Monitoring small and/or threatened animal populations using methodologies that provide accurate information is critical for effective and timely conservation decision-making. In recent years, “unmarked” methods that combine passive sampling of unidentifiable individuals with statistical models that purport to estimate demographic parameters (e.g., abundance) have proliferated. We highlight the risks of using such methods for small populations and the considerable value of individual-based monitoring.
Gerber et al. (Fri,) studied this question.