This lesson will help students understand how penguin strategies for energy use, while capturing prey, are an example of population dynamics and energy balance within food webs. Students will use data from cameras attached to diving penguins to practice analyzing data using tools and technologies in order to make valid and reliable scientific claims.
Two 45-minute class periods
- Students will be able to analyze penguin camera data for evidence of prioritization of prey and the effect of dive depth on prey variety.
- Students will be able to communicate how penguins prioritize capturing anchovies to ensure their chicks have the energy required to reach maturity and maintain, or even increase, their population.
Prep for Teachers
- If possible, arrange to have computer access for students to work individually or in small groups.
- Download and print the Penguin Camera Analysis handout.
- If individual computer access is available, upload the Penguin Camera Data to Google classroom or another document sharing platform. If not, download and print the Penguin Camera Data Set.
- Begin the lesson by posing the question: What are some of the challenges penguins may face feeding their chicks?
- How do penguins capture food?
- How might a disruption in the penguin food web impact the chicks vs. the adult penguins?
- Then, as a class, watch the video from the resource Matter and Energy in Penguins’ Aquatic Ecosystem until minute 01:57, which features penguins undertaking long foraging trips to feed their chicks. Ask students the following questions:
- How do the scientists study the penguins?
- How has your understanding of how penguins capture food changed?
- Why is it important for the adult penguins to find food as soon as possible?
- Distribute the data set, Penguin Camera Data. Each sheet from the Penguin Camera Data Set concerns a single, individual penguin (each penguin was assigned the number on the bottom of its sheet) and documents a series of dives. Review the data presentation with the students. The dive duration is given in column A (yellow). The estimated depth of the dive is given in column B (blue). If prey was seen, the minute at which it was seen is given in column C and if the penguin chased or caught the prey, the minute at which it chased, is given in column D. The type of prey from columns C and D is recorded in the Prey Type column, column E. And general notes are in column F. Most of the fish are anchovies and the 'shrimp' are actually not shrimp, but another crustacean called 'squat lobster' or 'lobster krill'.
- The students’ goal for analyzing the penguin data is to better understand how penguins find prey, how effective the penguins are at capturing prey once they find them, etc. In particular they may wish to focus on:
- Whether there is a prey preference, and if there is, what is the extent of the preference?
- Whether there is a link between prey types encountered and dive depth.
- The data set has worksheets with observations from 10 different penguins. Divide the class into groups of four or five students. The groups should divide the 10 penguins among themselves so each student explores data from two to three penguins. Penguins 7 and 8 have a lot of data and can be reviewed by one person. Penguins 3, 15, and 21 have less data and are a good combination if students have to explore the data from three penguins. Or assign penguins to students to facilitate the process.
For this part of the activity, the students should work on question one together so they all conduct the same analysis, but they should explore their assigned penguin(s) and answer question two individually.
- Have students come back together as a group to share their penguin data and answer the questions in Part II of the worksheet. Guide students towards these answers:
- There is a prey preference, only penguin 7 chased after shrimp. The other penguins caught anchovies sixteen times more than penguin 7 caught shrimp.
- Jellyfish and squid were encountered only at shallow depths, the deepest was 18 m. Fish were encountered at all depths but more frequently between 0 – 3 m. Shrimp were encountered at all depths, but more frequently between 33 - 82 m.
- Students can extend their analysis by comparing the energetic value of the different prey types. Students can research the caloric value of the anchovies vs. the shrimp. It will be difficult to find the value for squat lobster, so let students continue with shrimp, which has a comparable value.
- Once students have discovered that anchovies have a higher caloric value than the shrimp, inform them that the assimilation efficiency of penguins feeding on anchovy is approximately 80%. This means 80% of the energy within the prey can be used by the penguin. However, the assimilation efficiency for squid and crustaceans is only around 60%. Students can then calculate how much of the calories from each prey are actually available to the penguins.
- Finishing watching the video from the resource Matter and Energy in Penguins’ Aquatic Ecosystem from minute 01:57 to the end. Have students complete Part III of the worksheet and compare their analysis to Dr. Wilson’s.
- Hold a class discussion to evaluate students’ understanding of the importance of prey options for penguin conservation. Ask students the following questions:
- Based on your analysis, how might conservationists support penguins during lean years?
- Why is penguin conservation important? How might the ecosystem be disrupted if penguins are removed?