Veterinarians are one step closer to solving the mystery behind the unusually high occurrence of ear tumors that plagues a federally protected fox population on Catalina Island.
In recent years, scientists noted that half of the island's foxes had developed ear tumors, approximately two-thirds of which were malignant. Nearly every fox on the island was also found to be infected with ear mites.
Recovered Catalina Island Fox In New Kind Of Trouble
In 2009, a research team from the University of California at Davis, the Institute for Wildlife Studies and the Catalina Island Conservancy began treating the foxes with acaricide, a chemical agent that has proven effective in treating ear mites in domestic dogs and cats.
After a six-month trial period, the prevalence of ear mites dropped 88%. The presence of tumors also has dropped significantly, researchers say.
"It's rare to have a success story," UC-Davis student Megan Moriarty, the lead author of a new study about the mite treatment, says in a news release. "It was interesting to see such striking results over a relatively short time period."
Fighting Foxes Win Wildlife Photo Competition
Researchers still haven't pinned down exactly why so many of the island's foxes developed tumors, although they believe that genetics play an important role. While other island fox populations are commonly infected with ear mites, their cancer rates are far lower than the Catalina Island population.
"Catalina foxes have an over-exuberant tissue reaction to the same stimuli -- the mites -- and that appears to lead to the tumors," UC-Davis veterinarian Winston Vickers explains. "That's why we gravitate toward genetics in addition to other factors."
Vickers' and Moriarty's newly published research is detailed in two studies in the journal PLOS ONE.
Article first appeared on Discovery's blog Dscovrd.

Winston Vickers, a UC Davis wildlife veterinarian, examines a Santa Catalina Island fox for ear mites.

Winners of a well-known yearly wildlife photography competition have just been announced. Wildlife Photographer of the Year is developed and produced by the Natural History Museum, London. More than 42,000 entries in the contest were submitted from photographers in 96 countries. The overall top prize went to Canadian amateur photographer Don Gutoski, Wildlife Photographer of the Year, whose startling image of the end of a battle between foxes in Cape Churchill, Canada wowed competition judges. Gutoski's image depicts a red fox's victory over a northern Arctic fox in an area where the two species overlap in territory. Next we'll look at some of the other winning entries.

This warlike courting scene between ruffs was taken in Norway by 14-year-old Ondrej Pelánek, Young Wildlife Photographer of the Year, from Czech Republic. "I took this photograph at midnight when my father was sleeping. I was too excited, so stayed awake," said Pelánek in a press release.

Britta Jaschinski took home the Wildlife Photojournalist award for this shot of big cats performing obediently at the Seven Star Park in Guilin, China. The animals have had their teeth and claws removed and live in cramped spaces when not on stage. Jaschinski has spent 20 years documenting such cruelty of captive animals.

A Bryde’s whale rips through a swirling ball of sardines, gulping a huge mouthful in a single pass. The shot, taken during a dive off South Africa, was captured by Michael AW, winning him the Underwater Photo prize.

The winning Amphibian and Reptiles photo went to Edwin Giesbers, for this great crested newt in the Netherlands, hanging motionless near the surface of a stream. The photographer himself was also motionless in the water, in a wetsuit. It was a cold April morning, and the trees were still bare of leaves.

Juan Tapia captured the Impressions award for this captivating picture of a swallow bursting through a swallow-sized hole in the canvas of a painting. The painting covered a storehouse window on the photographer's farm, through a hole in which swallows tended to fly when looking to nest. Tapia decided to create a different view of their arrival on scene.

Amir Ben-Dov's "The company of three" depicts a trio of red-footed falcons in Israel, where they were resting during fall migration. The slate-gray falcon is an adult male while the remaining pair are sub-adult females.

In the United Kingdom, Richard Peters took the Urban photo honors when he photographed this fox in Surrey, England as it cast its profile on the side of a shed. Peters had cast the light himself and sought to convey the sense of living in the shadows that is suggested by urban foxes.

Jonathan Jagot has been sailing round the world with his family for five years, and for the past three years he has been taking wildlife photographs. When the family anchored off the island of Lençóis on the coast of northeast Brazil, Jagot saw his first scarlet ibi. And that led to this photograph, which won Jagot the Young Photographer prize in the 15-17 year-old category.

Pere Soler's "the art of algae" won in the From the Sky category. From high in a chartered plane, he captured the mosaic of marshes, reed beds, sand dunes, and beaches in Bahía de Cádiz Natural Park, on the coast of Andalucia, Spain. The delta spectacle of color simply dazzles.