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RAMAS® Multispecies Assessment



RAMAS® Multispecies Assessment is a conservation planning tool that intelligently combines status of viability information across multiple species to deliver geographically explicit habitat conservation values. Input what you know about population status, habitat requirements, and threats. The tool is flexible to fit your data: you can use as little data for each species as a location map and its listed status. If you have more data, build detailed habitat and metapopulation models. Taken to its full potential, Mutispecies delivers quantitative conservation guidance without the use of rules of thumb, providing a valuable counterpart to rules-based conservation planning tools.

Use RAMAS® Multispecies Assessment to 

  • link your GIS to an ecological model, 

  • use landscape data in your population viability analysis, 

  • incorporate changes in habitat into a metapopulation model, 

  • combine geographic and demographic data for risk assessment, and

  • compute the Multispecies Conservation Values (MCV) across your study site. 

System Requirements

Operating System: Microsoft Windows XP or newer.


Multispecies Conservation Values (MCV)

RAMAS® Multispecies Assessment estimates Multispecies Conservation Values based on the importance and magnitude of threats facing the component species. Estimating the Multispecies Conservation Value is a three step process:

  • Phase 1: Habitat suitability assessment for each species

  • Phase 2: Extinction risk and contribution estimation for each population

  • Phase 3: Estimating Multispecies Conservation Values


Phase 1: Habitat Suitability

  1. GIS layers are imported

  2. Habitat suitability function is applied

  3. Patch detection to determine spatial structure of populations

  4. Demographic parameters estimated based on spatial considerations


Phase 2: Extinction Risk and Contribution Estimation

  1. Build metapopulation model incorporating: stochasticity, stage structure, catastrophes, density dependence, population management, etc.
    Use threat status or other estimate of risk

  2. Run sequential models to estimate contribution of each population to the overall risk of extinction


Phase 3: Estimating the Multispecies Conservation Value

  1. Establish level of risk criteria

  2. Combine habitat suitability, extinction risk and contribution values for each species at each location on the habitat suitability map

  3. Output is a grid map of MCV values



RAMAS® Multispecies Assessment, which incorporates RAMAS® GIS, includes the ability to:

  • apply a suitability function to a series of map layers

  • estimate the habitat suitability

  • delineate populations

  • import existing GIS maps

  • import RAMAS® GIS Spatial Data files

  • build spatially explicit metapopulation models, which may have

    • stage or age structure

    • density dependence

    • stochasticity

    • dispersal

    • catastrophes

    • population management

  • import existing RAMAS® Metapop files

  • estimate the risk of extinction for a species

  • estimate the contribution of each individual population to overall metapopulation risk of extinction

  • utilize an externally generated numerical risk value

  • and estimate a multispecies conservation value (MCV).




Depending on the available memory,

  • Spatial models may have up to 5000 rows by 5000 columns

  • Metapopulation models can have up to 500 populations with 50 stages and 100 different types of age or stage matrices (each of which can be assigned to one or more populations). They can be simulated for up to 500 time steps with up to 10,000 replications.


RAMAS® Multispecies produces a variety of outputs during the 3-step process that summarizes the habitat suitability, metapopulation dynamics, and MCV. These include

  • Habitat suitability map for each species (exportable)

  • Risk of metapopulation decline

  • Abundance of the metapopulation and the expected variation,

  • Map of the MCV's across the study site (exportable)


User interface

RAMAS® Multispecies has an interactive, user-friendly menu system. Editing input parameters, displaying results, and selecting output options are done with this menu system that includes a context-sensitive on-line help facility. There is also a large set of error and warning messages, and each input parameter (whether input from keyboard or file) is checked for consistency to prevent errors. Both input data and results can be saved to disk files.


The program is accompanied by a manual for Multispecies Analysis which includes discussions on basics of each phase of the analysis and descriptions of various menus and screens. One chapter contains a tutorial that illustrates the concepts of metapopulation dynamics with the use of several examples, and demonstrates the use of the software by guiding the user through step-by-step instructions. Also included is a full version of the RAMAS® GIS manual, which includes includes discussions on basics of population and metapopulation dynamics.



