Catalina Photo Galleries
Catalina Radio Specials
Marine Protection
Current Research
Animals: Ecological Effect of Bison
Animals: Ecology of Feral Cats
Animals: Fox Pregnancy & Mortality
Birds: Eagles
Birds: Oranged-crowned Warbler
Field Lab
For Researchers
Oak Symposium Proceedings
Past Research
Research Needs
Ecological Process
Endemic Species
Game Management
Weather and Climate
Wildflowers in Bloom
Monthly News from
the Conservancy!

Enter Your Email Address:

June 2019
26 27 28 29 30 31 1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30 1 2 3 4 5 6

On Catalina Island, most feral cat colonies are within the boundaries of the City of Avalon and are maintained by the Catalina Island Humane Society. A few small colonies exist in the Island's interior which is stewarded by the Conservancy. While the severe impacts introduced cats have on native wildlife are well documented, the Conservancy seeks caring and humane solutions and supports the spaying or neutering and placement of healthy and adoptable cats. The following is the executive summary of a recent study conducted by Darcee Guttilla and Dr. Paul Stapp, independent researchers based at Cal State Fullerton:

The domestic cat (Felis catus L.) originated from the African wildcat (Felis silvestris) and was domesticated by the Egyptians by 4000 B.C. Because of its close association with humans, the domestic cat is one of the most successful biological invaders, with established populations on every continent and hundreds of islands worldwide. Although the exact introduction date of cats to Santa Catalina Island is not known, their arrival is probably the result of early European explorers that utilized cats as mousers on ships.

We define feral cats as cats that have reverted to a wild state, avoid human beings and are not dependent on supplemental feeding to survive. Conditions of domestication, including contact with human beings, must be duplicated in each generation for domestic behavior patterns to occur. A 1931 Department of Fish and Game report documented that more than 100 feral cats were trapped and killed from the island interior because they were believed to be the cause of low Catalina Quail numbers.

Historically, data collected on Catalina’s feral cats has been primarily limited to incidental observations associated with island fox research. In 1975, B. Propst reported cats in Catalina’s canyon bottoms and island fox higher up on the slopes, suggesting cats competed with the island fox for food and excluded the island fox from residing in areas occupied by cats. Propst noted cats did not appear to be a problem, but that every effort would be made to prohibit an increase in feral cat numbers. In 1979, P. Lonquich surveyed diet, morphological features, and behavior of feral cats, but was unable to conclusively document the impact of feral cats on Catalina’s native vertebrates. He recommended either an active spay/neuter program or a hunt and trap/euthanasia program to control the influx of cats into the island’s interior. He noted, however, that without complete prohibition of cats on Catalina, the effects on native fauna probably could not be eliminated. Today, within Avalon city limits and the town of Two Harbors, the Catalina Island Humane Society practices the trap-neuter-release (TNR) method of managing stray and homeless cat colonies at established feeding stations.

This study investigates the potential impacts of feral cats on Catalina’s native fauna, effects of a feral existence on the domestic cat, and the feasibility of TNR as a management tool for population control.

Research Objectives
  • Acquire baseline data on feral cat movements and home range
  • Determine the effect of sterilization on home-range size and distribution
  • Determine habitat preferences and spatial organization of feral cats
  • Estimate abundance of feral cats in native habitats and as a function of distance from
  • human habitation
  • Determine rates of disease and ectoparasite infection of feral cats
  • Estimate consumption of native prey

Cats were live-trapped from the island’s interior and given a thorough physical examination. Ectoparasites were collected and blood was drawn to test for disease (plague, feline leukemia virus, feline immunodeficiency virus, feline enteric corona virus, canine distemper virus, toxoplasmosis and feline calicivirus). Twenty cats were equipped with radio collars to monitor spacing behavior throughout the wet and dry seasons. Ten of the 20 cats were surgically sterilized to determine how sterilization affects home-range behavior. Relative abundance was estimated by a combination of scat collection, scent-baited track stations and spotlight surveys. Diet composition was determined by examining scat contents.

Darcee Guttilla or Dr. Paul Stapp
Department of Biology (MH-282)
California Sate University, Fullerton

P.O. Box 6850
Fullerton, CA 92834-6850
(714) 278 -2849
(714) 278 -2067 (lab)

Island Maps | News & Media | Activities Calendar | Site Map | Contact Us | Privacy Policy | Job Listings | Donate Now | FAQs | Login
P.O. Box 2739, Avalon, CA 90704 | Phone: (310) 510-1445
320 Golden Shore, Suite 220, Long Beach, CA 90802 | Phone: (562) 437-8555
Copyright © 2019 Catalina Island Conservancy. All rights reserved.