Basic Information Sheet: Fennec Fox

Fennec Fox (Vulpes zerda)

Fennec Fox

Photo credit: Yvonne N via Flickr Creative Commons

Natural history



Fennec foxes are highly specialized to desert life and found almost exclusively in arid, sandy regions. Densest populations are found in the central Sahara desert region of North Africa, but the range extends as far north as Morocco, east along the northern Red Sea to Kuwait, and south into northern Nigeria and Chad.

Fennec foxes are nocturnal hunters that dig burrows as shelter to sleep during the day and rear kits.* Scrub vegetation is used to line dens and may be eaten as a source of water.

Fennecs are highly social animals that reside in close family groups usually composed of at least one breeding pair, a litter of immature pups, and some older siblings. A group of foxes may be referred to as a “skulk” or a “leash”.

Fennec foxes are monogamous cooperative breeders that mate for life. Social structure is built around this pairing: each breeding couple have their own territory which is bounded by urine and fecal mounds, which they will vigorously defend.

Social rank among fennecs is communicated mainly through play and visual and tactile communication. Fennec foxes of all ages also make frequent and varied vocalizations such as chatters, whimpers, wails, growls, and shrieks.

*Juvenile fennec fox are general referred to as “kits”, however as canids ‘pups’ is also considered accurate. Youngsters are also referred to as “cubs”.

 

Sound recording of a fennec fox “singing” Source: Eosin-Y via Wikimedia Commons


Conservation status:



Fennecs once ranged broadly over northern Africa, but sport hunting and human density are shrinking their habitat and numbers and they are considered threatened in the wild.

The IUCN Red List cites fennecs as “data deficient”. The Convention on International Trade in Endangered Species (CITES) places fennecs in Appendix II.

Taxonomy



Class: Mammalia

Order: Carnivora

Family: Canidae

Genus: Vulpes: artic fox, fennec fox, red fox

Formerly, the fennec was classified as a separate genus (Fennecus) due to its rounded skull and weak dentition.


Physical description



Fennec foxes are the smallest canids. Females or “vixens” weigh approximately 0.8 kg (1.8 lb). Adult males or “reynards” reach up to 1.5 kg (3.3 lb) and stand 18 -22 cm (7-8.7 in) at the shoulder.

The most distinctive feature are characteristic large pinnae (15 cm or 5.9 in long), which function to dissipate heat and enhance audition.

A thick buff pelage covers adults, with white along the legs, face, ears and ventrum, in contrast to downy white juveniles. The violet (supracaudal) scent gland, common to all vulpines, is covered in black or dark brown fur, as well as the tail tip. The eyes, rhinal pad, and vibrissae are all black.


Diet



Fennec foxes, like other canids, are omnivores. They commonly hunt and forage for birds, small mammals, reptiles, eggs, carrion, insects, other terrestrial arthropods, leaves, roots, tubers, and fruit. In addition to foraging they commonly cache food. Fennecs obtain much of their food through digging.

Free-ranging fennecs can go without water indefinitely, however fruit, leaves, and roots serve as the sole source of moisture. The captive fennec fox should ALWAYS be offered fresh water.

In captivity, an exotic canine diet (e.g. Mazuri), high-quality dry or canned dog, or cat food is fed. Vegetables, fruits, pinkie mice, rodents, eggs, crickets, mealworms, as well as commercially available raw meat diets are also offered.


Housing



Fennec foxes are adept climbers and can easily escape fenced enclosures. Fennecs should be kenneled while unsupervised; large ferret or cat cages can be suitable. These desert dwellers require low humidity, and good ventilation. Avoid dusty cage substrates.

Fennecs practice site-specific defecation in marking their territories and can thus be litter box trained in a captive environment. Standard clay litter is recommended.

Fennecs can be leash or harness trained, but may be prone to slip out of restraint when startled. Therefore a leash or harness is recommended only for a confined, safe space.


Normal physiologic values


Lifespan: Fennecs can live for up to 10 years in The wild, while captives may survive up to 12 years.
Heart rate (resting) ~118 bpm
Respiratory rate (resting) ~23 bpm
Body temperature 38.2°C (100.8°F)


Anatomy / physiology


Dental formula The fennec fox has the same dental formula as the domestic dog: I3/3, C1/1, PM4/4, M2/3).Compared with other vulpines, their canine and carnassial teeth are reduced.  The teeth are also sharply cuspidate, which may facilitate a partially insectivorous diet.
Special senses Fennecs have highly developed sense of hearing and smell.
Unique physiological
adaptations to desert life:
Fennec fox metabolism is 67% of the rate predicted for an animal of its size.Fennecs will shiver when the ambient temperature drops below 20˚C (68˚F). In hot ambient temperatures the fennec radiates body heat by dilating blood vessels in its feet and large, vascular ears.The enormous ears are able to filter sound through many centimeters of sand, and can detect subtle differences in vocalizations from conspecifics.In contrast to some other canids, the feet are heavily furred to protect the pads from hot desert sand.Fennec foxes are nocturnal hunters. Night vision is enhanced by a reflective tapetum with elliptical pupils.

Fennec foxes allow their body temperature to rise to 40.9˚C (105.6˚F) before beginning to sweat, thereby reducing water loss. Fennecs only lose heat through panting when environmental temperature exceeds 35˚C (95˚F). Panting rates up to 690 breaths per minute have been observed.

Although fennec foxes will drink freely when given the opportunity, laboratory studies suggest that free-ranging fennecs can survive indefinitely without access to free water.

