Kenya ranch lost half its farmers as invasive cactus spread, but displacement went uncounted

Researchers are warning that invasive species can push people out of their communities, even though that form of displacement is rarely measured. In Kenya, for example, the spread of one cactus contributed to the departure of hundreds of farmers from their land.

What's happening?

According to Earth.com, a new study says invasive species belong in discussions of forced migration, alongside conflict and climate-related pressures. The paper, published in Frontiers in Conservation Science, was authored by Jamie Reaser, an independent conservation consultant, and Arne Witt, a scientist focused on invasive species at the nonprofit CABI.

In Laikipia, Kenya, the paper highlights the Mukurian Group Ranch, where a livestock officer said the cactus species Opuntia stricta had spread across about two-thirds of the land. As the cactus took over terrain that had previously supported local livelihoods, 600 of the ranch's 1,200 farmers left.

The authors also cite other places where invasive species have made ordinary work impossible. Near Douala in Cameroon's Wouri River Basin, water hyacinth became so overwhelming that 60% of working fishermen left and the local catch dropped by 76%. In parts of the Pacific, including New Caledonia, French Polynesia, and the Galapagos Islands, the little fire ant has made infested fields unworkable, contributing to the abandonment of some farms.

Why does it matter?

These cases show that invasive species are not only damaging ecosystems but also weakening food security, incomes, and people's ability to remain in their homes. When farmland becomes unusable or rivers can no longer support fishing families, communities can lose both economic stability and deep cultural ties to place.

The paper also underscores how little attention this dimension of the issue has received. As Earth.com noted, a 2017 review of more than 9,000 invasive-species papers found that just 4.4% dealt with social effects at all. Agencies monitoring global displacement do not count invasive species as one of the causes they record.

What's being done?

To close that gap, Reaser and Witt want governments to report land abandonment and human displacement linked to invasive species to the same agencies that already monitor displacement caused by war and disaster, per Earth.com. Doing so could make the problem more visible and help direct funding, planning, and emergency support to affected communities.

Better tracking could also shape how governments respond on the ground. If displacement data includes invasive species, officials may be more likely to invest in prevention, early detection, and rapid response before farms, ranches, and fisheries become unusable.

"In the case of invasive alien species, too little attention has been given to the link between their spread and forced migration," Witt said, per Earth.com.

"This is despite their close connections. Nevertheless, migration is a growing global concern."

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