There is a growing awareness among wildlife biologists and conservationists that relatively benign human activities or even our mere presence adversely affects many wildlife species. Those activities need not be hunting, chasing, shooting, destroying habitat, or in any way overtly harassing the wildlife, but simply being present.

Chapter III of the handbook Managing Development for People and Wildlife, prepared by Clarion Associates and the Colorado Division of Wildlife, states: "Human activities in or near wildlife habitat may cause some animals to alter their activity and feeding patterns. Although such alterations may seem relatively harmless at the time to the casual observer, they may have non-trivial consequences for the animal. For example, stress that results from human disturbance may lead to increased susceptibility to disease, reduced reproductive output in some species, or abandonment of the area temporarily or permanently."

Last year, the Ecological Society of America reported research conducted by wildlife biologists Robert Steidl of the University of Arizona and Robert Anthony of Oregon State University about the effects of human visits to the Gulkana National Wild River in Alaska upon resident bald eagles. The article reported: "Adult eagles decreased some activities by as much as 59% per day when humans were nearby. In addition, the percentage of time that they left their nesting area unattended increased by 24%. ... [W]hen humans were near the nests, the number of feeding bouts at the nest decreased by 20% per day. Further, the amount of prey consumed by the eagles decreased by an average of 29% per day."

Not all wild animals flee humans. Some even become accustomed (habituated) to our presence and activities, and a few may even approach people to seek food. Although such animals may appear to adapt well or to even prosper in the presence of people, they usually alter their normal foraging patterns and other behaviors. They may abnormally concentrate into a small area, scatter other animals, spread diseases, or directly imperil other species.

Wild animals that eat food from humans, whether supplied intentionally or unintentionally, frequently suffer nutritional deficiencies, become abnormally fat, or refrain (as with some birds) from normal migration. Animals that approach people bring risks to both themselves and people, as is the case with black bears in Yosemite National Park. Although the effects might not be immediately evident, the response of wildlife to human presence disturbs the dynamics of biological communities.

From the preceding and many other studies, it is clear that current reserves -- such as wildlife refuges, wilderness areas, open space preserves, and parks -- do not provide sufficient sanctuary for wildlife.

To provide such sanctuary, and in such degree as may be feasible, we propose that society reserve some habitat areas exclusively for native wildlife. We call such habitat "Human-Free Habitat."

Nothing in the proposal implies that people be denied any space that is essential to meet their needs or that provide important recreational opportunities. Good candidate areas must be relatively remote, as near to wilderness conditions as possible, and have high-quality habitat that is capable of supporting self-sufficient populations of native wildlife. Areas where, for example, ungulates could populate beyond what the range could support would be unsuitable. Also unsuitable would be areas with significant development, roads, or other human artifacts. Finally, good candidate areas would have suitable contiguous habitat, preferably with corridors, that allow animals to migrate or disperse.

One possible candidate for human-free habitat is Red Rock, which stands in San Francisco Bay near the Richmond-San Rafael Bridge. The rock supports a rich diversity of sea birds, such as gulls, herons, egrets, and endangered brown pelicans. According to the San Francisco Chronicle (06/07/2001), the rock carries a price tag of $10 million and, for various, reasons, would be difficult to develop. Clearly, Red Rock would be of extremely limited value to humans, probably used only as an infrequently visited vacation stop for a few people wealthy enough to buy the rock and build something on it. Perhaps some conservation organization or consortium will raise the funds, buy it, and then leave it alone. The wildlife will manage just fine.

Designation of any area as Human-Free Habitat would be on a site-specific basis, likely following appropriate public hearings, reviews, and environmental impact reports. Those processes would address potential problems and issues -- such as enforcement, restoration needs, or the presence of invasive species or human artifacts -- applying to the site in question.

Once before the public, the concept of Human-Free Habitat might spark a serious discussion within society and among wildlife professionals. Those discussions may raise awareness about the particular needs of wildlife and may lead people to understand the perspective of other species, as those beings struggle to live in an increasingly human-dominated world.

Edward M. Smith