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Home , Marsh, Pond, Salt marsh

HHHaaabbbiii tttaaat CCt ooompmpmpaaarrriii sssooon WWn aaalllk (3-6)(3-6)k Overview: In this activity, students will hike through and compare five different refuge , looking for plants and animals in each , and working on a Habitat Hunt Sheet. Content Standards Correlations: Science, p. 293

Grades: 3-6 TTTiii mmme FFe rrramamame fofoe r CCr ooondndnduuuccctttinining TTg hihihis AAs CCCtttiii vvviii tytyty

Key Concepts: A habitat Recommended Time: 30 minutes provides a home for a plant or Introduction (5 minutes) animal with suitable food, • discuss the five habitats from the Eucalyptus Grove Overlook water, shelter, and space. • hand out binoculars, clipboards, pencils, and Habitat Hunt (if There are five habitats along provided by the educator) the trail: the upland, salt , , , and Habitat Walk (22 minutes) salt . Each habitat • hike the trail from the Eucalyptus Grove Overlook to the Hunter’s supports plants and animals Cabin, walking through the upland, the , over the slough adapted to living in it. and mudflats, and ending at the salt pond Objectives: • stop at the numbered stops on the map and lead discussions Students will be able to: about the habitats and the plants and animals in each habitat • identify and compare the Discussion (3 minutes) five habitats on the refuge • answer any questions about the Habitat Hunt, using the answer • identify one plant or animal sheet in each habitat • name one reason each • collect the equipment and Habitat Hunt Sheets habitat is important HHHooow Thihihis AAs ccctttiii vvviii ty RRty eeelalalattteees tts o tto hhhe RRe efefefuuuggge’s RRe’s eeesssooourururccceeesss Materials: Provided by the Refuge: What are the Refuge’s resources? • 1 bird identification chart • significant wildlife habitat • 1 plant book • endangered species • 1 habitat components poster • migratory birds • 12 compasses • 4 bug boxes What makes it necessary to manage the resources? • 12 binoculars • The introduction of nonnative plants and animals that compete • 12 clipboards with or prey upon native plants and animals. • 1 brine shrimp and brine fly What can students do to help? poster Refuge staff control introduced plants and animals, but we need Provided by the Educator your help. • pencils & copies of Habitat Hunt (p. 215, one per • Plant native plants student, optional) • Keep your cat inside your house; they catch migratory birds • Only take your dog to places that permit dogs and keep it on a leash • Teach others what you have learned about refuge habitats

