will have 30 days to weigh in on the controversial bio-control initiative, which has been hotly debated for the past two years.

The assessment notes that the nonnative strawberry guava, which does not have a natural predator in Hawaii, crowds out native plants and animals and reduces the amount of water in soil, streams and groundwater systems by as much as 50 percent during dry periods. According to information cited in the study, strawberry guava also threatens Hawaiian archaeological sites and supports the proliferation of fruit flies, which can damage commercial produce.

"At its current trajectory, strawberry guava will take over all native plants statewide unless something is done," said Christy Martin, public information officer for the Coordinating Group on Alien Pest Species, which coordinates alien pest responses by the state departments of Agriculture, Health, Land and Natural Resources and other agencies.