A roaming dog killed some 50 adult wedge-tailed shearwaters at the Nature Conservancy's Mo'omomi Beach Preserve in northwestern Molokai, the conservancy said.

“;This is pretty traumatic,”; said Ed Misaki, the conservancy's Molokai director of programs.

Misaki said he has seen two or three dead shearwaters killed by predators but nothing of this magnitude at Mo'omomi.

On Oahu a pack of dogs apparently killed 86 wedge-tailed shearwaters at the Kahuku Golf Course last May, and an estimated 40 were found dead at the same golf course in 2007.

The dog at Mo'omomi was found with a shearwater in its mouth, conservancy officials said.

Conservancy spokesman Grady Timmons said the attack Wednesday was the worst since the conservancy began a predator control program at Mo'omomi in 1999.

Misaki said under a conservancy predator protection program, the number of shearwater nests has increased from a few nests to about 400 at Mo'omomi.

He said shearwaters spend most of their life at sea and only come in at this time of year to establish nests and reproduce.

Timmons said on the main Hawaiian Islands, shearwaters are mainly found in protected areas.

The birds cannot stand upright on their legs and have difficulty moving about on the land, making them easy prey while nesting.

Shearwaters, known as 'ua'u kani or Puffinus pacificus, sometimes make a wailing sound at night from their burrows in the sand. They total 270,000 pairs in the Hawaiian archipelago, the state said.