EQUUS GREVYI PDF

Scientific name. Equus grevyi. Weight. to kilograms ( pounds). Size. to centimeters in length ( inches). Life span. 12 to 13 years. Learn more about the Grevy’s zebra – with amazing Grevy’s zebra videos, photos and facts on Arkive. IUCN ENDANGERED (EN). Facts about this animal. The Grevy’s zebra is the largest of the three zebra species, with a body weight of up to kg. The black.

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Grevy’s grevvyi live in northern Kenya and a few small areas of southern Ethiopia. The last survey in Kenya in resulted in an estimated population of 2, Current estimates place the number of Grevy’s zebras in Kenya between 1, and 2, Grevy’s zebras inhabit semi-arid grasslands, filling a niche distinct from that of other members of the genus Equus that live within the same geographical range, such vrevyi wild asses which prefer arid habitats and plains zebras which are more dependent on water than Grevy’s vrevyi.

They usually prefer arid grasslands or acacia savannas. The most suitable areas have a permanent water source. In recent years, Grevy’s zebras have equue increasingly concentrated in the south of their range due to habitat loss in the north. During the dry season, when location near a permanent water source is especially important, zebras tend to become more concentrated in territories with permanent water sources.

In grrvyi seasons, they are more dispersed. Areas with green, short grass and medium-dense bush are used by lactating females and bachelors more frequently than non-lactating females or territorial males.

Lactating females may trade off forage quantity and safety to access nutrients in growing grass. Endangered Species”, ; “Grevy’s Zebra”, ; Cordingley, et al. Grevy’s zebras have large heads, large and rounded ears, and thick, erect manes. The muzzle is brown. The neck is thicker and more robust than in other zebra species.

These qualities make it appear more mule-like than other zebras. The coat grfvyi black grevyyi white narrow stripes, shaped like chevrons, that wrap around each other in a concentric pattern and are bisected by a black dorsal stripe.

The chevron pattern is especially distinct on the limbs, where the point of the chevron points dorsally, becoming more acute the further up the limb they climb; they reach a final peak at the shoulders and the withers. On the cranium, chevrons extend dorsally to the cheek, where the pattern becomes more linear.

The belly of this zebra is completely white, unlike other zebras. Grevy’s zebras are also the largest of all the wild equids and only domestic horses are larger.

Grevy’s Zebra

Grevy’s zebras exhibit slight sexual dimorphism; males are usually about 10 percent larger than females. Grevy’s zebra foals are born with a coat that has reddish-brown or russet stripes instead of the black of adults.

This gradually darkens to black as the zebra ages. A dorsal mane that extends from the top of the head to the base of the tail is present in all young zebras. This mane is erect when an animal is excited and flat when it is relaxed. A male mates with any females that come into his territory if they are in estrous. Mares are usually polyandrous and mate with one male before switching territories and mating with another, although sometimes mares become monandrous.

When a mare stays in a single territory, usually because she desires the resources that are present in that territory, she will stay with a single male and mate only with him.

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Churcher, ; Ginsberg and Rubenstein, Grevy’s zebras can mate year round, but the majority of breeding occurs from July to August and September to October. Foals are born after a 13 month gestation period, usually within the rainy months of the year. Peaks usually occur in May and June, the period of long rains, and in November and December, the period of short rains.

As birth approaches, females isolate themselves from the herd. Birth normally takes place lying down, with the young’s hoofs appearing first, and full emergence in 7 to 8 minutes. If birth begins with the mother eauus, it is completed lying down. The newborn frees itself from the amniotic membranes and crawls towards its mother’s head.

The mother licks it clean and ingests the membranes and some amniotic fluid, which may be important in initiating lactation or the maternal bond.

Zebras take an average of days to be weaned. Once weaned, they continue to stay with their mother. Females disperse sooner than males, females disperse at 13 to 18 months and males often stay with their mother for up to 3 years.

A newborn Grevy’s zebra foal is russet-colored with equux long hair crest down its back and belly. At this stage, imprinting occurs. Female zebras keep other zebras at a distance so that the foal can bond with its mother. Newborn foals can walk just 20 minutes after being born and run after an hour, which is a very important survival adaptation for this cursorial, migrating species. Foals nurse heavily for half a year and may take as long as three years to be completely weaned. Females achieve sexual maturity around 3 years of age and males achieve sexual maturity around 6 years of age.

