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What Are Courtship Behaviors of Bald Eagles?

Some bald eagle courtship behaviors get all the attention. Death-defying aerial displays define the mating ritual for many bird-watchers, and scientists have named maneuvers after gymnastics moves and theme park rides. These sky dances make up only a small part of an eagle's relationship with its mate, however. Year after year when the dancing ends, bonded pairs return to the same nest, claim the same territory and defend it against any eagle that dares to trespass.

Mating Season and Pair-Bonding
- The mating season varies by geographic location. In Washington state, for example, most courtship takes place in January and February, but bald eagles in Ohio being courting in late fall, take the winter off, then start again in late January.
  
  Bald eagles ordinarily mate for life, although they will replace a mate who dies. Pairs unable to produce offspring may separate and seek more compatible mates.
Nest-Building
- Bald eagle relationships center around nest-building. According to the Ohio Division of Wildlife, "scientists credit the activity that occurs during nest building as the most important element in cementing the pair bond." First-time mates spend weeks on construction, but long-term partners expand their existing nests every season by adding insulating materials. Typical nests can weigh hundreds of pounds with diameters of 3 to 4 feet, but one record-setting nest in Florida boasted a diameter of 10 feet and weighed three tons.
Aerial Displays
- One observer compares courtship to a "midair battle" in which bonded pairs "duel, dive, wrestle, arc across the blue sky, and screech incessantly." Scientists have called one characteristic display "roller coaster flight." In another daring maneuver known as cartwheeling, one mate will grip the talons of the other while flying upside down. Once joined, the two eagles flip over repeatedly while plummeting towards the earth. They can slow the descent by flapping their wings, and only fly out of the cartwheel to avoid crashing.
Defending Territory
- Bonded pairs must often compete for nesting sites. Because they need suitable trees as well as access to open water and other food sources, they will defend chosen areas against others, particularly breeding-age adults. Scientists have recorded fights leading to injury or death, but pairs can usually discourage encroachment by chasing off or intimidating eagles that enter their territory.
  
  Some studies suggest that male eagles will defend a territory until killed or forced out, but that female eagles will often relocate when a mate dies.

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