Lesson 2

by Nancy Stevick

Lesson 2: Research techniques - Photo-identification

Activity 2a: What is Photo-identification?
Activity 2b: Designing and Conducting a Photo-Id Experiment
Activity 2c: Matching Humpback Fluke Photographs
Activity 2d: A Simulated Research Cruise
Activity 2e: Research Techniques - Mark-Recapture Studies

Activity 2a: What is Photo-identification?


Black and white photographs of members of the class AND/OR
Black and white photographs of famous people the students would know

Photo-identification uses natural markings to identify individual animals over time. This research technique is used on many species of marine mammals. Initially, scientists used artificial tags to identify individual whales. Discovery tags were the first to be used in the 1920s. These were tags that were shot into the blubber of a whale, and then discovered after a whale was killed and flensed. While the use of these tags taught us about the movements of individual whales, their use was limited. Most whales that were tagged were not recovered, and those that were, had died and could provide no additional information. Over the years, a variety of other tags were used with limited success. In the 1970s, scientists discovered that individuals of many species could be recognized by their natural markings. These scientists began taking photographs of individual animals and comparing these photos against each other to identify individual animal's movements and behavior over time. Since its development, photo-identification has proven to be a useful tool for learning about many marine mammal species including humpbacks, right whales, finbacks, killer whales, sperm whales, bottlenose dolphins and other species to a lesser degree.

Photo-id enabled Allied Whale scientists to track individual humpback whales for over 20 years. The best photograph of each humpback is included in the North Atlantic Humpback Catalog. New photographs submitted to Allied Whale are matched against the photographs in the existing catalog. Information on each whale sighting (such as date, time, location) is kept in a database. Using this data, we have learned that humpbacks mature in 4-5 years, may have calves every two years, travel to the Caribbean in winter to mate and give birth, and appear to return to the same northern feeding area each summer.

For a more complete discussion of the research technique of photo-id, look at the Introduction to the WhaleNet On-line Humpback Catalog at Give students time to read the on-line version or print out the information for students to read (and to have as a reference). Explain that students will be using the data contained in the on-line catalog for their own projects. Before they do that, however, it is essential that they understand how photo-id works. The following exercises provide students with opportunities to act as scientists using photo-id as a research tool. Choose the exercises which best meet your time schedule and available resources. The exercise using styrofoam peanuts and the statistical formulae is an important foundation in an understanding of the uses and limitations of photo-id to determine population estimates and should be included in your unit. Don't be scared by the formulae. It is really simple math, and once your students realize this they will be thrilled to be using statistics.

Begin the discussion of photo-id by asking students how they identify each other or famous persons. The first characteristics usually mentioned are hair and eye color. Hold up black and white photographs and ask them to identify the individuals in the photographs. Of course, they can recognize each other and match the black and white photographs to the real person. Have them discuss the features they used in making their matches. Which of these features are permanent and which might change over time? Length of hair is a characteristic that can change, just as flukes might acquire new scars, nicks or bites. Have students focus on the permanent characteristics that can never change, but be sure to discuss characteristics that might change and how that might cause an individual to not be identified. Madonna is a well known figure whose appearance changes dramatically. If you can find photographs of her sporting different hair styles and colors, this will help students to see how one person can be difficult to match. Choose a few animals and discuss the ways each might change. Students might be more familiar with terrestrial animals, so you may want to begin the discussion with some of these. Are there any animals that change the color of their fur? What about scars and injuries?

Activity 2b: Designing and Conducting a Photo-Id Experiment

To better understand the technique of photo-id, students can design and conduct their own experiment. They can study any animal of their choice -- squirrels, neighborhood dogs, cats, birds or people. This will primarily be a behavioral study where students identify a small number of their subjects and record data on them for a short period of time.


Paper for sketching and recording data
Writing utensils
Cameras (Polaroid or digital preferred if available)

The steps to follow in designing a research project are:

1. Define a research hypothesis
2. Determine the methods to test the hypothesis
3. List materials needed
4. Write a research proposal to submit to the teacher
5. Begin their observations after proposal is approved
6. Complete observations/analysis
7. Prepare written report.
8. Present findings to class.

These experiments should be simple. The emphasis is on students identifying a small number of individuals and observing them. They should spend 30 minutes each day for their observations. They should record their observational data and either take photographs or sketch their subjects. This activity will allow students to sample the rewards and frustrations of being scientists. Some days, they may not be able to find their study animal, other days, they might have more information than they can possibly record.