Females tend to conceive once every two years. Males play little to no role in caring for the young, females are solely responsible for caring for grebyi young.

Grévy’s zebra

Immediately after childbirth, the foal imprints on the mother and can recognize her distinct scent, appearance, and vocalizations. An imprinted foal will directly follow its mother and can recognize the shape of the stripes on its mother’s backside. Until it is weaned, a foal will follow its mother grevhi learn to mimic all of her behavior.

Female foals become independent from their mothers sooner than male foals, even though both genders are weaned at around the same time. Males often remain with their birth herd until they reach three years of age and females have been known to separate at just 13 months of age. Like most other species the lifespan of Equus grevyi is longer in captivity than in the wild. In captivity, Equus grevyi usually lives between 22 and 30 years.

In the wild, the median age is closer to 12 or 13, although an 18 year old animal has been reported. Grevy’s zebras are different from most other members of the genus Equus in that they do not have concrete social structure. They are loosely social animals; herd composition can vary on a daily basis as new members enter a dominant male’s territory and old members leave.

Grevy’s Zebra, Equus grevyi

The two most stable relationships that Grevy’s zebras have are a stallion’s attachment to his territory and a mare’s attachment to her young. There is not a rigorously observed hierarchy of dominance within a group of Grevy’s zebras, although a dominance structure is present.

A territorial male has the right to breeding females in that territory. In the absence of females, males will associate in bachelor herds with a loose dominance structure. Males are territorial and claim prime watering and grazing areas. These territories can get up to 6 square kilometers in size.

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Males mark their territories with piles of dung, called “middens,” and emit loud vocalizations that let other zebras know they’re present.

Grévy’s zebra – Wikipedia

A territorial male may retain his territory for a period of 7 years before a younger, stronger male challenges him for it. Grevy’s zebra males are solitary in their territories, except when females arrive in breeding season.

Bachelor males, or non-territorial males, travel together in groups of 2 to 6. This social system is different from other zebraswhich form female harems in a single male’s territory all year.

During droughts, some Grevy’s zebras migrate to mountain pastures where food sources are more abundant, but territorial males often remain on their territories year-round. Lactating females have different resource requirements than non-lactating females.

When females are lactating, they need water at least every other day, so male zebras in territories with large, eqyus bodies of water in them usually get the opportunity to mate with more females.

Lactating females have more restricted movements and fewer male associates than non-lactating females. It is possible that male harassment also influences female distribution and associations with males.

Lactating females experience higher harassment rates from males than non-lactating females and tend to move faster during harassment periods “Grevy’s Zebra Trust: Territorial males have territories of as little as 2 square kilometers and as much as 12 square kilometers, although the average territory is 6 square kilometers.

The home range size of non-territorial zebras is sometimes as great as 10, square kilometers. Grevy’s zebras are extremely mobile and some individuals grevji been known to move distances of greater than 80 kilometers. No two zebras have the same stripe pattern. This, along with scent and individual vocalizations, allow individuals to be recognized by conspecifics.

Scent marking, especially by females, plays a significant rquus in breeding. Males often sniff the leavings of a female in order to determine if she is in estrous.

Males use dung and urine in order to mark their territory. Males use sounds and visual cues to assert their dominance. They may do this by baring their teeth, flattening their ears, kicking, or rquus other males. Territorial males often harass females into breeding with them using these same trevyi.

Grevy’s zebras are very vocal, though not quite as vocal as plains zebras. Their vocabulary includes several distinct pitches.

Individuals often emit these pitches when they are escaping predators or when they are fighting. Endangered Species”, ; “Grevy’s Zebra”, ; Churcher, Grevy’s zebras are herbivores and grazers with occasional browsing tendencies. They primarily eat tough grasses and forbs but, in the dry season when grasses are not as abundant, leaves can constitute up to 30 percent of their diet. Grevy’s zebras can digest many different types and parts of plants that cattle cannot.

Grevy’s zebras are water dependent and will often migrate to grasslands within daily reach of water. Most Grevy’s zebras can survive without water for up to five days, but lactating females must drink at least every other day in order to maintain healthy milk production.

Endangered Species”, ; “Grevy’s Zebra”, The stripes of Grevy’s zebras may act as camouflauge, especially at night. Zebras are often hard to spot from large distances at night.