The Importance of Predators: are deer out of control?
Use the following resources:
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Deer Out of Control (NY Times, Andrew Revkin, 2004)
Deer management at Prince William Forest Park
Ecosystems Unraveling: Pull predators out of the mix, and a once lush green world turns
into an ecological shop of horrors
Prairie Ghost (1-page handout received in class)
Summarize the point of each article/resource. Identify a common thread or theme to explain
how these articles fit together. Your summary should demonstrate that you have read both
articles, but also that you see what they have in common.
The following questions are to prompt your thinking. You should address these issues in your
summary, but not in a disconnected way:
1. Describe what is meant by “top-down” and “bottom-up” ecosystem dynamics. Why is
the former referred to as “trophic cascades”? Are these two apparently contrasting views
mutually exclusive?
2. Why did Lago Guri provide an especially useful study site for investigating trophic
cascades?
3. Why did John Terborgh believe that evidence from Lago Guri contradicted predictions of
the equilibrium theory of island biogeography? Why would this have important
conservation implications?
4. If the notion of trophic cascades is an accurate reading of how ecosystems work, how
might this idea inform conservation strategy? What sorts of ecological restoration might
be appropriate in North America or elsewhere?
5. One can frequently find counter-examples to any broad theory. What does this research
article say about the effect of deer on ecosystems? What does it tell us about the danger
of making management decisions without adequate information?
6. What is a "prairie ghost"? What are the pronghorn running from?
7. How are deer being managed at Prince William and Rock Creek parks?
Some additional links that might be helpful:
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Top-down regulation of ecosystems (Rewilding Institute)
Trophic Cascades Project
What can we do with too many white-tail deer?
Remember to quote any phrases or words that are not yours, and use quotes sparingly.