Story at-a-glance
- In 1999, canine distemper ravaged Catalina Island foxes, reducing their numbers by 95%
- A conservation program that included captive breeding, vaccinating against canine distemper and monitoring of the wild fox population began
- Their numbers quickly bounced back, and there were more than 2,000 foxes on Catalina Island at the end of 2017
- Researchers found a “remarkably high” prevalence of the ear tumors in the Catalina Island foxes, typically found alongside ear mites and ear inflammation
- Conservationists removed about two dozen of the surviving foxes as part of a captive breeding program, which represented only a small genetic sample; some of these foxes had ear tumors, and it’s possible they passed on a genetic susceptibility to the disease to future generations
- Treating the foxes for ear mites has helped to reduce the infection and inflammation, and the ear tumors appear to be less prevalent than they once were