Habitat destruction is the single most important danger to wildlife. Habitat loss is harmful, not only to a single kind of animal or plant, but to entire ecological communities. There are very few parts of the world that have not been altered, damaged, or destroyed by the destruction of natural habitats.
Boats can bring invasive species, like the zebra mussel and milfoil, into waterways.
URBAN DEVELOPMENT – As more and more people move to the cities, urban sprawl replaces natural habitats. Habitats that remain are fragmented and depleted of resources for animals.
ROAD BUILDING – Activities like agriculture, logging, mining, and the growth of towns and cities all require roads. Dirt roads, especially in forests or mining areas, can lead to erosion and even landslides. Paved roads create runoff, which can carry pollution into nearby soil, rivers, and lakes.
Roads also cut through natural habitats, breaking them into smaller pieces. This can make it harder for animals to find food, mates, and safe places to live. Animals near roads are also at greater risk of being hit by vehicles or harmed by legal and illegal hunting and trapping.
WATER DEVELOPMENT – Humans sometimes interfere with the natural flow of rivers and streams. We build dams, try to control floods, divert water for irrigation, and dredge waterways. These activities often result in higher water temperature and salinity, the removal of important nutrients and silt from the water, and changes in upstream and downstream habitats, including wetlands and marshes.
POLLUTION – Ecosystems can be harmed by pollution, including sulfur compounds, ozone, pesticides, and heavy metals. Some pollutants travel through the air, so their effects can be felt far from where they were released. For example, acid rain can damage forests, lakes, and other habitats many miles away.
Water can also be polluted by toxic substances such as mercury, lead, PCBs, and DDT. These chemicals can harm the immune, nervous, and reproductive systems of many living things. In the past, several bird species—such as the peregrine falcon, the bald eagle, and the osprey —had serious trouble reproducing because of the pesticide DDT. This chemical caused their eggshells to become thin and break easily, leading to population declines.
RECREATION – Outdoor recreation can also harm wildlife and habitats. Off-road vehicles can provide access to remote wilderness areas and can lead to the disturbance of natural habitats. Boats can bring invasive species, like the zebra mussel and milfoil, into waterways.
Habitat loss is a threat to the Columbia spotted frog, which is being considered for listing as an endangered species.
Learn more about habitats with Junior Naturalist Patrice as she looks at how all living things need a habitat where their needs can be met. Patrice joins Senior Naturalist Dave Erler as they look at how the Squam Lakes Natural Science Center has created an artificial habitat in its aviary.
Then take an up-close look at the common loon and its habitat, and Stevie and Taylor help biologist Kathy Wohlfort float a loon raft. VIEW NOW
Kodiak brown bear family in Alaska.
Habitat fragmentation is also a threat. This is the breaking up of large natural places into smaller fragments, or islands, of habitat. Some large animals, like mountain lions, moose, and brown bears, need large home ranges. When large stretches of natural habitat are broken up by human development, many animal populations decline.
Dams can cut off the natural flow of a river and impact wildlife.
Modern technology speeds up the process of habitat destruction. Serious damage can be done in a tiny proportion of the time that it would have taken in the past. By the year 2032, more than 70% of the Earth’s land surface is likely to be destroyed, fragmented, or disturbed by cities, roads, mines, dams, and other infrastructures of human civilization.
Forest fires can destroy and rejuninate a habitat.
Fire Destruction
Fire causes severe damage to tropical forest ecosystems, which do not normally burn and are extremely prone to severe fire damage. Tropical forest destruction, through fire, may affect our weather systems in new and unpredictable directions.
Fire Suppression
Fire is essential to the health of many ecosystems. Fire helps to quickly turn organic matter into mineral components that can help plants grow. Many plant species, such as lodgepole pine, need fire to trigger the release of their seeds. Fire can also help to clear out older growth from a habitat and give other plants a chance to grow and thrive. The prevention of all forest fires can actually lead to fires that burn for longer due to the accumulation of organic matter. The suppression of fire has caused the decline of many endangered ecosystems, including grasslands, savannas, pine barrens, and open forests.
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