‘Massacre’ of endangered birds linked to Hawaii’s booming population of invasive cats

It’s tragic when one endangered bird is killed, but when nine are slaughtered at once, it qualifies as a “massacre,” according to the Hawaii Department of Land and Natural Resources.

This killing spree, which involved Hawaiian petrels, played out last month on the island of Kaua’i, and trail cameras showed the lone culprit is counted among the state’s most destructive invasive species.

“A single, free-roaming cat again demonstrates the awful toll cats are exacting on endangered native Hawaiian birds,” state wildlife officials said in a Facebook post.

“Over the course of three days in a remote area of the Hono o Na Pali Natural Area Reserve, one cat ... killed at least nine endangered Hawaiian Petrel (‘u‘au) chicks. A team working in the area found the partially eaten baby birds outside their burrows. They were just over a month old.”

Hawaii is facing a “cat crisis,” state officials say. It’s estimated more than 2 million cats roam the eight Hawaiian Islands, including up to 1 million on Big Island and 15,500 on Kaua’i, where the petrels were killed, according to Aloha Pest Solutions.

“Feral cats are one of the most devastating predators of Hawaii’s unique wildlife,” the Hawaiian Invasive Species Council reports. “In addition to direct predation, feral cats also spread a potentially lethal parasite.”

That parasite (toxoplasma gondii) has resulted in many islanders disparaging the invasive felines as “zombie cats” and “kitties of doom,” Outsideonline.com reports.

Hawaiian petrels “are found exclusively on the main Hawaiian Islands,” and it’s believed one third of the world’s remaining population survives on Kaua’i, according to the Kaua’i Endangered Seabird Recovery Project.

Stray and feral cats are a chief cause of their demise, due to instincts that compel cats to kill even when they are well fed, experts say.

“Our native birds have no natural defense against mammalian predators because they evolved on these isolated islands without any mammals present,” André Raine of the Kaua‘i Endangered Seabird Recovery Project said in a release.

“Cats are particularly efficient non-native predators. They kill both breeding adults and chicks, and a single cat is capable of destroying a colony very quickly if it appears when birds are nesting and is not immediately caught.”

Raine says “predator control teams and land managers” have lessened the impact of the cats in recent years, but the killings on Kaua’i prove more needs to be done. The state’s official policy is to trap feral cats and encourage adoption, after the animal has been spayed and neutered.

This story was originally published September 7, 2020 at 6:36 AM with the headline "‘Massacre’ of endangered birds linked to Hawaii’s booming population of invasive cats."