WEBVTT - How Do Bald Eagles Work?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,

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<v Speaker 1>Lauren Vohlbaum. Here, if you're a fledgling nation selecting a

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<v Speaker 1>national bird, you could do a lot worse than the

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<v Speaker 1>bald eagle. It's got the stately profile and steely eyed gaze,

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<v Speaker 1>the dramatic contrast coloring, and huge wingspan, which is all

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<v Speaker 1>part of why members of Congress chose the bald eagle

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<v Speaker 1>to represent the United States in seventeen eighty nine. For

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<v Speaker 1>the article this episode is based on How Stuffworks, spoke

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<v Speaker 1>with Scott Cordon, wildlife curator at the Center for Wildlife

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<v Speaker 1>Education and the lamar Q Bald Junior Raptor Center at

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<v Speaker 1>Georgia Southern University. Cordon is an expert falconer and manages

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<v Speaker 1>the center's najerie, which includes two bald eagles. First off,

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<v Speaker 1>to be clear, these eagles don't have the bald moniker

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<v Speaker 1>because their heads look hairless, but rather because they're white.

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<v Speaker 1>Their name comes from the Middle English word bald b alde,

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<v Speaker 1>meaning white, but bald eagles don't develop those striking white

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<v Speaker 1>head and tail feathers until they're mature, somewhere between the

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<v Speaker 1>ages of four and five years old. Immature Bald eagles

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<v Speaker 1>are mostly dark brown in color, with mottled brown and

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<v Speaker 1>white wings. They also don't fully develop the bright golden

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<v Speaker 1>yellow coloration on their beaks and feet until they're mature.

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<v Speaker 1>When they reach full size, bald eagles are big, with

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<v Speaker 1>the female eagles growing a bit larger than males. Overall,

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<v Speaker 1>they can weigh around nine to fourteen pounds that's about

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<v Speaker 1>four to six and a half kilos, with a wingspan

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<v Speaker 1>of around five and a half to seven feet or

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<v Speaker 1>about one point six two one point two meters. Only

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<v Speaker 1>a few other North American birds, like the golden eagle

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<v Speaker 1>and the California condor, are as large or larger. Bald

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<v Speaker 1>eagles are in the sea eagle family, meaning they live

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<v Speaker 1>near rivers and coasts and hunt mostly fish and white fowl,

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<v Speaker 1>but they're considered opportunistic carnivores, which means that they usually

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<v Speaker 1>eat whatever is available, including other small game like rabbits, squirrels,

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<v Speaker 1>or rodents, plus deadfish that have washed up on shore,

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<v Speaker 1>or even stolen prey from other birds such as osprey's.

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<v Speaker 1>The scientific name for this type of food snatching behavior

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<v Speaker 1>is klepto parasitism, but it's most common among the immature birds.

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<v Speaker 1>Once mature, bald eagles can be formidable hunters. When a

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<v Speaker 1>bald eagle swoops down to catch its prey, it uses

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<v Speaker 1>its razor sharp talons to snatch the unlucky animal it's

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<v Speaker 1>decided to make a meal out of. They'll roam a

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<v Speaker 1>pretty wide hunting territory about twenty five miles across some

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<v Speaker 1>forty kilometers. But for all that, your average bald eagle

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<v Speaker 1>can easily live off of a couple of adult rats

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<v Speaker 1>per day. Corton said, most birds don't eat every day

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<v Speaker 1>because they'll catch something that's large enough to sustain them

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<v Speaker 1>for a couple of days. Instead, they might feed off

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<v Speaker 1>of something large and fill their a part of their

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<v Speaker 1>digestive system where they temporarily store food that can sustain

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<v Speaker 1>them for two or three days, sometimes even longer. A

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<v Speaker 1>Bald eagles are the only sea eagles endemic to North America,

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<v Speaker 1>and they really have the territory covered. The bald eagles

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<v Speaker 1>range stretches from southern Alaska to northern Mexico and from

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<v Speaker 1>coast to coast. Due to their distinctive plumage, they are

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<v Speaker 1>almost impossible to mistake with other birds, even other large eagles.

