||Burchell's zebra (Equus
burchellii); Grevy's zebra (Equus
||45 to 55 inches at the
shoulder (Burchell's); 50 to 60 inches (Grevy's)
||Burchell's: 485 to 550
pounds (Burchell's); 770 to 990 pounds (Grevy's)
||40 years in captivity
||Woodlands to open
||12 months (Burchell's);
13 months (Grevy's)
||Lions, hyenas, hunting
dogs, leopards, cheetahs
Zebras, horses and wild asses are all equids, long-lived
animals that move quickly for their large size and have teeth
built for grinding and cropping grass. Zebras have horselike
bodies, but their manes are made of short, erect hair, their
tails are tufted at the tip and their coats are striped.
Three species of zebra still occur in Africa, two of which
are found in East Africa. The most numerous and widespread
species in the east is Burchell's, also known as the common or
plains zebra. The other is Grevy's zebra, named for Jules Grevy,
a president of France in the 1880s who received one from
Abyssinia as a gift, and now found mostly in northern Kenya.
(The third species, Equus zebra, is the mountain zebra, found in
southern and southwestern Africa.)
The long-legged Grevy's zebra, the biggest of the wild equids,
is taller and heavier than the Burchell's, with a massive head
and large ears.
Zebras have shiny coats that dissipate over 70 percent of
incoming heat, and some scientists believe the stripes help the
animals withstand intense solar radiation. The black and white
stripes are a form of camouflage called disruptive coloration
that breaks up the outline of the body. Although the pattern is
visible during daytime, at dawn or in the evening when their
predators are most active, zebras look indistinct and may
confuse predators by distorting true distance.
The stripes on Grevy's zebras are more numerous and narrow
than those of the plains zebra and do not extend to the belly.
In all zebra species, the stripes on the forequarters form a
triangular pattern; Grevy's have a similar pattern on the
hindquarters, while others have a slanted or horizontal pattern.
Burchell's zebras inhabit savannas, from treeless grasslands
to open woodlands; they sometimes occur in tens of thousands
in migratory herds on the Serengeti plains. Grevy's zebras are
now mainly restricted to parts of northern Kenya. Although
they are adapted to semi-arid conditions and require less
water than other zebra species, these zebras compete with
domestic livestock for water and have suffered heavy poaching
for their meat and skins.
Family groups are stable members maintaining strong
bonds over many years. Mutual grooming, where zebras stand
together and nibble the hair on each other's neck and back,
helps develop and preserve these bonds. Family members look out
for one another if one becomes separated from the rest, the
others search for it. The group adjusts its traveling pace to
accommodate the old and the weak.
The females within a family observe a strict hierarchical
system. A dominant mare always leads the group, while others
follow her in single file, each with their foals directly behind
them. The lowest- ranking mare is the last in line. Although the
stallion is the dominant member of the family, he operates
outside the system and has no special place in the line.
Zebras are avid grazers. Both Burchell's and Grevy's zebras
are in constant search of green pastures. In the dry season,
they can live on coarse, dry grass only if they are within a
short distance (usually no farther than 20 miles away) of
Caring for the Young
When a foal is born the mother keeps all other zebras
(even the members of her family) away from it for 2 or 3 days,
until it learns to recognize her by sight, voice and smell.
While all foals have a close association with their mothers,
the male foals are also close to their fathers. They leave their
group on their own accord between the ages of 1 and 4 years to
join an all-male bachelor group until they are strong enough to
head a family.
Zebras are important prey for lions and hyenas, and to a
lesser extent for hunting dogs, leopards and cheetahs. When a
family group is attacked, the members form a semicircle, face
the predator and watch it, ready to bite or strike should the
attack continue. If one of the family is injured the rest will
often encircle it to protect it from further attack.
Did you know?
- Romans called Grevy's zebras 'hippotigris' and trained
them to pull two-wheeled carts for exhibition in circuses.
- At first glance zebras in a herd might all look alike, but
their stripe patterns are as distinctive as fingerprints are
in man. Scientists can identify individual zebras by comparing
patterns, stripe widths, color and scars.