Moving through the mosaic: identifying critical linkage zones for large herbivores across a multiple‐use African landscape

Context Reduced connectivity across grassland ecosystems can impair their functional heterogeneity and negatively impact large herbivore populations. Maintaining landscape connectivity across human dominated rangelands is therefore a key conservation priority.

Objective Integrate data on large herbivore occurrence and species richness with analyses of functional landscape connectivity to identify important areas for maintaining or restoring connectivity for large herbivores.

Methods The study was conducted on a landscape with a mosaic of multiple land uses in Laikipia County, Kenya. We used occupancy estimates for four herbivore species [African elephant (Loxodonta africana), reticulated giraffe (Giraffa reticulata), plains zebra (Equus quagga), and Grevy’s zebra (Equus grevyi)] and species richness estimates derived from aerial surveys to create resistance surfaces to movement for single species and a multi-species assemblage, respectively. We validated single-species resistance surfaces using telemetry data. We used circuit theory and least cost-path analyses to model linkage zones across the landscape and prioritize areas for connectivity restoration.

Results Resistance layers approximated the movements of our focal species. Results for single-species and multi-species connectivity models were highly correlated (rp>0.9), indicating similar spatial patterns of functional connectivity between individual species and the larger herbivore assemblage. We identified critical linkage zones that may improve permeability to large-herbivore movements.

Conclusion Our analysis highlights the utility of aerial surveys in modeling landscape connectivity and informing conservation management when animal movement data are scarce. Our results can guide management decisions, providing valuable information to evaluate the trade-offs between improving landscape connectivity and safeguarding livelihoods with electrified fences across rangelands.

Last Updated
March 18, 2021