Picture this: it is a chilly December day, you are taking a walk outside, and the fresh snow is crunching under your snow boots. Not a cloud in the sky, and out of nowhere, you see two beautiful adult bald eagles TUMBLING HUNDREDS OF FEET TOWARDS THE ICY GROUND BELOW → OH NO! Not to worry – this is actually totally normal mating behavior for our national mascot. Affectionately named the “cartwheel courtship flight,” this dance entails two eagles flying up high, locking talons, and hurdling down to the earth while spinning in a cartwheel-like fashion, only to release at the last possible moment.
While this incredible behavior is a common mating activity for bald eagles, it can alternatively be a ritualistic fight between males defending their territory. On an all-too-relatable note, the eagles will sometimes misjudge distance and hit the ground in their game of chicken with gravity. Luckily, this is not a super common occurrence! When not fighting for their rightful home base, eagles typically mate for life, with only a 5% reported “divorce rate,” according to bald eagle expert Bryan Watts.
In case you were bored with the first feat of acrobatics mentioned above, eagles have quite a few other mating rituals to further intensify their behavior! There is also one called the “roller coaster flight” in which one eagle will soar up into the sky, only to veer back down, and repeat. This is a beautiful display of communication and bonding demonstrated by even more beautiful animals.
In addition to their chancy mid-air cartwheel, paired bald eagles will engage in other activities to strengthen their bond. This includes foraging for nest materials with their partner, kind of like picking out wedding registry items for us! The feathered friends will start by gathering large sticks, then smaller ones, gradually transitioning to small soft materials like grass and pine straw to make egg cups which help insulate their developing eggs. It can take up to three months for a nest to be ready once the pair starts building it. Pairs will reuse a nest from one year to the next, so a robust investment in their nest the first time out can pay off later!
One more incredibly interesting aspect of eagle mating behavior is that sometimes there are more than two birds in the relationship! There have been reports of one male mating with two females as well as trios consisting of two males and one female. Regardless, teamwork is the name of the game, with all the adults working together to prepare, incubate, and raise their clutch in harmony. When the time comes, all three adults contribute to hunting for food for their large brood! While we don’t yet understand all the dynamics and behaviors that go into this type of bond, a trio of adult eagles has been documented numerous times in nature, including Illinois’ own famous eagles: Valor I, Valor II, and Starr, who nest along the Mississippi River in Fulton, IL.
Have you ever seen a daring display by bald eagles? Hopefully, now you know that this is normal and nothing to be worried about! Tell us any amazing stories you have on our Facebook page!
Written by Jamie Booth, class of 2023.
