MS-LS-2 Bald Eagle Diet

Created Feb. 7, 2024 by Jodie Jantz

SEA OTTER POPULATIONS AND BALD EAGLE DIETS MODEL-BASED INQUIRY UNIT

This template is meant to scaffold the design and implementation of MBI units. We take as a starting place three-dimensional instruction as described in the NGSS, the elements of Ambitious Science Teaching, the importance of anchoring instruction in real-world phenomena, and the perspective that students’ ideas are invaluable resources for instruction. These ideas provide the foundation for MBI units during which students collaboratively engage in the practices of science as they construct scientific explanations of an anchoring phenomenon. The template is divided into four stages and includes an assessment section at the end. Throughout the template, useful resources and examples are provided. Additional information and resources are available at www.modelbasedinquiry.com.

Unit Authors:

Allison Davidson, Ron Gray

This first stage of MBI focuses on doing the intellectually rigorous work of unpacking standards, identifying an anchoring phenomenon and driving question, and pinpointing the important science ideas students will need to build a scientific explanation of the phenomenon. In addition, in this stage we plan "with the end in mind" by constructing draft models and causal explanations that we can use as learning targets throughout the unit.

Science Area Focus (e.g., Middle School Life Science, High School Chemistry):

Middle School Life Science

What do you want to teach?

Disciplinary Core Idea(s) focus of Lesson: (Identify DCI at the bullet point(s) grade band progression)

LS2.A: Interdependent Relationships in Ecosystems

● Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. (MS-LS2-1)

● In any ecosystem, organisms and populations with similar requirements for food, water, oxygen, or

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PLANNING FOR ENGAGEMENT WITH IMPORTANT SCIENCE IDEAS

other resources may compete with each other for limited resources, access to which consequently constrains their growth and reproduction. (MS-LS2-1)

● Growth of organisms and population increases are limited by access to resources. (MS-LS2-1)

● Similarly, predatory interactions may reduce the number of organisms or eliminate whole populations of organisms. Mutually beneficial interactions, in contrast, may become so interdependent that each organism requires the other for survival. Although the species involved in these competitive, predatory, and mutually beneficial interactions vary across ecosystems, the patterns of interactions of organisms with their environments, both living and nonliving, are shared. (MS-LS2-2)

Why is the DCI above a core idea(s) in science? Identify the DCI in Framework for K-12 Science Education using the following links:

Physical Science: https://www.nap.edu/read/13165/chapter/9 Life Science: https://www.nap.edu/read/13165/chapter/10 Earth and Space Science: https://www.nap.edu/read/13165/chapter/11 Engineering, Technology, & Applications of Science: https://www.nap.edu/read/13165/chapter/12 An additional resource is Disciplinary Core Ideas: Reshaping Teaching and Learning from NSTA Press.

What does the Framework say about the core idea(s)?

LS2.A - The Framework poses the question: “How do organisms interact with the living and nonliving environments to obtain matter and energy?” Students have a difficult time understanding that energy is measurable and quantifiable. Through learning about the food web, students will gain a deeper perspective of how matter and energy are transferred between the biotic and abiotic factors of the environment. Students will also recognize that the biotic interactions between organisms have a significant influence on their growth, survival, and reproduction, both individually and in terms of their populations.

What are the Performance Expectations that you are working toward?

Performance Expectation(s): (Search by DCI)

MS-LS2-1: Analyze and interpret data to provide evidence for the effects of resources availability on organisms and populations of organisms in an ecosystem.

MS-LS2-2: Construct an explanation that predicts patterns of interactions among organisms across multiple ecosystems.

Summary: After reading through the specific DCIs focusing your unit, write a summary in your own words that describes why this is a/these are core idea(s) in science, along with the facets of the core idea(s) that are most important for students to understand:

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ANCHORING PHENOMENON

Identify a scientifically rich, complex phenomena that will require students to use multiple principles that are central to the DCI(s) and the big idea to explain (an occurrence or event that happens(ed) in the world). [This will serve as the reason for engaging in the unit.] Resources for learning about phenomena as well as example anchoring phenomenon.

