How Is a Cactus Like a Hotel?

How Is a Cactus Like a Hotel?
In this investigation, we will be looking at a special habitat – the
saguaro cactus – and how it is like a “hotel.” We will be asking
the questions: Is the cactus like an oak tree or maple tree that
lives near us? How are they the same? How are they different?
What lives in the cactus? What lives underground? How do
plants and animals survive in the desert?
In your drawing, show the structure of the saguaro cactus and
at least four different examples of wildlife that depend on the
cactus. Remember to show what goes on under the ground,
too!
How Is a Cactus Like a Hotel?
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How Is a Cactus Like a Hotel?
Suggested Grade Span
K–2
Task
In this investigation, we will be looking at a special habitat – the saguaro cactus – and how it is
like a “hotel.” We will be asking the questions: Is the cactus like an oak tree or maple tree that
lives near us? How are they the same? How are they different? What lives in the cactus? What
lives underground? How do plants and animals survive in the desert?
In your drawing, show the structure of the saguaro cactus and at least four different examples
of wildlife that depend on the cactus. Remember to show what goes on under the ground, too!
Big Ideas and Unifying Concepts
Evolution and equilibrium
Interdependence
Life Science Concepts
Evolution, diversity and adaptations
Structure and function
Physical Science Concept
Properties of matter
Mathematics Concepts
Comparison of attributes or effects
Data collection, organization and analysis
Diagrams
Graphs, tables and representations
Measurement
Time Required for the Task
Approximately 45 minutes.
How Is a Cactus Like a Hotel?
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Context
Last spring, my first graders compared desert habitats in the United States with local Vermont
wetland habitats. This inquiry provided an opportunity for students to make comparisons and
connections to an earlier investigation involving diverse African habitats. This helped the
children better understand the interdependence between survival adaptations and the
characteristics of wildlife and plants in each unique habitat. This particular habitat investigation
involved an in-depth look at the function of the saguaro cactus and underground survival in the
deserts of the United States. The “hotel” function of a saguaro cactus was also connected to
how it compared with the “hotel” function of a full-grown oak or maple tree in Vermont. The
question was asked of the class: How is a tree or a cactus like a hotel for a variety of wildlife?
What the Task Accomplishes
This drawing task demonstrates how children applied their skills in gathering a variety of
information about deserts from nature videos, nonfiction and fiction books, magazines,
observations of real cacti, and water investigations with sand and wetland soil. Through all of
these activities, the children learn to recognize how the adaptable desert cactus sustains an
amazing community of plant eaters, predators, scavengers and decomposers. This integrated
study of wildlife adaptations included daytime and nighttime habits.
During the desert unit, the first graders compared the effects of time and the use of the saguaro
by a variety of wildlife. The saguaro cactus takes almost 50 years to grow to be just 10 feet tall,
with no extending arms, before it starts becoming a hotel for a variety of wildlife. This amazing
cactus has a life span of 150 to 200 years! The students explored the differences and
similarities of wildlife needs in the daytime and nighttime. The wildlife included pack rats,
spotted ground squirrels, jackrabbits, bats, bees, Gila monsters, woodpeckers, elf owls, white
winged doves, ants, etc.
How the Student Will Investigate
I like to begin this investigation by reading Cactus Hotel, by Brenda Guiberson, a beautifully
illustrated book about desert wildlife and the life span of the saguaro cactus. This hooks the
children on this science unit and raises their curiosity. The structure and function of the parts of
the cactus were modeled, explored and questioned by the first graders as different types of
cactus were cut apart by an adult for comparisons. Different water and soil investigations were
done by the first graders to examine absorption qualities and rates. The structure of a cactus
was compared with maple trees around the school.
The students were then given a recording sheet that provided a large drawing space with a
border around it. They were asked to include at least four different examples of wildlife that
depended on the saguaro cactus, as well as a drawing of the structure of the cactus with its
spines. They needed to include underground survival in this desert scene and design a border
pattern that reflected a desert theme. The completed drawing needed to demonstrate a clear
understanding of the essential question: How is the cactus like a hotel for the wildlife that use it?
How Is a Cactus Like a Hotel?
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Interdisciplinary Links and Extensions
Science
Explore how soils other than sand absorb water and design investigations to compare them
with sand. Cut apart different types of cactus to look at the structure and natural protection
provided by these plants. Use a flashlight and a darkened room to examine how each spine on
the cactus provides a very small amount of shade for the cactus plant individually but
collectively help to protect the plant. Explore growth patterns with a very young cactus and a
familiar leaf plant (like a bean plant or marigold). (Note: Cacti grow very slowly, so you may
need to set up a long-term investigation in the classroom.) Graph light, water and growth
differences. Investigate how and why the wildlife is different and similar for predator/prey food
chains in the desert and in wetland habitats.
