Cooperative Research Units
Education, Research And Technical Assistance For Managing Our Natural Resources
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Estimating the Role of National Wildlife Refuges


December 2012 - December 2014


Problem statement:

Wildlife occurrence data are often collected throughout wildlife refuges, but are typically subject to measurement error associated with imperfect detection of species. Moreover, with amphibian and avian species, such data may be subject to both false negative and false positive errors.

So What? Why this research matters:

Traditionally, occupancy models to estimate wildlife occurrence and species distributions have only accommodated false negative errors, but false positives can affect the resulting statistical inference if they are not accounted for.


This project is in collaboration with scientists at the U.S. Geological Survey.

Research That Informs Decisions:

Formal statistical models that account for both false negative and false positives help to reduce the uncertainty and bias associated with inferring species occupancy. Our new methodology will help better understand the role of management at wildlife refuges versus other non-federal lands in conserving amphibian species.

Research Products and Activities

Peer Reviewed Publications

  • Ruiz-Gutierrez, V., M.B. Hooten, and E.H. Campbell Grant. (2016). Uncertainty in biological monitoring: a framework for data collection and analysis to account for multiple sources of sampling bias. Methods in Ecology and Evolution, 7: 900-909.

Current Staff

Federal Staff: 95

Masters Students: 239

Phd Students: 142

Post Docs: 53

University Staff: 240

5 Year Summary

Students graduated: 701

Scientific Publications: 1936

Presentations: 4260



  • Mevin HootenPrincipal Investigator
  • Viviana Ruiz-GutierrezStudent

Funding Agencies



Cooperative Research Units Program Headquarters Cooperators

  1. U.S. Geological Survey