• Curecanti National Recreation Area

    Curecanti

    National Recreation Area Colorado

Beavers

National Park Service Mission

...to conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations.




Black Canyon of the Gunnison National Park and Curecanti National Recreation Area Outreach Education is committed to: Creating an awareness and fostering an appreciation for the mission of the National Park Service and the natural, cultural, and historic resources of Curecanti National Recreation Area and Black Canyon of the Gunnison National Park.

EDUCATION LESSON PLAN

Curriculum enhancing activities designed to complement national and state content standards across a variety of disciplines.

Title: Beavers

Grade level: All Ages

Time length: 2.5 to 3 hours

Subject areas: Science, history

Teacher: Two NPS Education Specialists

Colorado Content Standards:

History (1.1) Students know the general chronological order of events and people in history.

(1.2) Students use chronology to organize historical events and people.

(1.3) Students use chronology to examine and explain historical relationships.

(4.1) Students understand the impact of scientific and technological developments on individuals and societies.

(4.2) Students understand how economic factors have influenced historical events.

Science (3.1) Students know and understand the characteristics of living things, the diversity of life, and how living things interact with each other and with their environment.

(6) Students know and understand interrelationships among science, technology, and human activity and how they can affect the world.

Theme: Beavers are nature's amazing engineers and are well adapted for the aquatic lives they live. Beavers not only affect their natural environment but they have affected history as well.

NPS focus: Public Law 39-535 (Organic Act)

Public Law 95-250 (Redwood National Park Expansion Act)

Vail Agenda Education Committee Report

Strategic Goal #1; Action Plan 60

Strategic Goal #2; Action Plan 4, 16

Strategic Goal #3; Action Plan 52, 62

Strategic Goal #7; Action Plan 63

Curecanti and Black Canyon primary themes: Natural resources/wildlife

Environmental concepts:

1. The sun is the source of all energy (energy flow).

2. Everything is connected to everything else (interrelationships).

3. Everything must fit how and where it lives (adaptations).

4. Everything is going somewhere (cycles).

5. Everything is becoming something else (change).

6. There is no free lunch (community).

Environmental learning hierarchy: Analogies, sensory awareness, ecological principles, problem-solving processes, and decision-making.

Materials:

Props: mounted beaver, beaver pelts, beaver hat, chewed sticks, and stumps

Trivia: trivia sheets

Aquatic adaptations dress-up: goggles, nose plugs, earmuffs, "teeth", flippers, "rudder", raincoat, and a heavy coat

Beavers and trappers game: trapper nametags, trapper hats, game pieces (marked to indicate food or trap)

Dam building materials: if outdoors, use natural stream and materials---if indoors, use playdough, aluminum bread pans and previously collected sticks and pebbles

Videos:

Beavers: The Biggest Dam Movie You Ever Saw. (1988). IMAX Films: Stephen Lowe Productions.

Rocky Mountain Beaver Pond. (1987). National Geographic Video: National Geographic Society.

I. INSTRUCTIONAL OUTCOMES

Knowledge level: Participants will be able to name at least four aquatic adaptations of the beaver. Participants will be able to identify at least two benefits of having beavers as natural engineers.

Comprehension: Participants will realize the importance of beavers as part of an ecological balance (i.e. riparian zones, new habitats for other species, food chain, etc.)

Application: Participants will be able to relate human dam building and engineering to that of the beaver's natural behaviors.

Analyze: Participants will be able to distinguish a beaver from other mammals. Participants will be able to point out a beaver's structures while exploring a natural habitat.

II. ANTICIPATORY SET

Get participants involved and excited about learning about beavers through an interactive trivia game. Put hand bells around the room for people to ring when they know an answer. Giving out prizes, such as beaver postcards, is a good incentive for active participation. This trivia game also starts off the program with some general facts about beavers and the history surrounding them, giving people the anticipation of the information to come.

