GSR: Simulator - Vortex

Basic Package Attributes
Title Vortex
Short Description VORTEX is an individual-based simulation model for population viability analysis (PVA).
Long Description VORTEX is an individual-based simulation model for population viability analysis (PVA). This program will help you understand the effects of deterministic forces as well as demographic, environmental, and genetic stochastic (or random) events on the dynamics of wildlife populations. VORTEX models population dynamics as discrete, sequential events (e.g., births, deaths, catastrophes, etc.) that occur according to defined probabilities. The probabilities of events are modeled as constants or as random variables that follow specified distributions. Since the growth or decline of a simulated population is strongly influenced by these random events, separate model iterations or “runs” using the exact same input parameters will produce different results. Consequently, the model is repeated many times to reveal the distribution of fates that the population might experience under a given set of input conditions.
Version 10.0.5
Project Started 1993
Last Release 1 year, 1 month ago
  • Lacy, R.C, Structure of the VORTEX simulation model for population viability analysis., Ecological Bulletins, 08-01-2020 [
  • Lacy RC, VORTEX: a computer simulation model for population viability analysis, Wildlife Research, 01-01-1993 [ Abstract ]
GSR Certification


Last evaluated11-05-2020 (318 days ago)
Detailed Attributes
Attribute CategoryAttribute
Type of Simulated DataGenotype at Genetic Markers, Sex Chromosomes (Requires complex use of features of the model ),
VariationsBiallelic Marker, Multiallelic Marker, Other (Phenotypes; with user-specified inheritance mechanism),
Simulation MethodForward-time,
Data TypeAllele Frequencies, Other (Extensive data on demographic rates),
File formatGenepop, XML (Will be available in version 10.), Program Specific,
Data TypeGenotype or Sequence, Phenotypic Trait, Individual Relationship (Pedigree information), Demographic (Extensive reporting of demographic data), Diversity Measures,
Sequencing Reads
File FormatGenepop, Program Specific,
Sample TypeExtended or Complete Pedigrees,
Trait TypeBinary or Qualitative, Quantitative (Possible, but with sophisticated use of functions in the program), Multiple,
DeterminantsEnvironmental Factors (Possible, but with difficulty), Gene-Environment Interaction,
Evolutionary Features
Population Size ChangesBottleneck, Carrying Capacity,
Gene FlowStepping Stone Models, Island Models, Sex or Age-Specific Migration Rates, Admixed Population, User-defined Matrix,
Life CycleAge structured, User-Defined transition matrices,
Mating SystemRandom Mating, Monogamous, Polygamous, Selfing, Age- or Stage-Specific, Assortative or Disassortative (With complicated use of program functions),
FecundityRandomly Distributed, Individually Determined, Influenced by Environment,
Natural Selection
DeterminantSingle-locus, Multi-locus, Fitness of Offspring, Phenotypic Trait, Environmental Factors,
ModelsDirectional Selection, Multi-locus models, Epistasis, Random Fitness Effects, Disruptive, Phenotype Threshold, Frequency-Dependent, Other (Program is highly flexible. fitness can be defined as any function of genotypes, age, sex, population status),
Mutation Modelsk-Allele Model (In version 10), Infinite-allele Model (In version 10),
Events AllowedVarying Demographic Features, Population Events, Varying Genetic Features, Change of Mating Systems,
InterfaceCommand-line, Graphical User Interface,
Tested PlatformsWindows,
LanguageC or C++,
GSR CertificationDocumentation, Application, Support,

The following 5 publications are selected examples of applications that used Vortex.


Hileman, E. T., R. B. King, and L. J. Faust., Eastern massasauga demography and extinction risk under prescribed-fire scenarios., The Journal of Wildlife Management, 01-26-2018


Licht D.S., Bison conservation in Northern Great Plains national parks: no need to panic., Great Plains Research, 01-28-2017

Licht D.S., Modeling viability of a potential Canada lynx reintroduction to Isle Royale National Park., Natural Areas Journal, 01-30-2017

Pacioni, C., Williams, M., Lacy, R.C., Spencer, P.B.S. and Wayne, A.F., Predators and genetic fitness: key threatening factors for the conservation of bettong species. Pacific, Concervation Biology, 01-31-2017


Ballou, J.D., K. Traylor-Holzer, A. Turner, A.F. Malo, D. Powell, J. Maldonado, and L. Eggert., Simulation model for contraceptive management of the Assateague Island feral horse population using individual-based data, Wildlife Research, 10-30-2008

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