TPO3-2 listen to the part of the lecture in the environment class. now, we have been talking about lots the loss of animal habitat from housing developments ,growing cities -small habitat losses. But, today I wanna begin talking about what happens when habitat is reduced across a large area. There are, of course, animals species that require large areas of (is) habitat and some migrate over is very long distances. So what's the impact of habitat loss on those animals -animals that need large (loge)areas of habitat.
Well, I’ll use the humming birds as an example. Now, you know a humming bird is amazingly small, but even though it's really tiny, it migrates over a very long distance, travels up and down the western hemisphere- the Americas, back and forth between where it breeds in the summer and the warmer climates where it’s spent the winter.
So, you would say that this whole area over which is migrates is its habitat. Because on these long-distance journey, it needs to come down to feed and sleep every thing so often, right? Well,
the humming bird beats so winster its wings,-get this- about 3000 times per minute. So yon think ,wow, it must be need a lot of energe, a lot of food, right? Well, it does. It drinks a lot of nectar from flowers and feeds on some insects, but its energy efficient too. You can’t say it isn’t, i mean, as is flies all the way across the Mexico, it uses up none of its body fat. But that doesn't mean it is doesn’t need to eat. So,
how humming birds have to rely on plates in their natural habitat. And it goes without of the thing saying, but the opposite is true as well. plates depend on humming birds, too. there are some of flowers that can only bepollomated
by the humming birds. without stopping to feed and spreading pollen from flower to flower, these plants would cease to exist. But the problem, well, as the nature habitat along these migration routes is developed by humans for housing or agriculture, or cleared for raising cattle, for instance, there is less food available for migration humming birds. their nesting sites a fact affected, too, the same by the same sorts of human activities. And all of these activitiespose a real threat to humming bird population. So help them survive, we need to preserve their habitats. and one of the concrete ways people have been doing this is by cleaning up polluted
by habitat areas. And then, we replanting flowers, replanting native flowers, that humming birds feed on. Promoting ecologicaltourism is another way to help save their habitat. as the number of the visitors, equal-tourists who come to harming bird habitats to watch the birds. the more the number of the visitor grows, the more local businesses’ profit. so ecological tourism can bring financial rewards. all the more reason to value these beautiful creatures on their habitat, right?
but to understand more about how to protect them to support humming birds the best we can. We’ve got to learn more about their breeding, nesting sites and migration routes, and also about the natural habitats we find there. that just help us determine how to prevent further to the decline in the population. a good research method , a good way to learn more, is by running about the rounding abandunt banding study. banding the birds allows us to track them over their lifetime. It’s been a practice that’s been by research of a year for years. In fact, most of what we’ve known about the humming birds, comes from banding studies, where we capture a humming bird and make sure all the information about it, like its weight and age and length, and all are required recorded and put into an international information database.
and then we place an extremely lightweight band on one of its legs. well, what looks like a leg.although technically it’s considered part of the bird’s foot. anyway these bands are perfectly save safe , and some humming birds have worn them for years with no evidence of any problems. the band is labeled with tracking number.
Oh, and there is phone number on the band for people to call for free, to report a banded bird to be found or funture to record recapture. so when a banded bird is recaptured and reported, we learn about the migration route.
its growth, how long it has been alive, on the life. it's life span. one recapture
bird was banned almost 12years earlier - she was one of the oldest humming birds on record. another interesting thing we learned is that some hummingbirds no longer use a certain route, they travel by a different route to reach their destination. and findings like these have been interest to biologists and environmental scientists in a number of the countries who are trying to understand the complexities
conplex of how changes in a habitat affect to species in it. 昨天的作业终于可以发了诺。。。
话说我想和上页的同学说,那个回复的时候直接高级编辑或者先回复再编辑重新粘贴,论坛就能识别word的颜色标记了。。。
汗,不知道大家还能看到不。。。
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