KILAUEA, Kauai – One of the longest predator-proof fences in the country is under construction at the Kilauea Point National Wildlife Refuge on the North Shore of Kauai.

When complete, the $1.7 million project will span 2.1 miles, enclosing 168 of the refuge’s 199 acres to protect native seabird species – some of which are uncomfortably close to extinction.

Kilauea Point Refuge is one of the most popular national wildlife refuges in the country, according to the U.S. Fish and Wildlife Service, which reports up to 500,000 people visit the site annually.

“Kauai has the highest number of ground-nesting seabird species (in the state) and the Service has utilized resources and partnerships to promote opportunities to protect these species,” USFWS said in a written statement. “One of these opportunities is through the construction of a predator-proof fence, which greatly enhances protections from some of Hawaii’s most harmful invasive predators, pigs, cats and rats.”

The specialized barriers, also known as mammalian exclusion fencing, incorporate buried skirts, tight mesh walls and hoods to ensure unwanted animals cannot dig, climb or jump into protected spaces. They are an increasingly popular tool for conservation within Hawaii.

Two other national wildlife refuges within the state, the Pearl Harbor National Wildlife Refuge and the James Campbell National Wildlife Refuge on Oahu, also use predator-proof fences. Those fences protect approximately 36 and 16 acres, respectively.

Kilauea Point’s 168-acre fence will also dwarf three other predator-proof fences constructed by the state on Kauai. Located near the rim of Kalalau valley and a very remote location above Na Pali Coast, the Department of Land and Natural Resources’ Pohakea, Kahuamanu and Honopu fences protect a combined 17 acres.

DLNR and its partners have also constructed ungulate-proof fencing to protect approximately 13,000 acres on Kauai. But these fences, most of which are located in remote areas, only protect native species from hooved animals and are designed to be crossed by hikers.

The first predator-proof fence constructed on Kauai was completed at the center of the refuge in 2014. Project partners then moved federally threatened ‘a‘o (Newell’s shearwater) and endangered ‘ua‘u (Hawaiian petrel) chicks into artificial burrows within the 7-acre enclosure called Nihoku in an effort to establish a protected seabird colony.

“Newell’s shearwaters have returned and the Hawaiian petrel has three nesting pairs that we’ve actually confirmed, so they’ve got eggs,” USFWS visitor services manager Jennifer Waipa said while touring the perimeter of Kilauea Point Refuge this summer.  “That’s huge. That’s super exciting.”

Waipa was joined by Thomas Daubert, executive director of the nonprofit Friends of Kauai Wildlife Refuges. Daubert shared his colleague’s excitement regarding the Nihoku project.

“Just think of what can happen when you move that protection out farther to a much wider space,” he said, referring to the new predator-proof fence, which will replace an existing perimeter barrier.

Kilauea Point Refuge is an ideal location to host seabird colonies, according to USFWS, due to its protected status and the absence of threats like artificial light attraction and powerline collisions.

But the hog-wire fence now surrounding Kilauea Point Refuge’s outer limits lacks the Nihoku site’s security. Pigs, dogs and cats have entered and killed koa‘e ‘ula and koa‘e kea (red- and white-tailed tropic birds), ‘ua‘u kani (wedge-tailed shearwaters) and moli, or Laysan albatrosses.

“To show up and see a bird that’s been killed by a mammal that’s come into a protected space – what’s more disheartening?” Daubert asked.

Several tropic birds wheeled above Daubert and Waipa as they inspected a newly installed portion of fence facing Kahili Beach, at the refuge’s easternmost end.

“Next season’s moli colony is going to be infinitely more protected than this year’s, thanks to this,” Daubert said, pointing to the fencing, which terminated near the black cliffs that line the refuge’s seaward side.

The cliffs act as natural barriers, according to assistant project manager Kainalu Obayashi, of contractor Pono Pacific.

“When we can utilize natural predator-proof obstacles, we will,” he said from his office on Oahu.

Pono Pacific, which bills itself as the longest-running private natural resource conservation company in the state, claims it has built 70% of predator-proof fences in Hawaii.

Construction at the Kilauea Point Refuge began in February. Obayashi estimates work will conclude in spring 2023.

Back at the refuge, Waipa noted birds – while the most talked-about beneficiaries of the refuge’s new perimeter – are not the only ones.

“Without these birds, we lose a part of our culture. We lose a part of the ohana,” Waipa said. “They’re an essential part of who we are as a culture.”