Describe the Anchoring Phenomenon chosen to anchor the unit in approximately one paragraph:

In the Aleutian Island coastal regions of Alaska, sea otter populations declined drastically throughout the 1990s. The exact reason is unknown but is likely attributed to increased orca predation from large amounts of whaling by humans. As the carnivorous otter populations declined, kelp forests in the Aleutian Island region also began to disappear at alarming rates. Additionally, the bald eagle diet in the same region was drastically changed throughout this period; the bald eagle primarily fed on marine fish but changed its diet to consist of other seabirds. Lastly, the bald eagle populations produced more eggs and young throughout this time period as well.

List resources (websites, articles, books, etc.) that help you better understand the anchoring phenomenon:

● A Comparison of the Bering Sea, Gulf of Alaska, and Aleutian Islands Large Marine Ecosystems Through Food Web Modeling (NOAA)

● Distribution and Status of the Bald Eagles in the Aleutian Islands (Research Gate)

● Mystery: Why is the Aleutian Ecosystem Collapsing? (Center for Biological Diversity)

● Indirect Food Web Interactions: Sea Otters and Kelp Forest Fishes in the Aleutian Archipelago (NCBI)

● Commercial Fishing Overview (Alaska Fish and Game)

Identify the Crosscutting Concept(s) that can also be used to orient to the anchoring phenomenon in ways that can focus and support the development of the mechanistic explanation of the phenomenon (explain this connection). [The performance expectations identified above should be used as a guide]

Summary: (Guidance and Example of Unpacking)

Organisms interact with the living and nonliving features within their environment which creates a cause and effect relationship among populations in the ecosystem. Individual survival and population sizes depend on factors, such as predation, availability of resources, and parameters of the physical environment (light, temperature, space for shelter and reproduction). Additionally, organism interaction serves the purpose to obtain matter and energy. Organisms obtain energy through photosynthesis or consuming other organisms in a complex set of relationships within a particular food web. These complex food webs serve as a basis for understanding the dynamic interdependence among organisms and the physical environment.

Based on the core ideas identified above, what is the Big Idea of the unit?

Big idea:

● Disturbances to the environment affect the relationship between the living and nonliving in a given ecosystem.

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Crosscutting Concepts:

Patterns: Patterns can be used to identify cause and effect relationships. (MS-LS2-2)

Sea otters are a keystone species and a secondary consumer for the Aleutian Islands ecosystem. The removal of the sea otters will have both direct and indirect effects on the entire ecosystem, even if the relationship appears to be largely disconnected.

Cause and Effect: Cause and effect relationships may be used to predict phenomena in natural or designed systems. (MS-LS2-1)

When the sea otter population declined, so did the kelp population. Since the bald eagle’s main food source lived within the kelp community, they had to change their feeding patterns in order to sustain life.

Develop a Driving Question that will help bound the work of the unit and frame the anchoring phenomenon for the students. The question should be causal and not easily answered. Causal questions usually begin with ‘why’. It is also important to make this question specific to your anchoring phenomenon by referencing the phenomenon in the question. Consider using a Crosscutting Concept to Orient Students to the Anchoring Phenomenon in your Driving Question. (e.g., Patterns/Cause and Effect)

Driving question:

Why did the diet of the bald eagle change as a result of the declining sea otter populations in the Aleutian Islands in the 1990s?

Provide a target written explanation of phenomenon. Be sure to consider the role of the crosscutting concept(s) you identified above as part of the explanation. This should be written slightly above that of an A student in your class and at the appropriate grade level. (Note: the explanation should identify how science ideas are coordinated to explain the occurrence or event that happened in the world) (Resources for understanding and constructing explanations):

Target explanation of phenomena:

Sea otters are a secondary consumer that prey upon sea urchins, which in turn feed on the kelp forests of the region, which serve as both a producer and a habitat for a large number of marine species, particularly an abundance of fish species. The kelp forests, in addition to providing energy to the entire ecosystem through photosynthesis, are a feeding ground for the bald eagle, an apex predator that lives in the nearby coastal regions of the ecosystem. Historically, bald eagle diets were primarily made up of marine fish that lived in the kelp forests, with the occasional seabird or sea otter pup.

