The Zebra

by Robert Wedderburn

One of the most striking and distinguished animals, and definitely the best dressed animal in Africa, the Zebra!

Geographical Range:
There are three species of Zebra and Six Subspecies of Zebra, one of which the Quagga has been extinct since the late 19th century. The three species of Zebra are Grévy’s Zebra (Equus grevyi) which is endemic to the savannahs of East Africa, the Plains Zebra from East and Southern Africa (E. quagga) and Mountain Zebra (E. zebra). 


Natural Habitat:
The Plains Zebra and the Grévy’s Zebra live in semi-arid grasslands. The Mountain Zebra is also commonly found in open grasslands but this species prefers rocky, mountainous and hilly habitats. Zebras are a nomadic and migratory species. 

Description:
Zebras are short in stature compared to most horses. They are around the height of a donkey and are strong stocky equines. Zebras are small but are a lot stronger than they look, and are very capable of biting or kicking to defend themselves.

The Zebra’s Stripes:

There is much to be said about the Zebra’s stripes, and we could make an entire documentary just about them, so I will be brief. Zebras have bold stripes that cover almost their entire bodies. In areas where stripes are no strips, Zebras are covered in white, but underneath the zebra’s coat, their skin is uniformly black. 

It is commonly thought that Zebra’s Stripes are used as a form of cryptic protection and camouflage against predators. This hypothesis was proposed by Alfred Wallace in 1896. His hypothesis was that the Zebra’s stripes break out its general outline and predators battle to see zebras as an animal. Although at first glance this is a reasonable hypothesis, Zebras’ stripes make them highly visible to predators during daylight on the african savannah.



In 1871, Charles Darwin remarked that “the zebra is conspicuously striped, and stripes on the open plains of South Africa cannot afford any protection” 

The Zebra’s Stripes are pretty useless when they are standing in the middle of a grassland, they are still very difficult to spot in areas with small shrubs or rocky outcrops. 

Try to spot the three Mountain Zebras on this rocky mountain. 

(Insert shot of mountain zebras here)

So it could still be a reasonable hypothesis. The Zebra’s stripes are also more useful as camouflage at night when Lions and Hyenas hunt.

The second hypothesis is that the stripes confuse predators when they are chasing zebras making it harder to distinguish individuals in a group. It is also hypothesized that it makes it difficult for predators to judge the zebra’s size, speed and trajectory via motion dazzle. This hypothesis has been proposed since the 1970s and in 2014 a computer study showed that the movements the Zebras make create a motion dazzle, like a wagon wheel effect. The scientists conducting the study concluded that this could be used against mammalian predators or flies. 

The confusion hypothesis has also been questioned and Lions seem to have no difficulty identifying individuals and chasing them down. 

The third hypothesis suggests that Zebras have their stripes to deter potential predators in the same way that brightly colored dart frogs do. 

The fourth hypothesis is that Zebras use the stripes to identify other Zebras from a far.

The fifth hypothesis is that their stripes help Zebras control their body temperature and thermoregulate. In 1971, biologist H. A. Baldwin noted that black stripes absorbed heat while the white ones reflected it and in 1990, zoologist Desmond Morris proposed that the stripes set up convection currents to cool the animal. 

A sixth Hypothesis is that the Zebras’ stripes help deter biting flies like horse flies which are responsible for transmitting lethal equine diseases, namely, African Horse Sickness, equine influenza, equine infectious anemia and trypanosomiasis. It’s now thought that although the Zebra’ stripes don’t deter flies from a distance, they do make it difficult for flies to land on Zebras. 

So in conclusion the Zebra’s stripes are most likely to deter biting flies like horse flies and tsetse flies. 

Zebra Lifespan:

Zebras reach sexual maturity at around 3 to 6 years of age and can live for around 25 years. 

Diet:

The Zebras are herbivores and a grazing species. Their diet is 90% grass and sedges. They are known as a pioneering grazer species as they are often the first grazers to arrive in an area and create the pathway for more specialized feeders such as the Blue Wildebeest and antelope species. Zebras are also known to feed on leaves, twigs and dig for bulbs and tubers during the dry season. 

