New gear lets researchers track seabirds at night

Surveying birds every year in June will help track population changes

The ‘ua‘u, or Hawaiian petrel, is one of the endangered seabirds that researchers hope to keep tabs on with new radar equipment. Monitoring the birds every year in June will allow scientists to see if conservation efforts are working. EMILY SEVERSON photo

A new truck-mounted radar unit will help scientists track seabirds on the Valley Isle, a long-awaited dream for the Maui Nui Seabird Recovery Project whose goal is to protect these endangered animals.

The truck, which arrived two weeks ago, will allow researchers to monitor the birds at 16 sites along the shoreline across the island every night for two hours after dark, providing a “snapshot” of information about any population changes. The survey will be conducted every year during the month of June.

The Maui Nui Seabird Recovery Project, a program of the Pacific Cooperative Studies Unit at the University of Hawaii at Manoa, works to discover seabird colonies and provides protections where funding and staffing permit by removing predators and invasive plants.

The organization also provides public education about the importance of Hawaiian petrels to the environment.

Project Manager Jay Penniman said Monday afternoon that these studies will help to determine how effective their management has been and what protocols they might need to change or adapt to “help guide the work of all the partner organizations trying to restore the populations of Maui’s seabirds.”

A new truck-mounted radar unit will help researchers track seabirds nightly at 16 sites along the Maui shoreline this month, allowing them to monitor changes in the birds’ population. STEPHEN ROSSITER photo

The two species considered endangered on Maui are the ‘ua’u (Hawaiian petrel) and the ‘ake’ake (band-rumped storm petrel), which is the smallest and rarest seabird that breeds in Hawaii. The ‘a’o (Newell’s shearwater) is listed as threatened.

After purchasing more supplies for the radar unit needed to monitor these three species, Penniman explained how seabirds, or na manu o ke kai, were the “original ecological engineers” of Hawaii.

Starting some 70 million years ago, the once-flourishing seabird populations would carry essential marine nutrients to the islands to form the soils that “our native plant community evolved,” he said.

“Not only do those nutrients nourish the plant community, they also nourish the nearshore coral reef habitats,” he said. “There are more and more papers coming out about the importance of having seabirds bringing in those nutrients and feeding the coral reefs and all of their habitats.”

In order to build resilience among the nearshore habitats while ocean temperatures rise, Penniman said that the environment needs seabird inputs and nutrients, which has shown to help corals grow four times faster.

“The coral reef habitats will be given their best opportunity to thrive and adapt to what’s going on,” he said.

Seabirds were also important to the Native Hawaiian community as a resource for navigation, fishing and providing information about nearby habitats.

According to Hawaiian proverbs, Penniman explained that the ‘ua’u were once “so numerous” they filled the sky as they returned to their nesting colonies at night for breeding.

However, as the islands became more populated with humans and as habitats were altered or lost, the numbers of birds have plummeted.

Another threat to these nocturnal creatures is artificial lighting, like street and resort lights, which can cause disorientation and increase the birds’ chances of hitting something or falling to the ground, where they are left vulnerable.

Since first starting to manage the Maui Nui Seabird Recovery Project in 2006, Penniman said that the team immediately realized the need for gathering more information about these populations so that they can better understand trends and how to protect them.

“We don’t really know how effective our management is being, and the radar unit gives us overtime information on pass rates of the bird flying up to their nesting areas,” he said.

Na manu o ke kai spend most of their lives at sea but return to their burrows during the breeding season as night falls. They fly 30 mph or more as they cross the coast heading to their burrows, which distinguishes them from slower-flying species like the pueo (Hawaiian short-eared owl) or ‘auku’u (Hawaiian black-crowned night heron).

Using the new radar unit, which is similar to marine radar equipment that allows navigators to see ships in the dark, the researchers will be able to see the birds as they fly inland.

The project will replicate a 2001 radar study conducted on Maui by Alaska Biological Research at 15 different sites.

Similar ornithological radar surveys on Kauai have helped document a “dramatic decline” in the numbers of ‘a’o and ‘ua’u since the early ’90s; these two species on Kauai have declined by 94 and 84 percent, respectively.

Data from the Kauai study and from Maui’s Save Our Seabirds program will help the Maui Nui Seabird Recovery Project determine whether the birds’ populations are stable, increasing or decreasing, Penniman said.

“Of course we hope that, because there’s been management going on, especially in the national park for the last 30 years, that the numbers have increased some, but we don’t know that,” he added. “We need data to be able to tell us ‘yes, our management is effective,’ or if the numbers are going down, we need to figure out what is the cause of that.”

The dream of launching such a survey and securing equipment finally became a reality this year after the group received funding and support through state, federal and private agencies to launch the radar study. Partners also include the American Bird Conservancy, the state Department of Land and Natural Resources’ Division of Forestry and Wildlife, Haleakala National Park and the U.S. Fish and Wildlife Service.

If passersby see the radar truck parked along the road, Penniman asked that they keep their distance to help ensure the safety of the project team. The surveys require strict concentration on the radar screen and observers with night vision goggles may be stationed outside the radar truck.

For more information about na manu o ke kai of Maui Nui and Hawaii, visit www.maui nuiseabirds.org.

* Dakota Grossman can be reached at dgrossman@mauinews.com.


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