III. TEACHING PROCEDURE/METHODOLOGY

Start the program by explaining to participants that the beaver (Latin name Castor canadensis) can be found in most regions of North America. Beavers live in wooded areas near water, such as streams, lakes, rivers and ponds. They usually grow to be 2-4 feet long and weigh 30-65 pounds. They are always growing and, as seen in the trivia game, can actually grow to be quite large! Some characteristics of the beaver's appearance are dark brown fur, black flat tails, ten teeth on each jaw and the two large, ever-growing, incisors. Beavers are very well adapted for life in the water, since that is where they spend the majority of their time. They have special nictating (winking) membranes that close over their eyes, ears and nose when they are under water. They also have a skin flap that closes over their mouth but behind the two big teeth. This allows them to work while submerged without getting water in their mouth. This is a beneficial feature on land as well, keeping wood chips out of their mouth. They have webbed hind feet that work like flippers for swimming. The beaver's tail also aids in swimming, acting as a rudder or paddle. Beavers have thick, warm, waterproof fur to keep them warm and dry while in icy cold waters. They have a large lung capacity, so they can remain under water for up to fifteen minutes while working. BEAVERS ARE VERY WELL ADAPTED FOR AN AQUATIC LIFESTYLE!!!"

Check for student understanding: AQUATIC ADAPTATIONS ACTIVITY

Have one person volunteer to be a beaver. Once they are positioned in front of the audience, ask everyone if they can remember some of the special things about beavers that help them to live an aquatic lifestyle. As the participants provide the answers, begin to dress the "volunteer beaver" with each item that represents the parts of a beaver.

Goggles: for eye membranes

Nose plug: for nose membrane

Earmuffs: for ear membranes

Flippers: for webbed hind feet

Paddle: positioned between feet for the tail (or use a real boat rudder)

Heavy coat: for thick warm fur

Raincoat: for the waterproof fur

Teeth: You can't forget those! made out of paper or other material

Have the volunteer take a big breath to represent the lung capacity.

Once the class has been through the process for the first time, others may want to volunteer to be a beaver, as well. If time allows, this activity becomes a great review.

Diet: "Beavers are herbivores (plant eaters). They eat twigs, leaves, bark, cambium (the growing layer under the bark), and aquatic vegetation. Some of their favorite trees include aspen, alder, willow, poplar, maple, birch, and cottonwood. As a snack, beavers sometimes will eat the bark off of a tree while working; rotating it like eating corn on the cob. In zoos, beavers are fed yams, lettuce, carrots, and commercial rodent chow.

Much of the food eaten by beavers consists of cellulose (a type of carbohydrate which makes up the cell walls of wood and plants), normally indigestible by mammals. Beavers also have a special adaptation that helps them digest their food. They have colonies of microorganisms that live in their intestines! These tiny creatures digest up to 30% of the cellulose a beaver ingests. Additional recycling of the plant material happens when beavers eat their fecal pellets: yes, beavers eat their own POOP!!! It may sound gross to us as humans, but it's only natural to them and it's very efficient (energy conservation)."

Daily Life: "Beavers are nocturnal animals, meaning they are active at night. (Animals that are active in the daytime are diurnal). Female beavers can reproduce at two and a half years old. Newborn or young beavers are called kits. They are born in the spring in litters of 1-6. Kits are born with their eyes open and are ready to swim the next day! By autumn, they are put to work. Beavers are very dedicated creatures--to their mates, their families, and their work. Kits remain with the family for up to two years, gathering food, harvesting trees, making lodge repairs, and even caring for younger siblings. Once a beaver finds a mate, it mates for life."

Engineering: (Pass around some sticks and logs with visible evidence that a beaver has been chewing on them.)

"Beavers are not only dedicated family members, but are very dedicated builders as well. Once they choose a site, almost nothing can make them abandon their operations! They've even been known to incorporate beaver traps into their dams.

Using their constantly growing, sharp incisors, they can snap a half-inch sapling in one bite! It only takes about twenty minutes for one to gnaw down a six-inch aspen. Beavers have been known to fell trees up to five feet in diameter. They don't intend to use these for structures, but they use them for gnawing and sometimes for getting to upper branches.

After being felled, the materials are rolled or pushed to the water and then floated to their proper location. Beavers are very strong and can transport their own weight in materials. You may notice lots of unused dead trees on the ground within beaver habitats: this is because green wood is a third heavier than dry wood and will sink. Green wood can also be shaped more easily than brittle, dead wood."

