Sunday, October 20, 2019

Zebra Facts

Zebra Facts Zebras (Equus spp), with their familiar horse-like physique and their distinct black and white striping pattern, are among the most recognizable of all mammals. They are native to both the plains and mountains of Africa; mountain zebras climb over 6,000 feet high. Fast Facts: Zebras Scientific Name: Equus quagga or E. burchellii; E. zebra, E. grevyiCommon Names: Plains or Burchells Zebra; Mountain Zebra; Grevys ZebraBasic Animal Group: MammalSize: Grevys and plains, 8.9 feet; mountain, 7.7 feet  Ã‚  Weight: Plains and Grevys zebra, about 850–880 pounds; mountain zebra, 620 poundsLifespan: 10–11 yearsDiet:  HerbivorePopulation: Plains: 150,000–250,000; Grevys: 2,680; mountain: 35,000Habitat: Once widespread in Africa, now in separate populationsConservation Status: Endangered (Grevys zebra), Vulnerable (mountain zebra), Near Threatened (plains zebra) Description Zebras are members of the genus Equus, which also includes asses and horses. There are three species of zebra: Plains or Burchells zebra (Equus quagga or E. burchellii), Grevys zebra (Equus grevyi), and mountain zebra (Equus zebra). Anatomical differences between the zebra species are fairly sparse: In general, the mountain zebra is smaller and has evolutionary differences associated with living in the mountains. Mountain zebras have hard, pointed hooves that are well-suited for negotiating the slopes and they have conspicuous dewlaps- a loose fold of skin underneath the chin seen often in cattle- which the plains and Grevys zebras do not. Various species of asses, including the African wild ass (Equus asinus), have some stripes (for instance, Equus asinus has stripes on the lower portion of its legs). Zebras are nonetheless the most distinctively striped of the equids. Westend61/Getty Images Species Each species of zebra has a unique stripe pattern on its coat which provides researchers with an easy method for identifying individuals. Grevys zebras have a thick black hairy strip on their rump that extends towards their tail and a broader neck than the other species of zebras and a white belly. Plains zebras often have shadow stripes (stripes of a lighter color that occur between the darker stripes). Like Grevys zebras, some plains zebras have a white belly. Zebras can cross breed with other members of equus: A plains zebra crossed with a donkey is known as a zebdonk, zonkey, zebrass, and zorse. The plains or Burchells zebra has several subspecies: Grants zebra (Equus quagga boehmi) and Chapmans zebra (Equus quagga antiquorum). And the now-extinct quagga, once thought to be a separate species, is now considered a subspecies of the plains zebra (Equus quagga quagga). Habitat and Distribution Most zebra species live in arid and semi-arid plains and savannas of Africa: Plains and Grevys zebras have different regions but overlap during migrations. Mountain zebras, however, live in the rugged mountains of South Africa and Namibia.  Mountain zebras are skilled climbers, inhabiting mountain slopes up to elevations of 6,500 feet above sea level. All zebras are extremely mobile, and individuals have been recorded to move distances of greater than 50 miles.  Plains zebras make the longest known terrestrial wildlife migration, a whopping 300 miles between the Chobe River floodplains in Namibia and the Nxai Pan National Park in Botswana. Diet and Behavior Regardless of their habitats, zebras are all grazers, bulk, roughage feeders that need to consume large daily quantities of grasses. They are also all full migrant species, migrating seasonally or year-round depending on seasonal vegetation changes and habitat. They often follow long grasses that grow after the rains, altering their migration patterns to avoid adverse conditions or find new resources. Mountain and plains zebras live in family groups or harems, typically consisting of one stallion, several mares, and their juvenile offspring. Non-breeding groups of bachelors and occasional fillies also exist. During parts of the year, the harems and bachelor groups join together and move as herds, the timing and direction of which are determined by seasonal vegetation changes in habitat.   Breeding males will defend their resource territories (water and food) that range between one and 7.5 square miles; the home range size of non-territorial zebras can be as large as 3,800 square miles. Male plains zebras ward off predators by kicking or biting them and have been known to kill hyenas with a single kick. Robert Muckley / Getty Images Reproduction and Offspring Female zebras sexually mature at the age of three and give birth to between two and six offspring over their lifetimes. Gestation periods are between 12 and 13 months, depending on species, and the average female gives birth about once every two years. Male fertility is far more variable.   Reproductive pairing is played out differently for different species. While plains and mountain zebras practice the harem strategy described above, Grevys zebra females do not join males in harems. Instead, they form loose and transitory associations with many other females and males, and females of different reproductive states group themselves into sets that use different habitats. Males do not ally with the females; they simply establish territories around water.   Despite their stable long-term harem structure, plains zebras often coalesce into herds, forming multi-male or uni-male groups, providing polygamous opportunities for males and polyandrous opportunities for females.  Ã‚   Diana Robinson Photography/Getty Images   Conservation Status The Grevys zebra is listed by the IUCN as Endangered; the mountain zebra as Vulnerable; and the plains zebra as Near Threatened.  Zebras once roamed all habitats in Africa, with the exceptions of rain forests, deserts, and dunes. Threats for all of them include habitat loss resulting from drought associated with climate change and farming, continuing political upheaval, and hunting. Sources About zebras. Yale Peabody Museum of Natural History, 2018.Gosling, L.M., et al. Equus zebra. The IUCN Red List of Threatened Species e.T7960A45171906, 2019.Hoekstra, Jon. Big Discoveries Still Happen – Zebras Make Africa’s Longest-Known Terrestrial Wildlife Migration. World Wildlife Fund, May 27, 2014.King, S.R.B. and P.D. Moehlman. Equus quagga. The IUCN Red List of Threatened Species e.T41013A45172424, 2016.Rubenstein, D. et al. Equus grevyi. The IUCN Red List of Threatened Species e.T7950A89624491, 2016  Walker, Martha. Equus zebra: mountain zebra. Animal Diversity Web, 2005.

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