The use and utility of surrogates in biodiversity monitoring programmes

Monitoring programmes are intended to inform effective biodiversity conservation and management (Legge et al. 2018). Well‐designed programmes can establish baseline conditions, determine trends in threatened species populations, quantify the effects of management, and provide warning of ecosystem changes (Magurran et al. 2010). For these reasons, biodiversity monitoring underpins the activities of land management agencies worldwide. However, it is not always possible to directly monitor key variables at ideal spatio‐temporal resolutions, due to resourcing or logistic constraints. For example, direct monitoring of koalas (Phascolarctos cinereus) can be cost‐ and time‐intensive as koalas are cryptic, occur at low densities, and are difficult to reliably observe in dense forest canopies (McAlpine et al. 2006).