Habitat loss??”due to destruction, fragmentation or degradation of habitat??”is the primary threat to the survival of wildlife in the United States. When an ecosystem has been dramatically changed by human activities??”such as agriculture, oil and gas exploration, commercial development or water diversion??”it may no longer be able to provide the food, water, cover, and places to raise young. Every day there are fewer places left that wildlife can call home. There are three major kinds of habitat loss: Habitat destruction: A bulldozer pushing down trees is the iconic image of habitat estruction.
Other ways that people are directly destroying habitat, include filling in wetlands, dredging rivers, mowing fields, and cutting down trees. ??? Habitat fragmentation: Much of the remaining terrestrial wildlife habitat in the U. S. has been cut up into fragments by roads and development. Aquatic species’ habitat has been fragmented by dams and water diversions. These fragments of habitat may not be large or connected enough to support species that need a large territory in which to find mates and food.
The loss and fragmentation of habitat make it difficult for igratory species to find places to rest and feed along their migration routes. ??? Habitat degradation: Pollution, invasive species and disruption of ecosystem processes (such as changing the intensity of fires in an ecosystem) are some of the ways habitats can become so degraded that they no longer support native wildlife. What are the main drivers of habitat loss in the U. S.? Agriculture: Much of the habitat loss from agriculture was done long ago when settlers converted forests and prairies to cropland.
Today, there is increasing pressure to redevelop conservation lands for high-priced food and biofuel crops. ?? Land conversion for development: The conversion of lands that once provided wildlife habitat to housing developments, roads, office parks, strip malls, parking lots and industrial sites continues, even during the current economic crisis. ??? Water development: Dams and other water diversions siphon off and disconnect waters, changing hydrology and water chemistry (when nutrients are not able to flow downstream).
During the dry season, the Colorado River has little to no water in it by the time it reaches the Sea of Cortez. Pollution: Freshwater wildlife are most impacted by pollution. Pollutants such as untreated sewage, mining waste, acid rain, fertilizers and pesticides concentrate in rivers, lakes and wetlands and eventually end up in estuaries and the food web. ??? Global warming: Global warming is the emerging driver of habitat loss. Wildlife that need the cool temperatures of high elevations, such as the American pika, may soon run out of habitat. Coastal wildlife may find their habitat underwater as sea levels rise.
What can you do to combat habitat loss? You can create habitat for wildlife in your own yard! Create a Certified Wildlife Habitat near your home, school or business. Plant native plants and put out a water source so that you can provide the f wildlife need to survive. National Wildlife Magazine Articles: The Case of the Disappearing Warbler A River Once Ran Through It Resources: , water, cover and places to raise young that Endangered by Sprawl: How Runaway Development Threatens America’s Wildlife (PDF) Sources: Precious Heritage: The Status of Biodiversity in the United States.
Stein, B. A. , J. S. Adams and L. S. Kutner. Oxford University Press, New York: 2000. In Search of Wildlife-friendly Biofuels: Are Native Prairie Plants the Answer? What is Habitat Destruction? A habitat is the natural home for an animal or plant. Habitat destruction is when an animal or plant loses its natural home, usually caused by something humans have done. If an animal’s habitat gets destroyed, it might die out. If this happens, it can affect all animals above it on the food chain. Habitat destruction is one of the main threats to biodiversity.
Biodiversity refers to the various kinds of plants and animals that live in a particular area. Arctic communities have less biodiversity because of the very few species of animals that live there. Tropical forests, however, have thousands f different animal and plant species, making them the most biodiverse areas on earth. Ecologists use biodiversity as a way of measuring how habitats are affected by land use. All species need specific food and a specific habitat to survive. The more specific these needs, the greater the risk to the species if their habitat changes or is lost.
What are the Causes of Habitat Destruction? We humans are a major cause of habitat destruction. While animal populations do not usually rise sharply, the number of human beings on our planet has risen steeply in the last few centuries. This huge increase is putting pressure on natural esources. Our needs are growing, and these needs are often causing habitat destruction. Here are some major causes of habitat destruction: Logging People are cutting down the forests and rain forests for wood and wood products. Usually, only large prime trees are cut down, such as mahogany.
However, smaller trees can be destroyed in the process and never replaced. Logging can cause soil erosion, and the logging roads that are built can damage rivers and streams. For most of the world’s poor people, wood is the only source of fuel they have. Eighty percent of all wood used worldwide is for fuel. Collecting wood for fuel does not necessarily destroy rain forests, but it does damage or degrade them. Agriculture Wild lands are being cleared for crops and domestic animals. The single biggest cause of deforestation is farming.
Animals used to living in a biodiverse habitat cannot survive in an area with one crop. Building Roads and Cities Humans are clearing trees and wild lands to make room for roads and cities. Cities replace the natural habitat of many species of plants and animals. Highways and freeways can destroy plants and also keep animals from safely traveling through their natural habitat. Forest Fires Forest fires destroy or damage between 15 and 36 million acres of tropical forest every year. Sometimes the fires are started on purpose as a way to illegally clear an area of trees.
Where is it Happening? Habitat destruction is happening all over the world and closer to your home than you might think. Tropical rain forests in Central and South America and in Southeast Asia and Oceania are being threatened. Rainforests now occupy less then h of the land that they did 100 years ago (that’s less than 2% of the earth’s surface). Borneo is one of the most biodiverse places on earth. There are many different kinds of animals on Borneo including sun bears, clouded leopards, gibbons, eight different species of monkeys, around 1,000 elephants, rhinos and orangutans.
However, the orangutan population has fallen 50% in the last 50 years. The number of rhinos has fallen to less than 50 rhinos. One of the main threats to Borneo’s biodiversity is the loss of lowland forests. In the past two decades, people have cleared about two million acres of these forests. The lowland forests are being cleared to make room for palm oil plantations. Many animals cannot survive on Just one crop. Around the world natural wetlands are disappearing. The U. S. has lost half its wetlands in the last 200 years.
Europe has lost two-thirds of its wetlands in the last 300 years. Tourism is hurting the natural habitats of animals dependent on mountains, coral reefs and beaches. An example is the green turtle that uses the island beaches in the South Atlantic Ocean to lay its eggs. Near Milwaukee, Wisconsin, United States, a Boy Scout troop planted one thousand milkweed plants to replace the ones bulldozed for a basin detention project. Each year, thousands of monarch butterflies stop and eat the milkweed on heir way south for the winter. How You Can Help?
You can get involved in local conservation efforts. Participate in conservation projects at school or in clubs. You can support environmental groups that campaign for local areas and areas around the world. Your family can become responsible shoppers. If your family buys tropical wood products, make sure that they come from a supplier that doesn’t harm the rain forests. Those products are often labeled FSC (Forest Stewardship Council). There are also programs and websites that allow you to adopt an animal that is endangered by habitat destruction.