describe the wild life of the vield
Answers
Habitat loss is the leading cause for the loss of species from extinction. Many migratory songbird populations have declined because they are very susceptible to cowbird parasitism. Songbirds that nest in forested areas near cowbird habitat (open areas) are the most vulnerable. The cowbird is a generalist parasite (the female relies on other birds to raise its young). It lays its eggs in other smaller bird’s nests. Most birds can spot the different egg, but most do not notice and keep incubating. Generally, the cowbird’s egg hatches first (warblers’ eggs hatch in 12-14 days; cowbirds’ eggs usually hatch in 10-13). This slight advantage gives the cowbird nestling a head start. The cowbird nestling almost always outcompetes the other nestlings for food. CLIMATE CHANGE Climate Change or global warming is the overall increase in average temperatures on Earth. The rate of warming has increased dramatically due to the increased outputs of greenhouse gases (particularly carbon dioxide) since the industrial revolution. Its effects on wildlife are dramatic. Entire populations will be effected. Many species are already in jeopardy of becoming extinct, like the Polar bear. Other species will have to adapt to a warmer planet. It is believed that many ecosystems will shift north. Our climate in New Jersey will be like the climate in South Carolina if nothing is done to reduce our impact on our planet. Climate change may also significantly alter the chemical balance of the seas, off-shore currents, and plankton distribution and abundance, thereby affecting migration routes of marine species and impacting the entire food web. INVASIVE AND EXOTIC SPECIES Invasive and exotic species are species that were introduced to North America that reduce biodiversity of native species. Many exotics were accidentally introduced during the colonial times when many plants (from other continents) were used as packing materials on ships. Animals from other continents may have also hitched a ride in those same ships or they were intentionally brought to North America. Invasive plants choke out natives and do not provide the same functions in the ecosystem. Exotic species can wreak havoc on native populations of wildlife by displacing them or altering their habitat. Most exotics are able to quickly adapt to our environment. For example, house cats are not native and can have devastating effects on bird populations. Surveys have shown that only 35% of the known 77 million pet cats are kept indoors (American Bird Conservancy). Feral cats compete with native predators, reproduce quickly, and transmit disease. It is estimated that hundreds of millions of birds and billions of small mammals are killed by feral cats each year (American Bird Conservancy). Cats are opportunistic and kill a variety of birds. Common birds like Cardinals and endangered birds like the Piping plover all can fall prey to feral cats. POLLUTION Pollution is man-made waste or by-products that are released into the environment. Pollutants can change ecosystems and can have severe effects on people, wildlife and the natural environment. Many organisms ingest or absorb harmful toxins that ultimately get passed along through the food chain. Persistent pollutants, like DDT, PCBs, and heavy metals bio-accumulate (are stored in fat) in predators. All of the effects, especially over the long-term, are unknown. In many species bio-accumulation can be associated with reduced reproduction or death. For example, the widespread and heavy use of persistent pesticides (DDT and DDE) in the 1950’s caused severe declines in many species of raptors. At the time, the effects of DDT on wildlife and the environment were unknown. It was quickly absorbed into soils and the environment and it was found to persist for a very long time. It caused egg shells to thin by inhibiting the production of calcium, which reduced their rate of reproduction. DDT is highly toxic to fish. It accumulates and gets concentrated through the food chain. When they were consumed by fish-eating raptors the DDT contributed to their decline. Since then, many pollutants have been banned in the U.S.; however, trace amounts are still found in many raptors and large fish. Non-point source pollution can also have major impacts, but it is hard to measure because it comes from all across our landscape. When the rain falls and washes our roads clean, for example, the runoff carries car oil, metals, sediment, trace toxins, and litter (and even heat) down the storm drains and into nearby streams and rivers. It washes fertilizers, pesticides, pet waste and grass clippings from our lawns; farm fields give up soil, nutrients, and chemicals too.