Dams: "Dams are constructed by diverting the stream to lessen the pressure of the flowing water. Then sticks and logs are forced into the mud of the streambed to form a framework. Once the framework is completed, mud, sticks, grass, leaves, rocks, and just about anything else available is added to the structure. Beavers carry mud by packing it against their chest. A common misconception is that beavers pound materials into place with their tails. They do not! An average beaver dam is about six feet high and fifteen feet long, but remember the record? Dams can be much larger, too! Dam building techniques vary, depending on the water conditions. In slow moving water, they may be built straight across a stream. In fast moving water, they are curved. If water is moving more swiftly than a dam can sustain, spillways or passageways are built to carry off excess water until the pressure subsides, or until the dam can be strengthened. Sometimes smaller dams are also built to lessen the pressure. Dams are generally wider at the base than at the top. They are also usually tilted upstream, against the force of the current. Once a dam has slowed down the current and broadened the food and building supply territory, work on the lodge(s) can begin. All the members of the colonies work constantly to maintain the dam."

Lodges: "Lodges are cone-shaped, approximately fifteen feet in diameter and about five feet above the water line. They are used for living quarters and as many as a dozen offspring can share the lodge at once. Like dams, they are started by "planting" the foundation sticks into the mud and building up from there. Lodges can also be burrows into banks or limestone caverns. The thick, sloping walls of branches, plastered over with a mortar of mud, protects the animals from predators. The mud becomes airtight and water tight, except for at the very peak where there is an opening for ventilation. The roof and walls of the domed lodge are a single structure, eliminating the weakness of the stress between roofs and walls that could collapse under the weight of snow. Once the mound is completed, the beavers approach from below the water's surface and chew tunnels and chambers. The tunnels are built so that the only access to the lodge is under water. This protects them from their predators, such as coyotes, mountain lions and eagles. Two chambers are cleared out inside the lodge. The first one is just a few inches above the water and is used as an eating place and an area to drain off excess water from the fur. The second is above the first and layered with shredded wood for sleeping resting, caring and nursing kits. The stacked chambers reduce the weight and possibility of cave-ins. During the winter, lodges are much warmer on the inside than the temperatures on the outside. You can even see warm moist air rising from the top of the cone, much like smoke rising from the center of a teepee. Before the water freezes in the winter, extra food and building materials are stored beneath the surface of the pond."

Canals: "Not only do beavers build dams and lodges, but they also build canals for easier transportation of construction materials. When rich food supplies surrounding the beaver's pond are used up, they can use the canals for accessing and transporting food materials to the lodge. Canals are also a good safety feature! When beavers are out working away from the pond, they can quickly swim to shelter by jumping into the canals if a predator approaches."

Comparison: "What other animal has the ability to alter their environment?" HUMANS!

"Humans drastically alter their environment when they construct dams and canals!!!"

SLIDES: If slides are available of human dam constructions, they can be a great addition to this program. Show slides (or pictures) of the progression of dam construction from the bottom up. Also show spillways, diversion tunnels and other features that can be compared to the natural features of beaver construction. Show comparisons of beaver reservoirs behind beaver dams and man-made reservoirs behind man-made dams. If available, show pictures of curved dams that tilt toward the direction of flow, just as beavers build their dams. Then ask the audience, "do you think humans had all of these ideas first?" "Of course not! They got all of these great engineering ideas from beavers, nature's engineers!"

Benefits: "Do any benefits occur when beavers alter the riparian zone?" "The beaver pond itself has a profound impact on the surrounding habitat. Yes, it causes the death of some trees, but even dead trees provide shelter for various animals. There are new wetland habitats for birds and various other animals, such as ducks, geese, fish, insects, reptiles, and amphibians. This also provides a good opportunity for the predators of all of those animals! Aquatic vegetation thrives around the pond. Pond water retention causes the local water table to rise. The pond and surrounding area acts as a reservoir, preventing rapid runoff of water and erosion of soil during rains. It also provides steady stream flow throughout the year. Good fishing becomes available, too."

"Even if an area is abandoned by its resident beavers, it is still a benefit to the surrounding habitat. When the pond fills with sediment and becomes no longer a pond, it turns into a lush, green meadow called a vega, a Spanish term for flat fertile ground. The vega provides rich grasses for grazing wildlife and livestock."

"Not everyone sees beaver ponds as a benefit to their everyday lives! Sometimes the actions of the beaver may cause flooding of yards, agricultural land or roads. To those people who don't appreciate every aspect of beavers, there are ways to passively coexist. Water control structures can be added to beaver dams to prevent excessive flooding. This can be easily accomplished by placing pipes in a break in the main channel of the dam. For those who have favorite trees that they do not want gnawed, they can simply place wire fencing around the base of each tree."

