Episode 280 – Bald Eagle: Warm Wings

“…and today we’re talking about what KJV onliest thinks ancient Hebrews made themselves bald as. But more on that later.”

To soar sorely is such a bore.

A raptor up high has a real chore.

Hunting for prey far down below,

Is a bald eagle’s typical M.O.

But how can they fly for so long,

Are their muscles really that tough and strong?

Or is it the rhythms of earth

That keeps them up–sailing the skies with mirth?

Flowing with convection is key

To flight in Life, Death, and Taxonomy.

Description of the Bald Eagle

  • Large raptor with dark brown feathers all over its body and a characteristic pearly white head and bold hooked yellow freedom beak for tearing up the Stamp Act specifically.
  • The bald eagle’s gaze is enough to turn even the staunchest red coat to stone thanks to its piercing yellow eyes and constantly furrowed freedom brow
  • Its yellow feet are thick and powerful for crushing oppressive overseas monarchies and its red blood is pumped by a heart that ever beats for liberty and democracy.
  • Its NATOes are tipped with razor-sharp black talons for gripping prey

Measure Up

Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We don’t have a new Measure Up intro!

Wingspan

  • 1.8 and 2.3 m (5 ft 11 in and 7 ft 7 in)
  • How many eagles go into the longest flight ever by great circle distance?
  • Hint: Great circle distance is the distance along a straight circle around the globe–similar to “as the crow flies.” The longest flight by ground distance is held as a completely separate record. The one we are looking for was made by Air Tahiti Nui’s flight TN64 in a Boeing 787-9, which flew from Tahiti to Paris.
  • 6,832,608.7 bald eagles. 15,715 kilometers (9,765 mi; 8,485 nmi) 

Weight

  • 3 and 6.3 kg (6.6 and 13.9 lb)
  • How many bald eagles go into the Antonov An-225 Mriya, the heaviest aircraft to ever do flying?
  • Hint: The Antonov was a Soviet cargo aircraft that was built in 1988 and was destroyed by Russian forces in the Battle of Antonov Airport in Kyiv, Ukraine in February 2021.
  • 101,587.3 eagles. The Antonov is 640 tonnes (705 short tonnes).

Fast Facts about the Bald Eagle

Range 

Almost all of North America. From Mexico to Alaska to Florida to Newfoundland.

Diet 

Bald Eagles will eat most any animal small enough to carry off in their talons.

They mostly eat fish, but they’ll also snack on mammals, smaller birds, communists, and even reptiles. But it won’t tread on snakes no siree. In fact, they have over 400 species on the menu.

They swoop down and snatch up their pathetic prey using special tools they have in their claws called spicules, also known as .45 caliber ACP hollowpoints in a 30-mag clip that’ll blow your lung out your back.

They also invade and steal the kills of other sniveling competition species that are too weak to do anything about it.

Behavior

They make nests that span over 8 feet and weigh a metric ton which is mostly made up of sticks they find. There was one in Florida that was over 9 ft long!

Their calls are a light series of squeaks and whistles, far from the freedom cry of your prototypical eagle and more like the battle fife of the republic.

They reach sexual maturity at about 5 years old and have an impressive mating dance involving plummeting, locking talons, and eating an entire 64 oz steak, so it’s free at the Texas Roadhouse.

They lay between 2-3 eggs, which actually are larger the further north you get. The chicks fledge after 14 weeks and are ready to take flight and police a grateful world for another 20 years (their average lifespan).

There used to be a lot of bald eagles in the US, but a pesticide called DDT resulted in thinner egg shells and very low egg survival rates, reducing them to just a fraction. (Some estimate from 500K to just about 1000 over the course of a century.

Wind generator companies are licensed to kill 4,200 bald eagles a year

It’s been the US national symbol since 1782 – five years before the ratification of the constitution. 

But before that, many native american tribes revered the bald eagle as a symbol of peace and fertility.

Major Fact: Soar on Wings Like Eagles

Eagles are known for their ability to see long distances, but the reason they need to be able to spot prey from miles away is that they scan the ground from high in the sky. 

Very high…

Eagles can comfortably fly as high as 20,000 feet above sea level. For perspective, a commercial passenger jet flies around 35,000 feet. 

They don’t just fly high, they fly long. Birds wearing tracking equipment have meandered through the wild blue yonder for 125 miles without landing. An effortless glide is around 20 to 30 mph, so they can remain in the sky for six hours without needing to put feet to branch. 

Bald eagles can sustain these long flight times and use minimal energy with a few different methods.

The first is called dynamic soaring.

Dynamic soaring involves flying in a loop between two air masses. Air masses have different temperatures and humidity levels and the air may move at different speeds. 

The loop starts when the bird moves from one airmass into a moving airmass head-on, which increases its speed and generates lift. Then the eagle makes an immediate 180-degree turn and starts to gain groundspeed as it glides down toward the earth at a gradual slope. After gaining all that speed, they can restart the loop without losing momentum.

Bald eagles can also fly using thermal convection currents. 

Heat transfer is one of the main causes of ocean currents, weather, and geological activity. Just like heat causes thermal convection in the earth’s mantle, it causes convection in the atmosphere. Thermal convection currents are created by the uneven heating of the earth’s surface, resulting in high-reaching columns of air. 

Warm air expands and becomes less dense, so it rises above cool air. The sun heats the ground, and the ground heats the air above it, which rises until it is cooled by the low pressures high in the sky. Then it loops back down and repeats, creating convection. 

Eagles use these currents to save energy, allowing warm air to generate lift like a hot air balloon or like Link opening his glider above some burning grass.

Ending: So squawk softly, carry a big stick to your nest, and bop some commie field mice on the head like the bald eagle here in LDT.