The diversity of animal life that exists in an area can be considered a measure of its biological richness, productivity and stability. That diversity is in turn dependent upon the diversity of plants, soils, other organisms, and weather in the habitat itself. When humans move into an area, changes in the habitats and ecosystems take place, causing changes in the assortment of plants and animals found there. Some species are driven out altogether, while some increase in number unnaturally. New species are introduced and can, in the absence of natural enemies, take over the niches of species native to the area. In the following activity, students will explore their surroundings to survey their local bird population for its diversity, learning which species are native and which are introduced. Students will then draw conclusions about the "health" of the natural diversity of bird life of the area.
Themes:
Patterns of Change, Stability, Systems and Interactions
Concepts:
- All organisms have special needs and interact in specific ways with each other and with their environment.
- Change through time in ecosystems is a natural process, but human intervention has quickened this change and sometimes caused an imbalance to occur, affecting the well-being of the ecosystem.
The Guanacaste Province of northwestern Costa Rica contains an area very rich in biological diversity called a "dry tropical forest." This area is relatively unprotected, and therefore, is endangered by encroaching agricultural and commercial development. In addition, local knowledge of the area's diversity of life and its value is limited. Dr. Gordon Frankie of the University of California at Berkeley has been conducting studies in this area for twenty-six years, and with UREP groups for the past twelve. He seeks to preserve this region for the uniqueness of life it supports by gathering data on the the diversity that exists here, censusing the area's birds, bees, and beetles.
Our work contributed to a determination of the future of the area. If it could be proved that a section of uninhabited land called "La Mula" supported a significant diversity of life, it should be preserved as a corridor between two sections already under protection by the National Parks of Costa Rica. Happily, after many years of data-gathering, about a month after our expedition was completed the government handed over the corridor to the Park Service for preservation and halted the plan for its development into rice fields.
Students will:
- learn techniques of field observation and data-gathering while studying the local bird population.
- understand that an ecosystem is a complex combination of elements, which can affect or be affected by each other.
- determine the effects of human intrusion on the birdlife in their area and make judgments regarding the positive/negative results based on their findings.
- recognize what biodiversity is and understand its merit for the maintenance of life on earth.
Reference books on birds and plants of the local area
(For each group of 4-5 students)
- Bird Field Guide
- Common backyard bird drawings (included with this lesson)
- Clipboard, pencil and Data Sheet
- Several sheets of drawing paper
Optional:
- Stopwatch
Binoculars
Instant camera/film
[Teacher Preparation --Scout out an area on the schoolyard or in a nearby park or vacant lot where there are trees and shrubs, and where you can safely take the students to work in small groups. A field trip to a nature preserve or other natural area is also a good choice if you can arrange it. Recruit parent volunteers to accompany the class if at all possible. Check the area for bird activity, keeping in mind that the earlier in the morning you go out, the more birds you will see.]
NOTE: Have students read the Student Introduction (separate page) to this lesson before leading them in the activities below.
Opening Discussion:
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Ask the students what the world would be like if everyone looked exactly the same. You will probably elicit responses such as, "It would be boring!" and "We wouldn't know one person from another!" Ask them to think about a world where there were just one or two kinds of dogs, cats, and birds, or only a few kinds of animals at all! What would life be like?
- Talk with the class about their knowledge of birds. Ask them if they can describe any birds they have ever seen, name any they are familiar with, and what they know about how birds behave. With older children, they can brainstorm different types of birds they are already acquainted with. Chart their responses for future reference.
- Explain to the class that they are going to be "Field Biologists" and gather information (data) on what kinds of birds are found in their local area. Divide the class into groups of 4-5 students, giving each group a clipboard and Bird Field Guide. In each group, designate a Recorder, Timekeeper, Artist, and Observer(s). They will use their senses of sight and hearing to locate and observe the birds, then write down what they find out on the Data Sheet as the group's artist sketches what is seen.
- Take the class to the designated area outside and set them to work:
Observers--Spot and watch the birds, describing to the Recorder and Timekeeper what they are doing and where they are (on a tree, on the ground, eating, singing, preening their feathers, etc.)
Recorder--Write down observations made of the birds.
Timekeeper--Time how long each bird does any particular behavior (to time behaviors, count "One steam engine, two steam engines," etc. if watches aren't available).
Artist--Draw a picture of any bird seen for a long enough period of time. - Observers can check in the Field Guide to see if they can find the birds seen. If enough description is written down while observing them, students can use the guide in class.
- Many birds are seen in groups. Have the observers count how many of a particular kind of bird is seen.
