This investigative case module was prepared as part of a BioQUEST faculty development workshop. The cases, resources, and implementation strategies were developed by participants for use with their own students. We invite you to adopt and adapt the following materials.

The BioQUEST Curriculum Consortium is committed to the reform of undergraduate biology instruction through an emphasis on engaging students in realistic scientific practices. This approach is sometimes characterized as an inquiry driven approach and is captured in BioQUEST's three P's (problem-posing, problem-solving, and peer-persuasion). As part of this workshop groups of faculty were encouraged to initiate innovative curricular projects. We are sharing these works in progress in the hope that they will stimulate further exploration, collaboration and development. Please see the following links for additional information:

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Investigative Cases
The Case: Rio Grande Wildlife Refuge

You are a professional ecologist working for the fish and wildlife service, and have been given an assignment to manage a new wildlife refuge along the lower Rio Grande River.  It is an unusual refuge since a portion of it must be constructed.

The fish and wildlife service plans to connect forest islands along the river, which will become not only a new refuge but also a wildlife corridor.

This will be an enormous project, since the refuge will encompass 250 river miles from Falcon Dam to Laguna Atascosa National Wildlife Refuge at the Gulf Of Mexico. The corridors main purpose is to preserve species diversity. Ten distinctly different wildlife communities exist along the river, and are critical for the survival of 115 species of birds and mammals. 

This will be an enormous project, since the refuge will encompass 250 river miles from Falcon Dam to Laguna Atascosa National Wildlife Refuge at the Gulf Of Mexico. The “corridors” main purpose is to preserve species diversity. 
Ten distinctly different wildlife communities exist along the river, and are critical for the survival of 115 species of birds and mammals. 

Several endangered species are found within these communities including the ocelot, and jaguarondi. 

These communities are the northern most range of many central and South American species. Other species include the green jay, the  hooked bill kite, ferruginous pygmy owl and fulvous whistling duck. 

By connecting islands of forests, animals will be able to move and have access to a larger forested area. One of your objectives will be to acquire 135,000 acres of privately owned forested and deforested land along the river. Building a wildlife corridor is a concept that relates to an ecological principal called Island Biogeography theory.

Case Author:
Mark Storey Texarkana College
Wayne McMillan Garden City Community College

Case Analysis

  1. Why is necessary to preserve communities for key species?
  2. Why should we use ecological theory in wildlife management ?
  3. If no protection plan is implemented how will species diversity be effected in these communities? 

Option: Include a know / need to know chart like the one below:

What do you know?
What do you need to know?

Learning Goals


    Introduce the discipline of Ecology in a practical manner.
  • To look at wildlife management as it relates to ecological principles and whole systems.
  • To introduce students to the global concern of "patchy" environments.
  • To familiarize students to survey techniques.



Investigations and Activities

An initial study is needed to obtain estimates of species richness and relative abundance of birds, mammals, reptiles and amphibians in experimental and control plots. Experimental plots should be narrow one hundred meter wide "corridor-like" forest patches. Control plots of similar habitat should be large (approximately 500 acres). 

You will also have to do a base line study of animal numbers and species in all existing forest islands. Breeding birds should be sampled by point count technique. Small mammals, reptiles, amphibians and some invertebrates should be sampled by pitfall array and Sherman live trap grids.

Web site search of key words found in the case scenario and background

Bio-Quest Eco-Beaker Introductory sampling modeling activity   

Field Study on bird diversity in Shelter Belts in SW Kansas
- Shelter belts provide a unique opportunity to evaluate Island Biogeography theory for  two reasons
1. Man made habitats with similar structural configurations.
2. Represent small (0.1- 2.9 ha) forest islands. Small 
islands provide a unique situation because some bird species
can be precluded from colonization due to territorial size 



Students will usually obtain additional references or resources
to help answer or explore their questions.

Special Data Items

Large Image Files of various area available here...

1. rio_gr9a.gif
2. rio_gr8a.gif
3. rio_gr7a.gif
4. rio_gr6a.gif
5. rio_gr4a.gif
6. rio_gr2a.gif


Student Products

Each student will submit a report which should include the following:

  1. What is Island Biogeography Theory (IBT)?
  2. How does IBT relate to the size of forest islands and the maintenance of species diversity?
  3. How might the data from your initial study of species numbers and richness (scenario) be used?
  4. Why is it important to facilitate movement between patches and what effect can isolation have on species?
  5. What is an egg parasite and how would it effect birds in forest islands?

Submit group reports based on the BioQUEST EcoBeaker introductory sampling simulation program.

Develop and present a group poster pertaining to the "Wildlife Corridor Concept"

Assessment and Evaluation Plan

  • Individual Report - 50%

  • Submit group poster - 40%

  • Peer evaluation of group activity - 10%



Course name:
Concepts of Biology
Likely sequence in syllabus:
End of semester , ecology unit
Time during term:
2 weeks
Lab and field
Students in course:
Freshmen non-majors
Collaborative elements:
Work in groups. Share access to resources. Likely to discuss cases outside of class
Additional notes:



Aerial images, maps and habitat sketches (circa 1987) courtesy of Rio Grande National Wildlife Refuge U.S. Department of Interior in-house planning document (un-published work). Refuge Manager: Robert Schumaker.

Additional slide images and background information on Forest Islands available on the web at:

Photo Credits

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