Song Sparrow

Field Trip Activities: Habitat Studies 207 SSSupupuppppooorrrtttinining InIng fofoformarmarmatttiii ooon fofon r TTr hihihis AAs ccctttiii vvviii tytyty Tidal Slough and Mudflats Habitats • A slough is a natural waterway. Newark slough at • A habitat is a home for a plant or animal. It pro- the Visitor Center is a finger of the which vides food, water, shelter, and space suitable to the carries bay water into the salt marsh with each high plant or animal’s needs. . • Each habitat has its own unique characteristics. • At low tide, when the slough water is carried out to • On the refuge, there are a variety of habitats, each the bay, the mudflats below the slough are re- of which supports different plants and animals. vealed. • Each habitat that you will explore in the Habitat • Small, drifting plants and animals () live Comparison Walk is described below. in the slough water, along with a variety of . • In the mudflats are a wide variety of mud Upland creatures, including snails, crabs, mussels, • The upland is the raised portion of land located crabs, worms, and amphipods. above the marsh, out of reach of the . It is a • Many birds feed in and near the slough. higher and drier habitat than the marsh. • Dabbling ducks, such as mallards and northern • There are a variety of native and nonnative (intro- shovelers, and shorebirds feed on mud crea- duced by people) plants in the upland. tures and plankton on the mudflats. • Native upland plants include California poppies • Diving ducks, such as , feed on and coyote brush. plankton and clams in the slough water. • Introduced upland plants include sweet fennel, • Egrets and herons, fish in the slough water, eucalyptus, wild oat, and acacia. stabbing at fish and crabs. • Animals in the upland include rabbits, ground squirrels, gopher snakes, lizards, hummingbirds, and Salt Pond other small, upland birds. • The salt pond is a human-made habitat. Cargill Salt • Animals may not be seen but evidence of them Company uses the to harvest salt through the may be found (e.g. nests, webs, tracks, holes, process of solar evaporation. scat, etc.). • Bay water is pumped through a series of ponds and after five years the is high enough for salt Salt Marsh crystals to form. The salt is harvested, processed, • The salt marsh is a transition zone between the bay and sold. or slough and dry land. • Salt ponds of varying encompass the • The salt marsh is a habitat that is flooded South Bay. The water of the salt by the tides twice daily. pond is very salty, and few organisms are adapted • Plants in the marsh are shorter and less diverse to live in the salt pond. than in the upland. • In lower salinity ponds, there are fish, water • Plants include pickleweed, alkali heath, Austra- boatmen, brine shrimp, brine flies, and ; in lian saltbush, salt grass, and lavender. middle salinity ponds, it is just brine shrimp, • Animals may not be seen but evidence of them brine flies, and algae; in the highest salinity may be found. ponds, only bacteria can live. • Animals in the salt marsh include voles, shrews, spiders, crabs, clams, ducks, shorebirds, hawks, and egrets. • The salt marsh is home to two endangered species that are found no where else - the and the California clapper rail. • Approximately 80% of the salt marsh surrounding has been destroyed. • Salt were dredged, diked, and filled. Ruddy Duck • Landfills, salt ponds, buildings, and roads were built on top of the salt marshes. 208 Field Trip Activities: Habitat Studies HHHooow ttw o LLo eaeaead TTd hihihis AAs ccctttiii vvviii ty bbty y FoFoy llllllooowwwinininggg • Plants in the upland get freshwater from rain, ttthhhe "Do"Doe , RR, eaeaeaddd, AA, sssk" TTk" eaeaeaccchinhinhing FoFog rmarmarmattt while plants in the salt marsh get saltwater from the slough and bay.) Introduction (5 minutes) Do Read Begin the walk at the Eucalyptus Grove overlook • “The waterway that winds through the marsh is with the following discussion about habitats. called the slough. This slough is named Newark Slough. Read • The slough is connected to the bay; when the tide “We are going to take a walk to look at and compare comes in from the bay it fills the slough, when the the different habitats that are found here at the tide goes back out, a habitat beneath the slough is refuge.” exposed. ” Ask Ask ? Can anyone tell me what a habitat is? (A ? What is this habitat? (The mudflats.) home for a plant or animal) ? The last habitat we can see is just beyond the salt marsh. What are those ponds of water Do called? (Salt Ponds.) Show habitat components poster. ? Is the salt pond a natural or a human-made habitat? (Human-made. Salt ponds were built on Ask top of salt marshes in order to produce salt.) ? What do animals need to survive in their habitat? (Food, Water, Shelter, Space) Read “Let’s start our habitat walk. We will be exploring Do each of the habitats we just discussed and the plants Reinforce this concept by pointing to each habitat within them. You will be working on a Habitat Hunt component on the poster. sheet during the hike.” Note: The Habitat Hunt is optional, the teacher must provide these sheets. Read “Animals need food, water, shelter and space to Do survive.” As appropriate, hand out to each student: a pair of binoculars, a clipboard, a pencil, and a Habitat Hunt Ask sheet (pencils and Habitat Hunt sheets are provided ? Can anyone identify the habitat we are by the teachers). standing on? (Upland.) ? What animals do you think live in the upland? Habitat Walk (22 minutes) (Gopher snakes, rabbits, ground squirrels, fence UPLAND lizards, and a variety of birds, including hummingbirds Ask and owls.) ? We are in the upland habitat now. Why do ? Where is the salt marsh? (The low, , you think the upland is an important habitat? wetland just below the upland.) (There are many different plants that grow in the ? What differences can you see between the upland; many animals live in the upland; humans use salt marsh and the upland? the upland to build on.) • (The salt marsh is lower than the upland, the salt marsh is sometimes covered by the tide. Stop #1 • The plants in the salt marsh are smaller than the Do plants in the upland, there’s a greater variety of Use the activity map and walk to stop #1. Use the plants in the upland. plant identification guide to identify the Acacia .

Field Trip Activities: Habitat Studies 209 Acacia Leaf knows for sure, but some possible answers are that the flowers are fluffy like a coyote’s fur, or that Flattened Leaf Stem coyotes like to hide in it.)