Have students think about the value of having a diversity of life forms around them. Discuss the roles various types of animals play in ecosystems, such as consumers of other animals or plants. [Example: if there were no snakes, we would have a rodent explosion.] Explain that, as each person has a job to do in the world, so do animals. If we remove one animal from an existing ecosystem, that system cannot function the same as it did before. Usually, a lack of or overabundance of something is created in that ecosystem. It is not the same, and other plants and animals are now affected by that missing animal.
Tell students that they will be carrying out some activities which will help them find out if the area in which they live has been changed from its natural state, and if these changes have been for the good or bad of the ecosystem.
After about an hour of observation, bring the class inside to compile and discuss what they saw. Have each group report back to the others about the kinds and numbers of birds they saw, and what they seemed to be doing. Groups can make a drawing of their observations, using the sketches of the group artist. Compare their observations to the list the class generated before going outside.
Next, have students use the reference books and field guides to find which birds are native (indigenous) and which birds were not always found in that area. Depending on the season of the year, some birds may be migrating through. However, they still are a part of the natural makeup of the birdlife there.
Some birds are not native to your local area, or for that matter, to the United States at all. Their presence is due to human intervention, such as captive birds escaping, intentional importation and release, and habitat alteration which can cause native species to decline and exotic types to flourish. Some of these birds commonly seen are:
house sparrow (England)If students are too young to do research to find out which are the native/non-native birds, find pictures of these common birds and show them to students before they go out in the field. (See the resource list for book titles.)
starling (England)
various types of parrot (South America and Africa)
pigeon (Europe and Asia)
spotted dove (Asia)
Other birds are native, but due to adaptation, have flourished and increased in numbers in urban areas. Some of these birds are:
house finchStill other birds have recovered from near extinction due to human intervention. The most notables are the brown pelican, observable near the ocean, the peregrine falcon and the bald eagle.
mockingbird
crow
mallard duck
Brewer's blackbird
[Note: The local branch of the Audubon Society is an excellent source for information on the birds of your area.]
Discussion Questions:
- Which birds were most commonly seen? Are they a native or a non-native species?
- What type of plants were the birds feeding on (seeds, flowers, etc.) that are native to your area?
- Was the area where you observed birds a natural area, or had it been changed by people, such as a schoolyard, parking lot, or city park?
- If it was an altered area, were native or non-native birds more numerous?
- Is it better to preserve native species in an area, or bring in other types to have more variety?
- In Hawaii, none of the birds in the urban areas are native species. What type of effects would this situation bring about? (Insects native birds eat could get out of control, animals that feed on native birds would have no food, non-native birds usually have few enemies and could overpopulate the area destroying habitat)
- How do birds get to an area where they are not found naturally?
- Why would people bring birds into an area from somewhere else? Do you think this is a good practice? Why, or why not?
- What kinds of changes would happen to an area when birds or other animals are brought in that are not native to that area?
- What can people do to preserve native species where they are found?
- Hear Ye, Hear Ye: Hold a "Town Meeting" to discuss the future of an area of undeveloped land in your town. Have various groups present their proposals for the land to "City Council" members. Council persons then vote on the plan they perceive as best for the city. Suggested groups could include:
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a. Farmers, who want the land opened for new farming plots
b. A lumber company, who wants to cut the trees for the wood
c. Developers, who want to build housing tracts and mini-malls
d. Preservationists, who want the land to stay in its natural state
e. Sports persons, who want to use the land for hunting and off-road vehicles - The Politics of Birds: Research an area near your school that is being considered for development. Find out what the plans are to help protect the wildlife that lives there. Write to the developers and invite them to come to speak to your class. Also invite a spokesperson from a nature organization such as Audubon or the Nature Conservancy to give their point of view on the issue.
- Plant It and They Will Come: Find out what types of plants the birds native to your area prefer for feeding and nesting. Plant them on your schoolgrounds or in your yard at home. Observe what birds come to visit.
- Feed Me: Build bird feeders and nesting boxes and observe them daily. Be sure to put them out of the reach of neighborhood cats.
In order to determine what the students have learned about native species, ecosystems, and human intrusion, have the students make murals in small groups, showing all the species that once lived in your area. Show the plant life which existed at that time also. Then make a second mural showing how that area looks today and the birds now found there. Have them include some of the causes of the decline of native species and the replacement by non-natives.
In your evaluation of their learning, look for:
- native birds no longer found in the area in great numbers
- commonly found non-natives such as sparrows, starlings, pigeons
- evidence of habitat encroachment through development
- any evidence of human intervention in bringing in non-native species purposely (like caged birds)
Birds In The City is a part of LAEP
Learning Exchange.