The Red Fox
Cunning, agile and charismatic are just a few of the adjectives that describe the Red fox. The largest member of the true foxes, the Red fox is a widespread and very adaptable species that takes up residency as one of Iowa’s most efficient predators.
The Red fox is Eurasian in origin and the earliest fossils date back 1.8-3.4 million years ago. They were thought to have migrated to the North American continent some time after the Wisconsin Glaciation. The earliest modern fossils have been found with the refuse of early human settlements suggesting that the Red fox was used by humans for food and pelts.
Red foxes are similarly built like modern domestic dogs yet they are much lighter than a dog of the same size. Their forepaws have 5 digits while the hind feet have only 4 and lack dewclaws. Red foxes are very agile and are capable of jumping over a 6-foot fence. They are also very good swimmers.
An average adult fox measures 14-20 inches high at the shoulder and 19-35 inches in body length. They typically weigh 8-16lbs with the largest specimen on record weighing 26.5lbs. An adult fox can trot at a speed of 3-8mph with a maximum running speed of roughly 31mph.
Just like other dog-like mammals, Red fox have binocular vision. Their eyesight is good but is mostly sensitive to movement and variations in terrain. Red foxes have some of the best hearing of any animal in Iowa and they are capable of detecting the sounds of a squeaking mouse at more than 300 feet away. Research has shown that a fox can detect the location of a sound up to 1 degree at frequencies between 700-3,000hz. Their sense of smell is very good but weaker than that of specialized domestic dogs.
Red foxes either establish stable home ranges or roam with no fixed territory. They will mark their territory and cache sites with urine to discourage would-be competitors from impeding on their domain. The home range of a Red fox can be as much as 20 square miles and they will routinely patrol this range throughout the year. Smaller home ranges of less than 3 square miles are more common especially when food and water resources are abundant.
They live in family groups through much of the year and share a joint territory among the dominant adults and juveniles. Fox kits will leave their families upon reaching adulthood if the chances of winning their own territory are high. If not, they will remain with their natal parents at the cost of postponing their own reproduction.
Reproduction in Red foxes occurs once a year and females typically come in to estrus around February. DNA evidence suggests that polygyny, incest and mixed paternity litters are not uncommon. An average litter size is 4-6 kits with higher numbers of young born where fox mortality is high. Mother foxes are very protective of their young and if the mother dies, the father will take over the paternal duties. Kits reach adult size by the age of 7-8 months and females will reach sexual maturity within 9-11 months.
Red foxes have a wide range of vocalizations and analysis has shown that adults are capable of producing 12 different vocal sounds. Most of the sounds can be classified as either contact or interaction calls. Contact calls are the most common and are usually a 3-5 syllable barking “wow wow wow” call. This call is made between 2 foxes calling to or greeting one another. The contact call is most frequently heard from December through February when breeding is taking place.
Interaction calls are anything from high pitched whines to barks and growls. During the breeding season in late winter and early spring, females will emit a long drawn-out “waaaaah” sound in efforts to summon a male.
Diet and Hunting
Omnivorous in nature, Red foxes feed on a wide variety of foods. They primarily feed on small rodents and birds and on rare occasions, they will feed on young deer and other newborn ungulate species. Foxes also feed on insects, reptiles, amphibians, carrion and a diversity of plant material including tubers and fruits. Red foxes prefer to hunt in the early morning light before sunrise and also late evening. When food becomes scarce especially in winter, foxes will routinely hunt and feed throughout the daylight periods.
The Red fox is a popular game species in many parts of its range. In Iowa, the Red fox is one of the predator species on the list for hunters to take and truly makes for a challenging game species. Knowing a little about the fox and its life history is important for not only managing the animal but also hunting them in their native environment. Their importance on an ecological level helps support the diversity of Iowa’s native species as well as helping to keep the balance of predator and prey in check.