Fig. 1. A conceptual diagram illustrating an “ecological hierarchy”. Hierarchical ecological information, defined by the grey outlines (spanning from a single pathogen to a host assemblage) may contribute to a whole-system model of disease flow within a host-pathogen system. As the time since an initial infection increases on the y-axis, transmission events may also increase, and the budget of susceptible organisms represented on the x-axis that could be exposed to infection, increase. The ecological scale shown constitutes both the structures and processes acting throughout an ecosystem. Consequently, scale can be parameterised by system dynamics, such as host or population behaviour(s) or group demographic processes, which describe expected fluctuations around ecological equilibria . Coloured polygons therefore propose example locations for these latent dynamics in the context of a “whole-system” model.