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(单词翻译:双击或拖选)
This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
Thirty million white-tailed deer now live in North America. "That's a lotta deer." Megan Gall1, a sensory2 ecologist at Vassar College in Poughkeepsie, New York. In her Hudson Valley locale, "there was a recent estimate here that you could have somewhere between 20 and 40 deer per square mile."
These prolific3 grazers have been blamed for many things: munching4 on baby trees "and that's a big problem because they are going to prevent forest regeneration." They also change the structure of the forest understory, "which is no good for birds that live there, small rodents5 that live there." And they co??ntribute to the lyme disease problem as tick hosts.
To all that, we can now add a new accusation6: that deer are altering the very acoustics7 of the forest, by pruning8 trees and changing the way sounds — like bird calls — travel through the trees.
Gall and her team investigated plots of forest where deer graze, and others where they were excluded. In each thirty-by-thirty-foot plot, they placed a speaker at one end, playing white noise, tones or trills. And recorded it all with a microphone in the opposite corner.
Then, they used software to analyze9 the recorded sounds. They found that while there was no difference in the loudness of the captured sounds among plots, the recordings10 captured in the grazed-upon plots did have higher sound fidelity11 — meaning they were closer in quality to the original playback tracks.
Now on the face of it, that might sound like a good thing. But as Gall explains: "If your sound has better fidelity, it's gonna be able to be picked up by more individuals. And so if you're a territorial12 animal you might get into more fights. If you're worried about predators13, predators might have an easier time hearing you. And so higher fidelity isn't always better." The results are in the journal PLOS ONE.
And to be clear, the researchers aren't arguing for any specific intervention14 here. "Yeah, I mean the deer situation is a little bit of minefield and I don't know how much I want to weigh in on it." But the findings might give advocates for increased deer management a bit more ammunition15.
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.
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1
gall
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v.使烦恼,使焦躁,难堪;n.磨难 | |
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2
sensory
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adj.知觉的,感觉的,知觉器官的 | |
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3
prolific
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adj.丰富的,大量的;多产的,富有创造力的 | |
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4
munching
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v.用力咀嚼(某物),大嚼( munch的现在分词 ) | |
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5
rodents
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n.啮齿目动物( rodent的名词复数 ) | |
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6
accusation
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n.控告,指责,谴责 | |
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7
acoustics
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n.声学,(复)音响效果,音响装置 | |
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8
pruning
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n.修枝,剪枝,修剪v.修剪(树木等)( prune的现在分词 );精简某事物,除去某事物多余的部分 | |
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9
analyze
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vt.分析,解析 (=analyse) | |
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10
recordings
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n.记录( recording的名词复数 );录音;录像;唱片 | |
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11
fidelity
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n.忠诚,忠实;精确 | |
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12
territorial
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adj.领土的,领地的 | |
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13
predators
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n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面) | |
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14
intervention
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n.介入,干涉,干预 | |
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15
ammunition
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n.军火,弹药 | |
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