Feral cats killing endangered Hawaiian birds, study finds Feral cats are being blamed for the decline in the endangered Hawaiian petrel. Don Bartletti / Los Angeles Times April 18, 2013, 2:24 p.m. Academic researchers and federal scientists have for the first time come up with direct evidence of feral cats killing endangered Hawaiian petrels. The study, by scientists from the University of Hawaii, the National Park Service and the U.S. Geological Survey, confirms what has been widely suspected, that wild cats are playing an important role in the population decline of the rare birds. The study involved monitoring of 14 Hawaiian petrel burrows with digital infrared video cameras in 2007 and 2008 on the island of Hawaii. The photographic evidence of feral cats at petrel nesting burrows. In one video, a cat was shown waiting near the entrance of a burrow for more than an hour. When a petrel chick emerged, the cat quickly grabbed it and the remains of the small bird were later found nearby. Researchers attributed other kills to the condition of the bird carcasses and the presence of cat scat. Hawaiian petrels spend most of their lives at sea and return to land to breed. The species was once widespread throughout the entire Hawaiian chain of islands but now numbers only about 15,000 birds distributed in isolated breeding colonies on Kauai, Lanai, Maui and Hawaii. Various means have been used to protect the birds. The park service -- with help from the U.S. Fish and Wildlife Service, National Fish and Wildlife Foundation, and the American Bird Conservancy -- is constructing a fence specifically designed to keep feral cats and mongooses out of Hawaiian petrel nesting habitat in Hawaii Volcanoes National Park.