Once their observations are complete, have students write up a brief description of their experiment, including their initial hypothesis, research methods, findings and conclusions. These can be handed in to the teacher and/or presented to the class as a series of seminars or in a conference format. Have students peer review each others' presentations and research technique.

Activity 2c: Matching Humpback Fluke Photographs


prints of fluke photographs from the On-line Catalog and this curriculum packet.
plastic holders or bags to store fluke photos

The fluke photographs contained in this packet are formatted nine to a page. Print out two copies of each page. Keep one page whole and cut the other up so that you have 9 separate fluke images. Make sure the whale name and catalog number are cut off the fluke images to be matched. If you think you might have difficulty matching the flukes, you can write the whale number or name on the back of each fluke photograph. Laminating or covering these pages with contact paper will make them sturdier. Put each fluke page and its matching fluke images together in a plastic page holder or bag.

These matching sheets are quite versatile. The whole class, small groups or individual students can match after they have completed assigned work. Students can play a matching game alone or with others like a bingo game. You can shuffle all the individual cards and student have to roam the classroom to find their matches. You can enlarge fluke photos and make a giant wall poster and have students match their flukes to that. Use your imagination. To make the matching more challenging, use different photos of each whale. You can get alternate photographs of these humpbacks from the On-line Catalog. Of course, if your class goes on a whale watch, you can use your own fluke photographs in this matching exercise. So students do not get frustrated, make sure that you include fluke photos of the whales they photographed in your sheets. The WhaleNet Guide to Whales and Marine Mammals of the North Atlantic Ocean CD-ROM contains the complete WhaleNet Humpback Catalog and a simple matching program. Information for ordering the CD-ROM can be found on the WhaleNet web site.

Activity 2d: A Simulated Research Cruise

Fluke Some classes have the opportunity to go on an actual whale watch. For classes that are not as fortunate, here is an activity which will give them the flavor of an actual whale watch.


posterboard, crayons, markers or paint for making flukes
4 screens or partitions to hide whales until they surface (optional)
camera and film
clipboards, data sheets from WhaleNet teacher packet, watches and pencils
Page of humpback fluke photographs

1. Have students cut out at least 8 large humpback flukes and color them with distinctive black and white patterns. You can have each student or pair of students create their own fluke. For each research cruise choose a different selection of flukes.

2. Arrange the room so two "research boats" are in the center and the 4 whale screens are surrounding the boats.

3. Each boat should have at least two observers. On each boat, one student researcher records the time and location (relative to the "boat") for each sighting, while the other photographs the flukes as they appear. Have students think of the boat as a clock with the bow at 12 , the stern at 6, the starboard beam (90 degrees to the right of the bow) as 3 and the port beam (90 degrees to the left of the bow) as 9. Use this clock system and distance to give a specific location for each whale, for example whale at 3 feet and 9 o'clock. Students should try to record data accurately enough so they can connect each data set with a specific humpback. Quick sketches of flukes showing distinctive markings beside the sighting data can help.

4. Other students are the whales, with one student assigned to each fluke. As the research boats "travel" through the ocean, the students make their whales come to the surface to breath (students make a loud exhalation) and fluke at irregular intervals. The whales should spout about 3 to 5 times before raising their flukes above the surface (screen) and going down on a deeper and longer (5-10 minute) dive. Teachers determine how long each research cruise should continue.

5. At the end of the cruise, students return to land and analyze the data to determine the number of whales they saw and to match the photos. Using a Polaroid or digital camera can speed up this analysis, but any type of camera can be used. You will just have to wait until the film is processed. Have each crew write up a report of their findings. Did the researchers on the two boats record the same data? Compare the researchers' findings and discuss any discrepancies.

6. A discussion of the benefits and difficulties of this research technique should conclude this exercise. What did the researchers really learn about the whales they saw? How could they have learned more in the time they had? With more time? Were the photographs useful in identifying individuals? Did students think that data recording and photographing were easy or difficult?

Activity 2e: Research Techniques - Mark-Recapture Studies


Shopping bag full of Styrofoam peanuts
Selection of colored markers
Paper and pencil

While it is important to estimate populations of marine mammal species for conservation and management purposes, it is impossible to get an accurate count of all the individuals of any one species. Researchers must survey a portion of the population, then use statistical formulae to determine population estimates. One of the simplest statistical formulae is the Petersen two sample capture-recapture estimator:

N1 = n1(n2+1)/(m2+1)

V1 = n1 (n2+1)(n2-m2)
(m2+1) (m2+2)


N1 = estimated population size
n1 = number of individuals identified from photographs in sample 1
n2 = number of individuals identified from photographs in sample 2
m2 = number of individuals identified from photographs in both sample 1 and sample 2
V1 = estimated variance of N1 .

