1) Listening Guide
Biologists studying right whales face the challenge of studying rare, extremely large organisms that spend the majority of their time underwater. This study and accompanying materials and lessons explore some of the challenges and risks of studying right whales and explores the reasons that scientists are willing to work so hard to study them. In addition, the story discusses an experiment designed to learn how male and female right whales find each other during mating season.
2) Listening Prompts for Students
a. How are scientists able to observe right whales?
b. What is the main question that the scientists wish to answer?
c. How did they try to answer this question?
d. What was the result of playing female calls?
e. What unexpected thing happened that scared the scientists?
f. Do you think that the whale was attempting to injure the scientists?
g. Why is it so important to learn more about reproduction of right whales?
3) Play the One Species at a Time Podcast
4) Reading Guide
Right whales are large baleen whales that feed by filtering plankton out of the water. Although the spend much of their life living alone, right whales sometimes form groups so they have a variety of calls to communicate with other members of their species. Right whales are considered to be an endangered species.
5) Reading Prompts for Students
a. What is the purpose of “baleen”?
b. What organisms are able to prey on right whales? What behaviors do right whales have to attempt to defend themselves from predators?
c. Why were right whales especially easy for humans to capture?
d. What are other important sources of mortality of right whales?
e. How many North Atlantic right whales are thought to remain in the wild?
f. What has been done to try to protect this endangered species?
6) Read the Encyclopedia of Earth Article
North Atlantic Right Whale
7) Watch Video (37 sec)
Breaching Right Whale. New England Aquarium right Whale Research Program
Total lesson time: 90 minutes
Listening Time: 5:34
1. What would it be like being a biologist that studies right whales?
Put students in small groups of 2 – 3. Have each group discuss the good aspects and bad aspects of studying right whales. Have each group come up with a list of three good things and three bad things about studying right whales. Have each student write a paragraph answering the question- “Would you like to study right whales? Why or why not?”
Note for Teachers: Question 1 of this lesson plan is similar to the first question addressed in the Killer Whale Lesson Plan. If you have already discussed the difficulty in studying killer whales, then you might either (1) have a general discussion about how difficult it is to study wide-ranging marine species in general or (2) skip this question and move on to Question 2.
2. Right whales are considered to be endangered species. How many right whales remain? What are the main sources of mortality of right whales? What roles have humans had in endangering right whales? Why is it important to learn more about right whale reproduction? What can be done to help conserve right whales? Have each student write a paragraph discussing- “Why are right whales at a risk of extinction and what can be done to help conserve them?”
3. How do male and female whales locate each other when it is time to mate?
Right whales typically travel alone or in small groups. Before mating, male and female right whales gather together in groups known as ‘surface active groups” that may contain up to 30 – 40 individuals. The ocean is a very big place, so how do males and females find each other?
Have students discuss possible ways that males and females find each other during mating season. Possible hypotheses include (1) males and females gather at certain locations at certain times of the year, (2) that males attract females by making some sort of signal (by sound, vision, or smell), or (3) that females attract males by making some sort of signal (by sound, vision, or smell). Which means of communication would be most effective for whales? (have the students think about the difference between communication between whales living in the water and people living on land. For example, sound travels much farther through water than does light.) Have students write a paragraph discussing ways that males and females might find each other.
Thinking Like a Scientist: Have students discuss what observations or experiments would help to support or reject our three hypotheses?
What experiment did the scientists in the podcast conduct? What happened when they played female calls? What did the scientists conclude about what causes right whales to form surface active groups. Have the student write a paragraph discussing how the playback experiment helped us to understand right whale behavior.
Studying large marine mammals such as right whales presents a challenge to scientists. Thus, scientists have had to come up with clever ways to study them. Because they are an endangered species, scientists would like to improve our understanding of right whale reproduction. If would be useful to know the reproductive status of female whales (e.g., are they pregnant, lactating, or non-reproductive). One way to determine reproductive status is to look at the concentration of hormones (chemicals) in the blood. However, it is difficult to collect blood from right whales.
Scientists have learned that hormones can move from the blood into the feces, so it is possible to estimate hormonal concentrations in the blood by examining hormone concentrations in feces. Fortunately for right whale scientists, right whale feces floats to the surface so scientists are able to collect the feces (don’t you wish you had this job?!?) and then analyze them to determine the concentration of hormones in the feces in order to determine the sex and the reproductive status of right whales.
This data comes from the following paper.
Assessing reproductive status of right whales (Eubalaenaglacialis) using fecal hormone metabolites.R.M. Rolland, K.E. Hunt, S. D. Kraus, and S. K. Wasser. (2005) General and Comparative Endocrinology.142:308 – 317. http://dx.doi.org/10.1016/j.ygcen.2005.02.002
The data in this table lists the average hormone concentration measured in nanograms of hormone per gram of dried feces (ng/g) for all males and non-reproductive, pregnant, and lactating females that were sampled.
Non-reproductive Pregnant Lactating . (ng/g) (ng/g) (ng/g) (ng/g)
Estrogen 57 38,237 1245 95
Progestins 295 201,240 273 333
Androgen 1245 8798 3011 10,203
Looking at the Data
1. Drawing graphs.
a) how does hormone level depend on sex? (compare non-reproducing females with males)
b) how does the level of the different hormones depend on the reproductive status of females? (compare one hormone at a time)
c) do the different hormones show the same pattern of change over the reproductive cycle?
Graph Interpretation Questions.
a) How does hormone level depend on sex?
bi) How does the level of estrogen depend on the reproductive status of the female?
bii) How does the level of progestins depend on the reproductive status of the female?
b iii) How does the level of androgens depend on the reproductive status of the female?
c) Do different hormones show the same pattern of change over the reproductive cycle?
Can scientist determine the sex and reproductive status of right whales based on hormone levels?
To answer this question, students need to answer the following questions.
- What hormone pattern is found in males?
- What hormone pattern is found in non-reproducing females?
- What hormone pattern is found in pregnant females?
- What hormone pattern is found in lactating females?
Is there a distinct pattern of hormone concentration associated with each of the four types of whales? Have the students discuss how they could use fecal hormone concentration to determine the sex or reproductive status of a right whale. Have each student write a paragraph describing their conclusions.
Scientists are interested in determining the sex and reproductive status of an unknown group of 5 right whales. They are able to collect feces and analyze hormone content.
Let’s see if you can identify the sex and reproductive status of the following individuals based on their fecal hormone content?
Individual Estrogen Progestins Androgens
. (ng/g) (ng/g) (ng/g)
1 102 315 12,265
2 35, 432 210,387 9034
3 215 265 2144
4 115 350 9,876
5 39,492 198,346 8645