Domestic Cat Predation in Hawaii

The Endangered Palila is at further risk from cat predation. Photo: Jack Jeffrey

Hawaii is considered the endangereds species capitol of the world, with more endangered plant and animal species per square mile than any other place on the planet. Hawaii is currently suffering a serious bird extinction crisis which began during Polynesian settlement over 1,600 years ago, and continued through the period of European settlement in the late 1700's to today. Hawaii's unique native birds and other animals are threatened by destruction of habitat for farming and human development, invasion of alien plant species, disease spread by introduced mosquitoes, predation by introduced rats, mongoose, and domestic cats, and habitat degradation by feral pigs, goats, sheep, and cattle.

Cats were probably introduced to the Hawaiian islands in the late 1700's, and now feral and free-roaming cats are a significant problem, even in higher elevations far away from human development. For example, the federally endangered Palila, a Hawaiian honeycreeper, is threatened by feral cats in their protected, but limited habitat of mamane and mamane-naio forest on Mauna Kea. Biologists have been monitoring the Palila population for years and have found that since 1998, 8 to 11 percent of monitored Palila nests were depredated annually by cats. Cat predation inhibits efforts to restore the Palila population. To learn more about the movements, ranges, and habits of feral cats in high elevation dry forests, biologists from the U.S. Geological Survey captured and attached radio collars to five male and three female feral cats and tracked them for 18 months. Because of the cats' large home ranges, and immigration of new cats from lower elevations, they concluded that controlling feral cats in Palila habitat will be very difficult. (Goltz, D., C.Murray, A.Agness, and P.Banko. 2001. Feral Cat Home Range, Habitat Utilization and Movements on Mauna Kea, Hawaii.)

The Hawaiian Crow or Alala was once abundant but is now highly endangered, due in part to predation by cats and other introduced predators. Photo: Jack Jeffrey

The 'Alala or Hawaiian Crow, is highly endangered. Endemic to the island of Hawaii, this crow was once abundant in the lower forests on the western and southern sides of the island. However, by the early 1990's, 'Alala could only be found in the Kona Forest Unit of Hakalau National Wildlife Refuge. By October 1999, there were only three individuals left in the wild. A captive-breeding program was started in the 1970s, and by 1998, 24 birds had been released. However, 18 died and the rest were recaptured to protect them and preserve genetic diversity. This bird has suffered from: over-hunting; loss and degradation of habitat; avian malaria and pox carried by introduced mosquitoes; predation by cats, rats, mongoose, and toxoplasmosis, a disease common to domestic cats and rats. An environmental assessment has been prepared, and other potential release-sites are being investigated, but it is difficult to find a viable site for 'Alala anywhere on the island.

The following federally threatened and endangered native birds in Hawaii are also known to be preyed on by domestic cats.

Hawai'i Creeper
Hawaiian Dark-rumped Petrel
Hawaiian Duck
Hawaiian Goose
Hawaiian Hawk
Hawaiian Stilt
Newell's Shearwater
Nuku pu'u
Large Kaua'i Thrush
Small Kaua'i Thrush

Further Information

"Managed" Cat Colonies in Hawaii

Hawaii Cats Indoors! Materials developed by ABC for the Hawaii Division of Forestry and Wildlife

Hawaii Cats Indoors! Power Point (zipped)

Cats Indoors! Educator's Guide for Grades K - 6

Hawaii Audubon Society

Hawaiian Ecosystems At Risk Project