Modelling Multi-Species Connectivity at the Kafue-Zambezi Interface: Implications for Transboundary Carnivore Conservation

Abstract

Linking wildlife areas with corridors facilitating species dispersal between core habitats is a key intervention to reduce the deleterious effects of population isolation. Large heterogeneous networks of areas managed for wildlife protection present site- and species-scale complexity underpinning the scope and performance of proposed corridors. In Southern Africa, the Kavango-Zambezi Transfrontier Conservation Area seeks to link Kafue National Park to a cluster of wildlife areas centered in Namibia and Botswana. To assess and identify potential linkages on the Zambian side, we generated a high-resolution land cover map and combined empirical occurrence data for Lions (Panthera leo), Leopards (Panthera pardus) and Spotted Hyena (Crocuta crocuta) to build habitat suitability maps. We then developed four connectivity models to map potential single and multi-species corridors between Kafue and the Zambezi River border with Namibia. Single and multi-species connectivity models selected corridors follow broadly similar pathways narrowing significantly in central-southern areas of the Kafue-Zambezi interface, indicating a potential connectivity bottleneck. Capturing the full extent of human disturbance and barriers to connectivity remains challenging, suggesting increased risk to corridor integrity than modelled here. Notwithstanding model limitations, these data provide important results for land use planners at the Kafue-Zambezi Interface, removing much speculations from existing connectivity narratives. Failure to control human disturbance and secure corridors will leave Kafue National Park, Zambia’s majority component in the Kavango-Zambezi Transfrontier Conservation Area, isolated.

Utility of Human Footprint Pressure Mapping for Large Carnivore Conservation: The Kafue-Zambezi Interface

“…An apparent anomaly is Machili Forest Reserve, with extensive settlement, agriculture, and transport infrastructure, having a mean Human Footprint Pressure score of 5.6, and with both leopard and spotted hyena occurring. The proposed supplemental addition to the protected area network identified in Lines et al [37], Open Area extension 1 (and 2), has a mean Human Footprint Pressure of 3.9, within threshold limits presented here, which indicates that both leopard and spotted hyena could inhabit these protected areas.…”

“…Kafue National Park and surrounding protected areas, collectively known as the Greater Kafue System, represents KAZA's major northern cluster (Figure 1) and Zambia's majority contribution to the KAZA Programme [34]. Connectivity between Kafue National Park and adjacent protected areas, centered on Chobe National Park and East Zambezi Region in Namibia, is contingent on movement across eight partially and nominally protected areas plus an adjacent open Communal Areas identified by Lines et al [37], as potentially important for corridor planning. In concert, these areas span ~13,000 km 2 , extending 140-170 km from the Kafue National Park border south-southwest towards the Zambezi River at the confluence of Zambia, Namibia, and Botswana [38].…”

“…Following the methods described in Lines et al [37], habitat suitability maps for lion, leopard, and spotted hyaena were generated using MaxEnt [48] which performs well compared to other modelling techniques using presence only data [49], and has been repeatedly used to model large carnivores distribution [50][51][52][53]. We present the modelling briefly below, and refer to Lines et al [37] for more details.…”

“…The arable land was extracted by a land cover map produced by Lines et al [37] using a mosaic of 24, geometrically and atmospherically corrected, Sentinel 2 images in an Object Oriented Image Analysis environment. The land cover map had a spatial resolution of 10 m and an overall classification accuracy of 91.6% [37]. A pressure score of 7 was assigned to all pixels covered by arable land and 0 to all other pixels [17].…”

Dispersal and connectivity in increasingly extreme climatic conditions

“…The core study area and its extended surroundings are part of the world's largest transboundary conservation initiative, the Kavango‐Zambezi Transfrontier Conservation Area (KAZA‐TFCA, Figure 2a), which attempts to re‐establish connectivity among several core habitats. Previous studies have indicated that this initiative has a high potential for improving connectivity among subpopulations of various species (Brennan et al., 2020; Lines et al., 2021), including African wild dogs (Hofmann et al., 2021). However, a better understanding of connectivity within this ecosystem under climate change is lacking.…”