Distribution, livelihood impacts and perceptions of an invasive cactus species ( Opuntia elatior Mill.) in the arid rangelands of Kenya, East Africa

We mapped the distribution of the invasive cactus Opuntia elatior Mill. in five countries in eastern Africa and conducted household interviews to assess perceptions of its benefits, impacts and management in Baringo County, Kenya. We compared our results to those of a previous socio-economic study on O. stricta in neighbouring Laikipia County. Opuntia elatior was only present in Baringo County, but was not seen elsewhere in Kenya or in Ethiopia, Rwanda, Tanzania and Uganda. Respondents (n = 153) stated that O. elatior is still spreading in Baringo. Over half of respondents (55%) mentioned that O. elatior was now present on 26–50% of their grazing land, contributing to ill health or death of livestock. Despite these impacts, most respondents (56%) reported no financial losses arising from O. elatior invasions, and only 11% and 13% of respondents reported annual losses of USD 66–331 and USD 331 - 662 per household, respectively. Other perceived impacts included reductions in grazing capacity, restrictions on the movement of people and livestock, injuries to livestock, decreased land values and the abandonment of invaded land, similar to what was recorded for O. stricta in Laikipia. Almost all respondents attempted removal of O. elatior and felt strongly that its elimination would improve livelihoods. We conclude that control of O. elatior using the biological control Dactylopius opuntiae, which is already established in Baringo, would be justified, as it would substantially reduce current levels of impact.