Abstract:
Important metapopulation dynamics are disrupted by factors such as habitat loss, climate
change, and human-induced mortality, culminating in isolated wildlife populations and threatening
species survival. Source populations, where birth rates exceed mortality and connectivity facilitates
dispersal, contrast with sink populations, where mortality outstrips births, risking localised extinction.
Recolonisation by individuals from source populations is pivotal for species survival. The leopard
is the last free-roaming apex predator in South Africa and plays an important ecological role. In
the Eastern and Western Cape provinces in South Africa, leopard populations have low densities
and fragmented population structures. We identified a leopard population that, after being locally
extinct for a century, appeared to recolonise an ‘island’ of mountainous habitat. We aimed to
understand potential factors driving this recolonisation using recent camera trapping surveys and
historical statutory destruction permits. We employed spatially explicit capture–recapture (SECR)
methods to estimate the leopard density and explore potential factors which best explain density. We
found that the recently recolonised Piketberg population now exhibits some of the highest densities
reported in the region (~1.8 leopards/100 km2
; CI 1.4–2.5). Livestock, human presence, elevation,
and the camera trap grid appeared to explain leopard detection rates. When considering the historic
data, the re-emergence of leopards in the Piketberg coincided with the cessation of the extensive
state-sponsored and state-enabled culling of the species, and the change in land use from livestock
production to crop agriculture, which likely contributed to the recolonisation. Elucidating these
factors deepens our understanding of leopard metapopulation dynamics in relation to land use and
species management and highlights the crucial role of private land and state agencies and associated
policies in species persistence.
