Mice pestering Maui

By Christie Wilson
Neighbor Island Editor

Mice are on the march again on Maui.

The skitterskatter of little feet is down by four as Kai Mahuna pulls a dead mouse from a bait trap in Maui Meadows. Christie Wilson • The Honolulu Advertiser

At the Maui Research & Technology Center bordering the mauka scrublands in Kihei, mice have become a common nuisance in the past month, said program assistant Laura Bertoldi.

"One of our people felt something tickling her foot and she thought it was the cord from her computer. She looked down and there was a mouse right on her foot," Bertoldi said.

Bertoldi has found droppings at her work station and one bold rodent climbed up the computer cords and hopped onto her desk in broad daylight.

"There's no shame with these guys. They're right there. They don't have any fear," she said. "They're cute as anything, but it's definitely out of control."

Maui has experienced periodic booms in its mouse population, particularly following periods of drought.

When winter rains nourish the vast open spaces between the uplands and the coastal areas, mice thrive on abundant grass seeds and can reproduce at a rate of six to 10 litters a year.

When drier summer weather diminishes the food supply, the creatures begin foraging downslope toward populated areas.

The last major infestation occurred in 1993, but the worst in recent memory is what pest control officials and others refer to as "The Great Mouse Invasion" of the 1970s, when the rodents proliferated to the point where they reportedly swarmed hotel lobbies.

After years of drought, heavy rains on Maui this past winter triggered the cycle again.

State vector control crews that spent much of the past year trying to eliminate mosquitoes in the lush Hana area after an outbreak of dengue fever are now busy chasing mice in the island's more arid regions.

The first indication of trouble came about a month ago, when the number of mice caught in traps used to monitor the population in brush areas in Kihei and Lahaina suddenly doubled, said Herbert Matsubayashi, environmental health program chief for Maui.

In response, crews have been treating large tracts of vacant land with an oat mixture containing the rodenticide zinc phosphide.

Department of Health entomologist George Kitaguchi said the compound is relatively safe and does not pose the threat of secondary poisoning to cats, owls or other animals that may eat the dead mice.

Although effective in curbing the rodent population, vector control efforts are limited by restrictions on where zinc phosphide can be used, he said.

Maui appears to be the only island suffering from a dramatic increase in the number of mice, Kitaguchi said, although there has been a slight surge on the Big Island.

Urbanization on O'ahu has eliminated widespread outbreaks, he said.

Mice have become the No. 1 pest complaint at the Terminix office on Maui, said service manager Robert Seybold. The trouble began in late April and quickly multiplied, he said, with most of the calls coming from South and West Maui, although Terminix is now hearing from Upcountry folks.

"It's overrun to the point where you can see them running around in the daytime. You can sit and watch them come out of the groundcover," Seybold said. "It's a tough problem because you don't have control over the source. You're only dealing with the aftermath."

Kihei resident Mark Rooney hired the company to set up bait stations at his Maui Meadows home after mice invaded his yard, devouring avocados and mangoes. The property abuts a large area of vacant land slated for development as Wailea 670.

"We've had dozens of mice in the last month," he said.

Terminix employee Kai Mahuna, who's been checking the traps at Rooney's house, said he collected 600 mice in a little more than a month at a Wailea mansion.

North of Kihei, hordes of mice have been fleeing the canefields adjacent to condominiums in Ma'alaea.

Marylyn Baker, resident manager of the Ma'alaea Banyans, caught 60 mice in her tiny one-bedroom unit in the past month, and her husband John has been scooping them out of the condo pool on a daily basis.

"My family was in the hot tub and a mouse came running up and just jumped right in. Of course my family jumped right out," she said. "It was awful. You would go outside and they were running around in the hallways. It was like some kind of nightmare."

The mice had infiltrated up to the fourth floor, and Baker was beginning to notice a growing flea problem. After a couple of visits from pest control crews, the infestation appears to be waning, Baker said.

Mice normally are nocturnal creatures who are expert at hiding. The fact that they are being easily spotted in daylight is an indication of the extent of the population. Pest control and state health officials said they expect the mouse explosion to run its course by September.

In the meantime, glue boards and snap traps are in short supply at Maui stores.

"We can't keep up with them," said Irene Naeole, assistant manager at Ace Hardware in Lahaina. "Three weeks ago people just started coming in all of a sudden. I put 72 traps on the shelf a week ago Tuesday and they were gone by the end of the day."

Dan Honma of Pukalani said he's relying on a more natural method of rodent control. His three cats have been earning their keep in recent weeks, and not a single mouse has made it inside the house alive, he said.

Reach Christie Wilson at cwilson@honoluluadvertiser.com or (808) 244-4880.