Grey Fox

The gray fox (Urocyon cinereoargenteus) is a solitary, nocturnal canine found often in our lovely deciduous forests. They have an extensive range throughout North America (below Canada) and the northern cap of South America in Venezuela and Colombia. They used to be more common in the Eastern United States, but human influence has allowed them to dominate across a greater area until they have spread from coast to coast.

A grey fox in Red Rock Canyon, Nevada -- James Phelps 2004

A grey fox in Red Rock Canyon, Nevada — James Phelps 2004

There are 16 recognized subspecies of gray fox, 7 of which are North of Mexico. The grey fox and channel island fox (Urocyon littoralis) are the only living members of their genus. Genetically, they are similar to the tanuki (Nyctereutes procyonoides) of Asia and the bat-eared fox (Otocyon megalotis) of Africa. The tanuki is the only other kind of canine that can climb well.

The grey fox appeared during the mid-Pliocene, 3.6 million years ago (mya). They likely migrated into Northeastern US in the post Pleistocene epoch during the Medieval Climate Anomaly warming period from  AD 950 to 1250, which was followed by the Little Ice Age from roughly 1350 to 1850. The evolution of the grey fox, and other canines, is fascinating, but it is detailed and could be tedious to read, so I plan to touch on it in another post.

Adult male and female grey foxes -- Apterex 2009

Adult male and female grey foxes — Apterex 2009

Grey foxes live to be around 8-10 years old in the wild. They are around 76-113cm in length, and weigh around 3.6-7kg. Their coloration is red on their face and legs, with a grey dorsum (back) and a ventrum (belly) that can range between white and orange-red. Their tails are around 28-44cm long and exhibit a black dorsal stripe, along with a continuation of the same red and grey. They lack the black stockings of the red fox (Vulpes vulpes). They molt once a year between early Summer and Autumn. Their skull is fairly distinct, as their temporal ridges (upraised lines of bone on the top of the skull) are widely separate, forming a U-shape. They have little sexual dimorphism (visible differences between sexes), other than females being somewhat smaller than the males. They are also unique in having oval, rather than slit, pupils, unlike the genus Vulpes.

A black and white house cat (Felis catus) showing yellow eyeshine -- Una Smith 2008

A black and white house cat (Felis catus) showing yellow eyeshine — Una Smith 2008

They have a tapetum lucidum, which helps them see well during their nocturnal activities. The tapetum lucidum is a highly reflective membrane just behind the retina (the back of the eye with the cells that actually sense light). The tapetum lucidum reflects light back onto the retina, and more light means better vision at night. You might be familiar seeing this in a dog or cat at night, when their eyes seem to glow different colors, like green, yellow or red.

An illustration of The Fox And The Grapes illustrated by Milo Winter, from The AEsop for Children by Project Gutenberg, 1919

An illustration of The Fox And The Grapes illustrated by Milo Winter, from The AEsop for Children by Project Gutenberg, 1919

They are an opportunistic omnivore. They hunt small mammals, like rabbits, small rodents, lizards, and birds, but they also eat a lot of wild plants. They particularly enjoy fruits when they are available, eating acorns, berries, grapes, and much more. In some areas, they can be primarily insectivorous and herbivorous. If they manage to collect more food than it can eat in one sitting, it might store the excess and mark the spot with their urine in order to find it again later. Their ability to climb helps them reach food in the trees that might otherwise only be available to birds and smaller animals. This reminds me of the Aesop’s fable “The Fox and the Grapes”. I will paraphrase it here:

A fox traveling along notices some grapes hanging high from a tree. Quite hungry, he leaps to catch the grapes, but as high as he jumps, he can’t reach them. Huffing, he remarks, “Those grapes look sour anyway.”

The fox in the fable was probably not a grey fox, since they would be quite able to climb up to eat the grapes. I suppose the new moral for this story would go to show that we should use our unique strengths to make the best of a situation, rather than to get irritated and give up.

