兔子是一种入侵物种,150多年来一直对澳大利亚大陆造成巨大的生态破坏。它们以无法控制的速度繁殖,像蝗虫一样消耗农田,并对土壤侵蚀作出重大贡献。虽然政府的一些兔子根除方法已经成功地控制了它们的传播,但澳大利亚的整体兔子数量仍远远超出可持续的手段。 1859年,维多利亚州温切尔西的土地所有者托马斯·奥斯汀(Thomas Austin)从英格兰进口了24只野兔,并将它们放入野外进行运动狩猎。在这些年里,这24只兔子成倍增加。到20世纪20年代,自推出以来不到70年,澳大利亚的兔子数量猛增至约100亿只,每年每只母兔的繁殖率为18至30只。兔子开始以每年80英里的速度迁移到澳大利亚。在摧毁了维多利亚州200万英亩的花卉土地之后,他们穿越了新南威尔士州,南澳大利亚州和昆士兰州。到1890年,在西澳大利亚州一直发现了兔子。澳大利亚是多产兔子的理想地点。冬天很温和,所以它们几乎可以全年繁殖。有大量的土地,工业发展有限。天然的低植被为它们提供了栖息地和食物,多年的地理隔离使得这个新的入侵物种没有天然的捕食者。目前,兔子居住在澳大利亚约250万平方英里,估计人口超过2亿。尽管规模很大,但澳大利亚大部分地区干旱且不完全适合农业。这个大陆的肥沃土壤现在受到了兔子的威胁。兔子过度放牧减少了植被覆盖,使风侵蚀了顶部土壤。土壤侵蚀影响植被和吸水。土壤有限的土地也会导致农业径流和盐度增加。澳大利亚的畜牧业受到兔子的广泛影响。随着粮食产量下降,牛羊数量也在减少。为了补偿,许多农民扩大他们的牲畜范围和饮食,耕种更广阔的土地,从而进一步促成了这个问题。澳大利亚的农业产业因兔子感染的直接和间接影响而损失了数十亿美元。在19世纪的大部分时间里,最常见的野兔控制方法是诱捕和射击。但是在1901年到1907年之间,澳大利亚政府通过建立三个防兔栅栏来保护西澳大利亚的牧区,采用了全国性的方法。第一道围栏在整个大陆西侧垂直延伸1,138英里,从北部的Cape Keravdren附近的一个点开始,到南部的Starvation港口结束。它被认为是世界上最长的连续围栏。第二个围栏大致平行于第一个,西向55-100英里,从原始分支到南部海岸,延伸724英里。最后的围栏从该国的第二个到西海岸水平延伸160英里。尽管该项目非常艰巨,但围栏被认为是不成功的,因为许多兔子在施工期间穿过了受保护的一侧。此外,许多人也在围栏中挖掘过。兔子的引入也使澳大利亚本土野生动物紧张。兔子被指责为毁灭了eremophila植物和各种树木。因为兔子会以幼苗为食,许多树木永远无法繁殖,导致当地灭绝。此外,由于对食物和栖息地的直接竞争,许多本地动物的种群,例如较大的bilby和猪足穗,已经急剧下降。澳大利亚政府还试验了控制野兔数量的生物方法。 1950年,携带粘液瘤病毒的蚊子和跳蚤被释放到野外。这种病毒在南美洲发现,只影响兔子。该发布非常成功,估计澳大利亚90-99%的兔子数量已被消灭。不幸的是,由于蚊子和跳蚤通常不居住在干旱地区,因此生活在非洲大陆内陆的许多兔子都没有受到影响。一小部分人口也对病毒产生了天然的基因免疫力,并且它们继续繁殖。今天,只有约40%的兔子仍然易患这种疾病。

澳大利亚迪肯大学生物学Essay代写:澳洲的兔子

Rabbits are an invasive species that has caused immense ecological devastation to the continent of Australia for over 150 years. They procreate with uncontrollable velocity, consume cropland like locusts, and contribute significantly to soil erosion. Although some of the government’s rabbit eradication methods have been successful in controlling their spread, the overall rabbit population in Australia is still well beyond sustainable means. In 1859, a man named Thomas Austin, a landowner in Winchelsea, Victoria imported 24 wild rabbits from England and released them into the wild for sport hunting. Within a number of years, those 24 rabbits multiplied into millions. By the 1920s, less than 70 years since its introduction, the rabbit population in Australia ballooned to an estimated 10 billion, reproducing at a rate of 18 to 30 per single female rabbit per year. The rabbits started to migrate across Australia at a rate of 80 miles a year. After destroying two million acres of Victoria’s floral lands, they traversed across the states of New South Wales, South Australia, and Queensland. By 1890, rabbits were spotted all the way in Western Australia. Australia is an ideal location for the prolific rabbit. The winters are mild, so they are able to breed nearly year-round. There is an abundance of land with limited industrial development. Natural low vegetation provides them with shelter and food, and years of geographic isolation has left the continent with no natural predator for this new invasive species. Currently, the rabbit inhabits around 2.5 million square miles of Australia with an estimated population of over 200 million. Despite its size, much of Australia is arid and not fully fit for agriculture. What fertile soil the continent has is now threatened by the rabbit. Excessive grazing by the rabbit has diminished vegetative cover, allowing wind to erode away top soil. Soil erosion affects revegetation and water absorption. Land with limited top soil can also lead to agricultural run-off and increased salinity. The livestock industry in Australia has been widely affected by the rabbit. As food yields decrease, so does the cattle and sheep population. To compensate, many farmers extend their livestock range and diet, farming a wider expanse of the land and thus further contributing to the problem. The agricultural industry in Australia has lost billions of dollars from the direct and indirect effects of the rabbit infestation. For much of the 19th century, the most common methods of feral rabbit control have been trapping and shooting. But between 1901 and 1907, the Australian government went with a national approach by building three rabbit-proof fences to protect the pastoral lands of Western Australia. The first fence stretched 1,138 miles vertically down the entire western side of the continent, starting from a point near Cape Keravdren in the north and ending in Starvation Harbor in the south. It is considered to be the world’s longest continuous standing fence. The second fence was built roughly parallel to the first, 55 – 100 miles further west, branching off from the original to the southern coast, stretching 724 miles. The final fence extends 160 miles horizontally from the second to the western coast of the country. Despite the enormity of the project, the fence was deemed unsuccessful, since many rabbits traversed over to the protected side during the construction period. Additionally, many have dug their way through the fence, as well. The introduction of the rabbit has also strained the native wildlife of Australia. Rabbits have been blamed for the destruction of the eremophila plant and various species of trees. Because rabbits will feed on seedlings, many trees are never able to reproduce, leading to local extinction. Additionally, due to direct competition for food and habitat, the population of many native animals such as the greater bilby and the pig-footed bandicoot has declined dramatically. The Australian government also experimented with biological methods to control the feral rabbit population. In 1950, mosquitoes and fleas carrying the myxoma virus were released into the wild. This virus, found in South America, only affects rabbits. The release was highly successful, as an estimated 90-99 percent of the rabbit population in Australia was wiped out. Unfortunately, because mosquitoes and fleas do not typically inhabit arid areas, many of the rabbits living in the continent’s interior were not affected. A small percentage of the population also developed a natural genetic immunity to the virus and they continued to reproduce. Today, only about 40 percent of rabbits are still susceptible to this disease.

发表评论

电子邮件地址不会被公开。 必填项已用*标注