Once the keystone species of the ecosystem, the sea otters, began declining, a chain reaction of consequences was set in motion. The decline in sea otters resulted in sea urchin populations exploding because there were fewer predators to control their numbers. The exploding sea urchin populations almost entirely decimated the kelp forests, through increased consumption with the larger number of urchins. With this reduction in kelp forests, there was less energy available for the marine ecosystem. There were also far fewer species living there because the kelp forests had provided both food and shelter for many organisms. This ultimately resulted in far fewer marine species available for the bald eagles to prey upon.

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Bald eagles, however, are opportunistic feeders and have extreme flexibility in what they can eat, depending on the food sources available. This adaptation makes the bald eagle a particularly resilient species even when faced with extreme alterations to its habitat and ecosystem. With a reduction in their primary food source, the eagles turned to another available source of energy: seabirds nesting in the cliffside regions of the Aleutian Islands. The unexpected consequence of this shift in diet was that the number of eagles and the birth rate of eagles increased, even though one food source of the eagle, the sea otter population, declined. This unexpected outcome can be explained by examining the nutritional content of the eagles diet; the seabirds are more calorically dense than the prior diet of fish that the eagles were consuming, providing more energy to the eagle population as a whole, and allowing them to more successfully reproduce.

Construct an example final model that you would expect your students to develop over the course of the unit. Be sure to include the system boundaries, components of the system, connections between those components, the “unseen” mechanisms at work, and labels. This will help you develop a template and/or conventions for the students’ models. Be sure to consider the alignment between your target explanation (above) and your final model. Resources for understanding scientific models.

Example Final Model [Example]: (insert drawing or image here)

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From your target explanation and example final model, identify ideas in science within the explanation that are central to students explaining the phenomenon [this can serve as an early ‘Gotta Have List’ that you go into the lesson considering, while also serving as a guide for identifying science activities students can engage in as part of the unit after initial modeling to work on developing more sophisticated explanations of the phenomenon] (Example):

Science Idea A: Keystone species

Science Idea B: Food chains and food webs

Science Idea C: Predator/prey interactions

Science Idea D: Feeding strategies

Science Idea E: Energy and trophic levels

For each science idea identified above, choose one activity, reading, video, simulation, or investigation that will help students understand this important idea and begin to see its usefulness in explaining the anchoring phenomenon. Do this for each science idea below: [possible resources: Phet Simulations, NGSS Pathfinder, National Science Digital Library, Argument Driven Inquiry]

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Science Idea A: Keystone species Keystone species reading passage Otters keystone species video (Monterey Bay)

Science Idea B: Food chains and food webs Food chains and food webs modeling with string activity Food Chain Gizmo

Science Idea C: Predator/prey interactions Food Chain Gizmo

Science Idea D: Feeding strategies Aleutian Island animal research

Science Idea E: Energy and trophic levels Energy and trophic levels lab

Identify the disciplinary core idea progressions for each of your DCIs. These will serve as resources for helping you draw on past learning to connect to current learning and help you understand how this learning will be useful for students in future learning. In other words, what does the progression say about your DCI in the grade bands just before and after yours?

Previous grade band By the end of grade 5. The food of almost any kind of animal can be traced back to plants. Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants. Some organisms, such as fungi and bacteria, break down dead organisms and therefore operate as “decomposers.” Decomposition eventually restores some materials back to the soil. Organisms can survive only in the environments in which their particular needs are met. A healthy ecosystem is one in which multiple species of different types are each able to meet their needs in a relatively stable web of life. Newly introduced species can damage the balance of an ecosystem.

