MORPH is an individual-based model designed to predict the effect of environmental change on a wide range of foraging animal populations. This page provides an overview of MORPH and explains how the software can be used.

MORPH is an individual-based model that can be applied to a wide range of forager-prey systems. It was developed in a general way to increase the number of systems to which it can potentially be applied, and to reduce the time taken for these models to be developed.

MORPH contains a basic framework to describe animal physiology and foraging behaviour, and the distribution and abundance of the resources required by the foragers. Its key assumptions are that individuals within populations behave in order to maximise their perceived fitness, but that perceived fitness may not always be positively related to the actual chances of survival and reproduction.

MORPH has been applied to numerous wader and wildfowl species, as well as freshwater fish, and has been used to predict the effects of environmental change caused by factors including habitat loss, sea level rise, disturbance from humans, nuclear power stations, wind farms and tidal barrages. However, MORPH is not restricted to these species and issues, and can potentially be applied to a diverse range of systems.

To be applied to a forager system, MORPH requires parameters describing:

  • Distribution of the food supply and how food quality and abundance changes through time
  • Rate at which foragers consume food given the abundance of food and competitors
  • Amount of food the forager must consume each day to survive
  • Distribution and seasonal changes in other factors which influence the foraging behaviour and survival of foragers

Stillman (2008) describes MORPH in detail. Stillman and Goss-Custard (2010), and Stillman et al. (2015) give an overview of its application.


Stillman, R.A. (2008). MORPH – An individual-based model to predict the effect of environmental change on foraging animal populations. Ecological Modelling, 216, 265-276.

Stillman, R.A. & Goss-Custard, J.D. (2010). Individual-based ecology of coastal birds. Biological Reviews, 85, 413-434.

Stillman, R.A., Railsback, S.F., Giske, J., Berger, U. & Grimm, V. (2015). Making predictions in a changing world: The benefits of individual-based ecology. BioScience, 65, 140-150.


MORPH is free software
Developed by Richard Stillman, Bournemouth University

For more information use the Contact page