To mitigate any potential feral ungulates from causing flight disruptions or safety hazards, Maui District Airports Manager Marvin Moniz said via phone on Tuesday that additional vinyl fencing was installed to overlap the existing wood fence outlining the airport property.

There was about a 3.5-foot gap between each wood slat on the existing fence — originally installed about 15 years ago. Wood is used instead of metal because it does not interfere with navigation airways.

“We felt that it was sufficient and still think it’s sufficient, but we weren’t sure how the deer were working their way through that fencing,” he said. “As a precaution, we decided to add additional fencing and keep them from squeezing through.”

The vinyl layer will keep even a “small kitten” from getting through now, Moniz said.

Vinyl fencing was installed about two weeks ago on top of existing wooden fencing in order to keep out axis deer, who have at times been spotted in herds of up to 700 around the perimeter of the fence, an airport official said. MARVIN MONIZ photo

Between materials and labor, the estimated $100,000 state Department of Transportation project was installed about two weeks ago and seems to be effective in protecting the Kahului Airport property from the overpopulated axis deer herds.

Brush growing along the fenceline was also cut back to avoid encouraging axis deer to come near the area during their search for food, Moniz said.

“With the additional fencing and increased patrols by wildlife services, we think that’s been a remedy for now,” Moniz said. “We’ve seen a reduction in the deer amount now because of the recent rains we had, things are greener now, so I think they’re moving back up the hill.”

Airport staff suspected that the one single deer that roamed onto the active runway earlier this month got in due to a utility gate being left open, but there otherwise has not been any incidents of that nature, Moniz said.

Weather conditions and unexpected delays in shipments of “critical mitigation materials” had stalled the state’s effort to manage the axis deer population, so Gov. David Ige issued an extension of a proclamation last week declaring that the disaster emergency relief period will last through March 7.

“The axis deer are threatening the safety, health and welfare of our residents and visitors on Maui,” Ige said in a news release last week. “I’m extending the disaster declaration to enable the state and county to handle the axis deer problem as quickly and efficiently as possible.”

Some of the materials that were delayed included FAA-approved fencing materials, which were required to “secure the airport perimeter to prevent the axis deer from encroaching onto airport property,” Jodi Leong, a spokesperson for Ige, told The Maui News last week.

“The Axis Deer Task Force is grateful to the emergency proclamation as it will allow ranchers, farmers and landowners impacted by the axis deer overpopulation to mitigate and expedite protection to their crops and herds,” said Maui County Council Member Yuki Lei Sugimura, who holds the Upcountry residency seat and announced last year the formation of the task force, which aims to manage and control the axis deer problem by finding resources and funding.

Though not directly involved with the mitigation project at the airport, the task force continues communication with local, state and federal government officials as well as representatives from the Maui County Farm Bureau, ranchers, veterinarians and hunters, among many others.

“We are also working to bring back foliage which the deer have ruined our ecosystem that is sending brown water to our delicate reefs,” Sugimura said in an email to The Maui News. “We saw that during the recent Kona low storms.”

Tens of thousands of axis deer roam Maui alone, including a few herds scavenging for water and leafy greens around the Kahului Airport, the areas of Kanaha Beach Park and Keopuolani Regional Park.

At one time, up to 700 axis deer were spotted around the perimeter of the airport fence, Moniz said, but that number has since reduced to about 300 as they move more north seeking greener pastures and water.

Herds of axis deer have already trampled trees and brush surrounding the Molokai Airport, according to the state Department of Land and Natural Resources.

About 111,000 acres of Maui Nui is already fenced, but many fences were built decades ago to keep pigs and goats out and are only about four feet high, low enough for axis deer to jump over, according to a news release last week by DLNR’s Division of Forestry and Wildlife.

Still, officials said that fencing is one of the “most effective” ways to keep axis deer out of native forests, which is why the DLNR and its partners are retrofitting existing fences to be 8 feet high to discourage deer from jumping over them.

At Kahului Airport, the same concept applies as wildlife services continue to do perimeter checks and airfield inspections.

“So far so good,” Moniz said. “I think the cutting of the grass, the additional fencing, increased support from wildlife services — that’s all been helping.”

* Dakota Grossman can be reached at dgrossman@mauinews.com.