Target grade band By the end of grade 8. Organisms and populations of organisms are dependent on their environmental interactions both with other living things and with nonliving factors. Growth of organisms and population increases are limited by access to resources. In any ecosystem, organisms and populations with similar requirements for food, water, oxygen, or other resources may compete with each other for limited resources, access to which consequently constrains their growth and reproduction. Similarly, interactions may reduce the number of organisms or eliminate whole populations of organisms. Mutually beneficial interactions, in contrast, may become so interdependent that each organism requires the other for survival. Although the species involved in these competitive, predatory, and mutually beneficial interactions vary across ecosystems, the patterns of interactions of organisms with their environments, both living and nonliving, are shared.

Next grade band By the end of grade 12. Ecosystems have carrying capacities, which are limits to the numbers of organisms and populations they can support. These limits result from such factors as the availability of living and nonliving resources and from such challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance of species in any given ecosystem.

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The second stage of MBI is the first enacted in the classroom with students. It involves introducing the anchoring phenomenon and driving question, eliciting students' initial ideas and experiences that may help them develop initial explanations of the phenomenon, and the construction of initial models of the phenomenon based on those current ideas. In designing units, this phase usually takes up the first day of the unit.

The Talk Science Goals and Talk Moves is a resource for responsiveness to student thinking throughout the unit. Additional resources are the Talk Science Primer and the Ambitious Science Teaching Discourse-Primer.

Day 1: Outline how you plan to engage students in beginning to coordinate their initial ideas into a scientific explanation of the anchoring phenomenon. How will you introduce the phenomenon and driving question? What is your plan for eliciting student initial ideas about the phenomenon? How will student groups begin to construct models (e.g., group sizes, directions to students including some introduction to what a model is, etc.). Be sure to include where and how you will use public records to help focus students reasoning during this process. Include any videos, templates, web resources, etc. you might want to use. Describe how students will share their initial models with peers in small group and whole group discussions. Utilize the Ambitious Science Teaching practices tool and primer (Example Day 1). Also consider our Openers and Closers Resource for supporting the design of daily lessons.

Outline Day 1:

● Introduce Phenomenon:

○ Begin slideshow presentation with many pictures

○ Introduce small-scale data set

○ Warm-up questions:

■ What information or experiences do you already have with the sea otter and bald eagle?

■ What may have caused the sea otter populations to decline?

○ Summarize phenomenon.

○ Introduce driving question: Why did the diet of the bald eagle change as a result of the

declining sea otter populations in the Aleutian Islands in the 1990s?

■ Have it written on a poster paper to display for the remainder of the unit.

● Eliciting Initial Hypotheses:

○ In small groups, ask students to come up with an initial hypothesis (written in complete

sentences) to answer the driving question.

○ Facilitate share out of hypotheses are write group’s hypotheses on ‘Initial Hypotheses’ public

record.

● Initial Models:

○ Give students guidelines about what a model is and how to make a model.

■ Draw relationships with arrows and labels.

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ELICITING STUDENTS’ IDEAS (TO ADAPT INSTRUCTION)

The goal of the next stage is to support the students' on-going changes in thinking by providing learning experiences that help coordinate their ideas and powerful ideas in science to build a scientific explanation of the anchoring phenomenon. This involves designing or adapting a number of purposeful tasks, coordinated with the important science ideas identified earlier, and the construction and use of public records such as a Summary Table to help keep track of ideas. Important in this stage is the revision and testing of the students' models. This stage makes up the majority of the unit as the class works to develop their explanations of the phenomenon through engagement in the practices of science.

Day 2-x: (Include time needed for each activity) [use more or less days as needed for engaging students in science activities depending on what might be needed to explain the anchoring phenomenon]

Identify how you will ‘put on the table’ science ideas you identified above that are central to explaining the anchoring phenomenon using science activities you identified for each idea above (e.g., activity, reading, video, simulation, investigation) that prioritizes students engaging in science and engineering practices to develop an understanding of the principle that will be helpful in later stages of the unit in explaining the anchoring phenomenon. Describe how you will use Summary Tables (examples) or activities across these activities to help students keep a record of activities, ideas, and evidences that will be used to later in the unit to revise their initial models of the anchoring phenomenon. You may want to include a model revision halfway through the activities. Utilize the Ambitious Science Teaching practices tool and primer. (Example Days 2-5). Also consider our Openers and Closers Resource for supporting the design of daily lessons.