Zebras are also able to go 5 days without drinking water but prefer to drink water on a daily basis. They need to drink a large volume of water everyday to be able to digest the large amount of grass they eat. 

Their Predators:

The main predators of Zebras are Lions and Spotted Hyenas. 

Communication:

Zebras communicate with various vocalisations, body postures and facial expressions. Social grooming strengthens social bonds in plains and mountain zebras.

The Zebra’s call is one of the most distinct animal calls of Africa and is often part of the soundtrack of the African Savannah. 

Social Structure and Breeding:

Zebras can 

The Plains Zebra is a highly social species and forms small families called harems which usually consist of one stallion and multiple mares. These breeding groups are fairly stable and remain together for months to years. Once a mare reaches sexual maturity and has her first oestrous cycle, a fight will begin between males from existing harems and bachelors groups to reproduce with her. This competition will continue between males until the mare ovulates and is impregnated by a stallion. She will remain with this stallion for good. Her oestrous cycles become less noticeable to outside males with age, meaning that competition for older mares is virtually nonexistent.

There are also groups of young males of up to 15 stallions called Bachelor groups. Males within these groups will separate and form their own harems once they reach sexual maturity. These Harems and Bachelor groups can form huge herds, especially in regions where they migrate.

ADD SOCIAL STRUCTURE OF MOUNTAIN ZEBRA AND GRËVYS ZEBRA

Zebra species differ in social behaviour, with plains and mountain zebras living in stable harems consisting of an adult male or stallion, several adult females or mares, and their young or foals; while Grévy’s zebras live solitary or in loosely associated herds. In harem-holding species, adult females mate only with their harem stallion, while male Grévy’s zebras establish territories which attract females and the species is promiscuous.

A large group of Zebras is commonly referred to as a herd, a zeal, a cohort or a dazzle. 


Taxonomy and Hybridisation

There are three species of Zebra and Six Subspecies of Zebra, one of which the Quagga has been extinct since the late 19th century. The three species of Zebra are Grévy’s Zebra (Equus grevyi) which is endemic to the savannahs of East Africa, the Plains Zebra from East and Southern Africa (E. quagga) and Mountain Zebra (E. zebra). 

The subspecies of Plains six subspecies of the Plains Zebra include the Maneless zebra (Equus quagga borensis), Grant’s zebra (Equus quagga boehmi), Crawshay’s zebra Equus quagga crawshayi), Chapman’s zebra (Equus quagga chapmani), Burchell’s zebra (Equus quagga burchellii)  and the extinct Quagga, (Equus quagga quagga)

Conservation Status:

The Plains Zebra’s  (Equus quagga) conservation status is considered near threatened, and there are around 500,000 in the wild today. 

The Grévy’s Zebra’s (Equus grevyi) population decreased drastically from 15,000 to 3000 zebras from the 1970s to the early 2000s. Thankfully their populations are now stable but there are still only around 2500 Grévy’s Zebra’s (Equus grevyi) in the wild and are considered endangered.

The Cape Mountain Zebra (Equus zebra) is still considered vulnerable. Their populations were decimated and hunted to near extinction. In the 1930s there were less than 100 Mountain Zebras in the wild. The population of the Cape Mountain Zebra (Equus zebra) is now around 2700 zebras. To put that into perspective, there are around 5600 Black Rhinos and 18,000 Southern White Rhinos in the wild. Although their populations are increasing it is truly a privilege to be able to still see these Zebras in the wild and it is thanks to the efforts of multiple generations of wildlife conservationists who have made this success possible. 

Outro:

I hope you enjoyed this documentary about the Zebra. If you have any questions about Zebras, I will be happy to answer them in the comments below. 

Remember to subscribe to my YouTube Channel, HIT THE BELL Icon, so you can receive more of my wildlife documentaries, share it with a friend and I look forward to seeing you on my next adventure. 

Refencences:

https://ielc.libguides.com/sdzg/factsheets/plains_zebra/taxonomy

https://www.livescience.com/27443-zebras.html

https://en.wikipedia.org/wiki/Zebra

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