Plains or Burchell's

PLAINS OR BURCHELL'S ZEBRA, Equus burchelli

SUBSPECIES Grant's or Boehm's zebra, E. b. boehmi
Selous' zebra, E. b. selousi
Chapman's zebra, E. b. antiquorum
Burchell's zebra, E. b. butchelli

WHAT IT IS

African version of the horse. Portly build. Male wt 550 lb (250 kg), ht 51-56 in (127-140 cm); female wt 484 (220 kg), ht slightly shorter than male. Color: no gender difference; background white to buff color; striping varies geographically (and individually), most complete and bold in equatorial race (E. b. boehmi), decreasing toward southern Africa, where E. b. antiquotum and butchelli have unstriped lower legs and belly and shadow stripes between black torso stripes. Juvenile coat longer with brown stripes.

WHERE IT LIVES

From southeastern Sudan to South Africa and west to Angola, in Somali-Masai Arid Zone, Southern Savanna, and South West Arid Zone. The extinct South African quagga, striped only on head, neck, and back, was probably not a different species but a distinctive subspecies adapted to the temperate highveld and arid Karroo. Quagga, the Hottentot name, may come from the qua.ha contact call of the plains zebra.

GOOD PLACES TO SEE IT

Too numerous to list; 2 of the best places to get very close are Ngorongoro Crater, Tanzania and Etosha NP, Namibia.

ECOLOGY

One of most numerous and successful large herbivores, adapted to a broad range of grassland habitats. Though usually outnumbered by wildebeest where the two grazers occur together and equally water-dependent, tolerance for taller grass and more wooded savanna gives the zebra much greater geographical range. A pioneer in the grazer community, first to enter tall or wet pastures, followed by wildebeests and gazelles after zebras have trampled and cropped the grass shorter; also crops short greenflush with its matched set of incisors and mobile lips much more efficiently than wildebeests and most other ruminants.

ACTIVITY

More active in daylight, spending nights preferably on short pasture relatively safe from ambush. Zebras graze individually an hour or so at a time at night but move about very little. Resting zebras often steep soundly, but at least one herd member remains standing and alert. At daybreak in warm weather, herds begin filing to pastures of longer grass and may cover over 10 mi (17 km) before settling for another night. Mass movements between pastures and sleeping grounds, and to water at midday, are also peaks of social activity; stallions in bachelor herds are especially active and entertaining to watch.

SOCIAL/MATING SYSTEM

Harem masters have exclusive mating rights with 2 to 6 mares. Harems are so stable that mares remain associated for life; their foals gain added protection from the family stallion's readiness to defend his wives and offspring against all threats to their survival-and his reproductive success. On balance, it is a win-win arrangement. When members of the herd become separated, the family stallion goes looking and calling for them, and the whole herd will adjust its pace to accommodate sick or crippled members. Home ranges can be as small as 11 mi square (30 km square) in the best habitat, to over 232 mi square (600 km square) in migratory popuiations.
Harem ownership is about as safe as territory ownership: respected as long as the family stallion is fit enough to assert his rights. When a breeding male gets killed, severely injured, or too old to outface challengers, some lucky stallion stands to inherit his whole harem. But such luck is as unlikely as winning the state lottery: with a potential life span of over 20 years, stallions stay fighting-fit for some 15 years. The normal way to become a harem stallion is by abducting fillies in heat, one at a time.
Between I and 2 years of age, fillies begin ovulating and advertise estrus by adopting a distinctive posture (see Courtship). Up to 18 stallions gather around a herd with an estrus filly and fight for her with the herd stallion and one another. This happens not just once but 5 days every month for about a year until the filly finally conceives. Abducting a filly from her father's herd is just the beginning of a recurrent ordeal, and the odds against a female bearing the offspring of the first stallion to steal her must be very low.
The fruits of conquest go to the inseminating stallion; the filly stays with him. After foaling, subsequent estrous periods are advertised so much more discreetly that rivals stay away-as long as the herd stallion is there to repel intruders. But newcomers are not welcomed by resident mares. The latest wife must keep her distance, protected and herded by her consort, during a probation of several weeks. A strict rank hierarchy is enforced, the first mare to join the harem and her offspring taking precedence over the second, the second over the third, and so on down to the latest conquest. This order is strictly enforced when a herd is filing. The stallion's usual position is behind his family, from where he can still direct the herd's movements when he sees fit.
Colts leave their families on their own initiative usually between 2 and 3 years to join a bachelor herd, there to remain until mature and ready to start a harem at 5 years. Bachelor herds include 2 to 15 males, are usually led by a young adult, and are quite stable, with a rank order based simply on age.

REPRODUCTION

Foals born in most months but a definite annual birth/mating peak early in the rains (Dec.-Jan. in East Africa). Mares in good condition conceive during the following "foal heat"; others reproduce at 2-year intervals. First foals at 3 to 3.5 years.

OFFSPRING AND PARENTAL CARE

A mare labors lying on her side, while the herd remains nearby and the stallion stands watch. Foals weigh approximately 70 lb (31-33 kg), are able to stand within 15 minutes and suckle in an hour. The mother keeps all other zebras away for several days, much to the distress of her previous offspring. But once the foal is imprinted on her, she allows other herd members to contact it; its sibling can establish close ties through mutual social grooming. However, the place closest to its mother is taken by the newborn.

PREDATORS

Plains zebra a mainstay of lions throughout its range, but spotted hyenas often hunt zebras in packs to overcome the close cooperation of the group and the stallion's aggressive defense. In the Serengeti one wild dog pack made something of a speciality of hunting zebras, but zebras are not their usual prey.

