Darwin's fox

Darwin's fox, also called Darwin's zorro, is a special kind of small wild animal from Chile. It belongs to a group of animals called canids, which are related to wolves but are not true foxes. This fox lives in the temperate rainforests of Nahuelbuta National Park, the Cordillera de Oncol, Cordillera Pelada, and Chiloé Island in Chile.

The fox was first found and collected by the famous naturalist Charles Darwin in 1834 on San Pedro Island. For a long time, people thought it was a type of the South American gray fox, but in 1990, a small group was discovered on the mainland. Scientists then learned it was its own special species.

Today, there are thought to be fewer than 1,000 of these foxes left, mostly on Chiloé Island with some smaller groups on the mainland. They face dangers from diseases carried by dogs and from people changing their homes. People are working to help them by vaccinating the foxes and protecting their habitats.

Characteristics

Darwin's fox is a small, dark-colored animal that weighs between 1.8 to 3.95 kg and has a head and body length of about 48 to 59 cm. Males have a broader muzzle compared to females, but otherwise look very similar.

This fox lives only in forest areas and does not mix with other similar species. It is smaller and darker than its relatives, with shorter legs, a broader skull, and a special mix of black, gray, and reddish fur. It also has white patches under its chin and belly, and a short, bushy, dark gray tail that helps tell it apart from other foxes.

Taxonomy and evolution

Lycalopex is a group of dogs from South America that is related to wolves but not actually true foxes. One of the first times someone wrote about Darwin’s fox was when Charles Darwin saw one on San Pedro Island in the Chiloé Archipelago in 1834 during a trip. He described it as different from other foxes.

At first, Darwin’s fox was called Vulpes fulvipes. Over time, scientists debated whether it was its own species or part of another fox group. In 1996, tests with DNA showed it was its own special species, and by 2005, it was given the name Lycalopex fulvipes.

For a long time, people thought Darwin’s fox only lived on Chiloé Island. But in 1990, a small group was found in Nahuelbuta National Park on the mainland. Scientists think these foxes may have been separated from others when land changed thousands of years ago.

Diet

Darwin's fox is an opportunistic omnivore and eats many different things. Mostly, it eats insects, but it also eats small birds, reptiles, fruits, seeds, and small mammals.

Studies of the fox's waste in Nahuelbuta National Park showed it mostly eats mammals like Akodon, Monito del monte, Southern big-eared mouse, and long-clawed mole mouse. It also eats birds, reptiles, insects, and plants. On Chiloé Island, the foxes mostly eat small creatures, especially insects and a type of tiny rodent, along with fruits. They also eat some fish, reptiles, birds, and Monito del monte. What they eat changes with the seasons, eating more rodents in winter and fewer insects.

Ecology

Darwin's fox lives in the temperate rainforests of southern Chile. It can be found in places like Chiloé Island and the mainland, where it lives in forests and shrublands. Sometimes, it also uses areas near the coast or with eucalyptus trees. Studies using radio-telemetry show that these foxes prefer areas with lots of native forest and avoid places with many roads.

These foxes are most active during twilight and before sunrise. Some people say they are not afraid of humans and can be tamed, but too much human activity can harm their populations. On Chiloé Island, they are harder to find where there is less forest or more dogs.

In the past, there were about 250 Darwin's foxes on Chiloé Island and fewer on the mainland. Recent counts show there are now around 639 mature individuals, with most living on Chiloé Island. The species is still considered endangered because its numbers are low and its habitat is threatened.

Conservation status

In 2016, experts said Darwin's fox is in danger because there are not many left. Keeping this animal safe is hard because of many problems.

One big problem is domestic dogs. Dogs can hurt the foxes and also spread diseases to them. To help, scientists in Chile give free vaccines to dogs to stop diseases from spreading.

Another problem is losing their homes. Darwin's foxes like to live in forests, but some forests are disappearing. Some places where they live are protected, like Alerce Costero National Park, Nahuelbuta National Park, and Chiloé National Park.

People sometimes harm the foxes because they think the foxes hurt their chickens. Building bridges and roads can also be a problem because it might let other animals come to the island where the foxes live.

Scientists are working on new ways to protect the foxes using special technology to learn more about their genes and health. However, this work needs more money and better equipment to succeed.

Diseases

Darwin's foxes can catch diseases from rural, domestic dogs that roam freely in Chile. These dogs often don’t get veterinary care, which can spread harmful germs to the foxes. Studies show that even though the foxes and dogs live in different areas, they sometimes eat the same food, which can help diseases spread.

Some diseases, like canine distemper and rabies, could potentially spread from dogs to Darwin's foxes, but there isn’t much proof that these diseases are currently affecting the fox populations. Darwin's foxes can carry a type of bacteria called Mycoplasma without showing clear symptoms. Another bacteria, Mycoplasma haemofelis, was found in Darwin's foxes for the first time in 2013. There is also evidence of other germs, like Toxoplasma gondii and Leptospira, in these foxes, which might be harmful to them.