Students will use evidence from their migration to explain how events in one ecosystem may affect another geographically distant ecosystem. For this extension exercise, use the
Exploration 1: Shorebird Migration Extension reading below.
Phenomenon
“Predators now wipe out 70 percent of shorebird nests in the far north, a shift in historical patterns that scientists pin on climate change.” (
Audubon)
Students will:
- Use evidence and scientific reasoning to explain how a decrease in Arctic lemmings may lead to a decrease in shorebirds returning to the Wadden Sea.
- Create a PowerPoint presentation of the correlation between lemming population size and shorebird population size.
Writing Prompt
Arctic foxes are predators that consume both lemmings and shorebirds. Lemming winters in the Arctic have led to less snowpack for lemming burrows. Lemming survival rates have decreased as a result of decreased snow cover needed for protection from predators. In the spring, when shorebirds return to the Arctic for nesting, there are fewer lemmings.
Assessment Questions
How might a decrease in the lemming population affect the survival of shorebirds breeding in the Arctic?
Students who demonstrate understanding should be able to explain that Arctic foxes consume both lemmings and shorebirds. When lemming populations are high, Arctic foxes favor lemmings over shorebirds. When lemming populations are low, Arctic foxes will increase consumption of shorebird eggs and young shorebirds. This leads to a decrease in shorebirds.
What might scientists observe in the fall as shorebirds stop at the national park on their migration to wintering grounds?
Students who demonstrate understanding should be able to use evidence from the migration activity to predict that shorebird species consumed by Arctic foxes will either have stable or decreased numbers upon return to the national park.
Construct a graph to show the relationship between changes in the lemming population and shorebird population.
They should realize that since this is an event occurring over time, the graph should be a line graph. The lemming curve should show a decreasing trend. There should be a lag in the decline of shorebirds as the foxes shift predation from lemmings to shorebirds. Students may assume that the fox population is constant.
