Coyote (Canis latrans)
The coyote is a member of the dog family, along with foxes and wolves. This medium-sized canid bears a close resemblance to a small German shepherd with a brown-gray coat and whitish belly. Adults typically weigh between 25 and 40 pounds but some larger individuals can weigh up to 50 pounds or more. Coyotes have a dark band that runs down the back and onto the tail, which is tipped in black.
Over time the distribution of the coyote has come to include most of North America except parts of northern Canada. Historically, the coyote was absent from much of the Great Lakes Drainage Basin before European settlement. The lands east of the Mississippi were vast deciduous forests inhabited by wolves. Once the Europeans arrived they began deforesting and farming the land, quickly finding conflict with the native wolves and their livestock. The wolves were extirpated and the coyotes that faced similar persecution in the Great Plains immigrated to the newly abandoned territory, quickly increasing in abundance. The prevalence of coyotes in these areas can have important ecological implications in their role as apex predators and subsequent impacts on prey species, especially in urban areas.
Coyotes’ habitat preferences reflect their diet as they are generalists and can utilize any habitat, but they are least tolerant of unbroken forested tracts, preferring both natural areas (prairies, bushy areas, woodland edges) and human-populated areas (farms, suburbs, and cities). In urban areas they prefer wooded patches and green spaces to allow for shelter to avoid humans.
Coyotes are carnivores, but also opportunistic generalists that will shift their diet to take advantage of the most available prey items. An existing misconception about urban coyotes is that they eat primarily garbage and pets, but literature reports that 90% of their diet consists of small mammals such as voles, shrews, and mice, as well as rabbits, hares, and muskrats. Coyotes will also eat birds, snakes, frogs, and insects. Fruits and vegetables are occasionally eaten, especially during the growing season. Urban landscapes have surpluses of food resources, including squirrels, rabbits, geese, and other species that thrive in urban environments. Coyotes can help to control population numbers for these overabundant prey species.
Coyotes have a highly variable social organization formed in response to different environmental variables such as food and space availability. The most basic form is a mated pair. Coyotes can live alone or in packs. Packs are often seen in northern regions with high concentrations of large ungulates. The packs are made up of 3-7 members consisting of a mated pair and their offspring of varying ages. The packs have a dominance hierarchy and a leader that is usually male but may be female. In rural areas, packs may have a territory of approximately 8 miles that they defend from other coyotes by chasing them out and define by marking boundaries with urine or feces. Urban home ranges appear to be much more variable in size. Coyotes have a series of ten or more unique vocalizations specialized for communicating different messages, including alarm calls, territorial howls, and distress yelps. Vocalizations vary from individual to individual based on age, social status, and sex.
Coyotes can be active at any time during the day but are generally most active at sunset and in the early morning and may have periods of activity during the night. In developed areas, coyotes tend to be mostly nocturnal whereas coyotes in natural areas tend to be active during the day (diurnal) or at dawn and dusk (crepuscular). Coyotes tend to move through urban areas using corridors such as railroad tracks or underpasses to avoid human and vehicle traffic, but the convenience of sidewalks and roads through towns further pushes the advantage of nocturnal behavior.
Wild coyotes have a life expectancy of around 3 years. The most common cause of death in urban coyotes is vehicle collisions. While urban coyotes have adapted to living in close proximity to roads, vehicle collisions still contribute heavily to mortality.
The female coyote comes into heat only once each year for 4 to 5 days, sometime between January and March. Coyotes mate typically in February. This strongly monogamous species develops pair bonds typically only broken by the death of one of the pair. After a gestation period of 58 to 65 days, the female searches out a den site or digs one herself in which she will give birth, usually in mid-April.
Outside of birthing season, coyotes sleep above ground in cover or in the open, but use dens during the pupping season. In urban areas, coyotes use many structures for den sites, from under buildings and inside parking structures, to remote woodlots and planter boxes. Females may re-use dens in consecutive years or may move pups to a new site for protection.
