These materials were developed by Alison Baird, Department of Geography, University of Texas at Austin, 1996. These materials may be used for study, research, and education in not-for-profit applications. If you link to or cite these materials, please credit the author, Alison Baird, The Geographer's Craft Project, Department of Geography, The University of Colorado at Boulder. These materials may not be copied to or issued from another Web server without the author's express permission. Copyright 1996. All commercial rights are reserved. If you have comments or suggestions, please contact the author or Kenneth E. Foote at

Research Problem

General Background Information

The Project

In this Project you will interpret some general vegetation characteristics from remotely sensed material. Using this information plus your knowledge of habitat requirements for the Golden-cheeked warbler and the Black-capped vireo, you will be able to predict the occurrence of these endangered species within the Eckhardt tract of the Balcones Canyonlands National Wildlife Refuge. You will then compare your estimates to records of actual sightings of these birds. The final product will be a report detailing this process and your results. There are five main steps in this project that lead up to your report:

Since the Eckhardt tract is located in two counties, you will need to:

There are several general types of vegetation communities within the Eckhardt tract which are distinguishable from one another in the infra-red (IR) photographs. You will need to consult both the March and September photos to check your assessment. The vegetation types you will be using are given below with a brief explanation of their physical characteristics and their appearance in remotely sensed material.

To determine the percentage canopy cover of any given area in this exercise, you will need a clear, plastic sheet that has a "dot grid." Lay this grid over the aerial photo (this is why it should be clear) and determine what percentage of each box is covered with trees, or vegetation of significant height. For example, a grassland will have a value close to 0% , while a savanna will have slightly more. You'll have the "eye" this percentage; exact mathematical calculations are not necessary. This figure is the "percentage canopy cover".

In order to display your calculations, you will probably want to lump the percentages into a category, such as "0%-20%" or "50-75%." Divide the Eckhardt tract into the resulting categories (use polygons). Try to avoid being too detailed--this map should only illustrate the general variation of canopy cover across the tract. HINT: Based on what is written in the vegetation section above, you might question the % canopy cover you measure for a shinnery. You may choose to set off these "special" areas with an asterisk or a footenote explaining why you measurements of canopy cover might be suspect.

If you were to send a technician into the Eckhardt tract to look for the golden-cheeked warbler and the black-capped vireo, in which direction would you send them? Where on the tract would you expect to find these two species? For this part of the exercise, you will need: Using the habitat requirements listed earlier in this exercise plus the information you illustrated in these two maps, identify those areas where you would expect to find these species.

Towards the last week of the exercise (after you have completed your "expected" results) you will be given the results of your field technician's observations. Digitize the "actual" results for both the black-capped vireo and the golden-cheeked warbler into your Microstation file. Compare the "results" to the "actual." How close were you? 

You do not need to hand in a digital copy of your maps, so you will have to determine your own guidelines for the organization of your file (colors, levels, etc.) in Microstation.

You will be handing in a report, similar to that which you compiled for the Texas Election Campaign Project. This report, however, is a professional assessment of your work in locating two endangered species on a section of the Refuge. The beginning of this report should contain a brief, to-the-point executive summary of your work and a summary map. The rest of your report should be a presentation of your methodology, results and some discussion. Include whatever maps you feel are necessary to show the different elements of your project, but please limit these to a reasonable number (up to 3 or 4). You will be graded solely on this report (including the maps) so make sure it is representative of your effort. 

Created 13 November 1995. ALB.
Last updated 25 January 2000. LNC.

 * A great deal of the materials for this exercise were provided by US Fish and Wildlife; many thanks for their generosity and extra special thanks to Dr. Chuck Sexton. ---alb