RL3 Guide Manual
Study-Trip Trail Guide
Grade 3
There are 5 trail points—3 trial points to observe and record habitat factors, 1 trail point to
compare and contrast, and 1 trail point to observe and record 2 animals’ adaptations.
Introduction

State team’s purpose on trail:
o Visit river habitats created by the work of the river.
o Make and record observations about the habitats on a map.
o Observe and record the adaptations of two river basin animals that live in one of
the habitats.
o Describe how their adaptations help them to meet their basic needs, everything
they need to survive.
o Describe how organisms help (contribute to) the living river basin system.
Transition:
o We are going to the ___________ (marsh, riffles, deep river pool), a habitat in the
river basin system made by the work of the river.
o What is the work of the river? [Erosion, sorting, deposition]
Trail Point 1--Marsh
 Briefly describe habitat:
o Remember in our model river where the water broke through the bank of the main
river because of the big rainstorm? The same thing has happened here. When
there is flooding, the water flows into the marsh. (Show direction of flow.)
 Observe and describe six (6) habitat factors – that is: what makes this habitat different
from other habitats.
o Describe and record student responses on observation map:
 Light conditions
 Is it sunny or shady? (Record.)
o Amount of sunlight determines what plants will grow to
provide food and shelter for animals.
 Banks of river
 What is on the banks of the river? (Record.)
o These plants could provide food and shelter for animals.
 Surface of or in the water
 What is on the surface of the water or sticking out of the water?
(Record.)
o Algae grow and provide food for animals.
o Plants growing in the water provide food and places for
small animals to hide.
o Plants and animals floating or swimming on the water can
be food for animals.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
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
Bottom material
 What is on the bottom of the river? Can you even see the bottom?
(Record.)
o Bottom material (mud, leaves, rocks, sand, etc.) determines
what animals and plants live there.
 Depth of Water
 Is the water shallow or deep? (Record.)
o Depth determines what plants can grow. Shallow water
usually means more plants can grow than in deeper water.
Sunlight has a harder time reaching the bottom in deep
water, and plants need sunlight to grow.
 Flow of the water
 Is it moving fast or slow? (Record.) [Little or no flow.]
o The river water loses energy when it overflows into this
area and the water deposits the soil it was carrying. The soil
builds up over time and grassy plants grow. The slow flow
and many plants make it a great habitat for small and baby
animals.
Let’s take a snapshot of this area so we can compare it to the other habitats we will visit.
Transition to next trail point (walk and talk):
 Now we are going to the ________ (marsh, riffles, deep pool) another habitat area
that the river created.
 Do you think it will be different from this one? A lot or a little?
 How does the river make different habitats? [Erosion, sorting, and deposition.]
Trail Point 2—Riffles
 Briefly describe habitat:
o Remember in our model river where the medium-sized rocks were deposited
because the river lost energy? The same thing has happened here. The river had
lots of energy, dug a deep pool, carried the soil up out of the pool (indicate pool
preceding riffles), lost energy, and deposited the medium-sized rocks here.
 Observe and describe six (6) habitat factors – that is: what makes this habitat different
from other habitats.
o Describe and record student responses on observation map:
 Light conditions
 Is it sunny or shady? (Record.)
o Amount of sunlight determines what plants will grow to
provide food and shelter for animals.
 Banks of river
 What is on the banks of the river? (Record.)
o These plants could provide food and shelter for animals.
 Surface of or in the water
 What is on the surface of the water or in the water? (Record.)
o The fast flowing water carries anything that falls on it away
quickly.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual


Bottom material
 What is on the bottom of the river? (Record.)
o Bottom material (mud, leaves, rocks, sand, etc.) determines
what animals and plants live there.
o Plants grow in silt. Remember the soft silt at the edges and
the end of the model river? And we said that soil is all sizes
of rock—boulders, big rocks, small rocks, sand,... and silt.
This rocky riffle area has soil—medium-sized rock—but
does not have the right conditions—silt—for plant roots to
grow.