Do Turn left at the bend towards the boardwalk. Along the right side of the trail, you will see a large bush Leaves that spreads out towards the marsh. This is California blackberry. Use the plant identification Ask guide to identify the California blackberry. ? These are Acacia trees, a that was introduced from Australia. What does STOP #3 introduced mean? (They were brought by Ask humans, they were not here naturally. Intro- ? This is California blackberry which is native duced plants compete with native plants for to California. How do its branches differ from space in the habitat.) those of coyote bush? (The branches have thorns) Why does the California blackberry have Do ? Have each student hold on to a “leaf” on the thorns? (To protect its fruit from being eaten by Acacia tree. Note: Remind the students not birds and mammals.) to pick the “leaves.” Read Ask The California blackberry flowers in the , which turn into fruit in the summer. ? How many of you think you found a leaf on the Acacia tree? (Take all answers) Do If you see any other interesting plants as you walk Do along the trail, you can identify them by using the Check each student’s “leaf” to see if they found plant identification guide. the correct leaf or not. Compare with the following picture. SALT MARSH Do Read • Walk along the boardwalk until it begins to bend to “The Acacia trees have very interesting the left. Have the students face left towards the adaptations. In fact, no one is holding a leaf upland. on the Acacia tree. What you are holding is a flattened leaf-stem. STOP #4 • Look more closely at the plant to see if you Ask can find the real leaves.” (Note: This should ? We are now standing over the salt marsh be true in most cases) habitat. Can you find where the salt marsh ends and the upland begins? (Students should notice a Do distinct plant border between the salt marsh and the Continue walking down the trail. At the bend in upland.) the trail, you will see a number of tall shrubs with small, green, pointy leaves; these are called ? Are the plants taller in the upland or the salt coyote bush. Use the plant identification guide marsh? (Upland.) to identify the coyote bush. ? Why do you think the upland plants grow taller? (Salt marsh plants have to be adapted to STOP #2 living in a salty environment. Salt marsh plants use Ask much of their energy for getting rid of salt, while ? These are coyote bush. How do you think they got their name? ( No one really

210 Field Trip Activities: Habitat Studies upland plants do not live in salt water (they get fresh slough connected to? (The San Francisco Bay. A water from rain) and can use their energy to grow slough is not a or , but a finger of the bay, tall.) with a mixture of fresh and salt water.) ? Which direction is the slough water traveling? Do (If the tide is coming in, the water is moving south Have the students look over the sides of the towards the hills; if the tide is going out, the water is boardwalk at the marsh below. moving towards the bay and the Dumbarton Bridge.) ? Does it look like high tide or low tide now? Ask How can you tell? (During high tide the water ? What is the predominant plant you see below comes up to the plants and may cover them, whereas us in the salt marsh? (Pickleweed.) during low tide the mudflats under the slough will be Ask visible.) ? What endangered species lives in and feeds ? There is a plant called cordgrass that grows on the pickleweed? (The salt marsh harvest along the edge of the sloughs and mudflats. mouse.) Does anyone see cordgrass? ? What animals might eat a salt marsh harvest • (Cordgrass is a tall plant that grows in clumps mouse? (Hawks, eagles, owls, northern harriers, along the edge of the slough. The leaves are long, egrets, herons, clapper rails, and other birds.) and thin (resembles grass). • If it is high tide you will see the tips of the cord ? What are animals that eat other animals grass sticking up out of the water. If it is low tide called? (Predators.) you will see the cordgrass growing in the mudflats. • Cordgrass can stay underwater for long periods of Do time when the tide comes in.) Have the students look for the predators of the salt marsh harvest mouse with their binoculars. Do Use the plant identification guide to identify the Ask cordgrass. Have the students use their binoculars to ? Do you see any of the predators of the salt look at the cordgrass. marsh harvest mouse? (Take all answers.) ? If the salt marsh harvest mouse went extinct, Ask would anything be affected? (The animals that ? The slough and mudflats are full of organisms feed on harvest mice would have one less source of called and . What food.) are they? (Phytoplankton are small, drifting plants, ? Why is the salt marsh harvest mouse and zooplankton are small, drifting animals.) endangered? (Loss of habitat. Less than 20% of ? What animals do you think live in the mudflats the salt marsh is left; the rest has been destroyed by or in the slough, that feed on the plankton? humans to build roads, buildings, salt ponds, and (Fish and mud creatures, such as crabs, clams, landfills.) mussels.) ? What animals feed on the fish and mud SLOUGH & MUDFLATS creatures? (Birds, such as shorebirds and the Do California clapper rail, an endangered species.) Continue walking along the boardwalk, until you are Why is the clapper rail endangered? (Loss of halfway across the bridge. Face right (north towards ? the Coyote Hills). The slough goes out to the Bay in habitat. The clapper rail needs the marsh and over the direction you are facing. 80% of the marsh has been destroyed.) ? Can you see any birds feeding in the slough STOP #5 or mudflats? Ask ? The slough is a natural waterway that winds Do through the marsh. What is this Have the students use their binoculars to look for

Field Trip Activities: Habitat Studies 211 birds feeding in the slough and mudflats. Encourage Ask students to identify any birds that they see with the ? Do you see salt crystals on this pickleweed? bird identification chart. (No.) ? If pickleweed does not sweat salt out like the SALT MARSH other plants, does anyone know how it gets rid Do of the excess salt? (Picklweed sends the salt to the After discussing the slough, continue over the bridge tips, which turn red and fall off.) and walk to the end of the boardwalk and turn to the plants on the left. You can get a close up view of the ? What do you think pickleweed tastes like? salt marsh plants at this point. (Salt, pickles, bitter.)

