LIHUE — Hawaiian Petrels nesting on Kauai are not above traveling thousands of miles in search of food for their chicks, according to a new study by the Kauai Endangered Seabird Recovery Project. Dr. André Raine, KESRP coordinator, described the
LIHUE — Hawaiian Petrels nesting on Kauai are not above traveling thousands of miles in search of food for their chicks, according to a new study by the Kauai Endangered Seabird Recovery Project.
Dr. André Raine, KESRP coordinator, described the long-distance voyages by the endangered seabirds as “mind-boggling” and “ridiculous.”
“It must be worth their while to take these really long journeys,” he said.
One bird flew more than 33,000 miles — greater than the circumference of the earth — during a three-month period as it traveled to and from its burrow in the mountains of Kauai.
Researchers, including Raine, found that breeding petrels on Kauai undertake the epic, multiweek journeys from their tropical nesting sites to a large area of ocean south of Alaska and the Aleutian Islands.
Beginning in late August, small solar-powered satellite tags were attached to the backs of five of the birds nesting in Hono o Na Pali Natural Area Reserve System, according to the release. The tags transmit signals of the animals’ locations every hour as they fly away from the island.
“I was watching them (on the satellite) and thinking, ‘Where is this bird going?’” Raine said, laughing. “It’s actually quite addictive to go every day and find out where the bird is.”
The study also found that the male and female parents alternate between short trips, often one or two days, and longer trips, some lasting several weeks and involving journeys farther than 4,600 miles.
When one parent comes back from an extended journey, the other heads out to sea, according to Raine.
He said it was the first time such a study has been done on Kauai, but that tracking devices have also been attached to petrels on Maui. Both the Maui birds and all five Kauai birds flew to the same general area of ocean, likely to prey on a particular type of squid, Raine said.
The Hawaiian Petrel — known locally as the Uau — is endemic to Hawaii. The species once nested on all the main Hawaiian islands but are now only thought to remain in isolated, remote regions on Kauai, Lanai, Maui and Hawaii.
The remaining number of Hawaiian Petrels is estimated at around 4,500 breeding pairs, according to the release. On Kauai, the birds face a wide range of threats including being eaten by introduced predators — including cats, rats and pigs — habitat change from invasive plants, collisions with power lines and grounding by artificial lights.
Additional threats at sea aren’t as well-known, making the satellite tracking study vital to the overall conservation of the species, according to the state Department of Land and Natural Resources.
Raine said studying the species on land is important, but that the technology is providing scientists with information on which areas of the ocean are important for petrels on Kauai — another important piece of the puzzle.
“Every time you start putting tags on birds, this secret world of them opens up,” he said. “This technology is revolutionizing our understanding of the species.”
The work on Kauai, partly funded by the Bureau of Ocean Energy Management, is one facet of a multispecies, multiisland study being undertaken by Dr. Josh Adams of the U.S. Geological Survey’s Western Ecological Research Center along with a team of Hawai-based collaborators.
Adams said in the release that each petrel chick is “the result of an annual investment of hundreds of thousands of kilometers of work at sea by its parents.”
“To know that these birds utilize such an enormous area of the Pacific Ocean gives us context and perspective on the scales involved when we talk about marine resource planning, conservation and changes in our ocean ecosystem,” he said.
Of the five satellite tags dispatched for the study, researchers were able to retrieve three, according to Raine. As designed, the other two eventually fell off the birds, he said.
The KESRP is a project of the DLNR’s Division of Forestry and Wildlife and administered by the Pacific Co-operative Studies Unit of the University of Hawaii and USGS.
Information: http://kauaiseabirdproject.org
With chicks beginning to fledge, the public is encouraged to look out for downed birds that have been attracted to artificial light sources.
Downed seabirds should be reported to the Save Our Shearwaters program, 635-5117.
• Chris D’Angelo, environmental reporter, can be reached at 245-0441 or cdangelo@thegardenisland.com.
