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Project
title or topic of activity
Thermoregulation
in Marine Mammals |
Author(s): |
Angela Gauthier, Patti Lucas, Alisha
Edwards, and Kim Ledford |
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Summary
of Activity
Students will learn how mammals maintain a fairly constant body
temperature under various conditions. Specifically they will become
aware of marine mammals and their utilization of blubber through a
hands-on activity. |
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Grade
levels
This activity is designed for grades 3-5. It can however be modified
to make it simple enough to perform in first and second grade classes. |
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Background
information
The students will be asked to call upon their previous knowledge
of mammals in order to assist them in understanding the activity.
This will be accomplished through the use of pictures of marine mammals
such as, walrus, polar bears, dolphins, whales and seals. Students
will also look at pictures of mammals that live in warm climates (tigers,
elephants, giraffes) and animals that live in cold climates (wolves,
elk, snow hares). These pictures will all be presented to the students
on cards. Each student will receive a card and be asked to discuss
that animals characteristics. Example questions include: What
is the animal? Where does the animal live? What is the climate like
where they live? How does this animal cool off/warm up? When all of
the cards have been explained the students will be asked what all
of the animals have in common. This will be the characteristics that
all mammals share. After viewing the pictures the students will be
able to make the connections between mammals and their characteristics
and will recall their previous knowledge and information given in
this station. The discussion will lead the students into concluding
that the characteristics of mammals are that they are warm blooded,
give live birth, have hair, breath air and have lungs, exhibit parental
care, have mammary glands, and have a placenta. After establishing
the fact that mammals are warm blooded the students will review ways
that mammals can maintain a constant body temperature in various environments.
Some things that the students could come up with are that when the
animals are hot they can pant, sweat, become lethargic, etc. When
animals are cold they can shiver, lie in the sun, and increase their
activity level. The presenter will ask the children to compare and
contrast land mammals such as elephants, dogs, tigers, and kangaroos
to marine mammals. The presenter will then propose the question, "how
do mammals that live in the ocean keep warm?" This will guide
the discussion to the use of blubber in thermoregulation. The students
will learn that blubber is a fatty layer of insulation that can be
found in marine mammals. We can compare where the students insulating
layers can be found (arms, legs, stomach) to where it is found in
marine mammals, which is over the entire body, directly under the
skin. Blubber helps to streamline the body. This reduces drag when
swimming and diving. Blubber can also serve as an energy reserve when
the animal is fasting. This is useful to seals and sea lions that
fast for three months during the breeding season. Walruses and seals
have blubber that is a few inches thick. Ask the students how thick
they think the blubber is on a whale. The answer is that it is two
feet thick on large whales. An interesting thing to discuss with the
students is that when seal pups are born they have very little blubber.
They rely on long hair to keep them warm until their blubber develops.
They also rely on metabolizing brown adipose tissue (fatty tissue).
This is the same tissue that human babies use to keep warm! |
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Credit
for the activity
The idea for the activity was obtained from the discovery channel
website. (http://www.discovery.com)
It was slightly modified to include more precise directions and more
background information. |
Estimated
time to do the activity/activities
The total time for this activity can be adjusted depending on the
grade level and the amount of background information that is presented.
To complete the entire activity as presented here it takes approximately
35-40 minutes. |
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Goals
of Activity/Activities:
Goals:
- Students will learn the characteristics of mammals.
- Students will understand what blubber is and its function in
marine mammals.
- Students will become more familiar with the process of making
observations and recording data.
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Materials
Needed
- Pictures of animals on small cards
- Vegetable Shortening
- Gloves
- Alcohol Thermometer
- Bowls
- Ice
- Paper towels
- Water
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Preparation
& teacher "heads up"
It is a good idea to have things set up before the students arrive.
The instructor should make place settings at each table for the
student to sit at by placing a paper towel at each place. Also have
gloves at each table, a container of Crisco, icy water, and extra
paper towels. Setting up is easy and should only take about 5-10
minutes.
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Step-by-Step
Procedure
The experiment will integrate the students knowledge of mammals
and their thermoregulation by being an active participant in this
activity. The experiment is designed to allow students to explore
thermoregulation though a hands-on procedure.
- Divide the group of students into smaller groups (3-4 in a
group).
- Next the two groups will each be given a large bowl filled
with water, ice and rubber gloves. The students will be directed
to place the ice in the bowl, creating an arctic-ocean environment.
The students will wait three minutes for the water to chill.
While they are waiting they will be instructed on how to use
the student data sheet, which is self-explanatory, and each
group will be given a sheet.
- After the water has chilled, the students will take the temperature
of their water and record that data in the appropriate box on
the data sheet.
- The students will then place one glove on either of their
hands. They will take turns having one student place their hand
in the water for thirty seconds and telling the other students
how it feels. For example, does his or her hand feel cold? Does
it hurt at all? How do you feel? The other students will record
these observations on the data sheet. When everyone has finished
experiencing the water temperature they will move onto the next
phase.
