The PVA Process

The core element of any PHVA workshop is a quantitative assessment of the risk of species extinction – a process known as population viability analysis, or PVA.

Population viability analysis evaluates the risk of wildlife population decline or extinction under current conditions, or under future conditions. The most common technique for conducting a PVA is by using computer simulation models. These models, ranging widely in their complexity, attempt to replicate the processes of reproduction, survival, dispersal, etc. that collectively define the demography of a particular species.

This demographic information serves as input data for the analysis. These data are added to a model with a structure that defines the characteristics of the species’ basic biology and habitat use. Given this basic structure and input data, the model can project the demographic behavior of our simulated population for a specified period of time into the future, under a specific set of assumed conditions. These underlying conditions can then be altered to determine the primary drivers of population growth or decline, as well as the best options for population management to minimize risk of extinction.

While we can use different types of modeling tools to conduct a PVA, our preferred option is the simulation software known as Vortex. For more information on Vortex and its capabilities, click here.

The process of PVA is integrated within the larger PHVA workshop process. Ideally, the PVA is conducted 2 – 4 months before the PHVA, and is typically attended by a smaller subset of participants with detailed expertise on the species’ biology, demography, and ecology. With a preliminary set of results from this analysis in hand, workshop participants can improve the rigor and utility of practical recommendations designed to effectively conserve the species or population under consideration.

To learn more about PVA and its use in PHVA workshops, we invite you to take a look at our PHVA Workshop Process Reference Packet.


Back to The PHVA Workshop Process.