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(单词翻译:双击或拖选)
We are not the only species that's come to dependent on the horseshoe crab1, they're critical to others too, like the Red Knot.
It's now May in Brazil, the Red Knots have built up their fat reserves and they are now in their breeding plumage. They are ready to begin of longest legs of their epic2 journey. They'll fly for as many as four days and nights without stopping, mostly over Open Ocean, with no landmarks3 to guide them. They'll use the moon, the stars and the sun. Their departure is mysteriously synchronized4 with an annual event, 4,000 miles north.
Here on the Delaware Bay, the water has warmed and the world's largest population of horseshoe crabs5 is beginning to spawn6. It's here that the Red Knot has always found the fuel for their journey to the Arctic, and the horseshoe crab has always provided that fuel in the form of eggs. The spawning7 season is an annual feast. It's a windfall for shorebirds, and a great opportunity for biologists. Migrating flocks have just begun to arrive. If the Red Knot's on schedule, they should be here soon.
Horseshoe crabs prefer spawning at the cover of night, but this is the height of their short season. It only lasts for few weeks. They come to shore when the tides are highest to lay their eggs deep in sand. Swarmed8 by hopeful males, the female digs down to bury her clutch. The males are smaller than the females, but they have a special claw that hooks on to her shell. Since fertilization is external, even unattached males would father some of the eggs. When her clutches are finally laid, the females break through the sand. In all the commotion9, eggs from prior spawns10 get unearthed11. What the crab accidently dig up is what the Red Knots depend on.
As the tide recedes12 and the crabs retreat, a flock of Red Knots appears in the sky. They've traveled for four days and nights without stopping. They're exhausted13 and initiated14. The flock will find a safe place to roost for the night and rest.
From all over the world, biologists have come to count shorebirds on the Delaware Bay. The spring migration15 offers a rare opportunity to assess populations. Many species of shorebirds are in decline, but the Red Knots that winter in South America are by far the most seriously. No one knows how many will make it to the Bay this year.
For the next week, more flocks of red knots trickle16 in. Once they're here, they need to eat. They only have about two weeks to refuel and set off again. Their breeding is tightly synchronized with the brief Artic summer. Their digestive system has shut down for the long journey. It's here that the horseshoe crab makes all the difference in the world. Their soft eggs are packed with protein and easy to digest. Some knots will double their weight in two weeks. While it's important food for other species, for the Red Knot it's essential.
This was a revelation to scientists and a key piece of the puzzle. As Red Knot numbers dropped, evidence began pointing to the Delaware Bay and to horseshoe crab eggs. Ongoing17 studies began to confirm the connection. There's been a steady decline in eggs on the Bay. Figuring out how many eggs there are is a tedious job, but it's become a critical piece in the puzzle.
That's a lot of work. We work about 40 hours a week. We take a sample roughly per one meter and we'll do this for about four hours other couple of days, then we're sought to eggs, then we count the eggs and that takes six or seven hours, and then we count the birds. From last year, it looks like the egg densities18 have dropped from same beaches and it's not a good sign. In Delaware in May, it's just a beautiful animal. I mean, it is, oh, I hate to see some go extinct.
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1 crab | |
n.螃蟹,偏航,脾气乖戾的人,酸苹果;vi.捕蟹,偏航,发牢骚;vt.使偏航,发脾气 | |
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2 epic | |
n.史诗,叙事诗;adj.史诗般的,壮丽的 | |
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3 landmarks | |
n.陆标( landmark的名词复数 );目标;(标志重要阶段的)里程碑 ~ (in sth);有历史意义的建筑物(或遗址) | |
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4 synchronized | |
同步的 | |
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5 crabs | |
n.蟹( crab的名词复数 );阴虱寄生病;蟹肉v.捕蟹( crab的第三人称单数 ) | |
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6 spawn | |
n.卵,产物,后代,结果;vt.产卵,种菌丝于,产生,造成;vi.产卵,大量生产 | |
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7 spawning | |
产卵 | |
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8 swarmed | |
密集( swarm的过去式和过去分词 ); 云集; 成群地移动; 蜜蜂或其他飞行昆虫成群地飞来飞去 | |
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9 commotion | |
n.骚动,动乱 | |
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10 spawns | |
(鱼、蛙等的)子,卵( spawn的名词复数 ) | |
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11 unearthed | |
出土的(考古) | |
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12 recedes | |
v.逐渐远离( recede的第三人称单数 );向后倾斜;自原处后退或避开别人的注视;尤指问题 | |
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13 exhausted | |
adj.极其疲惫的,精疲力尽的 | |
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14 initiated | |
n. 创始人 adj. 新加入的 vt. 开始,创始,启蒙,介绍加入 | |
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15 migration | |
n.迁移,移居,(鸟类等的)迁徙 | |
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16 trickle | |
vi.淌,滴,流出,慢慢移动,逐渐消散 | |
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17 ongoing | |
adj.进行中的,前进的 | |
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18 densities | |
密集( density的名词复数 ); 稠密; 密度(固体、液体或气体单位体积的质量); 密度(磁盘存贮数据的可用空间) | |
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