The Sun, the Wind and the Rain, by Lisa Westberg Peters; Puddles and Ponds, by Rose Wyler;
and Be a Friend to Trees, by Patricia Lauber are good science resources for making
comparisons in this unit.
Social Studies
Compare how the needs of Native Americans would be similar or different in forests and in
desert ecosystems in the United States. Explore which materials, necessary to meet housing
and other needs, would be utilized in the desert. Contrast these to materials used by northern
forest inhabitants. Investigate how different cultures would travel differently in these regions.
Make some adobe bricks. Examine why food crops would differ in the desert environment and
the northeast forest. Use Keepers of the Earth, by Michael J. Caduto and Joseph Bruchac, for
Native American extensions.
Language Arts
Use Ezra Jack Keat’s book Over in the Meadow, and the song version, to write new classroom
lyrics or a class book for desert plants and wildlife. Author Byrd Baylor and illustrator Peter
Parnall have produced excellent Native American books, such as The Desert Is Theirs, which
connects cultural and scientific information with poetic style and art techniques. Another
resource that shows teachers how to integrate information about the four North American
deserts is in Copycat, May/June 1999.
Mathematics/Technology
Have the children graph and compare rainfall data for deserts, wetlands, northeast forests and
tropical rain forests. (Use the Internet to gather this information.) Use measuring tools to
calculate the amount of water that drains through different soils in the classroom. Use oneminute and three-minute sand timers to compare everyday tasks that can be done in the
classroom or at home. Use a one-minute sand timer and containers to compare the amount of
water used to brush your teeth or wash your hands when the water is left running. Corn is
grown by many cultures in hot, dry regions of the world. Use real corn seeds to solve problems
by asking for equal amounts in rows when provided with 12 seeds. Investigate, by setting up a
fair test, how much water is needed to grow the seeds in different soils, or in sandy soil with
different amounts of water. Discuss the role of irrigation, and design your own system for
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carrying water through straws. Information learned about the four deserts in North America
(Great Basin, Mojave, Sonoran and Chihuahuan) can be compared using Venn diagrams.
Music/Movement/Art
There are Native American songs and dances that celebrate the importance of the sun for
growing crops, like "The Way to Start Your Day. Sun Song", by Jean Marzollo, and Welcome to
the Sea of Sand, by Jane Yolen, are beautiful picture books with illustrations that can be used
for art extensions. Guided imagery could be integrated to illustrate how a particular animal, bird,
insect or reptile adapts to the changes in temperature in the cycle of a day or night in the
desert. Children could work in cooperative groups to make collages of the ways wildlife, plants
and people need sun and heat. Illustrate writings with sand paintings.
Teaching Tips and Guiding Questions
When students engage in explorations they often need ideas to guide the inquiry process.
Open-ended and reaching questions ensure that students build understanding while they
manipulate materials, record data and communicate with their peers.
Questions that might guide their thinking during this lesson include:
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What does a hotel provide for people? How is this like a tree or cactus for wildlife?
What needs does a tree have for survival?
How does a woodpecker or barred owl use a maple or oak tree for survival or protection?
How does the woodpecker or elf owl depend on the saguaro cactus?
What needs do cacti have for survival?
How does a mammal use the saguaro cactus? How is that similar to or different from how
a mammal uses trees in forests?
How are the needs similar or different for wildlife during the nighttime and the daytime
concerning the saguaro cactus?
How is the outer protection on a cactus similar to or different from that of a maple or oak
tree?
How does an animal, bird, reptile or insect find water in the forest?
How do trees and cacti absorb water?
How would you show the runoff rate or absorption capacity of sand vs. soil from a forest
floor?
What role does shade play in the desert or in the forest?
After introducing the term symbiotic relationship, ask students to identify how different
plants and animals help each other to survive in symbiotic relationships.
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Concepts to be Assessed
(Unifying concepts/big ideas and science concepts to be assessed using the Science
Exemplars Rubric under the criterion: Science Concepts and Related Content)
Life Science – Structure and Function: Students identify the characteristics of organisms,
categorizing them as plant eaters, meat eaters, scavengers and decomposers.
Life Science – Evolution, Diversity and Adaptations: Students identify and describe
interdependence in food chains.
Physical Science – Properties of Matter: Students observe and compare the physical
properties of matter.
Mathematics: Students compare attributes or effects and use precise measurements and
diagrams. Students collect, organize and analyze data and use graphs, tables and
representations appropriately.