For a middle school level lesson, you can probably ignore the formulae for variance. An adequate discussion of the varying population estimates will be sufficient for these students.

You can create your own mark/recapture situation with a large shopping bag full of Styrofoam peanuts and a pen. Have several stations set up around the room so that your whole class can perform this experiment after you have demonstrated it. Then, get together for a discussion to compare results.

1. For 1 minute, have a student reach into the bag and pull out one peanut at a time and count them.

2. Have another student mark each peanut with a pen and put the marked peanut back into the bag. The number of marked peanuts equals n1.

3. For 1 minute, have another student reach into the bag and pull out one peanut at a time and count them. This number of peanuts equals n2.

4. See how many of the peanuts from the second sample were marked during the first sampling. This number equals m2.

5. Use these numbers in the Petersen two sample capture-recapture estimator to determine a population estimate for the peanuts in the bag. You can then count all the peanuts to check your accuracy.

6. Discuss what factors could affect your total estimate, such as sampling time (corresponds to effort), total number of peanuts (actual population), size of bag (distribution range). Perform two more counts changing 1 factor each time.

7. Prepare a short report on your findings including your raw data, population estimates, what factors you varied and how that influenced your results. Briefly discuss the problems of using this technique in determining marine mammal populations.

8. As a class, discuss how this simple experiment is inadequate for determining actual whale populations. What factors need to be addressed?

The ocean is not a closed system. Whales are born and die, they move out of one area and into another. Other factors include how frequently and consistently the population is being sampled. This is dependent on weather conditions, boat availability, funding, equipment, etc. How the data is collected is important, too, as students in the class should have discovered by their different results.

Objectives - The activities in this lesson satisfy the following objectives as stated in the Maine Learning Results.

English Language Arts

A(1) Formulate questions to be answered while reading.

A(2) Reflect on what has been discovered and learned while reading, and formulate additional questions.

A(4) Use specific strategies (e.g. rereading, consultation) to clear up confusing parts of a text.

A(6) Identify accurately both the author's purpose and the author's point of view.

A(8) Read for a wide variety of purposes (e.g., to gain knowledge, to aid in making decisions, to receive instructions, to follow an argument, to enjoy).

A(9) Explain orally and defend opinions formed while reading and viewing.

A(10) Adjust viewing and listening strategies in order to comprehend materials viewed and heard.

A(11) Generate and evaluate the notes they have taken from course-related reading, listening, and viewing.

B(9) Apply effective strategies to the reading and use of moderately long nonfiction texts (e.g., reference sources, articles, editorials, histories, biographies, autobiographies, diaries, letters, and commentaries) which have an appropriate complexity of content and sophistication of style.

C(3) Consult pertinent information sources on language use (e.g., dictionary, a thesaurus, a handbook on style).

D(1) Seek appropriate assistance when attempting to comprehend challenging text.

D(2) Identify useful information organizing strategies.

D(3) Identify both the author's purpose and the author's point of view when reading expository information.

D(4) Identify different ways in which information texts are organized.

E(1) Identify specific personal strategies, strengths, and weaknesses in writing, and use direct feedback from peers and teachers to revise and polish the content of their finished pieces.

E(2) Use planning, drafting, and revising to produce, on demand, a well-developed, organized piece that demonstrates effective language use, voice, and command of mechanics.

E(3) Ask questions and apply personal interpretations in class discussion following speeches and oral presentations.

F(1) Edit written work for standard English spelling and usage, evidenced by pieces that show and contain:

no significant errors in the use of nouns, pronouns, and adjectives.

few significant errors in the use of adjective forms (e.g., comparative, superlative), adverbial forms, prepositions, and prepositional phrases.

attention to the proper use of conjunctions

no significant errors in the spelling of common, frequently used words, and attention to the correct spelling of commonly misspelled words and less common words.

no significant errors in the common conventions of capitalization (e.g., proper nouns, names, titles) and attention to the less common capitalization conventions (e.g., capitalizing the names of nationalities).

no significant errors in the use of ending punctuation marks, few significant errors in the common uses of commas, and attention to the proper use of the colon, semicolon, hyphen, dash, apostrophe, and quotation marks.

attention to the correct use of commonly confused terms (e.g., affect and effect).

attention to the proper use of italics, marginal notes, and footnotes.

F(2) Demonstrate command of the conventions necessary to make an informal speech or presentation, effectively engaging peers and fielding responses.

G(3) Write pieces and deliver oral presentations that use structures appropriate to audience and purpose.

