230 Monitoring Threatened Species and Ecological Communities
species-by-species and site-by-site basis, by project coordinators and other species
experts, based on a conceptual model of the relevant system (Fig. 17.2). Building
such models requires knowledge of the dynamics of species populations and
threats, and how these interact with management and other environmental drivers
(i.e. Fig. 17.2a), which varies significantly between different systems. The ecological
evidence base for response targets varies depending on the species and site: some
may be based on well-documented process models and population viability
analyses, while others may simply rely on expert opinion and experience with the
system in question. Irrespective, both targets and the conceptual models from
which they are derived are guided by the program’s common objective of having
viable populations at priority sites (i.e. abundance is sufficient to avoid
demographic problems and the impacts of critical threats are below the threshold
for constraining population growth or reproduction).
The benefit of using a model that predicts management response as a
continuous function of time and management (Fig. 17.2b), rather than simply a
threshold target at a fixed point in time, is that it allows for the derivation of
intermediate targets. SoS operates under an annual reporting cycle, with annual
report cards for species published online. Project outcomes are evaluated by
comparing these targets with monitoring data on population and threat response.
If targets are being met, projects are interpreted as ‘on track’ to meet their long-
term objectives (ultimately, secure from extinction in NSW for 100 years). The case
F i g. 17. 2. (a) Example of a quantitative conceptual model of a threatened species system and (b) the
related model predicting population response to management. Shaded boxes represent managed threats;
unshaded boxes represent unmanaged threats or drivers. The solid line in the plot on the right represents
predicted change in some outcome metric (e.g. species abundance) over time in response to management;
the broken lines represent the target confidence intervals or acceptable range of outcomes (i.e. control limits
sensu Burgman et al. 2012).
(a) (b)