STOP #6 Read Read “I will pick some pickleweed for us to taste and find “Plants in the salt marsh live in salty with salty out. Remember never to eat a plant unless an slough water; it is the only water available to them. adult tells you it is safe. Some plants are These plants have adapted different methods to get poisonous and can make you very sick.” rid of the excess salt.” Do Ask Only the leader should pick some pickleweed ? Can you and I drink only salt water? (No.) and give a small taste to each student. Students should not pick any plants. Also, put a small sample ? What would happen to us if we drank only salt in the magnifying box to get a closer look at the water? (We would become more thirsty, get sick, pickleweed. and eventually die.) (Note: Tiny yellow specks on the leaves are the flowers. Found May - August.) Do Find salt grass, Australian salt bush, and/ or alkali Ask heath in the salt marsh, using the plant identification ? What kinds of animals do you think live in the book to identify them. Point them out to the students. salt marsh? (There are two endangered animals in the salt marsh- the salt marsh harvest mouse and the Ask California clapper rail. Other animals in the marsh ? How do these plants get rid of extra salt? include voles, shrews, rats, butterflies, insects, (Salt grass, Australian saltbush, and alkali heath spiders, and birds.) “sweat” the salt out through openings on their leaves.) Do Direct the students attention to the Hunter’s Cabin. Do Look closely at one of the plants leaves. Read • “The Hunter’s Cabin was built during the 1910s. Ask During this time period, a hunter could kill 100 ? Do you see salt crystals? (Note: this may be ducks with one shotgun blast! People got rich by difficult if the plant is wet. The salt would be in selling ducks for three cents each. solution and not visible) • Hunting is still a popular sport and is allowed in some remote parts of the refuge, but there are now Do limits on the number of ducks a hunter can take. Allow the students to feel the leaves on these plants, • The duck blind across the trail near salt pond is a but do not pick these plants. The leaves should replica built in 1983.” feel chalky from the salt. Walk down a little further on the trail and look at the pickleweed found under the Hunter’s Cabin sign on the left.

212 Field Trip Activities: Habitat Studies SALT POND Do Do Show the students the picture of the brine shrimp and Turn the students attention to the salt pond behind brine flies. Then focus the students attention on the you. The dock is available, but not big enough for the edges of the salt pond. whole group. Please have the students observe the salt pond from the . Ask ? Look in the salt pond water. Can you see any STOP #7 brine shrimp? Find a male and a female. What Ask is the difference? (Male brine shrimp have ? Look out over the salt pond toward the claspers and the females have egg sacks.) Dumbarton Bridge. Which direction is the ? Find a brine fly. How are brine shrimp and bridge? brine flies different? (Brine flies have wings, now • (Use the compasses with the students. To use the fills, and 6 legs, while brine shrimp have no wings, compass, point the arrow on the base of the gills on their legs, and 22 legs; brine flies are insects compass at the bridge. and brine shrimp are crustaceans.) • Holding the compass still and level, turn the dial on ? Migratory birds feed on brine shrimp and the compass until the two red arrows line up. brine flies in the salt pond. What does migrate • Read the direction where it says “read bearing mean? (To move from place to place, usually here.” The bridge is West.) seasonally. San Francisco Bay is part of the Pacific ? What is a salt pond? Flyway - a highway in the sky for migratory birds.) • (Salt ponds are a human-made habitat created for the production of salt. The salt ponds are Do surrounded by walls called . We are Have the students use their binoculars to look for standing on a now. migratory birds in the salt pond. • Bay water is moved from pond to pond becomes Discussion (3 minutes) saltier as the water evaporates. After five years of evaporation, the salinity is high enough to form Ask salt crystals. The salt is harvested and sold.) ? Why are the uplands so important? (The tall ? Where does the water evaporate to? (The sky trees and shrubs in the upland food and shelter for to form clouds.) migratory songbirds, raptors such as Red tailed hawks and Peregrine Falcons, also egrets roost in the How do the salt pond and the slough differ ? trees during the night.) from each other? ? Why are the salt marshes are important? (The • (The salt pond has much higher salinity water than salt marsh is home for endangered species and for the slough. Slough water is flowing whereas the migratory birds. Salt marshes guard against flooding, salt pond water remains still until moved into filter out pollutants from water, and provide a place another pond. for people to visit and learn about.) • The slough is connected to the bay while the salt pond is completely surrounded by levees. ? Why are the sloughs and mudflats are • The salt pond is a human-made habitat while the important?(The slough and mudflats provides food slough is a natural habitat.) for migratory birds and endangered species. Sloughs bring bay water into the marsh with each high tide, Since the salt pond has a higher salinity than ? providing nutrients to the marsh; mudflats are a home the slough what kinds of plants can live in the for mud creatures and sloughs are a home for fish salt pond? (Only algae grows in the salt pond.) and phytoplankton.) ? What kinds of animals do you think live in or ? Why are the salt ponds important? (Salt ponds near the salt pond? ( Brine shrimp, brine flies, provide food for migratory birds; some birds nest on shorebirds, ducks, gulls, and other birds.) the levees around salt ponds; they are a home for