 Depth of Water
 Is the water shallow or deep? (Record.)
o Depth determines what plants can grow. Shallow water
usually means more plants can grow than in deeper water.
(Sunlight has a harder time reaching the bottom in deep
water and plants need sunlight to grow.)
o Even though it is shallow and the sunlight could reach
down into the water, plants are not able to grow here
because there is not enough silty soil for plant roots to grow
in.
 Flow of the water
 Is it moving fast or slow? (Record.) [Fast flow]
o The river loses energy and deposits rocks here and this
builds the river bed up over time. The rocks make the
water tumble. This bubbly, shallow place is a great habitat
for insect larvae.
o We observed that the water was shallow but the flow is
fast. Sunlight could get through to the bottom but there
isn’t enough silty soil for plant roots to grow in because the
fast water washes the silty soil away.
Let’s take a snapshot of this area so we can compare it to the other habitats we will visit.
Transition to next trail point:
 Now we are going to the _________ (marsh, riffles, deep pool) another habitat area
that the river has made.
 Do you think the next habitat area will be different from this one? A lot or a little?
 How does the river make different habitats? [Erosion, sorting, and deposition.]
Trail Point 3—Deep Pool
 Briefly describe habitat:
o Remember in our model river where there were deep pools that were made by the
energy of the river? The same thing has happened here. Just before the deep
pool, the river deposited a lot of rocks (indicate riffles). Unloading the rock gave
the river more energy, and it used this energy to erode (dig out) the soil from the
river bed to create this deep pool.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual

Observe and describe six (6) habitat factors – that is: what makes this habitat different
from other habitats.
o Describe and record student responses on observation map:
 Light conditions
 Is it sunny or shady? (Record.)
o Amount of sunlight determines what plants will grow to
provide food and shelter for animals.
 Banks of river
 What is on the banks of the river? (Record.)
o These plants could provide food and shelter for animals.
 Surface of or in the water
 What is on the surface of the water or in the water? (Record.)
o Plants and animals floating or swimming on the water can
be food for animals.
o If bubbles are noted by students, record and explain
bubbles are normal (i.e. not necessarily pollution).
 Bottom material
 What is on the bottom of the river? Can you even see the bottom?
(Record.)
o Bottom material (mud, leaves, rocks, sand, etc.) determines
what animals and plants live there.
 Depth of Water
 Is the water shallow or deep? (Record.)
o Depth determines what plants can grow. Not as many
plants grow in a deep pool. Sunlight has a harder time
reaching the bottom in deep water and plants need sunlight
to grow.
o The deep pool habitat is a great place for some larger fish
and turtles.
 Flow of the water
 Is it moving fast or slow? (Record.) [Moderate flow.]
o As the water leaves the riffles, it has a lot of energy to pick
up and carry soil (remember soil is all sizes of rock) from
the bottom making the river bed deeper and deeper over
time creating a great habitat for fish.
Once you have done both riffles and deep pool:
 Pattern—pool-riffles—pool…
o All rivers have the same pattern—pool-riffles-pool-riffles-pool…and it keeps
going in that same pattern all along its course.
o The riffles and pools are made by the work of the river as it loses and gains
energy all along its course.
o Let’s look up and down the river (from here) to find this pattern.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
Transition:
 We’ve looked at three different habitats.
 What lives in habitats? [Plants and animals.]
 Why do you think all these habitat factors (light, depth, and flow) would
matter to plants and animals?
o Different habitats with different habitat factors mean that different
plants and animals will live in those different habitats because not
every plant and every animal is able to live in all places. Each
organism needs a place just right for it.
 What makes these different habitats?
 How does the river make habitats?
 Keep this in mind as we talk.
Trail Point 4—Compare and Contrast Habitat Factors
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
Compare and contrast the habitat factors of the three habitats.
 Light
 Banks
 Surface
 Depth
 Bottom
 Flow
o Summarize: There are similarities between the habitats but there were many
differences too.
