Animal Distribution Modeling for Conservation

 

Overview

As a member of the Biodiversity and Spatial Information Center at NCSU, Ashton is working to develop advanced, spatially-explicit animal population models. Her goal is not only to describe species ranges and probability of occurence in different habitats, but also to improve spatial predictions of population abundance, density, and productivity across diverse landscapes. Towards that end, she is interested in the spatial and temporal scaling of organism-habitat relationships, dispersal behaviour, the role of expert opinion in conservation planning, and species as members of complex ecosystems. Spatially-explicit animal population models have diverse applications, including:

  1. developing strategic plans for the aquisition of conservation lands
  2. identifying key areas of scientific uncertainty to guide allocation of limited research funds
  3. evaluating potential outcomes of alternative land management scenarios for threatened species or, alternatively, invasive species or infectious diseases
  4. predicting potential impacts of climate change on animal populations

As such, these models can serve as important tools for urban planners, wildlife biologists, traditional cultures, and others seeking to manage and conserve natural resources for future generations.

Roanoke-Tar-Neuse-Cape-Fear Ecosystem Models

RTNCF Ecosystem
Roanoke-Tar-Neuse-Cape Fear Ecosystem boundary. National Wildlife Refuges are shown in red.

Ashton is currently working with the US Fish and Wildlife Service in the RTNCF Ecosystem of North Carolina. The objectives of this 3-year pilot project are 1) to develop population objectives for species and abundance goals for RTNCF natural communities; 2) convert these population/abundance objectives into habitat objectives; 3) map potential conservation areas where deficits exist; and 4) step down population/abundance objectives to individual refuges and partner lands. Thus, each land manager will be able to see how his or her refuge contributes to objectives at broader scales, and can coordinate activities with other partner agencies and land managers to track progress toward meeting ecoregional population and habitat objectives. Further, the confidence intervals that will be provided by the literature and expert opinion will provide more focus on where additional research would be most beneficial.

She will develop examples of three quantitative species distribution modeling scenarios (inductive, deductive, and aquatic), with confidence intervals, for select USFWS Trust Species within the RTNCF ecosystem. Trust Species are those for which the Service has legislative mandate, and include federally-listed threatened and endangered species, interjurisdictional fishes, and migratory birds (USFWS 1999). Inductive models will be developed for terrestrial vertebrate species represented by sufficient point count data within the RTNCF ecosystem region to quantify habitat-specific species density and independently validate the models. This approach is being developed through another pilot project at SE-GAP (Williams & McKerrow 2005, Laurent et al. 2006), which is exploring the data requirements and limitations of various quantitative modeling techniques to define spatial gradients in habitat suitability for six forest bird species in North Carolina. Deductive models will be developed for selected terrestrial vertebrate species that are well-studied, yet for which there are limited point count data within the RTNCF region. The aquatic models will also follow a deductive approach, but will require different spatial datasets and different spatial analyses than the terrestrial deductive models. Expert opinion, literature review, and a Bayesian belief network will provide the foundation for these deductive models.

 

Literature Cited:

Laurent, E.J., S.G. Williams, and A.J. McKerrow. 2006. Developing a scientifically rigorous framework for enhancing and evaluating vertebrate models. Gap Analysis Bulletin 15.

Williams, S.G., and A.J. McKerrow. 2005. Refining Southeast regional GAP models for use in regional bird conservation planning: a pilot project. Gap Analysis Bulletin 13: 8-9.

U.S. Fish and Wildlife Service. 1999. Fullfilling the Promise: The National Wildlife Refuge System, Visions for Wildlife, Habitat, People, and Leadership. 94 pp.

Newsletters:

Preliminary Data and Products:

 

For More Information:

Contact: Dr. C. Ashton Drew
Regional Habitat Modeler
Biodiversity and Spatial Information Center
Box 7617, North Carolina State University
Raleigh, NC 27695-7617
919-513-0506
FAX 919-515-4454

Last updated: 11 March 2010