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<v Speaker 1>When you see that white head soaring above the trees,

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<v Speaker 1>it's a bald eagle for sure. These birds can be

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<v Speaker 1>very social under the right circumstances. When food is plentiful

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<v Speaker 1>and it's not nesting season, a few to a few

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<v Speaker 1>hundred may roost together and have been observed engaging in

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<v Speaker 1>play behavior even as adults. They also mat for life,

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<v Speaker 1>though if one of a pair dies, the surviving birds

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<v Speaker 1>sometimes finds a new mate and they take nesting seriously.

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<v Speaker 1>Mates built nests called aries together, which takes around one

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<v Speaker 1>to three months. They also trade parental duties, with both

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<v Speaker 1>birds incubating the eggs for the five weeks or so

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<v Speaker 1>that it takes for them to hatch, because it takes

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<v Speaker 1>the hatchlings ten to twelve weeks to grow to the

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<v Speaker 1>point that they fledge, that is, take their first flight.

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<v Speaker 1>Eagles only lay one clutch or a group of eggs

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<v Speaker 1>per year. Cordon said. If their eggs or their young

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<v Speaker 1>are destroyed early enough in the season, they will lay

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<v Speaker 1>another clutch to try to reproduce again. In fact, that's

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<v Speaker 1>part of how they got the bald eagle population back up.

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<v Speaker 1>They would remove eagle eggs from the nest early in

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<v Speaker 1>the season and the adult eagle would lay another set

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<v Speaker 1>of eggs. It's called a double clutch. Due to these efforts,

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<v Speaker 1>the bald eagle was removed from the federal endangered species

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<v Speaker 1>list in two thousand and seven and is off every

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<v Speaker 1>state endangered species list too, though it's still protected by

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<v Speaker 1>several laws to prevent the population from dipping again. But

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<v Speaker 1>back to those nests. A bald eagles have the largest

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<v Speaker 1>nest of any bird species in North America. Their average

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<v Speaker 1>nest size is up to five feet across and four

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<v Speaker 1>feet deep that's about one point five by one point

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<v Speaker 1>two meters. The biggest arion record was built by pair

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<v Speaker 1>bald eagles in Saint Petersburg, Florida. It measured twenty feet

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<v Speaker 1>by nine feet that's about six by three meters, and

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<v Speaker 1>weighed two tons. A Cordon explained eagles only live in

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<v Speaker 1>their nest during the mating season, incubation, and while they're

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<v Speaker 1>raising the fledglings. Once they learn to fly and everyone

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<v Speaker 1>is out, they don't live in the nest. The birds

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<v Speaker 1>will return to the same nest year after year if possible,

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<v Speaker 1>but will leave if the tree's built in can't sustain it.

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<v Speaker 1>They're also pretty smart. A Courton said, they tend to

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<v Speaker 1>never forget anything, and they hold grudges. If you're training

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<v Speaker 1>an eagle and you make a mistake, that can either

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<v Speaker 1>ruin the training you've done or set you back several months.

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<v Speaker 1>But it's important to note that the bald eagle wasn't

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<v Speaker 1>the only bird in the running for a national symbol.

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<v Speaker 1>A founding father, Benjamin Franklin and favored the turkey as

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<v Speaker 1>the national bird, calling it more respectable and with all

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<v Speaker 1>a true original native of America. Part of Franklin's beef

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<v Speaker 1>was that the bald eagle is a scavenger. Corton said,

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<v Speaker 1>of all the birds of prey other than the vultures,

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<v Speaker 1>bald eagles will most readily go to a dead animal

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<v Speaker 1>on the side of the road, where other birds of

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<v Speaker 1>prey will only carry in if they're starving. Nevertheless, the

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<v Speaker 1>bald eagle was chosen as a symbol of strength, courage,

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<v Speaker 1>and freedom, and despite Franklin's comments, the bald eagle is

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<v Speaker 1>indigenous only to North America. Today's episode is based on

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<v Speaker 1>the article Bald Eagle, size, diet and History is a

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<v Speaker 1>National Icon on HowStuffWorks dot com, written by Patty Rasmusen

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<v Speaker 1>Brain Stuff is production of by Heart Radio in partnership

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<v Speaker 1>with HowStuffWorks dot Com and is produced by Tyler Klang.

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<v Speaker 1>Four more podcasts my heart Radio, visit the iHeartRadio app,

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