G(4) Write essays and deliver oral presentations which identify a clear topic and reliably support that topic.

G(6) Write and deliver oral presentations that achieve distinct purposes (e.g., to summarize, to narrate, to inform, to explain).

G(7) Write and make remarks that use descriptive language to clarify, enhance, and develop ideas.

G(8) Write pieces and deliver oral presentations that include a variety of sentence structures appropriate to the purpose.

G(9) Write pieces that use a variety of transitional devices (i.e. phrases, sentences, paragraphs).

G(10) Deliver oral presentations that use a variety of strategies of address (e.g., eye contact, hand gestures, voice modulation, changes of rhythm).

H(1) Collect and synthesize data for research topics from interviews and field work, using notetaking and other appropriate strategies.

H(2) Separate information collected for research topics into major components based on relevant criteria.

H(7) Use search engines and other Internet resources to collect information for research topics.

H(8) Make limited but effective use of primary sources when researching topics.


A(2) Demonstrate understanding of the relationships among the basic arithmetic operations on different types of numbers.

A(4) Represent numerical relationships in graphs, tables and charts.

B(2) Create, solve, and justify the solution for multi-step, real-life problems including those with ratio and proportion.

C(2) Assemble data and use matrices to formulate and solve problems.

C(3) Construct inferences and convincing arguments based on data.

F(1) Demonstrate the structure and use of systems of measurement.

F(2) Develop and use concepts that can be measured directly or indirectly (e.g., the concept of rate).

G(1) Describe and represent relationships with tables, graphs, and equations.

G(2) Analyze relationships to explain how a change in one quantity can result in a change in another.

G(3) Use patterns and multiple representations to solve problems.

H(3) Analyze tables and graphs to identify properties and relationships in a practical context.

I(2) Identify patterns in the world and express these patterns with rules.

J(1) Support reasoning by using models, known facts, properties, and relationships.

J(2) Demonstrate that multiple paths to a conclusion may exist.

K(2) Use statistics, tables and graphs to communicate ideas and information in convincing presentations and analyze presentations of others for bias or deceptive presentation.

Science & Technology

A(3) Describe some structural and behavioral adaptations that allow organisms to survive in a changing environment.

B(4) Generate examples of the variety of ways that organisms interact (e.g., competition, predator/prey, parasitism/mutualism).

J(1) Make accurate observations using appropriate tools and units of measure.

J(2) Design and conduct scientific investigations which include controlled experiments and systematic observations. Collect and analyze data, draw conclusions fairly.

J(3) Verify and evaluate scientific investigations and use results in a purposeful way.

J(4) Compare and contrast processes of scientific inquiry and technological method.

J(5) Explain how personal bias can affect observations.

K(1) Examine the ways people form generalizations.

K(2) Identify exceptions to proposed generalizations.

K(3) Identify basic informal fallacies in arguments.

K(4) Analyze means of slanting information.

K(6) Support reasoning by using a variety of evidence.

K(7) Show that proving a hypothesis false is easier than proving it true, and explain why.

K(8) Construct logical arguments.

K(9) Apply analogous reasoning.

L(1) Discuss scientific and technological ideas and make conjectures and convincing arguments.

L(2) Defend problem-solving strategies and solutions.

L(3) Evaluate individual and group communication for clarity, and work to improve communication.

L(4) Make and use scale drawings, maps, and three-dimensional models to represent real objects, find locations, and describe relationships.

L(5) Access information at remote sites using telecommunications.

L(6) Identify and perform roles necessary to accomplish group tasks.

M(6) Give examples of actions which may have expected or unexpected consequences that may be positive, negative, or both.

Visual and Performing Arts

A(4) Use a variety of resources, materials, and techniques to design and execute art works.

C(6) Critique their own work and the work of others based upon an aesthetic criterion.


Evaluation for these activities really depends on what options are chosen and how the teacher decides to have students pursue each assignment. Exact criteria must be determined by the teacher and students for each situation prior to the research. Research proposals can be evaluated on their feasibility especially in reference to the natural history of the proposed study animal. At the end of the research projects, students can be evaluated on their methods, effort, interpretation of data and on their final reports.

For the simulated research cruise, students can be evaluated on their participation in class, their artistic skills in designing the flukes, their data collection skills, interpretation of data, the content, style and grammar of their final reports and the organization and authority with which they present their findings.

For the mark-recapture study, the important information to note is students' research technique, raw data and estimates (did they do the math correctly?), what factors did they alter, how well did they understand the effects of those changes in this experiment and could they relate this knowledge to an actual field research situation.

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