Field Trip Activities: Habitat Studies 213 brine shrimp and brine flies; they are used by humans to produce salt.) clean and healthy? (Never pour anything down storm drains, don’t litter, reduce, reuse, recycle, learn Read about the habitats and teach others, etc.) “All of these habitats are important because they provide food, water, shelter, and space for many Do different plants and animals.” If there is time at the end, review the Habitat Hunt Sheets. Collect binoculars, clipboards, pencils, and Ask Habitat Hunt Sheets. ? What can you do to keep these Bay habitats Return to the Eucalyptus Grove to meet your next group. HHHaaabbbiii tttaaat CCt ooompmpmpaaarrriii sssooon WWn aaalllk MMk aaap (3-6)(3-6)p

214 Field Trip Activities: Habitat Studies HHHaaabbbiii tttaaat HunHunt t DDt aaattta SSa hhheeteeteet

My name is Acacia grows in the Coyote brush grows California blackberry ______in the ______has______habitat. Where was it habitat. on its branches. introduced from? ______Australia or Europe

Pickleweed grows in The Salt Marsh Only 20% of the salt What large body of the ______Harvest Mouse is an marsh is left. Why? water is the slough habitat. ENDANGERED connected to? SPECIES that lives in ______the ______habitat. ______

______

______

Mudflats are found at Cordgrass grows at The snowy egret has a The great egret has a the bottom of the the edge of what ______habitat? colored and colored beak and When can you see ______them? ______colored feet. colored feet. ______

Look closely at salt Which direction is the Brine shrimp live in I can keep the Bay grass leaves. What is Dumbarton Bridge? a human-made habitat healthy and clean by on the leaves in dry ______called the weather? Which direction is the ______bay? ______What feeds on brine shrimp? ______

______

Field Trip Activities: Habitat Studies 215 HHHaaabbbiii tttaaat HunHunt t AAt nnnssswwweeer SSr hhheet (3-6)(3-6)eet

My name is Acacia grows in the Coyote brush grows in California blackberry UPLAND the UPLAND has thorns ______habitat. Where was it habitat. on its branches introduced from? ______Australia or Europe

Pickleweed grows in The Salt Marsh Only 20% of the salt What body of water is the SALT MARSH Harvest Mouse is an marsh is left. Why? the slough connected habitat. ENDANGERED DEVELOPMENT, to? SAN FRAN- SPECIES that lives in SUCH AS BUILD- CISCO BAY the SALT MARSH , ROADS, habitat. LANDFILLS, AIR- PORTS, SALT PONDS.

Mudflats are found at Cordgrass grows at The snowy egret has a The great egret has a the bottom of the the edge of what BLACK YELLOW SLOUGH habitat? colored beak and colored beak and When can you see MUDFLATS OR YELLOW BLACK them? WHEN THE SLOUGH colored feet. colored feet. TIDE IS OUT

Look closely at salt Which direction is the Brine shrimp live in What can you do to grass leaves. What is Dumbarton Bridge? a human-made habitat keep the bay healthy on the leaves in dry WEST called the SALT and clean? NEVER weather? Which direction is the POND DUMP DOWN SALT CRYSTALS bay? WEST, SOUTH- What feeds on brine STORM DRAINS; WEST, NORTH- shrimp? DUCKS REDUCE, REUSE, WEST AND SHOREBIRDS RECYCLE; PICK UP LITTER; LEARN AND TEACH OTH- ERS; ETC.

216 Field Trip Activities: Habitat Studies