Threatened Newell’s shearwaters have started laying eggs in an artificial colony in West Maui, perhaps due to “acoustic attraction” — recordings of their own calls.
The two 4.5-acre, predator-free enclosures were built near the Makamakaole Stream basin in 2012 and 2013 to offset accidental deaths of native seabirds at the Kaheawa wind energy facilities above Maalaea, the Maui News reported.
But this is the first sign of eggs.
Biologists confirmed that four of the 100 man-made burrow boxes — three with eggs — are being occupied by the seabirds this season.
“When I first heard about the project, I wasn’t involved,” project biologist Matt Stelmach said last week. “I was skeptical. … And, now that I’m involved, I’m really excited to see that it’s becoming a success, because it has the potential to change management practices across Hawaii, at least for seabirds.”
Scientists have tried to create new colonies of birds before, sometimes by transporting the creatures to new locations.
“But here in Hawaii we’ve never tried to do acoustic attraction, which is the unique aspect of this restoration effort,” Stelmach said.
Every night, seabird social calls similar to those at existing colonies were broadcast through weatherproof, solar-powered sound systems, according to TerraForm Power, owners of the Kaheawa wind farm. Within the enclosures, corrugated plastic burrows connect to underground plywood boxes that serve as nesting chambers, imitating the birds’ natural habitats.
A 6-foot-high mesh fence protects the enclosures from cats, rats and mongooses.
The goal was to attract the shearwater and the endangered Hawaiian petrel to an area where both species had been absent for more than a decade.
“As the colony gets larger and larger, it creates more attraction,” Stelmach said. “The likelihood is that as time goes on, the colony will draw in more seabirds, and we’ll be able to create a colony using social attraction.”