- Dry off the wet gloves and then liberally apply vegetable
shortening to their gloved hands. A second glove will be added
to represent the dermal layer, which covers the insulating blubber
of marine mammals. Once again the students will take turns placing
their hands in the water for thirty seconds, making observations
and recording observations.
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Images,
work sheets, additional web pages
Student Data Sheet
Students Name
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Water Temperature
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Observations w/out shortening
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Observations with Shortening
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Items
for discussion or conclusion
Questions:
During the discussion of the results the students will be engaged
in answering questions related to the experiment.
- What was the difference between the first time their hand
was in the water and the second time? Why did it feel different?
Possible responses: The first time there was no insulation
.
- What does this experiment show about the function of blubber?
Possible responses: Blubber acts as an insulator for mammals
- Besides blubber, what are some other physical characteristics
that help keep animals warm in cold climates?
Possible responses: Fur, hair, behavior, metabolism
- Think of some animals that live in cold climates and some
that live in hot climates. Compare and contrast their physical
characteristics.
For this question the students will be presented again with
the pictures of the mammals that were shown to them at the beginning
of the station. They will pick a few to discuss.
Possible responses:
Similarities:
Whales/Walrus
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Elephant/Tiger
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* hair
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* hair
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* warm blooded
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* warm blooded
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* fat reserves
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* fat reserves
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* give birth
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* give birth
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Differences:
Whales/Walrus
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Elephant/Tiger
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* sustains swimming and diving for long periods of time
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*short bursts of energy
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* cant live away from water
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* cant live in water
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* blubber layer
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*fat layer
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- Humans have a layer of fat under the skin, but not enough to
keep us warm. How do humans keep warm in cold temperatures?
Possible responses: clothes, manipulate temperature, move
into the sun
The wrap up will help bring closure to the station while giving
the students a chance to review what they have learned. A good way
to incorporate this will be to let the students explain in their
own words what they have learned while the presenter cleans up the
station. If time permits, students will be encouraged to ask any
additional questions.
Conclusion
This lesson should teach students the basic principles of thermoregulation.
The activity is simple and can be used to demonstrate an important
marine mammal adaptation. Blubber plays a very important roll in
the lives of marine mammals. It serves as an energy resource during
fasting, streamlines the body, and most importantly, acts as an
insulator.
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Assessment
The questions provided in the section titled "Items for Discussion
or Conclusion" should initiate and promote conversation. The
students responses and participation in this discussion should
serve as an assessment as to how much they learned and retained from
the activity. |
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Beyond
the Activity
Further
activities which relate to and extend the complexity of the experiment.
There are a few things that can be added onto this activity. First
of all, there can be a quick discussion comparing heat loss in water
and in air. The following activity can be used to illustrate the
concepts behind this:
The presenter will lead into the activity by asking, "Do
you think its easier to lose heat in water or air?" Then
the presenter will perform a demonstration to help show that heat
is lost in water more quickly than in air. The demonstration entails
taking two 50mL beakers and filling them with hot water. Then the
water temperature is measured in both beakers and recorded. One
of the beakers is set on the counter at room temperature. The second
beaker is placed into another beaker that is filled with water that
is at room temperature. An original observation will be made to
see which is cooling faster, and then the beakers will be left until
the end of the experiment and a final observation will be made.
The results will quickly be discussed. If for some reason, results
other than what were expected occur, the presenter can ask why that
is and reasons for error can be discussed.
Another simple addition to the activity can be used to compare
the different ways that marine mammals keep warm. As discussed in
the main activity, they can use blubber. But some marine mammals,
such as sea otters, need to rely on other means to keep warm. They
use their fur. Air gets trapped between their hair and forms tiny
chambers of air that help insulate the body. A quick way to add
this in would be to get a mitten made of synthetic rabbit fur, or
the like, and have the students put that on a hand and submerge
it in the water. Have the students determine which type of insulation
works better. Do they think that different forms of insulation correspond
to what climate the animals live in?
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Web
Resources
A web address with information on the topic of the activity.
Web
Address
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Additional
References
Reference
Campbell, Neil A. Biology. 4th ed. New York: The
Benjamin/Cummings Publishing Company, INC., 1996.
Castro, Peter and Michael Huber. Marine Biology. 3rd ed. Boston:
McGraw Hill Co., 2000.
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Spanish
keywords
optional
Thermoregulation = Termorregulación
Walrus = Walrus
Whale = Ballena
Marine mammal = Mamífero marino
Blubber = Grasa de ballena
Elephant = Elefante
Tiger = Tigre
Fur = Piel
Hair = Pelo
Warm = Caliente
Cold = Frío
Climate = Clima
Characteristics = Características
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