The Blue Wildebeest (Connochaetes taurinus, top) and the Black Wildebeest (Connochaetes taurinus, bottom) Images from animalia.bio
A staple of the vast expanses of the African savannah, the wildebeest are famed for the massive migrations of their enormous herds across huge distances and dangerous, crocodile filled rivers. Part of the large family Bovidae, made up of antelopes, cattle, goats, sheep and even toed ungulates, the wildebeest are thought to have evolved when the open grasslands of central Africa first developed. Today there are two species, the Blue Wildebeest, so named for the blue-ish grey sheen to their coat and the Black Wildebeest, with its much darker coat. The horns are oriented slightly differently between the two species, with the Black Wildebeests’ horns curving further forwards. Fossil records from central Africa show ancestral wildebeest with smaller, less forward-facing horns and less well-developed skulls than their modern counterparts, in particular the black wildebeest, indicating that over time there has been a shift towards more territorial breeding and the need for defensive horns. The Black Wildebeest diverged when they began to move into the more open highveld habitat of Central Africa and adapted to the ecological niche there, including a more territorial breeding strategy that relies heavily on line of sight, thus relying on the vast open spaces of the highveld and driving a need for more defensively designed horns.
A staple savannah species
Both species occur in short grass plains mixed with low scrub and woodland. Blue wildebeest have a larger population and a broader distribution through eastern and southern Africa, whereas the Black Wildebeest is less common and only exists in South Africa. Black Wildebeest once existed in Swaziland and Lesotho but in the 19th century were hunted into extinction, although they have been reintroduced in recent years.
Wildebeest are an essential part of the food chain, predated on by a range of iconic African predators, including lions, hyenas, African painted dogs and crocodiles, which catch them as they plunge across rivers on their migrations. Although a staple part of many predators’ diets, wildebeest are incredibly strong and deliver a powerful kick that makes any potential predator think twice; often predators will try to separate the sick or the young from the herd rather than tangle with an adult wildebeest and risk getting a fatal kick for their efforts. Aside from their strength, wildebeest form vast herds, often including zebra, which acts to confuse predators, decreasing any one individual’s chance of being hunted significantly, and allowing vulnerable juveniles to be protected by the sheer numbers of animals. Wildebeest are also known to be able to listen and understand the alarm calls of other species on the savannah such as baboons and have been shown to decrease their risk of predation by listening to baboon troupes alarm calling as a pride of lions stalks close by. Vultures are known to follow wildebeest migrations as a vital source of food for the scavengers, and in years where the migrations have been smaller, vulture numbers have dropped as the food source runs short. Wildebeest even have effects on the survival of giraffe calves, as the presence of huge herds distracts predators from the presence of calves. These essential impacts make wildebeest a keystone species; a species that has a disproportionately large, positive impact on their ecosystem.
Life on the move: mass migrations
A draw for hundred of thousands of tourists and wildlife enthusiasts every year, the Great Migration is the ever-moving journey of millions of animals every year, from calving grounds in Tanzania to the plains of the Serengeti, to the vast Masai Mara ecosystem before returning again after a year. An estimated 1.2 million wildebeest and 300,000 zebra, along with vast numbers of other herbivores like Thompsons gazelle and Topi, make the dramatic 1500km2 journey every year, followed by predators intent on catching the stragglers.
In late November and December, as the short rains begin, the wildebeest arrive to the Serengeti, feeding on the rich, nutritious grasses, remaining there until the synchronous calving finishes in February. In April they begin to fan out over the plains and by May, the great migration North has begun to seek fresh grazing and water. In June, the migration pauses as the wildebeest cross the Grumeti river, continuing northwards after this through July and August into the Serengeti National Park. In September, as they spread through the Serengeti, the wildebeest tackle the vast and deadly Mara river; arguably the most frantic part of the journey. By October, the wildebeest are making their thundering way back to the regenerated grasslands of the Serengeti, and the whole thing begins again.
This impressive spectacle is not only stunning visually, but also plays an essential ecosystem role; the migrating animals transport vital nutrients and are of course themselves a vital source of food for a range of predators and scavengers, as mentioned above. The rotational grazing of grasses along the migratory route also encourages grasses to grow faster after being grazed, increasing available biomass for grazing. Without this annual movement, the ecosystem would fall into serious decline.
A barrier to migration: fragmenting habitat
Although all species of wildebeest are currently listed as least concern by the IUCN, fast spreading agricultural and housing developments are reducing their spread and distribution. For instance, fences that have blocked migrations have led to mass die-offs by preventing wildebeest getting to vital water supplies. Large parts of wildebeest range is found within protected areas, but they are still vulnerable to human development in the path of their migration, meaning stepping up protection in these national parks may not be enough to protect the species from the damages outside of these areas. Diseases of domestic livestock can also be transmitted to wildebeest, especially as shrinking habitat forces them closer together, like African sleeping sickness, despite campaigns to eradicate it.
Intensive poaching in the early 1990’s led to a significant decline in wildebeest numbers, although their populations have bounced back healthily since then. Charities like the African Wildlife Foundation work with local stakeholders to provide alternatives to development in the path of wildebeest migrations, striking a tricky balance between modernisation and conservation. Bottlenecks along the migration routes are of particular concern, and efforts are underway to protect these choke points, as infrastructure development in these critical areas could be catastrophic for the protection of the wildebeest on their long journey.
Fortunately, the IUCN currently list all species of the wildebeest as least concern, with most populations either stable or even increasing. But the security of this iconic savannah species relies on protecting their migration route, and large swathes of land are still at risk from human development. There is a concern that the species may be forced into certain fenced off protected areas, forcing them to lose their magnificent migration and all the ecosystem benefits it brings.
The African Wildlife Foundation
- If you are interested in conserving not just wildebeest but all sorts of iconic African wildlife, check out the African wildlife foundation. They have been working for 60 years to preserve the unique African ecosystems by conserving wildlife, engaging and empowering local communities and protecting habitats.
- You can donate to their work or find fundraising ideas on their website.
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