Vortex is a computer model that simulates the complex dynamics of wildlife population growth and how those dynamics may change through time in the presence of threatening human activities. 

Written by Bob Lacy of the Chicago Zoological Society (and CPSG's Science Advisor), Vortex is the most frequently used tool for population viability analysis (PVA) in CPSG’s Population and Habitat Viability Assessment (PHVA) workshop process. The Vortex software is maintained by the Species Conservation Toolkit Initiative (SCTI). 

By providing a diverse set of input data on such parameters as average rates of reproduction and survival among individuals in a population – and the variation in those rates over time – Vortex users can create realistic and informative simulations of a variety of different wildlife species, across a broad spectrum of management intensities. Most importantly, the user can also test alternative options for species management by creating multiple scenarios and comparing their results to identify optimal conditions for endangered population viability.

Vortex in More Detail

Download the most recent versions of theVortex software and manual from the SCTI website.

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