Spotted Hyena (Crocuta crocuta) Fact Sheet: Physical Characteristics

* Because hyenas gorge, it is difficult to get accurate weight measurements. Both wild and zoo-kept females tend to weigh more than males. While weights for wild females may be bias due to social hierarchies that dictate access to food, individuals raised in zoos have controlled diets, a fact that suggests true sexual dimorphism in body weight.

Notable characteristics

• Largest of the four living hyena species (Brottman 2012; East and Hofer 2013)
• Highly variable in size, pelage, and morphology (East and Hofer 2013)

General body shape (summarized from East and Hofer 2013 unless otherwise noted)

• Head
• Massive with dog-like muzzle
  • Skull with enlarged sagittal crest and bowed zygomatic arches to accommodate large jaw muscles
  • Muzzle covered in short, black hair and with several rows of vibrissae/whiskers
• Body solidly built
• Neck and shoulders muscular
• Back sloping downward slightly; rump rounded
• Forequarters larger than hindquarters
  • Allows individuals to secure and carry off large portions of prey, c. 15 kg, such as a leg or a head (Kruuk 1972)
• Tail small
• Tipped with long, black hairs
• Color contrasted with light colored body, possibly serves as a visual signal (Mills 1984b)
• Ears short and rounded
• Feet
  • Four toes on each; all with short, blunt, non-retractable claws
  • Broad, naked pads on foot bottom

Coat/Pelage (summarized from East and Hofer 2013 unless otherwise noted)

• Hair short (Brottman 2012)
  • Composed of fine underhair (15-20 mm) and longer, coarser, flat-sectioned bristle hair (30-40 mm)
  • Back of neck and shoulders with longer hair (70-80 mm); giving the appearance of a mane (East and Hofer 2013)
• Coloration
• Light brown, beige, sandy, or ginger background color
• Spotted (black or brown) on neck, shoulders, back, flanks, rump, legs, and tail base; occasionally on belly
  • Size and density of spots varies
  • Intensity of spot color fades with age; spots on the oldest individuals often only on the legs (Kruuk 1972)

Teeth

• Specialized for applying extreme force (Rensberger and Stegen 1995; Stefen and Rensberger 1999)
  • Enamel reinforced to resist fracture
    • Complex 3-D structure of zig-zagging bands (Hunter-Schreger-Bands)
• Cheekteeth capable of crushing large bones, in sexually mature animal (c.2 years of age) (East and Hofer 2013)
  
  • Strength of bite increases with age; plateaus at 5-6.5 yrs (Binder and Van Valkenburgh 2000)
  • Maximum bite force c.4500 N, one captive individual; likely higher in the wild (Binder and Van Valkenburgh)
    • Enough to bite through an ungulate femur or crush a bowling ball (H Genter personal communication)
• Canines robust, sharp, and recurved (East and Hofer 2013)

Outwardly similar, though females are heavier than males (from East and Hofer 2013 unless otherwise noted)

• Males
• Lack a baculum (penile bone); unlike dogs and many other mammals
• Glans of male penis asymmetric, with a pronounced incision at base; terminates to a tapered tip; distinguishes males from females (see following description of females)
  • Pointing down when erect

• Females
• External genitals often confused with the penis of males; leading to inaccurate description of hyenas as hermaphrodites (East and Hofer 2013; Racey and Skinner 1979)
  • Modification is the byproduct of elevated androgens (testosterone and androstenedione); concentrations of androgens in blood samples from males and females are similar (Racey and Skinner 1979)
  • Unborn cubs show similarly high levels of androgens (Racey and Skinner 1979)
  • Androgens not elevated in ovarian tissue of adults (Racey and Skinner 1979)
• Clitoris elongate and erectile; similar in size to erect male penis
  • More symmetric than male glans with a less pronounced incision and a blunted tip
  • Pointing forward when erect
• False scrotum, containing fatty (adipose) tissue (Racey and Skinner 1979)
• 6 hypotheses constructed to explain the adaptive advantages of genital mimicry (see summary and reference list in East and Hofer 2013 for details)
• Udders pronounced in reproductively active females
  • Belly appears to descend towards the hind legs
• 4 nipples present
  • Front pair typically non-functional, limiting litter size

Vision (summarized from Calderone et al. 2003)

• Eye similar in size to humans
  • Nearly spherical
• Color vision possible, though likely limited
  • Few cone photoreceptors (cells responsible for color vision); 100:1 ratio of rods to cones
  • Most colors likely appear blue or green, as with dogs

Digestive system

• Acidid digestive tract increases digestive efficiency (from East and Hofer 2013)
• Capable of extracting nutrients from bone fragments
• Feces color reflects recent meals (from Bearder and Randall 1978)
• Pale, whitish feces when bone consumption is high
• Browner feces when consuming more meat

Chromosome number (from East and Hofer 2013)

• 20 chromosome pairs (2n=40)
• As with other hyenas

Similar species (from East and Hofer 2013)

• Brown hyena (Hyaena brunnea)
• Sympatric in southern Africa
• Distinguished by longer, pointed ears and longer, darker, spotless pelage
• Striped hyena (H. hyaena)
• Sympatric from Tanzania northwards
• Distinguished by longer, pointed ears, an erectile mane and dorsal crest, and prominent stripes (not spots) on body, legs, and neck

Dog-like feliforms. The dog-like muzzle and solid body build of the spotted hyena resemble that of canines, masking their more close evolutionary alliance with cats. The namesake spots are gradually acquired by cubs beginning around 1.5 months of age, and are often seen to fade with old age.

Image credit: © Clive Reid from Flickr. Some rights reserved.

Bearder and Randall (1978)
Binder and Van Valkenburgh (2000)
Brottman (2012)
Calderone et al. (2003)
East and Hofer (2013)
Kruuk (1972)
Mills (1984b)
Racey and Skinner (1979)
Rensberger and Stegen (1995)
Stefen and Rensberger (1999)