"Beavers are a major component in the web of life, and to remove them weakens the whole system!!!"

This is a good point in the program to take a break. After the break, have the participants reconvene at a designated location.

Begin the transition into the second half of the program by saying, "can you think of any predators of the beaver?" "What about humans?" Quickly introduce the historical role of trappers.

Human History: "Why did explorers seek to find unknown places in the western United States? Well, the dreams of gold brought many explorers to the West. However, there was another more reliable way to find wealth in a strange new land. Trappers and fur traders found new places to set their traps." (Hold up pictures of the trappers, found on the Internet, as you talk about them.) "Some of these trappers became famous like Kit Carson, who has many places named after him. Jim Beckworth later became a Crow Indian leader. There was also Joe Meek, Jim Baker, Jim Bridger, and many others. Life for a trapper was not easy. Some traps cost $12.00 to $15.00, and they weighed 8 to 10 pounds. Flint or percussion cap single shot black powder rifles were the only things the early trappers had for protection. There were no grocery stores, fast food places, rangers, or sheriffs, not even a 911 emergency phone number. Why do you think they would go to such wild parts of the country? The answer is, in part, beavers."

"Why was beaver trapping so lucrative? Lets go back in time, and think about Europe. In the mid-1500's, beaver hats were very popular. Everyone had to own one of those sporty beaver hats! They were very expensive back in Europe, and why do you think that is? The beavers were almost extinct in Europe, and the processing of the fur was very expensive."

"Up until the mid-1600's, beaver pelts had to be sent all the way to Russia to be processed. The hatters, as they were called, had a very secret method of turning a smelly beaver fur into an expensive, fancy hat. Some of the steps included removing the guard hairs (outer hair) with a knife until there was just wool-like hair left on the pelt. "Carroting" was the next step. The hatter would smear nitrate of mercury on the pelt. The hatter, at this time, became exposed to the lethal mercury that affects the nervous system. The hatter would slowly go mad, and that's where the name "Mad Hatter" comes from (Alice in Wonderland). This carroting would turn the pelt a carrot-like color. Then, the pelt could be shaved. The fur that was shaved off was then called "fluff." Eight to twelve ounces of fluff came from one pelt. The fluff was heated and shaped into an oval called a batt. Then, it was turned into a cone. Finally, with a block of wood, the fur was blocked into the shape of a hat. A rim for the hat was made, and then the whole thing was waterproofed and was made so stiff that it could support the weight of a 200-pound person. The cost of such a hat would be about the same as the price of a new car today. In 1635, King Charles said all members of high society had to wear beaver hats. Later, explorers found that there were many beavers in North America."

"By 1720, over two million beavers had been trapped. After the Louisiana Purchase, Thomas Jefferson sent Lewis and Clark to investigate the new territory. They found, among other things, beavers. By 1810, people were on their way to trap in the West. However, by 1850, there were few beavers remaining. Beaver trapping slowed down, just as the silk hat was becoming the new style. So, many beavers owe their lives to the tiny silk worm."

Check for student understanding: BEAVERS AND TRAPPERS SCENARIO:

Pick five students who want to be trappers. Remind the players that after the trap is set, the trapper just waits, so being the trapper means you have to be patient. Once the five trappers are chosen, each trapper is given one nametag. These nametags should have the names and photos of genuine historical trappers on them. Make each nametag on a different color background. Each trapper is then given five identical round washers or poker chips. Each chip must have the same color as the trapper's nametag. The color must be on one side of the chips only, and not visible on the other side. Give all of the trappers their five chips. The chips represent their traps. At this point tell the trappers to stand to the side and wait.

The rest of the students are the beavers. Have the beavers all stand at one side of the room or playing area. There, they will wait with their backs turned to the "habitat". The habitat only needs to be a short walking distance. A large classroom, hall or small outdoor area is perfect.

Have the trappers place their chips within the habitat, color side down. The ranger, at the same time, should place 15 chips on the ground. These chips should be identical to the trappers' chips, but should have no colors on the backs. The chips without color represent the food a beaver needs to survive. The trapping scenario is then ready to begin.

