Fennec Fox (Vulpes zerda) Fact Sheet: Physical Characteristics

Body measurements

Data sources: Asa and Cuzin (2013), Sillero-Zubiri et al. (2013)

Body

• Very small canid (fox, dog, or wolf) (Asa and Cuzin 2013)
  • About 200 mm (8 in) at top of shoulder (Dorst and Dandelot 1972)
    • Blandford’s fox (Vulpes cana) similar in size
  • Lower water and food needs, compared to similar canids (Williams et al. 2004)
  • Lose body heat more quickly, when active (Geffen and Girard 2003)

Head

• Eyes (Larivière 2002; Sillero-Zubiri 2009a; Asa and Cuzin 2013)
  • Large
  • Dark
• Snout/muzzle
  • Small (Larivière 2002)
  • Slender and delicate (Sillero-Zubiri 2009a; Asa and Cuzin 2013)
    • Possibly to grasp and pierce the shells of insects
• Skull
  • Small in total size (Asa and Cuzin 2013)
  • Broad braincase (Rosevear 1974)
  • Enlarged structures below ear holes (tympanic bullae) (Bueler 1973)
    • Provide exceptional hearing
• Teeth
  • Canines small, slender, and sharp (Harrison 1968; Asa and Cuzin 2013)
• Ears
  • Triangular (Dorst and Dandelot 1972)
  • Largest ears of any canid (fox, dog, or wolf), relative to body size (Asa and Cuzin 2013)
    • Likely help to dissipate heat and locate prey (Ewer 1973; Maloiy et al. 1982; Geffen and Girard 2003)

Legs

• Slender (Sillero-Zubiri 2009a; Asa and Cuzin 2013)

Tail

• Length approximately half of body length (Rosevear 1974)
• Long, bushy hairs (about 35 mm [1.4 in] long) (Rosevear 1974; Larivière 2002; Asa and Cuzin 2013)

Coloration and pelage

• Fur thick, soft, and fine (except guard hairs) (Dorst and Dandelot 1972; Bueler 1973)
  • Approximately 27 mm (1.1 in) long (Maloiy et al. 1982)
  • Wooly undercoat provides protection against temperature extremes (Bueler 1973)
  • Coat shed each year (Rosevear 1974)
• Upper body sandy or cream-colored (Gauthier-Pilters 1967; Rosevear 1974; Sillero-Zubiri 2009a; Asa and Cuzin 2013, and as noted)
  • Coloration provides camouflage with sand and reflects sun’s rays (Bueler 1973)
  • Color variations
    • May have light fawn, red, or gray hues
    • Some individuals have a darker band along spine (Rosevear 1974)
  • Underbody pale to white
• Legs, underbelly, and flanks almost white (Larivière 2002)
  • In North Africa, upper parts of limbs may be reddish (Sheldon 1992)
    • Nearly white in individuals farther south
• Head whitish, with dark streak extending from inner eye down to muzzle (Larivière 2002; Sillero-Zubiri 2009a; Asa and Cuzin 2013)
• Fur on bottom of feet covers pads (Harrison 1968)
  • Enables walking on hot, loose sand
• Ears (Bueler 1973; Rosevear 1974; Larivière 2002; Asa and Cuzin 2013)
  • Long hairs inside, especially along edges
    • White or nearly white
  • Back side cinnamon colored or sandy gray
  • Edges white
• Tail rufous-colored (Rosevear 1974; Shabadash and Zelikina 2004; Asa and Cuzin 2013)
  • Tip dark
  • Scent gland at base covered by dark fur

Reproductive structures

• Females have 3 sets of nipples (Asa and Cuzin 2013)

Similar species

(e.g., Dorst and Dandelot 1972; Asa et al. 2004)

• Rüeppell’s fox, Vulpes rueppellii
• Pale fox, Vulpes pallida
• Blanford’s fox, Vulpes cana

Hearing

• Excellent hearing (Gauthier-Pilters 1967; Asa and Cuzin 2013)

Adaptations to extreme heat

• Low metabolism (Noll-Banholzer 1979a; Maloiy et al. 1982; Geffen and Girard 2003)
  • Reduced energy and water needs
• Body temperature regulated with minimal water loss
  • Little water lost through urine due to highly efficient kidneys (Noll-Banholzer 1979b)
  • Little water evaporation through skin (Maloiy et al. 1982)
    • Body temperature regulated through ears and feet
• Body temperature and heart rate decrease midday during rest period (Noll-Banholzer 1979a; Maloiy et al. 1982)
• Also see Feeding

Body temperature and thermoregulation

• Body temperature at rest
  • About 37 to 38°C (98 to 100°F) (Noll-Banholzer 1979a; Maloiy et al. 1982)
• Heat stress
  • Upper thermal tolerance
    • Approximately 37 to 40°C (99 to 104°F) (Maloiy et al. 1982)
    • Temperatures above 32°C (87°F) not tolerated for long periods (Noll-Banholzer 1979b)
  • Panting usually occurs above 35°C (95°F) (Noll-Banholzer 1979a; Maloiy et al. 1982)
  • Lay on side to dissipate heat from exposed skin (Maloiy et al. 1982)
• Cold stress
  • Sensitive to cold (Rosevear 1974)
    • Stress usually occurs at 10 to 20°C (50 to 68°F) (Maloiy et al. 1982)
  • Known to sunbathe for brief periods during mid-morning (Rosevear 1974)
  • During winter, grow thicker fur and store body fat to prevent excess heat loss (Geffen and Girard 2003)
• Newborn animals sensitive to cold (Noll-Banholzer 1979a)
• Unable to regulate body temperature

The fennec fox is the smallest canid but has the largest ears, relative to body size.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Fennec foxes have thick, soft, fine fur.

Its wooly undercoat provides protection against temperature extremes.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.