Duration: 30 to 45 minutes
Vocabulary: migration, habitat, wintering area, nesting area, stopover area, limiting factor
Summary: [Based on activity for Project WILD] Students act as migrating birds traveling between habitats and using wetlands as resting sites along the way. Through this, they will experience some of the natural and human-made dangers facing these birds on their travels.
Objectives: Students will gain a deeper understanding of why wetlands are such an important habitat for migrating birds. They will be able to explain the way habitat loss affects these birds, and what human factors are contributing to it.
Materials: large open space (gymnasium, playground, mowed field, etc.), two paper plates for every three students (16 plates for 24 students) marked with large Xs on one side, flip chart and markers (optional)
The dictionary defines bird migration as the “regular seasonal journey undertaken by many species of birds.” It also says that bird movements include those made in response to changes in food availability, habitat or weather. Migration is marked by its annual seasonality. In contrast, birds that are non-migratory are said to be resident or sedentary. Approximately 1800 of world’s 10,000 bird species are long-distance migrants. Birds do this because the longer summers in the North helps birds raise more young, while staying in tropical areas for the winter means they have steady food supplies.
Wetlands are a very important type of habitat. They both give food, water, and shelter to a variety of plants and animals. While some animals live in wetlands year round, other animals just stop by these areas for water or shelter, like a migrating bird staying overnight in a wetland as if flies across the world. It might seem that because these wetland stopovers are temporary that they are not important, but this could not be further from the truth! Migration is a very difficult task for birds–many species fly great distances through turbulent weather, and they depend on wetland ‘stopover’ habitats as places to take refuge from storms and find food.
Many shorebirds spent their summer in the United States and Canada in what are called “breeding areas” and then migrate to South America, Central America, and the southern United States to visit what are called “wintering areas.” The distance that birds travel varies by species. Some birds, like the American Avocet, travel only within the United States, while other birds like the White-rumped Sandpiper have to fly over 20,000 miles round trip!
There are a variety of occurrences that influence whether a bird survives its migration are not, and scientists call these “limiting factors.” As the name explains, they limit the number of birds that live after these events. Limiting factors can be either natural or human-made, and birds face a variety of them when they migrate. A naturally occurring limiting factor could be the number of predators in a marsh waiting to eat tired birds. A human-made limiting factor could be the removal of wetland habitat to build houses, reducing the number of places birds can stop and rest.
Ask students what would happen if they tried to go on a long vacation in the car but there weren’t any gas stations. They wouldn’t make it very far! What about if there were only a few gas stations along certain roads? In this scenario all the people who wanted to go on trips would go this way, and they would have to wait in long lines and hope the gas doesn’t run out. This scenario can be compared to birds and migration. Without places for birds to rest and “refuel,” many of them would not make it. Likewise, as wetland habitat is destroyed, there are fewer and fewer places for birds to stop, meaning more and more birds have to compete for the same resources. Finally, explain the concept of migration and show students pictures (see Handouts section) of birds that migrate different distances.
Find an open space about 70 feet in length. Place an equal number of paper plates (X side up) in three areas on the field: in strips on both ends, and in a strip/clump down the middle. Include enough plates at first that there is one plate for two or three students to share in each of the three areas. Designate one end as the “wintering habitat,” the other end as the “nesting habitat,” and the middle area as the “stopover habitat.”
Explain to students that they are going to be shore birds who feed in the water, and they are going to migrate from their nesting habitat to their wintering habitat. (Note: This can change with the season, so that in the fall you begin the activity this way, and in the spring begin with the opposite). The Xed paper plates represent suitable shorebird habitat they will find between the two locations like wetlands and grasslands. They can stop at these locations to rest and find food. At the end of each “migration,” students will have to have at least one foot on a paper plate, and there can only be 2 or 3 (depending on # of students) students on each paper plate at one time. Any students that cannot find a plate (habitat) that isn’t “filled” will “die,” and have to move to the sidelines temporarily. Have students flap their ‘wings’ like birds as they run between the plates.
Explain to students that different factors will limit the survival of the birds. Sometimes there will be changes in the nesting or wintering habitats, like a loss of food or a change in weather. Other times, though, the change will take place in the stopover habitats, which they depend on just as much.
Have students begin to ‘migrate’ from one end to the other. They will first move to the stopover habitat, and then on to the other side. While they are at the stopover habitat, explain why these habitats are important. In this turn, there has been no loss of habitat in the area, and all of the birds can make it. Before the students return to head back, turn over four plates in the stopover habitat. This represents a loss of habitat due to humans building a mall where a wetland used to be. Have the students migrate again. This time, some will “die” because they have nowhere to rest and feed.
Repeat this process using different scenarios each time. Some sample scenarios could include:
Urban expansion, wetland drainage, conversion of wetlands to farmland, chemical spill in a wetland, drought reducing the water in a wetland, pollution of food supply, and illegal hunting taking away paper plates.
Group works to preserve wetlands, restoration of wetland habitat, farm management that is bird-friendly, normal rainfall so there is enough water, and the education of a school about habitats for wildlife can result in the addition of more plates.
Ask students to identify factors that cause migrating bird populations to decline or increase. What causes were human-caused and what were natural environmental factors. Which of them pose the most long lasting threat to migratory bird survival?
Keep track of how the numbers of migratory birds (students) fluctuates in your game and then have students graph these numbers into “migration cycles.” Do this by comparing the number of birds against the factors that caused the numbers to fluctuate and compare how they change over time.
Ask students to come up with ways they can help save wetland habitat and make posters, or give a presentation to a younger class.