Which habitat factor was the most different in each of the habitats? [Usually flow.]
 How does the fast or slow flow make each habitat different? [Flow
determines if the river is going to erode and make the river bed deeper or
deposit soil building the bottom up over time which will make the water
shallow.
 Habitats with different habitat factors mean that different plants and animals
will live in those different habitats. Each organism needs a place just right
for it.
Which habitat factor was the most similar among the habitats? [Sunlight.]
 Plants need sunlight to grow. Sunlight is one reason why you saw so many
plants.
What living organism did you see at every trail point? [Many different plants.]
 Record on observation map.
 All plants provide food and shelter in the habitats that the river created.
 All the plants we see in all these habitats have strong roots to hold them in
place by holding onto the soil. These strong roots are an adaptation that helps
plants to survive in their habitats.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
Transition (stationary):
 What do all plants and animals need to survive? (Very important transition
question to review the basic needs and to observe and discuss the types of
adaptations plants and animals have.)
o Review the basic needs: water, oxygen, food, and protection.
 State: As plants have adaptations, so do animals have adaptations that help them to
get their basic needs and to survive in their habitat.
 Define/review definition of adaptation and the difference between structural and
behavioral adaptations. Use examples as necessary and relate to basic needs.
 Adaptation=how organism looks—structural—or how it acts—behavioral.
Transition (walking):
 Now we are going to go back to the _____________ (marsh, riffles, deep pool) to
observe the adaptations of two organisms that live there that help them get their basic
needs to survive in their habitat.
Trail Point 5—Organism Observations including Basic Needs, Adaptations, and
Contribution Discussions (Marsh, Riffles, or Deep Pool)
 Organism Observation (Two animals. Props provided.)
o Tell students they will observe two organisms (prop or picture) that live in this
habitat, paying attention to adaptations they can see and how the adaptations help
the organism get its basic needs, what it needs to survive.
o Tell students that X and X live in this habitat.
o Record on map that X and X live in the _________ (marsh, riffles, deep pool.).
 If this last trail point is at ________________ (marsh, riffles, deep pool) observe and
discuss:
o Marsh
 Mosquito wriggler
 Bullfrog
o Riffles
 Insect Larvae
 Brook Trout
o Deep River Pool
 Whirligig beetle
 Large Mouth Bass
 Discuss one organism at a time:
o As organism (prop or picture) is passed from student to student, ask each student
to name a feature (adaptation) that they notice. Direct students to name a feature
(adaptation) not already named.
o Discuss each organism’s adaptations in relation to how adaptations help the
organism to meet its basic needs (include if adaptation is structural or behavioral).
 Start with observable adaptations and relate to basic needs; then “teach”
the adaptations that are not observable or obviously evident to students.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual

See Organism Information section below—after summary—for detailed
information on the organism’s adaptations and how these adaptations help
secure the organism’s basic needs.
 Water
 Oxygen
 Food
 Protection
o Record one adaptation discussed for each animal and label as structural (S) or
behavioral (B).
After both organisms have been discussed:
o Explain to students why each organism lives in this habitat (habitat rationale).
(See below in Organism Information for each organism.)
o Discuss contributions both organisms make to the system (mainly as food).
 There are many different organisms that live in the river basin system
other than what we have observed and discussed. One way they all
contribute to the system is as food for something else.
Transition to summary:
Today we built a model river, observed three different habitats that the river created, and
discussed two animals and their adaptations that allow them to live in a habitat that is just
right for them.
Let’s review what we have learned.
IV. Summary:
What is the work of the river? (Ask “leading” questions as necessary.)
 Eroding soil
 Sorting soil
 Depositing soil
 Creating habitats
What is a habitat?
 A place where plants and animals get everything they need to survive and reproduce.
What are the four things every living organism needs to survive and reproduce, that is: what are
its basic needs?
