Digging Around for the Facts

The eggs in the live-feed photo at right were laid by a captive raised Desert Tortoise female the Victor Valley located in the Western Mojave Desert. This clutch of Desert Tortoise eggs are being incubated in the LCER/AAE biology classroom using a water bath warmed with an aquarium heater. The water/air temperature fluctuated between 30 and 32.5 degrees C ( 86 to 92 degrees F). The hatchlings from this clutch will be adopted out to area K-12 teachers and students with the help of the High Desert Chapter of the California Turtle and Tortoise Club and will find their way into a classroom to be apart of our developing "Tortoise in the Classroom" project. To learn more about how to take care of a Desert Tortoise in the classroom visit this link and navigate to "Captive Care". If you are interested in adopting a tortoise, contact e Dave Zantiny (@ DZANT738@aol.com) Adoption Chairperson of the High Desert Turtle and Tortoise Club.

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INTRODUCTION: What are Tortoises? Where do they live? How do tortoises populate their environment? What makes for healthy tortoise habitat? What role do tortoise play in the cycling of matter (carbon, oxygen, nitrogen) and energy in an ecosystem? How would releasing captive raised tortoises back into their native environment impact that ecosystem? These are the kinds of questions that biologist and ecologists ask when attempting to learn more about any organism and how that species fits into the larger scheme of life on earth. As we watch desert tortoises emerge from their eggs and develop in our classroom and learn how we can care for their needs, you will be on a WebQuest. This Digging Around for the Facts WebQuest has been designed to help you understand what it means to be, live, and survive as a "Desert Tortoise" or population of Desert Tortoises in a given ecosystem.

SCIENCE STANDARDS: This WebQuest has been designed to specifically address the High School California Academic Content Standards for Biology/Life Sciences stressing the science and study of Ecology. This standard specifically states that the:

6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept, students know:

a. biodiversity is the sum total of different kinds of organisms, and is affected by alterations of habitats.

b. how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of non-native species, or changes in population size.

c. how fluctuations in population size in an ecosystem are determined by the relative rates of birth, immigration, emigration, and death.

d. how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles via photosynthesis and respiration.

e. a vital part of an ecosystem is the stability of its producers and decomposers.

f. at each link in a food web, some energy is stored in newly made structures but much is dissipated into the environment as heat and this can be represented in a food pyramid.

g.* how to distinguish between the accommodation of an individual organism to its environment and the gradual adaptation of a lineage of organisms through genetic change.

TASKS: Stability in an ecosystem is a balance between competing factors. The student's task will be to determine and describe a healthy, stable ecosystem that can support a viable population of "introduced" captive raised tortoises and/or their unhatched eggs. In order to accomplish this task each student will need to:

  • Determine and describe the taxonomic classification (Kingdom @ species) for the kind of tortoise being raised in the classroom.
  • Determine and describe what this kind of tortoise needs to survive, grow and reproduce in a natural ecosystem.
  • Determine and describe the abiotic and biotic factors that will influence the fluctuation of a population of captive raised and wild tortoises if they are to be reintroduced back into their natural habitat.
  • Determine and describe the role captive or wild tortoise will play in the cycling of energy and matter (carbon, oxygen, nitrogen) whether they live in a domestic setting or are free ranging "wild tortoises". in their terrestrial ecosystem?
  •  Determine if the captive raised desert tortoises and/or their eggs should be released back into the wild.

SITUATION: It is June, the summer after your sophomore year at the University of California in Riverside. Your major is biology. You have just begun a summer internship with the California Department of Fish and Game (CDFG). Since your home address is in the Mojave Desert, you have been assigned to region 6, the "Inland Deserts" district of the CDFG.

Judy, your supervisor, has been busy all year participating with a statewide team of wild land managers to develop the "West Mojave Coordinated Management Plan". The day you arrive she receives the following request from her supervisor in Sacramento:

"We need to know if a captive raised Tortoises and/or their unhatched eggs can be/should be repatriated back into the open Mojave Desert to help bolster the number of a declining population in the wild. A preliminary findings report is needed in Sacramento by July 1st."

Because of her other time commitments, Judy decides to make this task your internship project. Giving you a couple of examples of other "preliminary finding" reports, you and Judy put together a rough outline of information that will be needed in the report:

SECTION 1: Title Page, Abstract and Problem Statement

1.      Title Page

a.     Title page consists only of:

    • a descriptive title for the report,
    • author's name, and
    • the reports completion date.