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SUPPORTING ON-GOING CHANGES IN THINKING (WITH THE AIM OF

USING SCIENCE IDEAS BEHIND ACTIVITIES TO MAKE SENSE OF

ANCHORING PHENOMENON)

■ Represent ‘unseen’ processes through magnified snapshots.

○ Work in groups to construct their first model that answers the driving question using their initial hypothesis.

○ Facilitate share out session - ask each group to quickly show their model and share in 2-3 sentences what they chose to include. Comment on interesting ideas and patterns between

models.

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Outline Day 2-8:

Day 2: Aleutian Island animal research

● Class is introduced to the idea of different feeding strategies of different animals

● In small groups, students will select one animal from the Aleutian Island ecosystem and will conduct research on that organism’s diet, feeding strategies, growth, reproduction, and habit.

● Each group will create a poster representing what they learned.

● The class will do a gallery walk/jigsaw to share out information they learned about each of the important animals in the ecosystem.

● Introduce summary table: Each group works on 1-2 sentence responses to the summary table columns. Facilitate a share out of responses and write consensus statements in each box.

Day 3: Food chains and food webs activity

● Class is introduced to the idea of food chains and food webs.

● Class will begin with a review of biotic and abiotic factors in ecosystems with a card matching game.

● Students will model both food chains and food webs by each student taking the role of an organism or sunlight in the ecosystem and will pass the ball of string from student to student.

○ Students will identify patterns about food chains and food webs.

● Students will create a food web based on the Aleutian Island ecosystem involving the otters, eagles, urchins, and kelp.

● Summary table: Each group works on 1-2 sentence responses to the summary table columns. Facilitate a share out of responses and write consensus statements in each box.

Day 4: Food chain gizmo investigation activity

● Class will be introduced to the idea of predator/prey interactions.

● Students will design and conduct an investigation into how predator or prey populations affect on another within an ecosystem.

● Students will draw conclusions about the relationships between populations in an ecosystem based on the results of their investigation.

● Summary table: Each group works on 1-2 sentence responses to the summary table columns. Facilitate a share out of responses and write consensus statements in each box.

Day 5: Model revisions

● Review the summary table so far and talk about what evidence the activities have given us, and how it answers aspects of our driving question. Review the purpose of model revision and the conventions they could use.

● Groups discuss how they want to illustrate the concepts learned in the activities and revise their models. Then each group shares their model and the class will ask questions like “what is the evidence for including _____ on your model”, “Where did you draw _____ evidence on your model”, “How does _____ element answer our driving question?”, “Why did you include ____, and what does it tell us about ____ science concept?”

● Summary table: Each group works on 1-2 sentence responses to the summary table columns. Facilitate a share out of responses and write consensus statements in each box.

Day 6: Keystone species video and reading discussion

● Class is introduced to the idea of a keystone species.

● Small groups will conduct a guided reading and discussion of an article about keystone species.

○ Teacher monitors and helps facilitate discussions.

● Class will watch a short video clip that introduces otters as a keystone species in Monterey Bay.

● Summary table: Each group works on 1-2 sentence responses to the summary table columns. Facilitate a share out of responses and write consensus statements in each box.

Day 7-8: Energy and trophic levels lab

● Class is introduced to the relationship between energy and trophic levels.

● Students will design and conduct an investigation to explore the amount of energy is available at different trophic levels in an ecosystem using a predetermined set of materials.

● Summary table: Each group works on 1-2 sentence responses to the summary table columns. Facilitate a share out of responses and write consensus statements in each box.

