听力原文
Yael: Today, we're talking penguin eggs.
今天，我们来谈下企鹅的蛋。
Don: Why?
为什么？
Y: Penguins lay their eggs on hard surfaces near coastlines, or they might dig burrows if the soil permits. And because they're optimized for swimming rather than walking, it's difficult for penguins to gather a lot of soft nesting material. See the problem?
企鹅在海岸边坚硬的地表产蛋，如果土地合适，它们也会挖洞。因为它们更擅长游泳而不是走路，对企鹅来说要收集到很多柔软的筑巢的材料是很难的。明白问题了吧？

D: Hmm! the penguin lifestyle isn't exactly eggshell-friendly.
企鹅的生活方式对蛋壳来说并不很友好。
Y: And that's not counting the nasty fights penguins can get into over things like space for their nests or burrows, and the stones that some species pile up around their nests if they're in the open.
那还不包括，企鹅为了争夺筑巢或洞穴领地而发生的激烈争斗，而且如果企鹅在开阔地，它们会在巢穴旁堆积石块。
D: I bet all that hubbub isn't very good for eggs either. So do penguins lose more eggs than other species?
我打赌所有的吵闹声对蛋也是不利的。那企鹅会比其它物种损失更多的蛋吗？
Y: Actually, according to one study, only 2.6 percent of penguin eggs break from causes other than human interference or predators. That rate is similar to the rate in the rest of the bird world, even including those birds that have cushy nests and never fight near their eggs.
事实上，根据一份研究显示，排除人类的破坏和掠夺者的影响，只有2.6%的企鹅蛋会破裂。这个机率和其它鸟类是一样的，甚至包括那些有舒适的巢穴且从不在蛋附近打架的鸟类。
D: So how do they do it? By producing thicker shells?
那企鹅是怎样做的？产出更厚的蛋壳？
Y: Yep. Penguin eggshells are fifty percent thicker than expected for their size. But it isn't easy to produce thick egg shells. It requires a lot of calcium, more than female penguins normally get in their diets.
是的，企鹅蛋壳比估计的尺寸要厚一般。但是不容易产出厚蛋壳，这需要很多钙，远多于雌性企鹅正常猎食中所获得的钙。
D: And they can't just run to the store for a supplement.
而且它们还不能去商店来补充。
Y: Nope. So in the period right before they lay eggs, female penguins eat a lot of mollusks. The clam and mussel shells in their stomachs slowly leach calcium which is then used to form eggshells. Incidentally, thicker shells also help prevent breakage for birds that lay eggs on rocks, and for ostriches and rheas.
不能。所以在企鹅产蛋前，雌企鹅会吃很多软体动物，胃中的蚌和贝壳类会缓慢 过滤用于形成蛋壳的钙。顺便说一句，厚蛋壳还能避免企鹅在岩石上产蛋时蛋壳的破损，就像鸵鸟和美洲驼一样。

D: I always did wonder about those ostriches.
我总是对这些鸵鸟感到惊奇。

生词注释
burrow n. 洞穴
nasty adj. 险恶的
hubbub n. 吵闹声
supplement n. 增补
mollusk n. 软体动物
leach v. 过滤