GLOBAL WARMING AND THE DISAPPEARING ADÉLIE PENGUIN

OVERVIEW: In this lesson, students explore principles of global warming and the increased moisture capacity of warmer air (which has caused increased snowfall in Antarctica), and investigate the Adélie penguin’s population crash in recent years. Ohio Science Content Benchmarks and Indicators addressed:

6-8: Life Sciences D. Explain how extinction of a species occurs when the environment changes and its adaptive characteristics are insufficient to allow survival (as seen in evidence of the fossil record). 8.5 (Evolutionary Theory)

Investigate how an organism adapted to a particular environment may become extinct if the environment, as shown by the fossil record, changes.

Life Sciences B. Describe the characteristics of an organism in terms of a combination of inherited traits and recognize reproduction as a characteristic of living organisms essential to the continuation of the species. 9-10: Life Sciences D. Explain the flow of energy and the cycling of matter through biological and ecological systems (cellular, organismal and ecological). 10.9 (Diversity and Independence of Life)

Describe how matter cycles and energy flows through different levels of organization in living systems and between living systems and the physical environment.

10.11 (Diversity and Independence of Life) Explain how some energy is stored and much is dissipated into the environment as thermal energy (e.g., food webs and energy pyramids).

Life Sciences F. Explain the structure and function of ecosystems and relate how ecosystems change over time.

10.15 (Diversity and Interdependence of Life) Explain how living things interact with biotic and abiotic

components of the environment (e.g., predation, competition, natural disasters and weather).

10.17 (Diversity and Interdependence of Life) Conclude that ecosystems tend to have cyclic fluctuations around a state of approximate equilibrium that can change

when climate changes, when one or more new species appear as a result of immigration or when one or more species disappear.

Life Sciences G. Describe how human activities can impact the status of natural systems.

10.18 (Diversity and Interdependence of Life) Describe ways that human activities can deliberately or inadvertently alter the equilibrium in ecosystems. Explain how changes in technology/biotechnology can cause significant changes, either positive or negative, in environmental quality and carrying capacity.

Prior knowledge: Students should be able to describe global warming and some of its possible causes, including human pollutants. Materials needed: - Balloons, preferably multicolored.

- Air pump — can be a hand bicycle pump, battery powered mattress inflator, or plug-in air compressor - Freezer - Sharpies

Procedures: PART 1 — Why does warming increase snowfall?

1. Explain that while global warming has consequences everywhere on the planet, many of its effects are intensified in Antarctica, which is defined by a large quantity of permanent ice.

2. Explain that over the past 50 years, the average air temperature on the

Antarctic Peninsula has increased by at least 4.5°F, an increase that is 5 times greater than the global average. This has resulted in a decline in the overall amount of sea ice extending from Antarctica (including the disintegration of huge ice shelves), and an increase in the amount of snow and rain on the continent. (sources: http://www.ucsusa.org/global_environment/global_warming/page.cfm?pageID=507, http://yosemite.epa.gov/OAR/globalwarming.nsf/content/ImpactsPolarRegions.html)

3. To help students understand the somewhat counterintuitive idea that global warming increases the amount of snowfall, have them conduct the following experiment.

a. Students should form small groups — each group gets 2 balloons, one each of two different colors.

b. One balloon is blown up normally, using human breath (warm, moist air).

c. Assist students in blowing up the second balloon with the pump — this air is room temperature, and less humid. Make sure balloons are labeled with sharpies.

d. Balloons should be labeled with sharpies, then placed in a freezer. If space is an issue, on a cold winter day simply tie balloons together and place outdoors.

e. Groups should collaborate to outline the differences they expect to find in the balloons upon removal, then create a working hypothesis, making predictions about these expected differences.

f. After 30 min. in freezer (or overnight), have students remove and analyze balloons, working together to write down descriptions of the differences found

g. Groups should use their observations to draw general conclusions about the properties of air and water/water vapor with respect to heat.

4. Guide students to the main relevant point here: that warm air can hold

more moisture, which precipitates when temperatures drop. Thus, warming means more snow in Antarctica.

PART 2 — Why are Peninsula Adélie penguin populations declining?

5. Explain that several islands around Palmer Station are home to many

colonies of Adélie penguins, where young are hatched and raised, as well as gentoo and chinstrap penguins. Present student groups with the following graphs on population change in the three species, and have them answer the following questions on their own paper.

(Figures taken from Palmer LTER website, www.palmer.usap.gov)

Questions:

1. What is the general trend in each of the three species? 2. What is another way of saying that the gentoo penguin population

changed 300% in 1983?

3. Estimate the decrease in the Adélie population in the past 30 years.

4. Predict what populations of these three birds might be in another 25 years.

5. What might be some problems with these predictions?

6. How might the first graph be misleading? What might be a better

way of presenting the data?

6. Present students with the following information on Adélies — they should use it to answer the numbered questions that follow. Life as an Adélie penguin near Palmer Station:

• You spend 90% of your life at the edge of the sea ice, but return to the same place on the same island to breed every year

• You nest in a colony with large numbers of other Adélies

• You (mostly) stay with your mate for life • If you are a male, you begin building your nest alone, then your mate

joins you to help. • If you are a female, you lay 2 or 3 eggs in the summer, on a site that is

normally not covered with ice or snow. • You and your mate take turns sitting on the eggs. If there is heavy

snowfall in the breeding season, you and your mate can get buried in up to 3 feet of snow while sitting on your eggs! You survive this, but when the snow melts, the eggs often die because they suffocate in the melted water. This is because eggs must be able to exchange gases (oxygen and carbon dioxide) through their shells.

• Once chicks hatch, you and your mate take turns gathering food to bring back and regurgitate for them until they get too big to feed alone — then both you and your mate leave the nest to gather food, leaving chicks huddled together for warmth and protection.

• In order to develop and survive, your chicks need to be fed lots of krill — small, shrimp-like organisms.

• In order for krill to thrive, they must feed on the algae and phytoplankton on the underside of sea ice.

• Of the chicks that successfully fledge (i.e., swim away in February), only 8-12% survive to become adults.

Questions:

1. As a group, use your prior knowledge of the effects of global warming to explain two possible reasons for the decline in peninsular Adélie populations over the past 25 years. Be SPECIFIC AND THOROUGH IN YOUR ANSWERS!

2. While these Adélie populations are declining, the ones further

south appear to be actually increasing! List some reasons this might be the case.

3. What are some reasons that chinstrap and gentoo penguins

might be surviving on the peninsula better than Adélies? (Internet research required).

Teacher guidelines: From the previous activity, students should be able to explain that warming can cause more snowfall — and that this can bury Adélie eggs, suffocating them upon melting. Secondly, they should make the connection that less sea ice will mean less krill (once they figure this out, you can tell them that in fact Antarctic krill populations are thought to be only 1/5th what they were 30 years ago), and that this could also account for the decline.