Construct a draft summary table that includes each activity, the intended understandings from the activity, and how the activity helps develop an explanation for the anchoring phenomenon. See examples and modified templates here. Adapt the table based on the number of activities in the unit. While the goal is for students to come to consensus statements to be included on the table, having already planned for what

Activity What we learned How it helps us explain the phenomenon

Aleutian Island Animal Research

Opportunistic feeders can eat a variety of food sources depending on what is available. Apex predators are predators at the top of the food chain with no natural predators.

Eagles are opportunistic feeders, so they are able to flexibly change their diet from fish to seabirds. Eagles and otters are both apex predators in the ecosystem. Kelp serves as both a producer and habitat for the ecosystem.

Food Chains and Food Webs Modelling Game

A food chain consists of a producer and a single line of consumers. A food web is more complex and shows the feeding relationships between many different producers and consumers. Food chains and food webs show the transfer of energy from the Sun into ecosystems. A change for one member of a food chain/web can affect all other members.

Aleutian Island ecosystem food web links all of the organisms involved in the phenomenon: otters, urchins, fish, kelp, seabirds, eagles. The kelp forests are the link between the otters and eagles; otters feed on urchins which feed on the kelp, which is where the fish live and the eagles feed on those fish.

Food Chain Gizmo Investigation

When a predator population increases, the prey population will decrease because more of them are being eaten. When a predator population decreases, the prey population will increase because they are reproducing faster than they are dying off. A change in one population affects the entire food chain.

When the otter population decreased, it caused the urchin population to increase because they were not being eaten as much. This caused the kelp forest to decline because the larger urchin population was eating more. The decline in kelp caused a decline in the fish, which was the eagle’s main food source.

Keystone Species Video and Reading

A keystone species is a very important species in an ecosystem. Many other species rely on the keystone species. When a keystone species is threatened, it can affect both the biotic and abiotic systems in an ecosystem.

Otters are a keystone species in the Aleutian Island ecosystem. When the otters are removed, it causes far-reaching consequences, like the eagles changing their diets.

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The Energy and

seabirds are at a higher trophic level, Trophic Levels

thus more nutritionally dense, than the Lab

marine fish the eagles used to consume. Due to the high trophic level of the seabirds, the eagles do not have to eat as many seabirds to get the same amount of energy from marine fish. This allowed the eagles’ birth rate to increase and populations to thrive.

Identify how students will test their models using primary or secondary data they collect themselves or are provided through outside resources. Be sure to list the sources of data if they are provided:

How will students test their models?

Students will make predictions about would happen to the ecosystem if the otter populations were restored to their original, pre-1990s condition. We will then read current studies on the populations of the region to determine how the populations have changed after the 1990s, and what conservation efforts are being made.

At the end of an MBI unit, we press the students for evidence-based explanations. This involves, at a minimum, finalizing the student models, building consensus through discussions, the construction of the Gotta-Have Checklist, and the writing of individual evidence-based explanations of the anchoring phenomenon. We most often consider either the final model or evidence-based explanations the summative assessment of the unit.

Final 2-3 Days: (Include 2-3 days at the end of the unit)

Part 1. In this part of the unit, students will engage in building or revising (with the teacher) the ‘Gotta Have List’ to be sure that it represents what they think should be included in the final models. Additionally, students should engage in refining their initial models by both referring to the finalized ‘Gotta Have List’ and ‘Summary Table’ that was developed across the unit. You might also consider having groups of students comment on other groups’ initial models with ‘Sticky Notes’ prior to students making final revisions to their group models (see ‘Sticky Notes [examples]’. Once students are ready to revise their models based on what they learned across the unit. Be sure to identify how you will ensure that they use the Gotta Have Lists and Summary Tables as resources for supporting their final revisions. Utilize the Ambitious Science Teaching practices tool and primer. (Example Days 6-7). Also consider our Openers and Closers Resource for supporting the design of daily lessons.

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PRESSING FOR EVIDENCE-BASED EXPLANATIONS

The higher the trophic level of a food chain, the less energy there is available. Organisms at higher trophic levels have to eat less individual prey animals less often, because there is more energy available in each organism.