2.      Abstract

Separate page abstract clearly summarizes the significant findings and preliminary conclusion in less than 200 words. Don't mention anything in this section for the first time.

3.      Problem Statement

a.      A problem statement is brief and concise, clearly stating the problem that is being addressed.

b.     Include just enough background information to establish the importance for arriving at a solution or best finding.

SECTION 2: Review of Literature

1.      Tortoise Taxonomy: (4 or fewer paragraphs and an illustration)

a.      What is a tortoise? What kind of tortoises are native to the southwest, specifically the Mojave Desert? (one paragraph with an illustration)

b.      How are is the tortoise that is native to the Mojave Desert different from other tortoises? (one paragraph)

c.      What kind of tortoise is native to the Mojave Desert? Identify as many common and scientific names for this kind of tortoise as possible. (one paragraph)

d.   Illustrate the taxonomy of the "tortoise" that is native to the Mojave Desert. In the illustration include some examples of other tortoise "kinds" that are closely related to the tortoise native to the Mojave Desert at the "family" and "genus" level of classification.

Before conducting your research for this section of the report, review your notes and read (skim over) chapters __ and __ in your textbook (Biology: The Dynamics of Life, 2002).

2.     Tortoise Life Cycle:

a.       Describe and illustrate the life cycle of wild Mojave Desert tortoise. (4 or fewer paragraphs with an illustration)

b.      Describe the stage(s) of this life cycle that is most sensitive to environmental change and why that is. (4 or fewer paragraphs with an illustration)

3.      Healthy Desert Habitat:

a.      What are the abiotic requirements needed to support the species before, during and after spawning. List and describe each requirement. (Where possible, research and find the "limits" or "range of tolerance" for each requirement that you identified.) (6 or fewer paragraphs)

b.      What are the biotic components needed to support the species (after the eggs have hatched). List and describe these components. (6 or fewer paragraphs)

c.      What are the biotic components of a tortoise's environment that it must avoid in order to survive? List and describe these components. (4 or fewer paragraphs)

d.      What are the biotic components of a tortoise's environment that aide in recycling its matter back into the greater ecosystem? List and describe these components. (6 or fewer paragraphs)

e.      Construct a chart and classify the biotic components you identified above as producers, prey, predators or recyclers. (2 or fewer paragraphs with a chart)

Before conducting this next two searches, read section 2.2 Nutrition and Energy Flow in your textbook (Biology: The Dynamics of Life, 2002).

4.      Tortoises and Regional Biogeochemical Cycles: How do carbon, oxygen, and nitrogen cycle through tortoises?

a.      Identify major carbon sources that tortoises rely upon for their survival. Briefly describe the role carbon plays in tortoise anatomy (structure) and physiology (function). (3 or fewer paragraphs)

b.      Identify major nitrogen sources that tortoises rely upon for their survival. Briefly describe the role nitrogen plays in tortoise anatomy (structure) and physiology (function). (3 or fewer paragraphs)

c.      Identify major oxygen sources that tortoise rely upon for their survival. Briefly describe the role oxygen plays in tortoise anatomy (structure) and physiology (function). (2 or fewer paragraphs)

5.      Energy Flow: (4 or fewer paragraphs with diagram)

a.      Where in the "cascade" or flow of energy from the Sun to the vastness outer space do tortoises fit?

b.     Capture in a detailed and labeled diagram tortoise's place in the "cascade of energy".

SECTION 3: Field Data

1.      Current & Historical Information: Abiotic Factors

a.      Describe the maximum, average and minimum temperature in selected location across the tortoises Mojave Desert home range. This web site might be helpful: http://wgsc.wr.usgs.gov/mojave/climate-history (1 paragraph)

b.      Using information gathered in section 3.1.a, and available data or data freshly collected from your fieldwork, describe if repatriated tortoises and / or their eggs could survive in Mojave Desert landscape surrounding the Mojave River Campus of the Academy for Academic Excellence. Address any seasonal variations that might effect survival. (4 or fewer paragraphs)