A pair of grey foxes at a golf course near San Francisquito Creek in Santa Clara County -- Bill Leikam 2011

A pair of grey foxes at a golf course near San Francisquito Creek in Santa Clara County — Bill Leikam 2011

Grey foxes excel at climbing trees thanks to their particular anatomy. In some places, they are known as the “Tree Fox” for this reason. Their claws are strong and curved at the ends, so they can get a good hold into bark. They have been witnessed climbing up a tree at a nearly vertical angle! Their legs are shorter than the red fox, allowing it to climb better. The trade-off is that red foxes are able to run more quickly. They can descend the tree by either walking down it backwards, or running down head-first if the tree is slanted. They are also able to jump between branches. They are so good at climbing that they will often make dens up in a hollow tree, or perhaps in a hole someone else has dug.

A fur bag made of the grey fox -- Kuerschner 2011

A fur bag made of the grey fox — Kuerschner 2011

The grey fox has been hunted historically, and is still harvested today, for their beautiful fur, like many other creatures. Fortunately, this has not affected their populations greatly. They are listed as a species of Least Concern. Apparently, early European settlers (and fox hunters) who came to North America didn’t like that the grey fox preferred to climb up a tree or into a hole instead of leading a long chase like the red fox. The settlers introduced their red foxes into some of their colonies for a better hunting experience.

A red fox snarling at a grey fox on the San Joaquin National Wildlife Refuge, CA -- USFWS Pacific Soutwest Region 2013

A red fox snarling at a grey fox on the San Joaquin National Wildlife Refuge, CA — USFWS Pacific Soutwest Region 2013

This introduction has led to red foxes being common in the eastern United States. At first, the two species were found in different areas, as the red fox preferred boreal forests (colder, more conifers like pine trees) and the grey fox was found in deciduous forests (warmer, trees shed their leaves in the Fall). The red fox has spread out throughout the US, but the grey fox apparently still dominates in areas where they overlap. Notably, the grey fox can be found in a remarkable range of habitats from the deciduous forests, the open desert or rocky canyons of Arizona, even to grasslands and, of course, urban areas.

A grey fox in North Carolina. She has four kits under the wooden paneling behind her. -- Dcrjsr 2010

A grey fox in North Carolina. She has four kits under the wooden paneling behind her. — Dcrjsr 2010

Grey foxes have an annual breeding season that varies depending on where they are found. Roughly, this can be between late Winter and early Spring. They form a monogamous pair. The female is pregnant for about seven and a half weeks. Their litter can be between one to seven kits, who are able to hunt along with their parents at three months old. At four months old, the kits get their adult teeth and are able to find their own food. However, the family stays together until Autumn. The kits learn from their parents and play with each other to practice the skills they will need as an adult. In Autumn, the kits become sexually mature adults and leave to find their own territories and families. The offspring might still meet their parents, if they live close enough, but they no longer have extensive interactions.

Grey fox kit at the Baylands -- Bill Leikam 2011

Grey fox kit at the Baylands — Bill Leikam 2011

As mentioned earlier, the grey fox has spread through a large area, partially due to their adaptability to humans in their habitat. From what I gather, it seems that both the grey and red fox (Vulpes vulpes) are able to adapt to living around people. They have a fairly flexible diet, one that can include small pets like chickens or rabbits, but is more likely to be rodents in your yard, or any fruit available, like grapes or strawberries. They are said to avoid garden vegetables and adult cats (who could be a fierce rival in a fight). They rarely carry rabies, and are overall rather benign as far as wild guests go. If you have a fox living near you, please leave it alone, and be glad for the view you get of a natural animal. If you truly do not wish to see them again, this link has many suggestions for scaring them away humanely.

A grey fox in captivity at the Lindsay Wildlife Museum in Walnut Creek, CA. -- Milonica 2012

A grey fox in captivity at the Lindsay Wildlife Museum in Walnut Creek, CA. — Milonica 2012

The grey fox seems to be a beautiful and resourceful creature. Their general nocturnal, shy nature speaks of caution, though sometimes they can be more bold when forced to tolerate humans in close proximity. Often, I hear of foxes being associated with mischief, but I do not really see that here. They seem to represent adaptability and a strength that doesn’t need to be boasted of. They are flexible in their lifestyle, and also stay their course of survival despite the challenges of human encroachment into once-wild lands. It is rather inspiring, and they carry a regal image in my mind. I definitely respect the grey fox.

A grey fox resting in the rocks -- Gary Stolz, USFWS 2013

A grey fox resting in the rocks — Gary Stolz, USFWS 2013

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