they glide for a lot of their flight once they're airborne.

它们在空中飞行时经常滑翔
If you watch,

如果你观察过
my office overlooks the Grove Street cemetery,

我的办公室俯瞰格罗夫路公墓
there's some hawks that live in the cemetery,

公墓里住着一些鹰
must be a good place for hawks.

这一定是鹰的风水宝地
They take off and then they glide for long periods,

它们起飞之后会滑翔很长一段时间
they can circle and there's very little motion of their wings.

它们能够在几乎不动翅膀的情况下盘旋
They're basically doing-- they're taking advantage of the forward thrust

它们大体上说是利用了它们自己
that they have created and they're coasting

产生的向前推力它们在滑翔
but their wings are doing this.

但它们的翅膀在这么做
They're holding their wings in a position

它们将翅膀保持一个姿势
that creates an airfoil,

使之受到类似机翼受到的作用