Sequence | Background | Objectives | Materials | Activity | Extensions | Evaluations

TOPIC-TITLE Marine & Aquatic Habitats Activities - Estuaries Are for the Birds! AUTHOR Rodie Higginbotham GRADE SUITABILITY Elementary School SCOPE Gifted Resources Ornithology Curriculum/Primary

Sequence Before this lesson the students should have completed the following: "What Makes a Bird a Bird?" "What Kind of Beak Is That?" "How To Read a Bird," and "Why , Where, and How Do Birds Migrate?" < < go top

Background Summary Coastal estuaries perform many functions. Among these functions is providing essential habitat for about 75 percent of all the waterfowl that migrate across the United States. Although migratory birds cannot call the brackish water habitat their permanent home, it provides nourishment for their continued existence. Estuaries support large populations of shorebirds, colonial nesting seabirds, and many other bird species. Southern estuaries supply about half of all the fish and shellfish produced in the United States. Most of these species of fish, shrimp, oysters, and other shellfish spend part or all of their lives in these brackish environments. Many marine species use estuaries as nurseries. These species depend on the different levels of salt concentrations to guide them to and from the nursery areas. Because of the abundance of small fish and other prey, many waterfowl and shorebirds feed in estuaries. Freshwater inflow is a critical element in the health of estuaries. Freshwater brings essential nutrients that support the first level (microscopic phytoplankton) of the estuarine food chain. However, too many nutrients can be harmful. Nutrients are found in fertilizers, detergents, sewage, and other substances. Nutrients are carried by rivers, streams, and rainwater into the estuaries. This influx of water can also carry toxic substances and pesticides that can cause immediate death, or these toxins can accumulate in animal tissues. Therefore, some of these toxic substances can place future generations as risk. The effects of this bioaccumlation may be spread throughout the food chain, as predators may consume contaminated food and pass the harmful effects of the contaminant to their offspring. < < go top Objectives Students will be able to do the following: Recognize that birds act as indicators of pollution because of their sensitivity to environmental change. Role play the manner in which marine debris can be hazardous to waterfowl. (This is for the extension activity.) < < go top Materials A small plastic swimming pool Gummie® fish (Goldfish® crackers or "Snorklers") Drinking straws White poster board - cut 3" x 24" A hole punch Brass fasteners < < go top Activity Inform the students who are going to imitate a Great Blue Heron. Explain to the students the Great Blue is a solitary hunter; therefore, there can only be three birds in the estuary feeding at any one time. (This is because of the size of the plastic pool.) Give these three students the rigid drinking straws. Explain that the straw is the Great Blue Heron's beak. Students must spear their food in order to eat. It has been recorded that Great Blues can thrust their beaks into the water so fast that it will blur a photograph taken at 1/1000 second shutter speed. Tell the three Great Blue Herons (with beaks) to remove their shoes and place the straws in their mouths. The Great Blue Herons (students) are to step into the plastic pool. They are wading birds so they should stay near the side, which represents the shallow edge of the estuary. Next, place Gummie® fish in the center of the pool. When a sound is made, the Great Blue Herons should begin to feed. The first student to spear a fish with the straw must step out of the pool and say, "yum yum." This student may eat his/her catch (note: provide this and subsequent Great Blue Herons with new, fresh Gummie® fish rather than those Gummie® fish extracted with straws). The other herons must put their food back into the water. This is repeated until one student "catches" three fish. This game can then be played again with three new students until each student has had the opportunity to participate. < < go top Possible Extension The students will become Cormorants for the next activity. Give half of the group a brass brad, a hole punch, and a strip of 3" x 24" poster board. Assign partners. Have Commorants (students) secure the strip around their partner's neck with the fastener. (Remember birds do not have hands.) At the signal, instruct each Cormorant to remove the plastic debris from their necks. No hands are allowed. After five to eight minutes, repeat the activity with the other half of the class. (It is important to have parental and student permission before conducting this activity.) Students may research the effects of toxic substances and pesticides used in their homes and report to the class ways people can monitor and reduce the use of these substances. < < go top Teacher Evaluation Place the students into three separate groups, those who caught three fish, two fish, and zero or one fish. Give the students who caught three a short eulogy. Tell them they died quickly. Tell the group that caught two that their fish contain toxic substances that had accumulated in their tissues so their eggs did not hatch; therefore, their future generations are at risk. No other explanations are necessary. Allow the students to create the script. < < go top