The graceful deer has become something of a nuisance for many communities in the United States. Grazing deer damage ornamental plants and help themselves to farmers' crops; more seriously, deer wander onto roadways and cause traffic accidents that frequently result in injury and even death. These problems are enough to prompt communities such as Princeton to take measures to bring local deer populations under control.

Such measures are broadly accepted because there is an overabundance of deer in the country (New York state, for example, estimates that it's home to 1 million deer). A number of factors have provided ideal conditions for the deer population to explode near residential areas:

1. There are few natural predators around — such as wolves, bears, and lynx — to keep deer populations in check.
2. There are restrictions on hunting near areas populated by humans.
3. Deer are prolific reproducers: one buck (male deer) can mate with several does (female deer).
4. Suburban neighborhoods offer deer a nutritious diet of ornamental plants and fertilized lawns.

Generally, animal rights activists don't argue with the need to control burgeoning deer populations; what they do disagree with are the means used. In Princeton, the professional hunting company, White Buffalo Inc., plans to kill 400 deer this season using sharp-shooting and what's known as the "net and bolt" method. First, deer are lured to sites by bait such as corn meal. Then, they are either shot by sharp-shooters taking aim from tree stands, or they are captured in a net. Once under the net, they are killed with a skull-puncturing device.

Princeton residents who object to the deer-culling support neither method. They denounce sharp-shooting as dangerous to residents, and call the net-and-bolt method "medieval barbarity." Proponents, whilst acknowledging the fact that the deer will have a stressful struggle when first caught in the net, claim that the method is almost as humane as shooting with a rifle.

• Your students can hear both sides of the argument in this news segment from the National Public Radio program, "All Things Considered," on deer hunting in Princeton. (You'll need to scroll down the page to find the segment.)

In Defense of Animals, the animal rights organization, flatly rejects hunting as a reasonable and effective means of controlling deer populations in the long-term.

• To understand the IDA's point of view, students can read their fact sheet on deer population control.

Whatever methods are used, deer population management provides an interesting context for you to discuss the dynamics of animal populations with your students.

• population — a group of organisms of the same species living in a specific geographic area
• population ecology — the study of the different factors that affect the size of a population over time

Students can explore some of the factors affecting population size by using Logal Middle School Science Gateways simulation activities.

The most basic ideas behind population ecology have to do with the births and deaths of organisms in a population. Your students can become familiar with these concepts by exploring within the activity, Population Growth Curves.

Continuing with the activity, Factors Affecting Population Growth, your students can dynamically explore how changing life span, maturity age, and number of offspring can affect population size. In the activity, Carrying Capacity, students explore how a population's habitat can limit population size.

As stated above, the lack of natural predators has allowed deer populations to grow unchecked. In the activity, Predator-Prey Relationships, your students will be able to explore the population growth curves for wolves and deer living in the same habitat. Your students will see the natural oscillations in the growth curves and understand the cause and effect that normally exists between predators and prey.

Think About the Problem

1. A habitat's carrying capacity is the number of organisms that can be supported by the environment in which they live. Ask students why town officials in Princeton, New Jersey aren't waiting for the deer population to reach its local carrying capacity. What density-dependent factors limit deer population growth? What density-independent factors limit deer population growth? What exactly happens when a population size matches the local habitat's carrying capacity?
2. Researchers at the University of Florida have found that deer have a way of compensating for population losses due to hunting. Have students read the article "Does Make Up For Losses of Hunted Bucks." Traditional hunting laws state that hunters can only kill bucks — male deer — during hunting season. But the reduced number of bucks has not inhibited deer population growth. Why not?
3. The debate in Princeton, New Jersey has gone on since the Township first voted to decrease the number of deer back in late 1998. Have your class identify the major "sides" in the debate. What are the positions taken by each side? What arguments have they used in making the case for each position? What are the counter-arguments used by the other side? If you have time and the class has interest, encourage students to role-play the Princeton debate. Assign roles, including homeowners, local politicians, hunters, animal rights activists, forest rangers, people injured by car/deer collisions, etc. Students can review all materials from this article in making their preparations for an in-class "town meeting" to debate the merits of a deer-culling hunt.
4. Students can read about deer management in Fairfax County, Virginia. This Web site includes information on the problem of deer overabundance and managed hunting.

Restoration of wolf populations: In 1995, wolves were reintroduced to Yellowstone National Park. The scheme was met with enormous opposition from local ranchers and farmers, who complained that wolves took large numbers of livestock. In 1997, a district court ruled that the government's move to reintroduce wolves to Yellowstone Park was illegal. The wolves were threatened with removal from the park until this time last year, when the U.S. Court of Appeals in Denver overthrew the lower court's original ruling.

By all accounts, the wolves are now doing well. The latest figures from Yellowstone show that there are about 180 adult wolves living in the park, a considerable increase on the 31 that were introduced in the winters of 1995 and 1996. It's estimated that 70 pups were born in Yellowstone last year, although as nature dictates, not all of the pups will survive this winter.

• Find out about the history of wolves in the west from the National Wildlife Federation.
• The influence of the wolf population on the coyote population in Yellowstone makes for an interesting case study of how animal populations affect one another. Learn more in this article, "Coyote is no longer top dog in Yellowstone."
• For another case study, read how Yellowstone's grizzly bears are doing well thanks to the efforts of wolves and squirrels.

Reducing wolf populations: Last year, as a response to protests from livestock farmers, the Norwegian government decided to reduce its wolf population by shooting at wolves from helicopters.

• Students can learn about why the Norwegian government took measures to reduce the wolf population in this article from the Environment News Service, "Norway licenses wolf cull."
• A recent report from the World Wildlife Fund describes the outcome of the culling of Norwegian wolves.