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Frequently Asked Questions


FAQs will periodically be added to the pages for each software package below. Answers to the FAQs may or may not be provided (!) and users are encouraged to submit both proposed FAQs and answers via the forms on the pages. Submitted FAQs may or may not be included, at the sole discretion of the website manager. Please ask questions about the use of the software tools only, not about modeling in general or conservation issues.


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Here is the most recently submitted FAQ:

Q:>  Hello, my sincere thanks for the prompt and informative answer to my last question. This question pertains to how Vortex implements carrying capacity, and what possibilities there may be to implement in other ways. I understand that Vortex truncates population by altering mortality rates at the end of each time step if the population has gone over carrying capacity. This creates a "hard ceiling" for the population, and doesn't really allow boom and bust dynamics (at least so far as my scenarios have shown). I am trying to assess extinction risk for a species that has large observed population fluctuations. Analysis of a time series of abundance for this population results in estimated K's that are quite a bit lower than the occasional booms that population experiences, but I am unable to simulate this effectively in Vortex because of population truncation if I set the carrying capacity to the independently estimates K. Is it best to simply set the Vortex K to some arbitrarily high number but have the populations start at a more realistic number, to give them freedom to boom and bust? Additionally, can anyone recommend a good way to implement density dependence in juvenile survival? We have evidence that nest success and juvenile survival may decrease for this species at high densities, but not adult mortality or possibly even the proportion of females breeding. Many thanks! URL:

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