Resource - Rubric EXAMPLE as possible resource for summative assessment of group consensus models or individual student evidence-based explanations. This rubric was developed by using the science ideas identified above that were important for explaining the anchoring phenomenon and using these as indicators for the rows. The levels of each indicator is then assessed by considering the extent to which students or groups models or explanations are useful in explaining the anchoring phenomenon using the science idea of each row.

Identify formative assessment techniques you will employ throughout the unit. Please provide specific examples.

What formative assessment techniques will you use?

Each lesson will begin with a warm-up question, which will serve as a review of previous material, or as a tool to elicit student ideas. There will be exit tickets used at the end of each lesson to assess whether students have met the goals for that lesson.

Also, teacher notes and observations throughout small group discussions will also serve as a type of ongoing formative assessment.

Provide a final evidence-based explanation at a level you would expect from your students at the end of the unit. The evidence-based explanation builds on the target explanation by including specific evidence from the activities.

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Outline Day 9-10:

Day 9: Final Models

● Students will work in groups to revise their models for the last time. [Teacher note: Consider using the Selecting, Sequencing, and Connecting Primer to plan for facilitating productive whole class discussion]

● Facilitate a share out session to compare and contrast the groups’ models to help build consensus around the scientific explanation. Day 10: Final Evidence-Based Explanations

● Facilitate the construction of a “gotta-have-it checklist”. These are consensus ideas about what must be included in their final evidence-based explanation.

● Using a different color, coordinate the checklist items with the evidence we have to support that claim.

● Individual students will begin writing their final evidence-based explanation. Students will be given sentence stems to help guide their thinking and to make sure they are using evidence if needed.

○ For example: “I learned ______ because in class we did ______ which showed that _____.”

● Students will have all of the public records to reference and will have the remainder of class period to write their explanation.

○ If they don’t finish it becomes homework.

ASSESSMENT OF STUDENT LEARNING

Final Evidence-Based Explanation:

Sea otters are a keystone species for the Aleutian Islands ecosystem, which includes a variety of marine and terrestrial species, such as kelp forests, marine fish, orcas, bald eagles, and various seabird species. A keystone species is one that many other species depend upon, such that the removal of the keystone species will have far-reaching direct and indirect effects on the entire ecosystem. In the article we read during our food chains/webs modelling activity, the wolves of Yellowstone were a keystone species which, when removed, affected the other living things in the ecosystem as well as the physical and environmental aspects. The video clip we watched during out keystone species and reading activity, showed us that otters were a keystone species in Monterey Bay, California, so otters are also a keystone species in the Aleutian Islands. Since otters are a keystone species, this can help explain the connection between otters and bald eagles even though they are two largely disconnected predators, one lives in the sea and the other on land, respectively.

Bald eagles, however, are opportunistic feeders and have extreme flexibility in what they can eat, depending on the food sources available. This adaptation makes the bald eagle a particularly resilient species even when faced with extreme alterations to its habitat and ecosystem. We know this because of the research we conducted concerning the Aleutian Island animals from the Alaska Fish and Game website. With a reduction in their primary food source, the eagles turned to another available source of energy: seabirds nesting in the cliffside regions of the Aleutian Islands. The unexpected consequence of this shift in diet was that the number of eagles and the birth rate of eagles increased, even though one food source of the eagle, the sea otter population, declined. This unexpected outcome can be explained by examining the nutritional content of the eagles diet; the seabirds are more calorically dense than the prior diet of fish that the eagles were consuming, providing more energy to the eagle population as a whole, and allowing them to more successfully reproduce. This aspect of the phenomena can be explained by examining the idea of energy and trophic levels, which we observed in our energy and trophic levels lab.

Provide a rubric for the evidence-based explanation. See here for an example.

Rubric:

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MS-LS-2 Bald Eagle Diet

Standards

Nebraska's College and Career Ready Standards for Science

Nebraska's College and Career Ready Standards for Science

Nebraska's College and Career Ready Standards for Science