 Water
 Oxygen
 Food
 Protection
One at a time:
 Ask each student to:
 name an animal and one of its adaptations,
 describe how that adaptation helps it to get its basic needs, and
 describe how the animal helps the river basin system.
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
Concluding statement:
The work of the river creates habitats, plants and animals living in those habitats are all
parts of the river basin system. Remember a system has parts that all work together. The
river basin system has parts too—both living, such as plants and animals, and non-living,
such as water and soil—that work together to keep the river basin healthy.
Organism Information
Adaptation and Habitat Rationale
Not all adaptations are readily observable—some “teaching” will be needed. Italicized
bolded adaptations are not readily observable.
Mosquito wriggler—immature aquatic form of adult flying mosquito
 Basic Need—Adaptation—Purpose of Adaptation
o Water—very small holes in skin—absorbs water through skin; must be in water
to develop into pupa
o Oxygen—breathing siphon (tube) reaches to surface of water—to breathe air
while body is under water, i.e. no gills
o Food—mouth hairs—to sweep food (algae) into mouth
o Protection—short larval stage—cannot move quickly to get away from predators
(fish, frogs, birds) so is a larvae for a short time, changes into adult and flies away
 Additional information
o Lives in slow/non-flowing water so siphon can easily stay at surface to breathe
o Small body—only1/4 to ½ inch
o Very important food source for fish
 Habitat rationale
o Mosquito wrigglers live in marshes because they can find everything they need to
live—the basic needs of water, oxygen, food, and protection. They live in
slow/non-flowing areas of the river where the breathing tube can stay at the
surface of the water and where they can find algae to eat.
Bullfrog Adult
 Basic Need—Adaptation—Purpose of Adaptation
o Water—very small holes in skin (needs to stay moist)—absorbs water through
skin (does not drink water through mouth)
o Oxygen—very small holes in skin—absorbs oxygen through skin when in and
out of water, as long as the skin is moist
—lung—to breathe when out of the water
o Food—long sticky tongue—to help catch food (insects, etc.)
—Un-webbed front feet—to capture and hold food (prey)
—Strong muscular legs—to jump to catch food
o Protection—webbed back feet—to help swim away from predators (birds,
snapping turtle)
—strong muscular legs—to help get away from predators
—coloring of skin—to blend (camouflage) into habitat
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
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Additional Information
o Lives in marshes and ponds (near water)
o Even though frogs have lungs, frogs primarily (mostly) obtain their oxygen
through the skin.
o Very small holes in skin have two purposes: taking in water and taking in oxygen
from the water meaning that frogs need to stay wet to absorb the oxygen from the
water.
Habitat rationale
o Bullfrogs live in marshes and ponds because their basic needs (water, oxygen,
food, and protection) are met. They need to live where it is moist because they
can get their water and oxygen through holes in the skin. They live in areas that
have lots of plants to camouflage themselves. In addition, an important food—
mosquito wriggler—is found in marshes and ponds.
Whirligig beetle (adult)
 Basic Needs—Adaptation—Purpose of Adaptation
o Water—chewing mouthparts—drink very small sips of water or chew plants
which contain a lot of water
o Oxygen—trapped air bubble near leg—to use to breathe when underwater hunting
food or escaping predator
—very small air holes in skin
o Food—divided eyes—to see above and below water at the same time to capture
food
—paddle-like back legs—to move quickly on surface of water to catch food
—pointed front legs—to grip prey
o Protection—divided eyes—to see above and below the water at the same time to
escape predators
—paddle-like back legs—to move quickly on surface of water to escape
predators
—grouping behavior—to protect themselves from predators
 Additional Information
o Makes a nasty tasting liquid that keeps predators from eating it
o Lives in areas of river where flow is slower
o Eats mosquitoes and other insects
 Habitat Rationale
o The whirligig beetle lives on the surface of deep pools in the river because it
can find everything it needs to live. It has adaptations such as its divided eyes
to help it get its food and stay safe from predators. Deep pools have slow
flow which is a good habitat for beetles because they are not very big.
