《ProtectionofWildlifeandEndangeredSpecies.doc》由会员分享，可在线阅读，更多相关《ProtectionofWildlifeandEndangeredSpecies.doc（3页珍藏版）》请在三一文库上搜索。
1、Protection of Wildlife and Endangered SpeciesWhile Wisconsin is blessed with many natural areas, our wildlife still face several threats over the long term. We need to support programs which will protect wildlife and endangered species, or risk losing some of them. Key Threats to Wildlife 1. Habitat
2、 Loss - Because our population is growing and our cities are sprawling into the countryside, fewer natural wildlife habitat areas are left each year. And the habitat that remains has often been degraded to bear little resemblance to the natural wild areas which existed in the past. In many areas, on
3、ly islands of habitat remain, isolated in the middle of large agricultural or urban developments - preventing normal interactions, healthy breeding or safe travel for many species. Some wildlife species, such as deer, rabbits and chipmunks, are adaptable to many conditions, but other creatures have
4、very specific plant, moisture and temperature requirements. These are the endangered species which we risk losing if we dont preserve adequate amounts of habitat for their survival. Canvasback duck populations have declined with the loss of wetland habitat 2. Climate Change - Because many types of p
5、lants and animals have specific habitat requirements, climate change could cause disastrous losses of wildlife species from Wisconsin. A one or two degree change in average annual temperature will translate into large changes in Wisconsin, affecting snow cover in the winter and excess heat in the su
6、mmer. Many northern Wisconsin plants and animals depend on a blanket of snow to insulate them from extreme low temperatures of winter. It may be 25 degrees below zero in the open air, but barely freezing (32 degrees) beneath the snow. Without this insulation, many plant species (even trees) will dec
7、line or disappear entirely. Hibernating mammals, reptiles, amphibians and insects will be harmed also. Similarly, higher temperatures would increase evaporation year round, and may reduce rainfall, leading to drier than normal conditions across the state. Plants and wildlife are sensitive to moistur
8、e changes, so they will be harmed by this dryness. Coldwater trout streams may become too warm to support trout, or may dry up. Unfortunately, trees and plants cant simply pick up and move to a more hospitable location. Instead, they will die where they stand, exposing and starving the wildlife that
9、 depend on them. Drought tolerant plants and trees will gradually spread to replace them by seed, but this process takes time. In many parts of Wisconsin, natural habitat is chopped up and isolated in small islands. This means plants and animals have no bridge to allow them to move with the changing
10、 climate. (see Climate Change in Wisconsin) 3. Pesticides and Toxic Chemicals - Pesticides are deliberately spread to make the environment toxic to certain plants, insects or rodents, so it shouldnt be surprising that other plants and wildlife are often harmed at the same time. While many of the wor
11、st pesticides have been outlawed in the past 30 years, scientists have found numerous worries with several pesticides which are still legal and commonly used. In addition, many chemical pollutants are toxic to wildlife, such as PCBs, mercury, petroleum byproducts, solvents, anti-freeze, etc. 4. Non-
12、native Species - Over the past 150 years, many non-native plants, mollusks, insects, fish, birds, mammals, and diseases have found their way to Wisconsin. These include such well-known headaches as buckthorn, carp, zebra mussels, spiny water fleas, purple loosestrife, gypsy moths, Eurasian milfoil,
13、feral cats, white perch, West Nile Virus, Japanese beetles, and starlings. These aliens are often aggressive competitors with native wildlife, or predatory, especially after theyve left their own natural environments and controls. 5. Mismanagement - Some native wildlife can become a problem when rel
14、eased from their natural population controls. When wolves are scarce and hunters too few, white-tailed deer will often strip the woods of native wildflowers (such as Trilliums) and even certain tree species (such as Hemlock), when their populations are allowed to become too high. Canada geese are be
15、autiful birds, but when city folk feed native geese as if they were pets, their populations can rise to uncomfortable levels in urban areas, resulting in polluted waterways and manure-laden lawns. Gulls can become similar problems, when they scavenge for scraps from our garbage heaps and landfills.