Biologists report this week that nesting success for seabirds has increased at Kaʻena Point State Natural Area Reserve on the northwest tip of Oahu, Hawaii. Some 2000 seabirds breed here and this year, the dominant species, Wedge-tailed Shearwater, has topped previous high-count for chicks by almost 15% over a previous high count in 2007 – achieving the highest count since 1994.
Increased nest success is the direct result of efforts to place predator-proof fencing around 59 acres of primary nesting areas. The fence design came from New Zealand, another fascinating island archipelago where seabirds struggle against predation by introduced predators such as rats, cats, dogs, and mongooses. Large seabird chicks born in burrows and often on their own for periods of time as adults go to sea to feed particularly vulnerable. Last year, one of our Naturalist Journey’s tour groups visited one of these fenced “ecological islands” New Zealand, and saw first-hand the robust construction required to keep predators OUT.
The fence was completed in March, 2011, in time for the seabird nesting season. In addition to the more numerous Wedge-tailed Shearwaters, sixty-five Laysan Albatross pairs set up nesting on site; about half of them producing chicks, and this number is hoped to more than double in the next five years. Laysan Albatross on low-elevation islands of northwestern Hawaii suffered a high degree of loss in last year’s tsunamis. Kaʻena Point is a safer, higher, elevated site, an example of what may be needed if sea levels rise with climate change. It is hoped that other species may be attracted to the site, including Black-footed Albatross. Participants on our Naturalist Journey’s Hawaii tour with seabird expert Doug Pratt should have great looks at the enormous Laysans and their chicks.
The fence in Hawaii is 6.5 feet tall, reinforced with a mesh skirt buried below ground and a wire hood curving out above. Marine grade mesh protects direct entry, and painting the fence green has lessened its visual impact to park visitors. The cost estimate was $250,000 and it took about five weeks to install. This was a joint state (Hawaii Department of Land and Natural Resources), federal (U.S. Fish and Wildlife Service), and private (several non-profit NGO’s). Essentially, with the fence in place, managers have created a “mainland island”, important safe nesting habitat for magnificent Laysan Albatross alongside the more numerous Wedge-tailed Shearwaters.
Naturalist Journeys offers a Hawaii tour nearly every year, as for birders, Hawaii is an important location for seeing tropical seabird species in addition to its legendary endemic honeycreepers. Two species are endemic to the islands, Hawaiian Petrel and Newell’s Shearwater; both can be encountered on pelagic birding trips. The day cruise we take off the west coast of Kauai is ideal for our search, and there is still space on this year’s Hawaii tour. Join Doug Pratt, the Birds of Hawaii and the Tropical Pacific field guide author, who will is in his element on deck as the boat plies the waters between Niihau and Lehua, in addition to the endemics calling out Black Noddies, Wedge-tailed Shearwaters, Laysan and Black-footed Albatrosses, up to three types of tropicbirds, Black and Brown noddies, Greater and Lesser frigatebirds and Red-footed, Masked and Brown boobies, and one year, a Christmas Shearwater. Through ecotourism, projects such as this predator-proof fence can find support and with that, seabirds will prosper. The journey also highlights seabirds when visiting scenic Kilauea Lighthouse on Kauai. Tour dates are Feb. 26-March 9, 2012.