2.      Current & Historical Information: Biotic Factors

a.      List and describe other terrestrial animal species that currently reside on or adjacent to the Mojave River Campus or have been identified by other as living in the here. (1 paragraph with a table)

b.       Determine if introducing tortoises and/or their eggs to the Mojave River Campus wildlands would jeopardize the survival of the existing animal residents . (4 or fewer paragraphs)

c.     Determine if the eating habits of repatriated tortoises would jeopardize the survival of any native flora or fauna. (4 or fewer paragraphs)

3.      Natural Reproduction Viability

Using information gathered in section 1.2.a-c, and available data or data freshly collected from your fieldwork, describe if the eggs laid by captive raised Tortoises should repatriated back into the wild (i.e. Mojave Desert). Address situation that might effect survival of the receiving population or of the repatriated tortoises. (4 or fewer paragraphs)

SECTION 4: Significant Findings & Preliminary Conclusion

1.      Compare the findings collected in your review of literature to what you learned about the "terrace" habitat and the surrounding desert and its inhabitants and highlight any important findings specific to the question of "should captive raised tortoises and/or their eggs be released or repatriated back into the Mojave desert." (1 paragraph)

2.     Give a preliminary answer to the question, "should captive raised tortoises and/or their eggs be released/ repatriated back into the Mojave Desert?", and support it using findings gathered and stated in the report. (1 paragraph)

AVAILABLE RESOURCES: Besides making books in her field office's library available to you, Judy has provided you with the following list of web resources that she uses when preparing similar reports. She also suggests that you check out resources that are available at local libraries and turtle and tortoises clubs in your community to help you with your task.

Judy's Web Resource List:

Some of the following web sites will require that you download Acrobat Reader. It can be downloaded for free @ http://www.adobe.com/products/acrobat/readstep2.html

Links to Resources that support Mojave Desert Studies

Tortoise Information, Organization supporting research

Tortoise Taxonomy, Tortoise Identification, Distribution

Tortoise "Kind" Gallery

Tortoises of North America

Tortoise Biology

Genetic Studies

Tortoise and Turtle Enhancement Programs

Habitat requirements


Tortoise Habitat Gallery

Desert Food Webs & Chains

Tortoise Ecology / Biotic components

Tortoise Ecology / Life Cycle

Mojave Desert Wildlife

Information Data Bases

Mojave River Weather Information

Collecting Data at the "terrace" and in the surrounding desert

    • For more information, e-mail Mr. Huffine @ mhuffine@lcer.org or call @ 760-946-5414 ext. 238

PROJECT EVALUATION: Judy, your CDFG internship supervisor uses a rubric to evaluate her work before sending it on to Sacramento. She will be using the same rubric to evaluate your draft. Your summer internship program grade with the university will depend on her assessment. The rubric that she will use is as follows:

Preliminary Findings Report Evaluation Rubric

Authors Name:


This analytic rubric is used to verify specific tasks performed when producing a "preliminary findings report. If the task has been successfully completed, all points are awarded. No points are awarded if the task is not complete. If a score of < 70 pts. Is awarded, the draft Preliminary Findings Report will need to be reworked.


Scoring Criteria






Title Page,

Problem Statement

30 points

The Abstract is a separate page that clearly summarizes the preliminary findings and conclusions in less than 200 words.



The Title Page consists only of: a descriptive title for the reports, author's name, and reports completion date.



The Problem Statement made the goal of the preliminary findings report clear and contained sufficient.



Sufficient Background information to establish the importance of the arriving at a sound preliminary finding.



Section 2

Review of Literature

15 points

Scientific terms and concepts are properly used.



Research findings are presented in the writer's own words, not "cut and pasted".



Quoted research is properly cited using either footnotes or on a bibliography page at the end of the report



Section 3

Field Data

30 points

Current data is cited.



Collected data is presented in a manner appropriate for facilitating easy analysis (i.e. data is presented in charts, graphs, as pictures, illustrations, model etc)



Preliminary findings are clearly stated based solely on cited research and collected field data



Section 4

Significant Findings and Preliminary Conclusion
15 points

The most important findings are restated.



The researcher's final thoughts about the proposed preliminary finding or solution to the problem are stated.



No new information is introduced.



10 points

A single page bibliography is provided.




Total Points




Authors are expected to honestly evaluate their own work. If the difference between the author's evaluation and the supervisor's evaluation is more than 10 points, The draft will have to be reworked by the author.

Copyright © 2008, Matthew Huffine, Lewis Center for Educational Research, Apple Valley, California 92307