Abstract:
Carnivore survey protocols that properly address spatial sampling and detectability issues are seldom
feasible at a landscape-scale. This limits knowledge of large-scale patterns in distribution, abundance
and their underlying determinants, hindering conservation of globally threatened carnivore populations.
Occupancy analysis of data from logistically efficient sign surveys along consecutive road segments (spatially
auto-correlated replicates) offers a potential solution. We adapted and applied this newly-developed
method over 62,979 km2 of human-modified land in South Africa. Our aims were to (1) generate unbiased
estimates of brown hyaena occupancy and abundance (2) investigate two suspected determinants of occupancy
using a combination of biological and socio-economic sampling techniques, and (3) use simulations
to evaluate the effort required for abundance and occupancy estimates with acceptable bias, precision and
power. Brown hyaena occupancy was estimated at 0.748 (±SE 0.1), and estimated overall density in agricultural
land (0.15/100 km2, ±SE 0.08) was an order of magnitude lower than in protected areas. Positive
attitudes to carnivores and presence of wildlife farms exerted strong positive effects on occupancy, so
changes in these factors may well exert monotonic impacts on local metapopulation status. Producing reliable
occupancy and abundance estimates would requireP6 replicates andP12 replicates per site respectively.
Detecting 50% and 30% declines in brown hyaena occupancy with adequate power would require
five annual surveys at P65 sites and P125 sites respectively. Our results suggest that protocols based
on spatially auto-correlated sign survey replicates could be used to monitor carnivore populations at large,
and possibly even country-wide spatial scales.
