Animal Talk with Pecker: Domestication of the Silver Fox

Nature is the ultimate potter, shaping and molding the beautiful creatures we see today. Our wild, untamed environments have produced equally wild creatures, designed to thrive in the savage, unforgiving territories they inhabit. So what is it that separates that which is wild from that which is domesticated? Is it simply temperament, the spirit of the animal? What about the physical characteristics; do the stripes make the tiger? Come with me as we explore the beauty of nature and the genetic transformation of the Silver Fox.





The silver fox is the same species as the red fox (Vulpes vulpes) with a genetic mutation that results in melanism - the darkening of the fur. The pelts of silver foxes vary from completely black to a light bluish color. These foxes pass their genetic mutation to their offspring. As with the red fox, the silver fox has an elongated body and relatively short limbs. The tail, which is longer than half the body length, is fluffy and reaches the ground when in a standing position. They make up the largest species of the genus Vulpes. The average size is 14-20 inches at the shoulder and 30-50 inches in total body length (tail included). Foxes are incredibly light and agile with weights ranging from 5-31 lbs. Foxes weigh considerably less than similarly sized dogs due to smaller bone size and density. Despite their relatively short legs, their light bodies allow them to reach a top speed of up to 30 MPH.





The silver fox can be found over much of the northern hemisphere. The gene mutation that results in the silver fox mostly occurs in cold regions. In the former Soviet Union, silver foxes occur mostly in forest zones and forest–tundra belts, particularly in middle and eastern Siberia and the Caucasus mountains.





While silver foxes have existed over much of the northern hemisphere for millennia, our journey will take us to 1950’s Soviet Russia, where the animal fur trade was poppin. Silver-gray Fox pelts were like Louis V. bags (or limited edition Carhartt camo jackets, depending on where you’re from). The skins were pricey and in high demand, being one of the most valuable animal furs on the market. Due to the high demand, a state-sponsored Department of Fur Animal Breeding was created at the Central Research Laboratory in Moscow. Dmitry Belyayev, a scientist working at the laboratory, developed an interest in the genetics of the animals he was studying and breeding.

One subject that fascinated him was the question of how such a remarkable diversity of canine breeds had arisen from the domestic dog's lupine ancestors. Like other scientists, he "could not figure out what mechanism could account for the differences in anatomy, physiology, and behavior." The genetics of domestication had also been of great interest to Darwin. It was recognized that domesticated animals differ in several ways from their wild counterparts, but it was not known what principle of selection had guided the Neolithic farmers who had first domesticated these species thousands of years ago.

Belyayev's hypothesis was that domesticated species were the result of generations of animals selectively bred for their “tameness.” Could that explain the temperamental and morphological differences of the domesticated species from their wild counterparts? Belyayev sought to answer that question.





Dmitri Belyayev was dismissed from his post at the Moscow laboratory in 1948 for his insistence that Darwinian artificial selection could produce rapid evolutionary change. He then embarked on an experiment to prove his hypothesis. Led by Dmitry Belyayev, researchers at the nearby Institute of Cytology and Genetics gathered up 130 foxes from fur farms. They then began breeding them with the goal of re-creating the evolution of wolves into dogs, only this time using foxes. With each generation of fox kits, Belyayev and his colleagues tested their reactions to human contact, selecting those most approachable and least aggressive to breed for the next generation. His goal was not simply to produce friendlier, tame foxes. He wanted a truly domesticated breed of silver fox.

Many wild animals can be tamed by raising them from birth. This is essentially a learned behavior. That animal, however, is unlikely to exhibit a true affection or dependence on you. And most importantly, its behavior is not passed down to the tamed animal's offspring. Domestication is actually a change at the genetic level, where desirable traits for the purpose of human interaction or utility are selectively bred.





Our Soviet comrade, Belyayev, found something remarkable as he continued selectively breeding only those individuals that were the most docile, friendly and showed the least fear of humans. He found that only within a few generations, the foxes began to act dog-like. And as they began to act more dog-like, they began to look more dog-like. Selecting which foxes to breed based solely on how well they got along with humans seemed to alter their physical appearance along with their dispositions.

After only nine generations, the foxes were whining and wagging their tails in response to a human presence, behaviors never seen in wild foxes. The researchers recorded fox kits born with floppier ears, smaller canines, smaller skulls and piebald (multicolored spots) patterns appeared on their coats along with white fur (pictured below). The foxes who were more docile had less adrenaline and testosterone. These slight differences in the endocrine system led to the physical changes of the breed. And the changes were amplified with each generation. The ironic result of domesticating silver foxes for their beautiful coats was that the truly domesticated foxes exhibited coats that were no longer silver. Recovery of this trait would now require additional selective breeding.





Nature has molded these creatures physically and psychologically, built for the wild. Without the wild, the creature is without a purpose. A tiger only has its stripes because it must have them to survive. A domesticated version would be no tiger at all. Our friend, the silver fox is no different. It will live on as the wild creature it was intended to be, while other limp, fruity versions of it grace the homes of people who think they have a fox.

Gather your friends and family and tell them what you've seen here. Tell them that nature is beautiful and miraculous. And tell them Pecker sent you.

Join me in celebrating the Silver Fox.