Skills to be Developed
(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:
Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)
Scientific Method: Observing, predicting, hypothesizing, collecting and recording data,
manipulation of tools, drawing conclusions, communicating findings, challenging
misconceptions and raising new questions.
Other Science Standards and Concepts Addressed
Scientific Theory: Students look for evidence that explains why things happen and modify
explanations when new observations are made.
Life Science – Structure and Function: Students describe and group animals by what they eat
and where they live. Students understand that living things are found almost everywhere in the
world and are interdependent. Students identify and explain how plants play an important role in
ecosystems.
Physical Science – Properties of Matter: Students describe and sort objects and materials
according to observations of similarities and differences of physical properties.
Earth and Space Science – Earth Structure and System; Earth’s History: Students describe
and identify characteristics and forces that shaped deserts and northern forests.
History/Social Science: Students describe and identify the interrelationships of Native
Americans in the ecosystems of desert and northeastern forests.
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Mathematics: Students demonstrate number sense, count and group numbers. Students use
graphs to identify trends and patterns. Numerical data and precise measurements are used in
describing events, answering questions, providing evidence for scientific explanations and
challenging misconceptions.
Suggested Materials
It is helpful for children to see and take apart a variety of cactus plants and then compare them
with the structures and function of neighborhood shade trees. Provide videos of desert and
northern forest ecosystems. Reading Rainbow has a video of the life cycle of the saguaro
cactus. Read books by Vermont author and naturalist Jim Arnosky, such as Raccoons in the
Corn, Deer at the Brook and Come Out Muskrats.
For this assessment activity, students need only a recording sheet and drawing materials. They
will also benefit from having visual materials available to them in the room.
Materials for additional soil investigations might include sand, water, forest soil, coffee filters,
one or three-minute sand timers, 6-oz. clear plastic cups to hold the filters over when collecting
the water for measurements, uni-fix cubes or 1/2-inch marked rulers. Plastic tubs for the
cooperative groups to put their investigations into will limit spills on desks.
Possible Solutions
In the drawings of the Cactus Hotel, you are looking for appropriate details of the size, structure
and spines of the saguaro cactus. There should be at least four different examples of
appropriate wildlife that are using the cactus. The placement of the flowers on the cactus would
indicate an understanding of this plant’s life cycle. Each drawing should also show the use of
shade and underground tunnels near the cactus during the heat of the desert day for survival
(e.g., mammals, reptiles).
The border was an extension of the desert habitat theme, and the use of patterns integrated
and reinforced mathematical concepts. It should show a clear pattern, such as “a-b,” with
pictures used.
Task-Specific Assessment Notes
Novice
The student’s drawing does represent examples of different wildlife that use the saguaro
cactus. The owl, woodpecker, snake and scorpion are appropriate examples to use for this
desert habitat scene, although all would not live in the saguaro. The bottom hole in the cactus is
unclear as to the inhabitant and does not detail an underground habitat. The desert border is
very elaborate but doesn’t follow the criteria of any kind of patterning. The drawing does
demonstrate some evidence of understanding the assessment task.
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Apprentice
The drawing shows more details on the saguaro cactus, with spines and blossoms. There are
three labeled examples of wildlife using the cactus, although the variety is not there. The
student did complete an appropriate border a-b pattern, which connected the mathematical
concept. There is a suggestion of an underground habitat at the base of the cactus, but it is
unclear. This student is beginning to understand the scientific concepts explored in this habitat.
Practitioner
The student’s drawing demonstrates a clear understanding of the scientific concepts learned
about the cactus habitat. There is more detail in the spines and placement of the arms on the
saguaro. The blossoms are appropriately placed on the cactus, and there are three examples of
different wildlife inhabiting the cactus. There is a higher level of scientific reasoning reflected in
the use of shade from the cactus, the tunnels dug by the desert fox, and the rabbit close to the
saguaro. There is also an ant colony and squirrel using the tunnels.The student effectively
identifies relationships of predator/prey, and the hotel concept, and also uses an a-b pattern on
the desert border.
Expert
The student’s solution is complete and detailed, as demonstrated by the use of spines, arms,
blossoms and numerous examples of wildlife inhabiting the saguaro cactus. The student selects
the dove, elf owl, insects, squirrel and a bird nest for the cactus, which demonstrates the hotel
concept. The student effectively portrays predator/prey interdependence (for example, the wild
pig is in the shade eating a fallen saguaro blossom, and two snakes are in the shade, perhaps
heading for the jackrabbit’s series of tunnels). There is an appropriate mathematical connection
with the use of an a-b pattern for the desert border. This student’s completed drawing provides
evidence of prior knowledge, extended thinking and scientific reasoning.
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Novice
How Is a Cactus Like a Hotel?
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Apprentice
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Practitioner
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Expert
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