The average litter contains 6 pups, ranging from 4 to 7, each weighing around 9 ounces each. Coyotes are able to adjust litter sizes in response to food availability and population densities, increasing survival rate. The pups are born covered with short, woolly hair and with eyes closed until they open at 14 days old. During the third week, the pups begin eating food regurgitated by the mother and begin learning how to hunt at two months. Occasionally the father or older siblings from an earlier litter will watch over the growing young or bring them food. At 4 to 5 weeks old the pups begin fighting among themselves which results in the establishment of a dominance hierarchy. The fighting is gradually replaced by displays communicating dominance and submission. After this, fighting decreases and playing increases. At 6 weeks, the pups will travel short distances from the den with adults and pups begin dispersing and spending more time away from the parents by August. Many of the young disperse from the den after 6 to 9 months but most do not breed until their second winter. In some cases, young coyotes remain with the parents and form a pack in the winter.
Red Fox (Vulpes vulpes)
The red fox is a small sized member of the dog family, ranging from about 7-15 pounds. This species generally has a red or yellowish-red coat with a white underside extending from the chin to the tail. The tail is reddish speckled with black and tipped with white. The red fox’s feet and long, slender legs are black, resembling stockings and contrasting sharply with their red back.
Of all terrestrial carnivores, the red fox has the largest geographical range in the world. They can be found on almost every continent. In some areas, they are considered invasive and out-compete native mesocarnivore species.
Foxes are generalists and can successfully use a variety of habitats. They prefer open country with reliable cover nearby and frequent forest-field edges, brushy fence lines, and the wooded borders of streams and lakes. They are well-adapted to human development and frequently inhabit urban areas, large parks, cemeteries, or golf courses.
Red foxes are generally solitary hunters and use their acute hearing to locate prey. Typical prey includes small mammals such as squirrels, mice, and voles, as well as ground nesting birds and rabbits. These canids are opportunistic and will feed on snakes, crayfish, salamanders, insects, nuts, and seasonal fruits. Occasionally, foxes cache—or store—their food under dirt and leaves. This behavior is more common in winter when food is less available.
There is some variation in the social organization of foxes, the most common of which being the joining of a male and female during the breeding season. The pair may move more separately outside of the season. In areas where the density of red foxes is higher they may live in social groups consisting of one male to several females. One of the main forms of communication between foxes is scent-marking with urine or feces which can carry information about the animal’s sex, breeding condition, and possibly their individual identity.
A fox’s home range consists of pathways between areas of consistent use. The estimated size is from 1 to 5 square miles but varies based on season, diversity of habitat, abundance of food, and the individual’s sex. When adults are caring for young they may stay closer to the den and during winter they may travel farther in search of less abundant food sources.
Urban foxes are largely nocturnal (likely to avoid human encounters) and become active about 2 hours before dark until several hours after dawn, although it is not uncommon to see foxes during the day. Foxes spend most of their time searching for food, so the length of time a fox is active depends on how easily it can find it. During most of the day, foxes sleep out in the open as dens are only used for breeding.
The average life span is only 1 year, but some will survive for 5 to 6 years. Vehicle collisions are major sources of mortality in urban areas. Unwary young are threatened by large hawks, owls, and vehicles.
Outside of the breeding and pupping season, male foxes are solitary but forms strong pair bonds with a single female in early winter and remains with her until the young disperse in late summer. Copulation occurs between early January and mid-March and gestation lasts for 51 to 54 days.
During the breeding season, the pair resides in an underground den. Rural red fox dens are usually vacated woodchuck burrows, but urban foxes will use buildings, junk piles, and other man-made structures for shelter. Foxes on the UW-Madison campus have used several campus buildings for den sites in the last few years! Dens are abandoned in late summer but are often used for multiple years.
The pups are blind when they are born, but are covered by woolly fur and already have their distinct white-tipped tail. A litter typically contains 5-8 pups weighing around 3.5 ounces each. At five weeks old, the pups begin playing around the entrance to the den and at eight weeks, they begin eating meat. The male has an important role, bringing the vixen birds and mice to feed on, watching over the pups as they venture out of the den, and accompanying the young on their first hunting trips. By late September, the family begins to disband, the juvenile males leaving first and dispersing. The young females typically stay closer to home, occasionally remaining with the parents and helping her parents raise the next litter. Both females and males become sexually mature in their first winter.