Random versus game trail-based camera trap placement for monitoring terrestrial mammal communities

Cusack and colleagues directly compared placing cameras randomly across the landscape versus targeting them on game trails, using paired deployments in an African savanna. They found that trail-based placement increased capture rates for many species, especially carnivores that travel along paths, but introduced biases in species composition and detection relative to random placement, which better represents habitat use but yields fewer photos. The trade-off has major consequences for density and occupancy inference, since spatially explicit models assume placement is independent of animal density. The study quantified these effects and informed design choices about when each strategy is appropriate. It is a frequently cited reference on the consequential, often underappreciated, decision of where exactly to put camera traps.