Maintenance Activities

Dust-bathing; rubbing against trees, rocks, termite mounds, etc. Zebras line up to dust-bathe (often on wildebeest stamping grounds) and scratch. Rubbing on isolated trees wears away bark; rocks worn smooth with grooved paths around them reflect centuries of rubbing.

Advertising Harem or Territory Ownership

Adult male standing apart from female herd or coming to meet an approaching herd or individual. A territory or harem owner (the former may also be all alone).

GREETING/CHALLENGE RITUAL

Greeting of equals. Meetings of equal adult males, at territorial boundaries (Grevy's zebra) or between their herds by family stallions. Males and young greet in similar fashion but with little or no aggression.

Both approach with heads outstretched and ears cocked, or 1 stands in erect posture watching other approach.

Contact and smelling: nasal contact and sniffing; rubbing cheeks; moving into head-to-tail position and sniffing penis, pressing and rubbing sides.

Resting/ pressing chin on partner.

Aggressive actions: biting, short squeal, kick threats, and kicking out with front feet (not at each other), often just before parting (parting jump).

Parting jump.

Dunging ceremony: Ostentatious defecation with tail raised, often preceded by nosing and pawing earlier deposit before over-marking the spot.
Territorial interactions; less common between harem stallions.

Challenge rituals end with males returning to their respective herds/territories, often in grazing attitude (displacement grazing).

HERDING AND HAZING BEHAVIOR

Herding/hazing posture. Controlling herd movements with threat displays.
Chasing. Especially of females by amorous territorial males.

CONTACT/ADVERTISING CALLS

Braying (Grevy's zebra, ass); barking (plains, mountain zebras). Equivalent to neighing of horse. Not confined to stallions in the harem species, but males are most vocal. Calls are individually distinct.

Aggression

Standing in erect posture with head high, ears pricked, tail arched. Dominance display.

High stepping (prancing).

Broadside display. Blocking way.

Head-low threat (ears back, snaking head movements). herding/hazing posture.
BITING THREATS

Threat face: ears back; teeth bared; tail-swishing.

Biting-intention movements, ranging from head movements Only, through rearing and rushing.
KICK THREATS

Lifting hindquarters or forequarters in direction of adversary.

Rearing.

Chasing. Mainly between members of bachelor herds and during battles to abduct fillies in heat.

OTHER ACTIONS ASSOCIATED WITH THREAT DISPLAYS

Stamping and pawing, dunging ritual, short squeals.
FIGHTING TECHNIQUES

Biting and slashing: ears, neck, body. Look for bloodstains. male canine teeth make superficial wounds.

Attempted leg bite, countered by dropping to ground.

Kicking out with hind feet. Dangerous, as kick can break leg or jaw.

Kick threat or actual kicking with hind feet while moving away.

Defensive threat.

Submission

Bachelor d declining challenge of harem stallion by displaying submission: laying ears back and making open-mouthed chewing motions squealing. Resembles display of mare in heat. Ears back suggest threat but chewing is submissive-an intention movement to nibblegroom. Only immature animals and adult bachelor males display active submission.

Moving away from threatening superior.

Grooming initiative. Appeasing behavior, as social grooming is initiated by lower-ranking individual.

Sociable Behavior

Nose-to-nose contact. Greeting behavior, prelude to friendly or aggressive interactions (as in challenge ritual).

Social grooming: scraping and nibbling partner's neck, shoulders, and back, performed by both partners at once. Most frequent between relatives, especially mother and foal.

Resting in pairs and mutual head-resting. Position enables pair to see in all directions and to brush flies off each other's face.

Blowing with loose lips (as in horses). Often heard in grazing herd; an "all's well" social-contact sound.

Courtship

SIGNS OF ESTRUS

Swollen, everted labia and mucous discharge; frequent urination; fighting and chasing among stallions; kick threats and kicking with hind feet in response to premature mounting attempts.

Mare-in-heat display: tail and neck extended, ears back, lips retracted and open-mouthed chewing. Similar to submissive display and to female urination posture.

Mating posture (full estrus). Similar to mare-in-heat display, but with hind legs spread, mouth wide open, backing into male.
MALE BEHAVIOR

Chasing, nipping, mounting attempts (sometimes on the run). * Rather violent, especially Grevy's zebra.

Urine-testing ą urinating on the spot afterward. Unusually conspicuous in equids, with pronounced lip-curl.

Dunging on female's excrement.

Nuzzling, social grooming; resting chin on female's back or rump. Preliminary mounting attempts without erection.

Parent and Offspring

Maternal protectiveness. Mother keeps other zebras, including last offspring, away from foal for first days, until maternal bond established and foal recognizes own mother.

Social grooming. Frequent, important for maternal and sibling social bonding.

Play

Running games, play-fighting. Common only among young and bachelors.

Response to Predators

Alert posture: standing with head high staring in one direction, stamping and snorting.

Flight.

Closing ranks around young and defense by herd stallion. Harem system.
SOUNDS OF ALARM

Snorting, e-hah gasp with open mouth.

Drawn-out squeal. Distress cry of captured or injured animal.

Qua-ha call of plains and mountain zebra. Contact call, given at highest intensity and frequency following disturbance.

DIFFERENCES IN PLAINS ZEBRA BEHAVIOR

Advertising Herd Ownership

GREETING/CHALLENGE RITUAL

Greeting of equals features open-mouthed chevang movements, but with ears cocked, unlike submissive display.

Dunging ceremony. Resembles territorial boundary marking, as though the herd and the space surrounding it is the territory.

Sociable Behavior

Mutual grooming and standing and resting in pairs. Most frequent between relatives, especially mother and foal, but occasional between all herd members. Also in bachelor herds.

Reprinted from "The Safari Companion" by Richard Estes
nature@nature-wildlife.com