Tuesday, July 17, 2012

An Island Fox with a Will to Live

male island fox after recovery from leg amputation
FIF strives to connect the scientists in the field with the local community that cares about Channel Island foxes. We are thrilled to offer this:
Report from the Field
By Calvin Duncan, Island Fox Biologist, Catalina Island Conservancy
No matter how many times it happens, it is always amazing to see the resilience of animals and their ability to bounce back from serious injury. While conducting the annual Island-wide fox trapping survey and vaccination efforts last fall, Conservancy biologists captured a five-year-old male fox suffering from a compound fracture (broken bones exposed through skin) on his rear right leg.

The injury occurred several weeks prior to his capture and we suspect that another dominant male fox in the area was likely to blame. “Island foxes are extremely territorial” reports Julie King, the Conservancy’s senior wildlife biologist. “Injuries sustained by fighting males can often be permanently debilitating or even fatal.”
In most cases the proper approach is to let nature, as cruel as it may often be, take its course, but the Conservancy is still actively working to recover the Catalina Island fox population from its near extinction in 1999. For that reason, we actively treat injuries detected in the field and work to improve the health and survival of each fox captured during the annual survey. Approximately 80% of the fox population on Catalina Island is also vaccinated against both canine distemper virus (CDV) and rabies as a means of protecting the population against another potential disease introduction.
In this particular case, the injured fox was immediately transported to the Animal Clinic in Catalina for assessment and potential treatment. In addition to the obvious leg injury the fox was also extremely thin due to its inability to effectively forage for several weeks. Conservancy biologists consulted with Avalon veterinarian Dr. Richard Denney and agreed upon an approach that would require the amputation of the injured leg.
According to Julie King there have been several wild foxes on Catalina and the other Channel Islands that have sustained injuries where the amputation of a leg was necessary and the foxes were released and survived.
“At the conclusion of the captive breeding program in 2004, an adult female was released with only three legs” says Julie King, “while monitoring her post-release, she was found to have traveled several miles before settling into a territory and successfully raising pups.”
Biologist Calvin Duncan with recovering fox
Though the bone fracture on the male island fox occurred within the tarsal bones or “ankle joint,” the leg was amputated mid- femur and the remaining nub was tucked under the skin. According to Dr. Denney this was necessary in order to eliminate the chance that the fox would attempt to walk on the remaining limb leading to abrasions and potential infection.
After the surgery the fox was transported to the Conservancy’s Middle Ranch Wildlife Field Clinic where he was cared for by Conservancy biologists during his twenty-day recovery.
On October 4, 2011 he was fitted with a radio collar and successfully released at his original capture location. We continue to monitor this fox as he makes his adjustment back into the wild and to date he is doing well.
This is another example of how radio collars are used to help monitor individual island foxes.

Video of an island fox barking taken by Calvin Duncan