Largemouth Bass
 Basic Need—Adaptation—Purpose of adaptation
o Water— very small holes in skin—to absorb water (freshwater fish do not drink)
o Oxygen—gills—to breathe underwater (Water comes in through mouth with food
and goes out the gills; as water passes over gills the oxygen is removed.)
o Food—large mouth—to eat anything it can find
—fins—to swim well to catch food
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
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
o Protection—fins—to swim to get away from predators (birds, snapping turtle)
—scales—to protect body
Additional Information
o Lives in deep pools of clear water (well-oxygenated) in streams and rivers. This
large fish needs large space and also needs adequate oxygen.
o Eats anything it can find.
o Washes food (e.g. whirligig beetle story)
o Males make nest in shallow sandy/gravelly areas of river near weedy areas (for
young to hide.)
o Note: There are more observable adaptations that students may name: body
shape, coloring, muscular body, lateral line (senses vibrations). All either help get
food or protection.
Habitat Rationale
o Large mouth bass can find everything they need to survive in the deep river pools
of the river. They are big strong fish that need to live in the larger areas of the
river such as deep pools. These large fish will find many types of food there.
Aquatic Insect larvae—immature swimming insects
 Basic Needs—Adaptation—Purpose of Adaptation
o Caddisfly Larvae (average size 1/2” in length)
 Water—very small holes in skin—to absorb water
 Oxygen—very small holes in skin—to absorb oxygen to breathe
—gills on underside (hair-like)—to breathe in water
 Food—some build nets to trap food—to eat
 Protection—streamlined body—to fit under rocks in small spaces
—cases attached to undersides of rocks—larvae build to
help hold them in place in fast flowing water
—proleg at back end of body—to hold body in case
 Additional Information
 Omnivore—eats algae, plants and small animals that flow by
 Prefers fast water habitat where the amount of oxygen is high
 Important food for fish
 Larvae live 1 year in water before metamorphosis into flying
adult
o Mayfly Nymph (1/4-1/2 inch long)
 Water—very small holes in skin—to absorb water
 Oxygen—very small holes in skin—to absorb oxygen to breathe
—gills on abdomen—to breathe in
water
 Food—different types of mouthparts—filter food, scrape food or
catch food—to eat
 Protection—claw-like legs—to grip rock to stay put in fast-flowing
water
—flat body—to be able to crawl under rocks to be
protected from being washed downriver by fast-flowing
water
© 2007 Mill River Wetland Committee, Inc.
RL3 Guide Manual
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
Additional Information
 Eats algae and decaying plant and animal material
 Prefers fast water habitat where the amount of oxygen is high
 Significant source of food for fish
 Some larvae live 1-3 years in water before metamorphosis into
flying adult
 Adult lives up to a day.
Habitat rationale
o These insect larvae live here because all their basic needs are met such as the
availability of the food they need to eat—algae and debris—and their structural
adaptations (flat body and claws) enable them to stay in the fast flowing water.
Brook Trout
 Basic Needs—Adaptation—Purpose of Adaptation
o Water—very small holes in skin—to absorb water (freshwater fish do not drink)
o Oxygen—gills—to breathe under water (Water comes in through mouth with food
and goes out the gills; as water passes over gills the oxygen is removed.)
o Food—large mouth—to eat anything it can (insect larvae, small fish, etc.)
o Protection—fins—to swim away from predators
 Additional Information
o Live where these areas are close together:
 resting areas—pools
 feeding sites—riffles, and
 protection areas—undercut banks and areas where plants hang out
over the water
o Younger fish eat insect larvae
o Larger fish eat insect larvae, small fish or even salamanders
 Habitat rationale
o Trout live in this area because this habitat meets all their basic needs. The
riffles have food, the nearby pools are resting areas, and they can find
protection near the overhanging bushes or the undercut bank.
© 2007 Mill River Wetland Committee, Inc.