KA‘ENA, OAHU — The Department of Land and Natural Resources (DLNR) has completed construction of the first predator-proof fence in the Hawaiian Islands at the Ka‘ena Point Natural Area Reserve, a wilderness area at the northwestern tip of O‘ahu that DLNR manages as a natural area reserve and state park. Spanning 700 yards, and enclosing over 59 acres, it provides a safe habitat for native plant and animal life.
“Protection of the natural and cultural resources of Ka‘ena Point has been an ongoing effort of DLNR. Completion of the predator-proof fence is a significant step as we continue to care for the natural resources there, in partnership with wildlife agencies such as the Hawai‘i Chapter of the Wildlife Society, the U.S. Fish and Wildlife Service – which provided the bulk of funding through its coastal program — and the community,” said William J. Aila, DLNR Chairperson.
“We will continue to work with the Ka‘ena Point Advisory Group and others on an integrated management plan and education effort to protect, preserve, and restore the native environment of Ka‘ena,” he said. “We appreciate the community’s respecting the disassembled boulder barricade while the fence was under construction. The protective barricade has since been rebuilt in place.”
“The U.S. Fish and Wildlife Service is excited to have provided funding for this unique project which seeks to restore and maintain the environmental integrity of Ka‘ena Point,” said Loyal Mehrhoff, field supervisor of the Pacific Islands Fish and Wildlife Office. “The project will protect 11 known endangered plant species, ground nesting native seabirds and the endangered Hawaiian monk seal, and serve as a model for future conservation efforts throughout the Pacific.”
The fence will keep out predators such as cats, dogs, mongooses, rats and mice as young as two days old from the Reserve so that native wildlife like the Laysan albatross and endangered native coastal plants can flourish. As the recent tsunami caused the loss of more than 112,000 Laysan albatrosses in the Northwestern Hawaiian Islands, there is a high need for elevated areas like Ka‘ena Point to provide safe nesting habitat, especially as sea level is expected to rise due to climate change.
The protected area is close to being free of predators through intensive baiting and trapping efforts since fence construction began. Scientific monitoring is being undertaken to track the results of the fence over time. Methods are in place to detect if pests have re-entered the Reserve so that personnel may implement a rapid response.
As part of the predator proof fence, unlocked double-door gates have been installed at major entry-ways to allow the public to have continued use of the reserve seven days a week for hiking, bird-watching, fishing, cultural practices, and volunteer work. While an overwhelming majority of people who have been to Ka‘ena Point have been in strong support of the project, modifications to the design have been made to address concerns, including the installation of a third walk-through gate mid-way between the Wai‘anae and Mokule‘ia entrances.
With the completion of the fence, recovery of native plant and animal habitat is expected in a few years. There are currently 65 nesting pairs of Laysan albatrosses including 35 chicks. That number is expected to double in next five years as young chicks return to breed and it is hoped that more native bird species will use Ka‘ena Point as a nesting area, including the Black-footed albatross which has been seen recently in the area
Volunteers interested in helping at Ka‘ena Point are encouraged to contact the Friends of Ka‘ena at info@friendsofkaena.org
For more information on the project, go to www.restorekaena.org
FACTS ABOUT THE KA‘ENA POINT PREDATOR PROOF FENCE:
The first of its kind in Hawai‘i and the United States, the fence was built by a New Zealand and local crew of approximately seven people. Construction began last November and was completed this March. The New Zealand-based technology has proven to be effective in both mountain and coastal environments, similar to Hawai‘i, and able to keep predators as small as two-day-old mice from entering protected areas.
The Ka‘ena Point predator-proof fence is 640 meters long (2100 feet or 700 yards) and 6.5 feet (2 meter) tall fence follows the existing upper roadbed to minimize disturbance and enclose the tip of the peninsula, a total of 59 acres, or less than 1/10 of a square mile. Three unlocked double-door gates were installed at each entrance to the reserve (from Mōkūle‘ia and from Wai‘anae) and mid-way between the other two, to allow access by people. The fence material includes marine grade stainless steel for strength and corrosion resistance, and a rolled hood to prevent animals from climbing over. The fence is painted a dark green to blend in with the natural environment when seen from a distance.
After the fence was constructed, project personnel began to remove predatory animals from the reserve by using traps for larger animals and a combination of bait boxes and traps for rodents. These methods were selected after a one-year study of rodent abundance and behavior.
Scientists will continue to monitor native plants, seabirds and invertebrates after predator removal to evaluate the effectiveness of the fence. Methods will be in place to detect if pests have re-entered the reserve so that personnel may implement a rapid response.
How the fence works:
The Excluder predator-proof fence is four-tenths of a mile long, in the Ka‘ena Point Natural Area Reserve. It is part of an integrated management plan and education effort to protect, preserve, and restore the native environment of Ka‘ena. The Ka‘ena wilderness area at the northwestern tip of O‘ahu is managed by DLNR as a natural area reserve and state park.
The 6.5 foot high fence is designed to keep out predators like cats, dogs, mongooses, rats and mice from the reserve so that native seabird species that nest in the reserve, like the Laysan albatross, and endangered native coastal plants can flourish again in a safe environment.
How to use and care for the gates:
- The fence has three entrances which are unlocked at all times.
- Each entrance consists of a double-gated entry.
- Persons entering or exiting the reserve can open one gate and once it closes, are then able to open the other gate to enter.
- Only one gate can be opened at a time, so as to prevent entry of animals that need to be kept out of the natural area reserve.
- If the doors are not sliding easily, check the bottom of the door to ensure that a rock is not caught under it, or that the other door is closed
Why is a fence needed?
For decades, despite trapping efforts, predators were a continual problem in the reserve. In fall 2006, dogs killed 21 shearwater chicks in a single night at Ka‘ena Point. In 2007, more than 125 native seabirds were killed in one evening, most likely by one or more dogs. Rats are known to kill and eat nestling chicks, which are too young to fly away. Rats and mice also eat seeds of native plants, preventing the growth and spread of new plants.
Before construction of the fence, a community consultation process took place over three years to educate the public about problems with predators in the reserve and the need for a fence. This process built a strong foundation of community support from groups such as the Friends of Ka’ena, as well as west side and north shore neighborhood boards and other community groups. Public education and support and cooperation with proper use of the fence will continue to be essential to the success of this effort to protect native wildlife at Ka‘ena Point.
The U.S. Fish and Wildlife Service provided funding for the unique project to restore and maintain the environmental integrity of Ka‘ena Point and protect 11 known endangered plant species, ground nesting native seabirds and the endangered Hawaiian monk
Endangered plants known to exist at Ka‘ena
• Achyranthes splendens var. rotundata (no known Hawaiian name)
• ‘Awiwi (Centaurium sebaeodes)
• ‘Akoko (Chamaesyce celastroides var. kaenana)
• Pu‘uka‘a (Cyperus trachysanthos)
• Ma‘o hau hele (Hibiscus brackenridgei)
• Kulu‘i (Nototrichim humile)
• Carter’s panicgrass (Panicum faurier var. carteri)
• Dwarf naupaka (Scaevola coriacea)
• Schiedea kealiae (no known Hawaiian name)
• ‘Ohai (Sesbania tomentosa)
• Vigna o-wahuensis (no known Hawaiian name)
For more information on the project, go to the website: www.restorekaena.org