‘Devil’ invades Maasai Mara threatening wildebeest migration

By Gatonye Gathura

The ‘Devil’ and other alien plants, have invaded the Maasai Mara, threatening one of the world’s greatest natural wonders, revels new survey.

Conservationists and the Kenya Wildlife Service want the aliens taken out now.

Most introduced innocently as ornamentals by hotels, conservationists say now they are disrupting the world’s greatest animal migration.

“It is critical that all invasive or potentially invasive plants be removed from tourism facilities in the Mara – asap,” says conservationist Arne Witt of the Centre for Agriculture and Biosciences International (CABI).

Witt had led a research team from the Kenya Wildlife Service and Stellenbosch University, South Africa who now want all invasive alien plants at the Mara removed.

In case of resistance from the tourist lodges as had happened in South Africa, the conservationists want authorities to invoke the letter of the law.

In the survey, the team identified 245 invasive plant species but homed on six, which they say are an immediate danger to the existence of large mammals in the Mara-Serengeti ecosystem.

If nothing is done Witt says this will have severe impacts on migration of large animals, especially wildebeest, zebra and gazelles.

“This will, in turn, have a substantial negative impact on tourism, which is a major economic activity in the region.”

The annual Maasai Mara migration involving more than two million animals is regarded as one of the greatest natural wonders of the world.

The offending plants, which include the Devil weed (Chromolaena odorata), Witt says are invasive (replace other vegetation), toxic or unpalatable, meaning there’s less forage available for wildlife to feed on.

In their study published in May in the conservation journal Koedoe the researchers had investigated the extent of invasive plant species at the Masai-Mara National Reserve in Kenya and the adjacent Serengeti National Park in Tanzania.

The study spanning between 2011 and 2016 concluding six species of 245 present immediate and grave danger to wildlife existence and migration.

The six the researchers say are known to be aggressive invaders with potential to reduce the capacity of the land to support grazing mammals.

Some are also known to be poisonous, or having the ability to affect the health of livestock or wildlife.

Further the researchers investigated the type of ornamental plants, those planted for their decorative purposes, at 24 tourist facilities. Here they report more than 200 alien species which have been introduced for ornamental purposes.

Of these, 23 species were found to have spread over the limits of the tourist facilities into the wild with possible serious consequences on native vegetation.

As a starter in confronting the problem the team want all alien plants, around tourist facilities whether invasive or not be removed immediately.

“If allowed to establish widely control costs can run into millions of dollars,” she told the Standard on Saturday.

The Devil weed, a name also shared with the Datura species, and appearing at the top of the list of six is from Central and Southern America.

An invasive plants database hosted by CABI indicates the Devil has reduced the chance of survival of Nile crocodiles in South Africa and lowland gorillas in Cameroon.

It is described as having the capacity to smother whole plantations of coffee and cocoa and becoming the dominant plant in grazing lands.

Due to the high nitrate content in its leaves, the Devil is reported as poisonous to cattle and generally not grazed.

The Devil weed also called the Siam weed may not be a household name in Kenya, but not so with Prosopis juliflora, also in the risk of six.

Prosopis juliflora, called ‘Mathenge’ in Kenya is known for its dominance tendency and poisoning of livestock mainly in Baringo County and other parts of the Rift Valley and the Coast region.


The notorious six

 Chromolaena odorata

Lantana camara,

Opuntia stricta

Parthenium hysterophorus

Prosopis species and hybrids

Tithonia diversifolia




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