(Photograph = elephants in area colonized by Opuntia, Shirley Strum)
Introduction
For more than 40 years, Dr. Shirley Strum has watched baboons in Kenya, and, alongside them, the people, plants, and weather that shape their range. Over those decades, one constant has grown harder to ignore: in the drier country, prickly pear has slipped its bounds and begun to dominate. What started as scattered plants around settlements and roads now forms dense, thorny thickets that shut out grass, snag livestock, and complicate wildlife management. Baboons help move it—so do elephants and goats—and birds and other fauna almost certainly play their part, turning fruits and fallen pads into new outposts.
The Details
Laikipia, in Kenya, was once virtually uninhabited, it’s now being steadily degraded by the incursion of land-hungry Homo sapiens and also by the spread of Opuntia stricta, otherwise known as the prickly pear (Sydney Morning Herald).
Opuntia lingered in the broader region for decades before it surged. The timing tracks with heavier pressure on rangelands—more people, more grazing, more bare soil. From there, the plant does the rest: fruits carry thousands of seeds that pass through baboons, elephants, and goats; birds likely add distance dispersal; broken pads root after storms or along paths and fences. Wet seasons give seedlings a start, then long droughts thin competitors and leave the armored rosettes standing. Poor, rocky soils don’t slow them, and the plants shrug off heat, wind, and browsing.
The fix is work, not wishes. Accurate IDs matter, since different lineages respond differently to control. Mechanical removal helps if follow-up is relentless and fragments are dried or destroyed; herbicide can clean up resprouts when timing is right. In some places, precisely matched cochineal strains suppress specific taxa; mismatched agents waste effort. The durable path is integrated and local: map patches, treat edges first, rest and reseed grazed ground, and keep stock out long enough for grass to close the gaps that Opuntia seeks. If you want to help Dr. Strum’s conservation efforts, visit BaboonsRUS.
All photos by Shirley Strum.
