people taking part, others with hundreds. The logistics of the Christmas bird count, he adds, are simple.
\circle, um, around the exact center point. And it's always the exactly same area that's done every year, usually, even on the same weekend during the count period. And what the ideal would be, which is virtually impossible, is this census: every single individual bird within that circle on the count day.\
Mr. LeBaron says experienced bird counters can get a good idea of the total bird populations within the count circle based on the number of birds they actually see. The editor points out, however, that the counts are not only for experienced bird watchers.
\Beginners will go out in a party with experienced individuals who know both the area and the birds in the area, in the field where more eyes and ears are better. And then anybody can point out a bird, and someone in the field will always be able to identify the bird.\ C Now listen to what Mr. Lebaron says about the information concerning birds. Complete the outline.
Outline
I. Total number of known species -- about 9 300 II. Habitat
A. Larger numbers living in the warmer climates e.g. more than 300 different species counted in Panama B. far fewer species native to colder climates
III. Value
A. importance to the environment
1. indicator of the quality of environment 2. sensitive to habitat alteration
B. esthetic value
1. getting pleasure out of looking at birds and listening to birds
2. mental quality of life degraded without birds
IV. Birds' population
A. some species -- declining B. many types -- increasing
Audioscript:
Mr. LeBaron says there are about 9 300 different known species of birds. Larger numbers of them live in the warmer climates. For example, more than 300 different species have been counted in Panama, while far fewer species are native to colder climates. Aside from their esthetic value, Mr. LeBaron says birds are important to the environment because they can signal changes in it.
\the environment within the given area. Whether it is a relatively local area, or even primarily on the worldwide bases, they are one of the first things to be altered. They are quite sensitive to a habitat alteration or to other threats. And often times when birds are disappearing out of the area, it just means there is a degradation of the quality of the habitat within that area which will adversely affect everything in there including humans.\
National Audubon Society editor Jeffrey LeBaron calls the world's bird populations a source of wealth that humans must protect. \birds. And if they start disappearing just the er, the quality of life,
um, may be not physically, but the mental quality of life can be degraded quickly.\
Jeffrey LeBaron says that while the National Audubon Society's annual Christmas bird counts show a decline in some species, many types of birds are actually increasing their populations.
Part III Dolphin captivity
in captivity：养在笼子（或池子，等）里；囚禁 announcer：播音员
thesis statements：文意，简述论文，论文主题 Colorado Public Radio：科罗拉多州公共广播电台 aquatic park：水上公园
Denver：丹佛（美国科罗拉多州） ire： 愤怒 dolphin ：海豚
instigate：教唆;煽动;激起
a former navy dolphin trainer ：前海军海豚训练员 Florida：佛罗里达州 ranges：范围
family-oriented：面向家庭的；群居的
concrete tank：混凝土水箱，混凝土油罐，混凝土贮水池
sonar：声呐装置
bounce off：试探（某人对某一新设想和意见），大发议论 ocean explorer：海洋探险家 reject：拒绝;抛弃
suicidal：自杀的，自杀性的;自我毁灭的，自取灭亡的;于己不利 pool ：池子
a very sophisticated brain：发达的大脑
sophisticated：复杂的;精致的;富有经验的;深奥微妙的 Portland：波特兰 (俄勒冈州) Oregon.：俄勒冈州
captive dolphins ：被捕的海豚
Sarasota Bay：萨拉索塔湾（佛罗里达州） Florida：佛罗里达州 the census data ：统计数据 distribution：分配，分布 debate：讨论;辩论;争论 marine mammal：海洋哺乳动物 organisms：有机体;生物 operate：操作，运行 metabolically：代谢的
anti-educational：对抗教育，反教育，逆教育 natural behavior ：自然行为