However, not all biologists agree that building or preserving corridors is the best way to proceed, because it still allows much of the animal's habitat to be diverted for human use (Thwaites, PAGE). They suggest that corridors are an expensive solution, but often those biologists prefer to see less land diversion.
Another solution is voluntary conservation efforts, called "Habitat Conservation Plans" (HCPs). Since these are voluntary, however, they vary greatly in quality and effectiveness. In addition, they allow considerable habitat destruction, and they do not always fully address the long-term survival needs of the endangered animals (Kostyack, PAGE). Naturalists have noted that the number of HCPs established in areas of development often do not reflect the level of threat faced by endangered species in the area (Kostyack, PAGE). Critics of how HCPs are currently used believe the government should work harder to require landowners to protect endangered species living on their land (Kostyack, PAGE). Another approach is to act to enforce The Endangered Species Act (ESA). However, that law can be difficult to enforce on the local level and on a day-to-day basis. For instance, there is often a "take" restriction for those who hunt and fish, but those rules are hard to enforce.
The red cockaded woodpecker, once common throughout the south, has been on the endangered species list since the EAS was first passed in 1973. This bird needs old-growth pine groves, so they can find trees with dead centers where they can carve out holes to nest in. As the population in the south has grown, this woodpecker's habitats have continued to erode (Nickens, PAGE). It takes each bird several years to dig its nest. In addition these birds live in what amount to family clans, in close proximity to each other. Adults other than the breeding parents help incubate the eggs, dig new homes, and defend the clan's territory, which has to be a cluster of old-growth pines. As old growth trees are cut down to make way for development, the red cockaded woodpecker has less and less habitat (Nickens, PAGE).
Sometimes solutions are simpler than might be imagined. In the case of Australis'a Richmond birdwing butterfly, the solution was as simple as replanting the birdwing vine on private...
The first year, the team working to preserve the butterfly planted only 800 vines but immediately spotted butterflies at the vines (Pyper, PAGE).
For the Richmond birdwing butterfly, the solution was both simple and inexpensive. However, the example of the mountain pygmy-possum demonstrates that often biologists need detailed information about how the animal lives, feeds, and reproduces in order to find a solution. For birds that must live in wetlands, there is only one solution: wetlands must be preserved for them, even though developers might want to drain the land and use it for some other purpose.
For other animals it may be even more complicated. The California mountain lion needs a wide range, and the spread of population into their territory has put the mountain lion and human civilization into conflict. It will take creative thinking to find a way for both humans and mountain lions to live safely and productively in close proximity to each other.
SOURCES
Editor. "Habitat is a wonderful word." The News & Record (Piedmont Triad, NC). December 17, 2000.
Gerhardt, Gary. "Habitat Destruction Puts Least Tern at Risk." Denver Rocky Mountain News. August 7, 1997.
Kostyack, John. "Reshaping habitat conservation plans for species recovery: an introduction of a series of articles on habitat conservation plans (Symposium on Habitat Conservation Plans)." Environmental Law. September 22, 1997.
Nickens, Eddie. "Woodpecker wars (red-cockaded woodpecker as an endangered specie)." American Forests. January 1, 1998.
Pyper, Wendy. "Changing habitat: the revival of the Richmond birdwing butterfly offers hope that through research, education, dedication and teamwork, local communities can secure a future for threatened species." Ecos. January 1, 2001.
Thwaites, Tim. " Safe passage.(wildlife conservation aided by strips of conserved habitat)(Wildlife Corridors)." International Wildlife. July 17, 1998.
