Women in Kenya declare war on invasive colonial-era plant species

LAIKIPIA, Kenya – An ornamental plant brought by the British colonialists to Kenya in the 1940s has been killing indigenous vegetation, especially grasses and bushes, thus creating food shortages for livestock and wild animals.

Scientists say that the invasive plant Opuntia stricta or the prickly pear, is spreading fast across northern Kenya, degrading the land by killing vegetation that comes in its way. Since the thorny plant with no use for humans or animals can grow with limited water and in aired conditions, it has been multiplying itself through seeds and vegetative reproduction.

To restrict this invasive species, local women can be seen using cochineal scale insects to kill the plant. The insects feed on its sap in its flattened stem.

“We harvest the plants in the fields, infect them with the bugs, and throw pieces of it where the plants are growing in the wild. The bugs spread so fast, and within a few weeks, all the plants in the area dry up,” said Jane Neparakuo, a 42-year-old woman involved in the project.

Jacqueline Lenaloi, a researcher working with the Northern Rangelands Trust (NRT), said the involvement of women in the fight against the invasive plant in the rangelands has been a game-changer.

He said the cochineal scale insect comes from South Africa and cannot affect other plants.

“It is only specific to Opuntia. After the plant is eradicated, the cochineal insect also dies. These insects also have no effects on livestock if they feed on it,” he added.

According to researchers, the invasive prickly pear locally known as matunda has off late emerged as a serious problem for the herders, as the increase in temperatures and dry spells are taking the toll on other green covers.

Colonial legacy

“They (British) brought it to an outpost in Doldol in Laikipia county for ornamental purposes because it is very beautiful, with yellow flowers, purple fruits, and rich green stems. So, it could easily pass as a potted plant,” said Lenaloi.

The colonialists also propagated this plant as they used its thorns for fencing purposes.

The plant feeds on anything else that grows around it. It has taken over the northern Kenya rangelands, killing the perennial grasses that the wildlife and livestock used to feed on.

The researchers say that elephants also contribute to its propagation.

According to Lenaloi, an elephant can feed on around 2,000 seeds of the plant every day and they pass on them to wide areas with the dung.

He said the elephants eat the plant for want of proper vegetation. Because of continuous drought over the past years, there is little proper vegetation available in the region.

“They (elephants) are not to blame. They feed on it just because of the drought,” she added.

The absence of vegetation has affected the economy of nomadic herders who earn living by rearing livestock.

Causes injuries to animals

The invasion plant not only affects indigenous vegetation, but its thorns also cause injuries to livestock and wild animals, who try to eat it in absence of grass.

“I lose a cow after every four days. Yesterday I lost two goats,” said 68-year-old George Ole Sentari.

“We have no water and no vegetation, so our livestock is forced to feed on this plant for survival. The problem is that it brings so many wounds to their eyes, mouths, and internal organs after they eat it for a while,” Sentari said.

Sentari said he started sighting this plant in his area around 1978.

“The plant has killed so many livestock, especially goats in this area. The thorns prickle the mouth and get stuck between the teeth. It has served as a temporary food measure for our animals, but eventually, they die. I have lost 20 cows and 40 goats since the drought started a few months ago. They didn’t die due to the drought but due to eating the plant,” he said.