Tell the beavers to now turn and face the habitat. Instruct the beavers to walk through their habitat, and pick up one chip and look at the bottom side. If it has no color, then the beaver may proceed to the other side of the habitat. However, if the beaver finds a color on the bottom of the one chip that they picked up, then that beaver has been trapped and must stay in that spot. Once all the beavers have passed through the playing area or have been trapped, then the trappers go into the playing area and match their card color to the chip color of the trapped beavers. The trappers must politely escort the beavers to the ranger, who asks the trapped beavers to stay in a designated area. The ranger may give a star or other sticker to the trappers for each beaver/pelt that was trapped. Once all of the trappers have traded their pelts, they are given their traps back.

Now, ask the remaining beavers to turn in their food chip and once again turn their backs to the habitat. Next, give the trappers 30 seconds to place/reset their traps and get off the playing area. Now, tell the beavers that there is less food on the field. If any of them do make it back to the other side, they may pick one of the beavers from the waiting area to rejoin the game, (representing reproduction). The game is played until the beavers become extinct. The trapper with the most pelts/stars at the end is the winner.

After the game, ask the students about the impact of extinction on the pelt industry. "What will happen to the trappers?" "How will the food chain be changed by the loss of beavers?" "Could something like the events in this game really happen in our world today?"

IV. CHECK FOR STUDENT UNDERSTANDING

See section III.

V. GUIDED PRACTICE

DAM BUILDING:

If outdoors, find a stream with building materials (sticks, rocks, and mud) near by. Make sure students know not to damage any living plants! If they remember the beaver's dam building techniques taught during the "teaching procedure," they should be able to attempt construction on their own dams following the same principles. This can also be fun as a competition with teams. WARNING: this will be messy!!!

If indoors, use the same activity by modifying it to miniature dams. Have participants build dams in bread pans using clay, sticks and pebbles. After everyone's dam construction is completed, go around and pour water above each dam. See whose dam holds back the most water!

VI. INDEPENDENT PRACTICE

Not appropriate.

VII. CLOSURE

Close the program by doing an overview of how important beavers are as a strand in the natural web of the environment. Reiterate the role beavers played in our cultural history.

VIII. SELF-EVALUATION

Indicate what you judge to have been the strengths of the lesson, what changes you made during the lesson and what changes you would make if you were to teach the unit again.

IX. REFERENCES CITED

Shipman, Wanda. (1994). Animal Architects: How Animals Weave, Tunnel, and Build Their Homes. Mechanicsburg, PA: Stackpole Books.

Stong, Paul. (1997). Beavers: Where Waters Run. Minocqua, WI. NorthWord Books.

Corrigan, Patricia. (1996). Beavers for Kids. Minocqua, WI. NorthWord Books.

X. RELATED INTERNET SITES

None at this time.

BEAVER TRIVIA

1. What is North America's largest rodent?

a) porcupine

b) prairie dog

c) beaver

d) marmot

2. The beaver is the national symbol of what country?

a) United States

b) Canada

c) France

d) Russia

3. The heaviest beaver ever recorded weighed _____________lbs.

(found in Wisconsin)

4. How many beavers were harvested in the state of Colorado in 1980?

a) 8,937

b) 1,231,803

c) 978

d) none

5. In 1825, beaver pelts sold for

a) $10-$20 per pound.

b) $1-$2 per pound

c) $100-$110 per pound

d) $4-$6 per pound

6. Is it legal to leg-hold trap beaver in the state of Colorado?

a) yes

b) no

7. The largest beaver dam on record was found in Three Forks, MT and was __________feet long!

8. Beavers are…

a) dirty, disgusting creatures, because they are rodents.

b) cute, clean creatures that groom themselves regularly.

c) amazing, ingenious engineers!

d) none of the above.

9. What animal on our continent was the most influential in motivating trappers to go West?

a) elk

b) beaver

c) bison

d) alligators

10. The prehistoric ancestors of beavers during the Pleistocene Age weighed about _____pounds.

a) 2-6

b) 50-85

c) 100-200

d) 700-800

11. The most famous T.V. show about a beaver was called ________________________.

Answers to beaver trivia:

1. c

2. b

3. 110

4. a

5. d

6. no

7. 2,140 ft long, (14 ft high, 23 ft thick at base)

8. b & c

9. b

10. d

11. "Leave it to Beaver"

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