By Alexis Newman
With reference to Dora the Explorer (a beloved childhood television show), Swiper began swiping quite a long time ago. Dating back to the Illinoian glaciation during 300 000 to 130 000 BP, the fossil record shows red foxes having crossed the Bering Land Bridge from Eurasia into North America. The red foxes migrated southward into what is now the United States throughout the Sangamon interglacial from 130 000 to 100 000 BP, only to be separated into two groups during the Wisconsin glaciation from 100 000 to 10 000 BP. One population resided within the region of Alaska and the Yukon, while the other remained in the southeastern United States. Glaciations and interglaciations are caused by Milankovitch cycles (changes in the way the Earth orbits the sun) in combination with glacial-climate feedback loops. The intensity of summer heat insolation at high northern latitudes depends on the Earth’s position facing the sun, causing continental ice sheets to either grow or recede. This influences the planetary albedo (the land’s sunlight reflectivity) and in turn affects the global mean temperature, further freezing the glaciers to cause a glaciation or further melting the glaciers to cause an interglaciation period. When the next interglaciation began, what was left of the two red fox populations began to merge throughout what is now our great Canadian landscape (Aubry et al 2669).
The home ranges of red foxes commonly rest along the edges of forests, using tall grass and shrubbery for hunting and foraging coverage. The open land of neighbourhood lawns and paved parking lots, as well as high human-density (urbanistic) areas, are generally avoided, since such conditions often put red foxes in vulnerable positions for attack (Adkins and Stott 344). Red foxes are mostly nocturnal-crepuscular mammals, actively traversing their territory boundaries over the course of each night, hunting, and scavenging for food sources (Arroyo et al 129). Once a red fox finds food remains or finishes their own meal, they will urine mark directly on it or within 15 cm of it to signify that the vicinity holds no more food (Henry 87). While scavenging, a red fox can urine mark up to 70 times per hour, each time lasting an average of 2.25 seconds (Henry 85). Urine marking is the elimination of bodily wastes with added glandular secretions to elicit information to and from other red foxes. While signalling food shortage is the primary reason for urine marking, other reasons for doing so include displaying dominance, locating mates, following trails, reinforcing pack bonds, and indicating pregnancy in female foxes (Henry 83).
This bodily function would make little sense if red foxes were solidary hunters with their own territories, as there would be no one around to receive their messages. Thus, red foxes can mostly be found as monogamous pairs (occasionally polygynous) along with their offspring, forming a small group with a dominant versus subordinate relationship (Baker et al 1482). Once the cubs are old enough, they disperse to breed and form their own families or they inherit the territory upon their parents’ decease. Red foxes aggressively defend their territory from neighbouring groups, which often results in fighting (Baker et al 1488). The red fox opponents will stand on their hind feet and attempt to knock each other over, shoving their chests with their forepaws and biting each other’s muzzles (Baker et al 1296). This combat is riddled with screaming and crying sounds. The victor will stand its ground while baring teeth, snarling, and arching its back, as the loser flees with its head hanging. There are several degrees of fighting, such as a vicious brawl, a brief skirmish, or a passive quarrel; however, it is very rare that any serious injuries ensue any kind of fight (Vincent 755). Red foxes will also fight over the right to a mate and to maintain a certain position of social hierarchy (Vincent 757).
Considering all that has been previously discussed, the family of red foxes living in my backyard is rather unusual. Here is a picture of one of the smaller red foxes sunbathing on the front path to my house. Contrary to normal red fox behavior, this family is seemingly very accustomed to human presence, as none of them make any effort to flee when we are outdoors. They act like a pack of cats lazing about, watching us, occasionally scratching themselves, and napping. The strangest thing is their nearly constant daytime presence as opposed to their supposed nocturnal nature. They appear to be quite happy, which is probably due to the abundant food sources on our property such as our squirrel population (having severely depleted consequently). Red foxes are omnivores, which we tested by throwing a strawberry to one of the cubs. It enjoyed the juice from it, but the whole family was completely obsessed with the den of newborn groundhogs in our front yard. They stalked the hole at all hours of the day, taking turns waiting while concealing themselves in the garden plants. They could not be shooed away for long, and it goes to show how devoted they are as hunters. Here is another picture of one of them right outside my front door in plain sight, staking out its prey. We make sure to keep our distance and be as active outdoors as possible to show them that this is our territory, yet they seem perfectly fine with sharing it and have shown no intention of leaving any time soon.
References in MLA Format
Adkins, C. A, and P. Stott. “Home ranges, movements and habitat associations of red foxes Vulpes vulpes in suburban Toronto, Ontario, Canada.” Journal of Zoology, vol. 244, no. 3, (1998), pp. 335-346.
Arroyo, B, Caro, J, Delibes-Mateos, M, Díaz-Ruiz, F, and P. Ferreras. “Drivers of red fox (Vulpes vulpes) daily activity: prey availability, human disturbance or habitat structure?.” Journal of Zoology, vol. 298, no. 2, (2016), pp. 128-138.
Aubry, Keith B, Perrine, John D, Sacks, Benjamin N, Statham, Mark J, and Samantha M. Wisely. “Phylogeography of the North American red fox: vicariance in Pleistocene forest refugia.” Molecular Ecology, vol. 18, no. 12, (2009), pp. 2668-2686.
Baker, Philip J, Harris, Stephen, Iossa, Graziella, and Carl D. Soulsbury. “Body mass, territory size, and life-history tactics in a socially monogamous canid, the red fox Vulpes vulpes.” Journal of Mammalogy, vol. 89, no. 6, (2008), pp. 1481-1490.
Baker, Philip J, Harris, Stephen, Iossa, Graziella, and Carl D. Soulsbury. “Fitness costs of dispersal in red foxes (Vulpes vulpes).” Behavioral Ecology and Sociobiology, vol. 62, no. 8, (2008), pp. 1289-1298.
Henry, J. D. “The use of urine marking in the scavenging behavior of the red fox (Vulpes vulpes).” Behaviour, vol. 61, no. 1-2, (1977), pp. 82-106.
Vincent, Robert E. “Observations of Red Fox Behavior.” Ecology, vol. 39, no. 4, (1958), pp. 755-757.
McGill University Lecture: Long-term Climate Change Patterns (climate change “rhythms” over the last 2 million years). ENVR-200-051 Fall 2016.