Records show that 1998 and 1999 were the hottest summers of the century. How did you adjust to the heat? Did you change your diet? Did you change your style of clothing? Did you spend more time indoors or by water? People have the ability to control their immediate climate by going inside and turning up the air-conditioning. How do you think animals cope with climate change?

The list of phenomena being attributed to global warming is growing: record heat waves, extremely severe storms (hurricanes, tornadoes, etc.), extreme trends in precipitation (dry areas getting drier, wet areas getting wetter), and the rise of diseases spread by fleas and mosquitoes (encephalitis, malaria, yellow fever, etc). A study issued last month by the National Academy of Sciences claims that global warming is also disrupting the hibernation and migration patterns of animals and birds.

The study notes that while there is a trend toward warmer spring temperatures, the average snowmelt in high altitudes has remained the same and the snow may actually be getting deeper due to increased precipitation. Birds that migrate to high-altitude summer breeding grounds may have to wait for the snow to melt before they can eat and breed. For example, American robins are migrating about two weeks earlier than they did two decades ago, so they may be faced with short food supplies until spring foliage appears.

• Read ENN’s article about the study: Global warming ruffles wildlife, study says.

Another recent study showed that the increasingly snowy winters in the Isle Royale National Park in Michigan are changing wolf behavior, with far-reaching effects. The wolves are hunting in larger packs, enabling them to triple the number of moose they kill for food. The declining moose population has in turn led to an increase in balsam fir saplings, which are usually eaten by the moose.

• Read CNN’s article about the study: Wolf response to climate change studied.

Other studies have been conducted showing the effect of global warming on different animal species:

• Birds may sing a song of climate change
  
  
• Sea ice retreat may doom Arctic wildlife
  
  
• Global warming to hit prairies hard

Learn about the Problem

• To learn about the dynamics in a food web, use the Biology Gateways activity (Requires Logal Express. Get a free trial subscription now.): Exploring Food Chains and Food Webs.
  
  
• Then take a closer look with the Biology Gateways activity: Predator-Prey Relationships.

Think about the Problem

There are several major differences in the food chains described by the first two studies: robins starving and wolves thriving, both due to increased snow in their habitats. Contrast the situations, and answer the following questions.

• In which of the two food chains is the producer directly affected by climate change?
• In which of the two food chains is the consumer directly affected by climate change?
• In the food chain with the wolves, how does the predators’ changed behavior affect the herbivores and the lowest trophic level? Draw a rough graph containing the general growth curves of the wolves, moose, and fir saplings.

For the Teacher: Extending the Problem

• The EPA Global Warming Site is full of information, including sections designed especially for kids & educators and wildlife advocates.
  
  
• The World Wildlife Fund is running a special Climate Change Campaign, aimed at raising awareness of the threats of climate change and persuading governments to introduce responsible policies. The site contains articles about the effects of climate change on wildlife and ecosystems.
  
  
• The National Wildlife Federation has a Climate Change & Wildlife Program site, which offers information useful to students.
  
  
• Students should be aware that not everyone in the scientific community believes in the existence of global warming. Divide the class into six groups: "believers" among scientists, politicians, and the business community; and "non-believers" in the same three groups. Have each group gather representative information, and then hold a mock debate on the subject of whether global warming is fact or fantasy. While students do not have the expertise to make a judgment on this debate, they can understand the issues at stake.
  
  Students can start their research with the following sites and articles:
  
  
  • Global Climate Coalition (the business lobby)
    
    
  • Global Resources (site of the Union of Concerned Scientists)
    
    
  • "Global Warming: The Origin and Nature of the Alleged Scientific Consensus" (article)
    
    
  • Intergovernmental Panel on Climate Change (sponsored by the UN and the World Meteorological Organization)
    
    
  • "The Collapsing Scientific Cornerstones of Global Warming Theory" (article)
    
    
  • U.S. Department of State (press releases, statements, and speeches by State Department personnel)
  
  
• See the Teaching the News article, "Mapping Global Warming," for more links and ideas.