Bringing Endangered Species to the Classroom
Waller, Pat, The American Biology Teacher
How does the conservation of endangered species fit into your biology curriculum? While it is a familiar topic to many students, there is a great opportunity to expand awareness at all grade levels. It has become especially timely, considering the frequent news coverage of climate change and increases in the number of endangered species worldwide.
Endangered-species conservation can be taught in many curricula, including the life sciences, general science, environmental science, ecology, and social science courses. Incorporating this vital subject is an opportunity for teachers to offer cross-disciplinary or interdisciplinary lessons in elementary and middle schools. At the high school and college level, endangered species provides students a chance to explore the interrelationships of science, technology, and society.
Endangered-species conservation can be taught throughout the year, although early spring is the traditional time when many teachers include it in their lesson plan. This also coincides with national Endangered Species Day (20 May 2011). Below, I provide biology teachers with some basic knowledge, a few classroom activities, and resource material to help enrich biology curricula.
** The Basic Facts
Under the Endangered Species Act (ESA), species can be listed as either endangered or threatened. Currently, 1200 species are so designated by the U.S. Fish and Wildlife Service (FWS). "Endangered" means that a species is in danger of extinction throughout all or a significant portion of its range. "Threatened" species are those likely to become endangered within the "foreseeable future." All species of plants and animals, except pest insects, are eligible for listing as endangered or threatened. "For the purposes of the Endangered Species Act, Congress defined species to include subspecies, varieties, and, for vertebrates, distinct population segments" (FWS).
While species naturally go extinct at a steady rate, human actions have greatly increased the rate of extinction. In 2004, the International Union for the Conservation of Nature (IUCN) estimated that extinction rates increased by 100-1,000 times since humans first appeared. Renowned Harvard biologist E.O. Wilson now estimates that the rate will reach 10,000 times higher than background extinction by 2030. Scientists call this the "sixth great wave" of extinction--the greatest die-off of species since the dinosaurs. Recent, likely species extinctions in the wild are: the Yangtze River dolphin, Hawaiian crow, Western black rhino, Scimitar-horned oryx and Spix's macaw. A number of human activities lead to extinction.
Plant and animal species become threatened or endangered for one of several primary reasons:
* Habitat destruction. Loss of habitat to commercial development and natural resource extraction, as well as flooding, fire, and other natural causes, has been a major reason. More recently, global warming has had a significant impact on habitat loss.
* Commercial exploitation. Many species have become endangered because of overfishing and hunting.
* Poisoning. Pesticide and herbicide chemicals often take a long time to degrade, and build up in the soils or throughout the food chain. Some groups of animals such as amphibians are especially vulnerable to these chemical pollutants. In addition, predators such as hawks, owls, and coyotes can be harmed if they eat poisoned animals.
* Introduced species. The spread of non-native species has greatly affected native populations around the world. Invasive species compete with native species for resources and habitat. They can even prey on native species directly, forcing native species toward extinction.
** Why Should Students Learn about This Topic?
The problem of endangered species is significant for many reasons. Students should be aware of the following:
* Ecological importance. …