Reproduction Like all foxes, fennecs have three pairs of mammary glands.The breeding season runs from January to February, but vixens remain in estrus for only 1-2 days.Altricial pups (kits) are born after a 50-day gestation in annual litters of two to four pups. For the first 2 weeks pups are cared for in a den by the dam until their eyes open, but full weaning does not occur until nearly 3 months.Parent-raised offspring are weaned by 8-10 weeks of age.Parent-raised offspring are weaned by 8-10 weeks of age, although full weaning may not occur until nearly 3 months.Hand reared kits are sometimes forced weaned although this practice is generally not recommended: Kits are pulled at 10-12 days, and fed a fox milk replacer such as Day One® Formula 35/32 (Fox Valley Animal Nutrition; Lake Zurich, IL). Solid food may be introduced at 1 month in force-weaned animals, and weaning can occur as early as 6 weeks.

Adult size and sexual maturity are reached at 6-9 months of age.

Sexual dimorphism Not pronounced, though males tend to be larger in mass (see physical description above).In general, males (reynards) are a bit more friendly and sociable than are vixens, and may make better pets for a beginning owner. However, they can turn aggressive as they become sexually mature, which makes neutering a very important consideration. One additional benefit is that the males are often simpler to potty train than are the females. However, in addition to the potential aggression, males do have a much stronger odor in general than do females, and they are more likely to “hump” things, particularly as they enter sexual maturity.
Other Like all foxes, paired anal sacs are present. There are also glands located between the toes.


Important medical conditions



Fennec foxes are susceptible to all diseases of domestic dogs
Common clinical presentations include:

  • Obesity
  • Heat stress
  • Dental disease
  • Trauma (bite wounds)
  • Gastrointestinal upset secondary to poor diet and/or stress
  • Fur rings
  • Neoplasia
  • Renal or liver disease
  • Cardiomyopathy
  • Pneumonia
  • Dermatitis (mites, otitis, fleas)
  • Conjunctivitis, corneal lesions (foreign body), glaucoma
  • Neonatal death (nervous mothering)

Fennecs become very nervous and aggressive during breeding and rearing. To prevent neonatal deaths, avoid disturbances until the kits reach 3-4 weeks of age.

Zoonotic potential: Rabies virus, tuberculosis, leishmaniasis

Histoplasmosis and toxoplasmosis have also been described in case reports.


Preventive care


  • Annual to biannual physical examination
  • Fecal parasite testing
  • Killed rabies virus vaccination
  • Recombinant canarypox vector canine distemper virus and canine parvovirus vaccination
  • Flea control
  • Canine heartworm prevention
  • Spay or neuter companion pets, unless these individuals are to be used as part of a breeding program with an experienced fox owner


Restraint



Use same methods of manual or chemical restraint as for canines.

Venipuncture



Jugular vein, cephalic vein, lateral saphenous vein

**Login to view references**

References and further reading

References

Adams, R. 2004. “Vulpes zerda” Animal Diversity Web. Accessed November 24, 2014.

Alderton, D: Foxes, Wolves & Wild Dogs of the World. New York, Sterling Publishing Co., Inc., p144-146, 1999.

Bekoff M: Social behavior and ecology of the African Canidae: a review, In Fox MW (ed): The Wild Canids. Malabar, Florida, Krieger Publishing Company,Inc., p123-125.

Conroy JD, Levine ND, Small E. Visceral leishmaniosis in a fennec fox (Fennecus zerda). Pathol Vet 7(2):163-170, 1970.

Dempsey JL, Hanna SJ, Asa CS, Bauman KL. Nutrition and behavior of fennec foxes (Vulpes zerda). Vet Clin North Am Exot Anim Pract 12(2):299-312, 2009.

Himes, EM et al: Tuberculosis in fennec foxes, JAVMA, Vol 177, No. 9, Nov 1,1980, p825-826.

Johnson D. Introduction to fennec foxes, Exotic DVM, (2003), 5.4:42-45

Kingdon, J. 1997. The Kingdon Field Guide to African Mammals. San Diego, CA: Academic Press.

Kottwitz JJ, Preziosi DE, Miller MA, et al. Heart failure caused by toxoplasmosis in a fennec fox (Fennecus zerda). J Am Anim Hosp Assoc 40(6):501-507, 2004.

Mitchell S. The wonderful world of foxes. Veterinary Information Network Rounds. January 12, 2014. Available at http://www.vin.com/members/cms/project/defaultadv1.aspx?id=6081708&pid=8116&catid=&. Accessed on November 29, 2014.

Montali, RJ et al: Clinical trials with canine distemper vaccines in exotic carnivores, JAVMA, Vol 183, No. 11, Dec 1, 1983, p1163-1167.

Padilla LR, Hilton CD “Canidae” In: Fowler’s Zoo and Wild Animal Medicine. Ed. Miller RE & Fowler ME. Vol. 8. 2015: p. 457-467.

Pressanti C, Delverdier M, Iriart X, et al. A case of Trichophyton mentagrophytes infection in a fennec fox (Vulpes zerda). Vet Dermatol 23(5):456-e87, 2012.

Sheldon JW: Wild Dogs: The natural history of the nondomestic Canidae. New York, Academic Press, Inc., p91-95, 1992.

Raju NR, Langham RF, Bennett RR. Disseminated histoplasmosis in a Fennec fox. J Am Vet Med Assoc 189(9):1195-1196, 1986.

Woo GH, Jho YS, Bak EJ. Canine distemper virus infection in fennec fox (Vulpes zerda). J Vet Med Sci 72(8):1075-1079, 2010.