As the cat is out of the bag, so to speak (the Eagle’s location is being shared widely on social media platforms), the following is some information that may minimize further confusion and help folks better understand what is happening with the adult eagle and sub-adult eagle living in our midst.

The sub-adult appears to be about 3.5 to 4 years old and is un-banded. The adult (with the pure white head) was thought to have been banded at a north of Boston town (in 2015 or 2016)  and is referred to as MM. Eagles get their “names” from the first two letters of the leg bands they received just before they fledged their nests.

The pair have been constructing a nest together. Is it unusual for an adult and sub-adult to bond and nest?  Prior to live nest cams, ideas about Bald Eagle nesting and mating behaviors were more rigid. But much, much more is known now and it’s wonderfully captivating!

MM was perched when the sub-adult flew in. MM gave several loud croaky gull-like greetings. He/she assumed the dominant position and copulation took all of ten seconds (which is typical for birds!) MM dismounted and the pair stayed side-by-side together for sometime afterward.

Although MM took the dominant position, that does not mean he/she is a male. Female Bald Eagles also approach. Both male and females initiate bonding and both may assume a dominant position when bonding.

It’s also difficult to tell by observing. Eagles are sexually dimorphic, meaning the females are bigger than the males. To compare MM and his friend side by side, MM looks to be a bit smaller however, juveniles also appear a little bigger than adults due to longer feathers that help them fly more easily.

Bald Eagle MM and subadult, possibly 3.5  to 4 years of age 

More reading –

Courtship, Copulation and Other Romantic Things – https://medium.com/@exploreorg/courtship-copulation-and-other-things-romantic-3c31d93e1627

Successful nesting by Bald Eagles Ages Three and Four –

Click to access p00113-p00114.pdf

Click to access 17(2)-p0085-p0086.pdf