Ninety-five bird species have been driven to extinction here since man's arrival—most of them due to invasive species. That makes it critically important to find ways to limit the impact on invasives on Hawai'i's declining bird species.
Standard wire fencing has proven effective at keeping large animals like sheep, goats, and pigs—none of which are native to the islands—from wreaking havoc on sensitive bird habitats.
Basic fencing like this is used to encircle the upper elevations of Mauna Kea volcano on the Big Island to protect mamane forests. These native trees, which are the main food source for the Palila, are heavily browsed by introduced sheep and goats.
But special predator-proof fencing is needed to keep out smaller animals like cats and rats, which are efficient killers of chicks and even adult birds. This high-tech fencing, developed in New Zealand, is paneled with fine wire mesh and topped with an arched hood.
“It even has a skirt buried underground,” says George Wallace, ABC Vice President of Oceans & Islands, “to prevent predators from jumping, climbing, squeezing, or digging their way through into protected areas.”
Predator-proof fencing was first used on Hawai'i in 2011, when a 2,040-foot long, marine-grade stainless steel was built at Ka'ena Point on O'ahu, Hawai'i's third-largest island, to create a 59-acre predator-free sanctuary.
Only a year after this project's completion, record numbers of Laysan Albatross and Wedge-tailed Shearwater chicks fledged. Black Noddy, a seabird not previously recorded breeding on O'ahu, also nested inside the enclosure.
The most recent predator-proof fence protects a six-acre area on Kaua'i, geologically the oldest of the main Hawaiian islands. Safeguarding six acres within Kilauea Point National Wildlife Refuge, the fence will benefit bird species already resident on the site, including Laysan Albatross and Nene (Hawaiian Goose), a distant relative of Canada Goose.
In addition, new populations of threatened seabirds such as Hawaiian Petrel will be established on the protected site.
Wallace is particularly excited about the potential to help reintroduce Newell's Shearwater within the fenced area. This 13-inch seabird has experienced precipitous population declines in recent years.
“This is a major step forward for Newell's Shearwater,” he said. “Fencing is a conservation strategy that we are going to see used more and more in Hawai'i as we struggle to deal with widespread non-native predator populations on very large islands.”
Many of our Hawai'i Program's partners contributed to this project in addition to ABC: the U.S. Fish and Wildlife Service's Kaua'i National Wildlife Refuge Complex, Pacific Rim Conservation, and the Kaua'i Endangered Seabird Recovery Project. The National Fish and Wildlife Foundation provided funding support.
We thank them all for their invaluable contributions to saving Hawai'i's native birds.