The Kavango–Zambezi Transfrontier Conservation Area Programme promotes landscape-level connectivity between clusters of wildlife management areas in five neighbouring countries. However, declining regional biodiversity can undermine efforts to maintain, expand and link wildlife populations. Narratives promoting species connectivity should thus be founded on studies of system and state changes in key resources. By integrating and augmenting multiple data sources throughout eight wildlife management areas, covering 1.7 million ha, we report changes during 1978–2015 in the occurrence and distribution of 31 mammal species throughout a landscape linking the Greater Kafue System to adjacent wildlife management areas in Namibia and Botswana. Results indicate species diversity is largely unchanged in Kafue National Park and Mulobezi and Sichifulo Game Management Areas. However, 100% of large carnivore and 64% of prey diversity have been lost in the Simalaha areas, and there is no evidence of migrational behaviour or species recolonization from adjacent wildlife areas. Although temporal sampling scales influence the definition of species occupancy and distribution, and data cannot elucidate population size or trends, our findings indicate an emerging connectivity bottleneck within Simalaha. Evidence suggests that at current disturbance levels the Greater Kafue System, Zambia's majority component in the Kavango–Zambezi Transfrontier Conservation Area, is becoming increasingly isolated at the trophic scale of large mammals. Further investigations of the site-specific, interacting drivers influencing wildlife distribution and occurrence are required to inform appropriate conservation interventions for wildlife recovery in key areas identified to promote transboundary connectivity in the Kavango–Zambezi Transfrontier Conservation Area.