Multi-Species Impacts of Invasive Opuntia Cacti on Mammal Habitat Use

Biological invasions impact ecosystems worldwide, including through changing the behaviour of native species. Here, we used camera traps to investigate the effects of invasive Opuntia spp. on the habitat use of 12 mammal species in Laikipia County, Kenya, an internationally important region of mammalian biodiversity. We found that Opuntia impacted mammal occupancy and activity. These effects were evident when Opuntia was considered at both site level and landscape scales; however, some mammal species showed different responses to increasing Opuntia at these two scales. The effects of Opuntia were generally context dependent, with their strength and direction varying among mammal species and between seasons. As well as having important implications for mammal conservation, ecosystem functioning and the future spread of Opuntia, our findings highlight behavioural changes in large mammals as a potentially important pathway through which invasive species impact ecosystems.