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Wildlife & Nature

The Guardians of Popoia: Understanding Flat Island's Nesting Seabirds

2026-08-14•Kailua Guide

The Guardians of Popoia

Just off Kailua Beach, Popoia, also known as Flat Island, is a haven for wedge-tailed shearwaters (ʻuaʻu kani). This low islet of about 3.7 acres is a State Seabird Sanctuary, and its vegetated ground is where these remarkable birds come ashore to raise their young. Their Hawaiian name is often translated as "calling" or "moaning" petrel, after the eerie wailing they make around their burrows at night.

The Underground Burrows

The wedge-tailed shearwaters on Popoia have a fascinating nesting habit. Instead of building nests in trees, they dig burrows into the ground, where each pair lays a single white egg. On Oʻahu the birds return in spring to clean out and claim their burrows, lay their eggs around June, and raise a chick that fledges around November after more than 100 days in the nest. The burrows lie just under the surface and can collapse under a careless footstep, crushing the egg or chick inside.

Respecting the Island and its Inhabitants

When visiting Popoia, it's essential to respect the nesting birds and their habitat. The islet is a State Seabird Sanctuary with restricted access: visitors must stay below the high water mark and must not enter the nesting area inland. Read the signs when you land, keep your distance from any birds you see, and never reach into a burrow. Bulwer's petrels (ʻou) also use the islet, so the whole interior deserves the same care.

Appreciating the Ocean Wanderers

Wedge-tailed shearwaters are true seabirds. They spend most of their lives at sea over the tropical and subtropical Pacific and come to land mainly to breed. When the chicks fledge in late fall, they head straight out over the open ocean. These birds are a testament to the adaptability and resilience of life on our planet.

Conclusion

Paddling out to Popoia and learning about the wedge-tailed shearwaters is a memorable experience. By following the sanctuary rules, we can appreciate these ocean wanderers from a respectful distance and learn from their remarkable habits. Whether you're a nature enthusiast or simply looking for a quiet hour on the water, Popoia rewards visitors who tread lightly.

Tips for Visiting Popoia Island

  • Stay below the high water mark and out of the nesting area at all times.
  • Read and follow the sanctuary signs posted on the islet.
  • Keep a respectful distance from the birds and never touch or reach into a burrow.
  • Do not remove plants, animals or anything else from the sanctuary.
  • Bring binoculars to watch from the shoreline.
  • Nesting runs roughly from spring through November, and shearwaters are most active around their burrows from dusk into the night.
  • Kayak rentals are in Kailua town, since commercial activity, including rental vendors, is not allowed inside Kailua Beach Park.