Viability of the Northern Spotted Owl Metapopulation in the Northwestern U.S.

Citation: Akçakaya, H.R. and M.G. Raphael. 1998. Assessing human impact despite uncertainty: viability of the northern spotted owl metapopulation in the northwestern USA. Biodiversity and Conservation 7:875-894.

This project focused on factors affecting the viability of the Northern Spotted Owl Strix occidentalis caurina throughout its range in the United States. The study used RAMAS®/GIS to incorporate two sources of variability in determining the threat the species faces. One of the goals of the project was to demonstrate the effect of uncertainty (resulting from lack of information or measurement error) on the assessment of human impact.

Methods: Variability vs. Uncertainty

The study used RAMAS®/GIS to develop a spatially-explicit, stage-structured, stochastic metapopulation model of the Northern Spotted Owl throughout its range in the United States. The model was used to evaluate the viability of the metapopulation using measures such as risk of decline and time to extinction. The model incorporated natural variation (resulting from temporal fluctuations in environmental factors) in the form of randomly distributed vital rates (survivals and fecundities). In addition, demographic stochasticity was modeled to describe chance variations in reproduction, survival and dispersal. These types of natural variation (environmental and demographic) were used to express the model results in probabilistic terms such as the viability of the species (for example in terms of the chance of survival or risk of extinction).

Uncertainties that result from a lack of knowledge were incorporated in the form of parameter ranges, and were used to estimate upper and lower bounds on the estimated viability of the species. The effects of this type of uncertainty on the assessment of human impact was analyzed by comparing the species' viability under current conditions, and under an assumed loss of spotted owl habitat in the next 100 years.

Results: Viability

Based on the habitat maps provided by the Forest Service, RAMAS®/GIS found 18 habitat patches. The size distribution of the patches was very skewed, with the 4 largest patches making up about 96% of the total area of all patches, and the seven largest making up about 98%. Because of the large differences in sizes of neighboring populations, the viability results (risk of decline) were not very sensitive to the rate of inter-patch dispersal of juvenile spotted owls.

Results: Effect of uncertainty

The model predicted a large difference between lower and upper bounds on the viability of the northern spotted owl, based on the best-case and worst-case scenarios which were parameter combinations that resulted in best and worst chance for survival. According to sensitivity analyses, the viability of the metapopulation was most sensitive to the set of vital rates used (the dependence of fecundities and survival rates on habitat), and also sensitive to the degree of spatial correlation among vital rates of the populations, and to the carrying capacities of the populations. In addition, metapopulation occupancy was sensitive to dispersal and Allee effects. Thus, the ranges of parameters were quite large, and resulted in wide range of risks of extinction. Despite this uncertainty, the results were sensitive to parameters related to habitat loss: under all assumptions and combinations of parameters, the model predicted that habitat loss results in substantially higher risks of metapopulation decline. This result demonstrated that even with relatively large uncertainties, risk-based model results can be used to reliably assess human impact.



Applied Biomathematics uses RAMAS® Multispecies Assessment to combine the habitat and risk assessment of each species in a location into a single map of conservation values for landscape conservation, planning, and management. We are here to help, and can lead projects in modeling, results synthesis, report writing, and peer reviewed publications. 

Modeling and Analysis

We have extensive experience in developing landscape conservation maps, and we are available to perform original research in this area to suit your needs.

Data Synthesis and Report Writing

Our expert scientists can assess and summarize data and existing research and clearly communicate this synthesis in reports useful for policy development or decision making. 


Using RAMAS® Multispecies Assessment? We offer technical support and can answer your questions about the use of this software for your research project. 


Site or classroom licenses allow 25 simultaneous users.


Technical support is free for colleges, government, and non-profit organizations.


Technical support for private users is available at an annual fee of 30% of the software price.

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