03/27/2025
Two amazing nests?!
🦅Eagle 101: Auxiliary Nests🦅
It's a nice spring day and you're out doing some driving, hiking, or birding. You spy a nice Bald Eagle nest in the tree line, and then, suddenly, not very far away you spot another large Bald Eagle nest. You may be met with a feeling of confusion - aren't eagles fiercely territorial and keep a good distance between themselves and other eagles? What is going on? Well, fear not because what you aren't seeing isn't abnormal or unusual at all. You have likely spotted an auxiliary nest!
A good portion of Bald Eagle behavior revolves around the nest site, which makes perfect sense when you consider that almost half of the year involves raising the young or preparing to raise the young. They build nests that can grow to enormous size through the years and they do fiercely guard that territory. And sometimes, ambitious pairs of eagles build more than one nest. Those nests are typically in close proximity to each other. They will only occupy one nest during any given year, making that occupied nest the "primary", and the second nest the "auxiliary", and they may also alternate nest occupation year to year.
We're not entirely sure why eagles do this. Perhaps something happens with the first nest that creates the perceived need for a new nest. Whatever, the reason, the phenomenon is not all that uncommon. Keep your eyes peeled for auxiliary nests the next time you are out doing some nest viewing.
This photo from Minnesota was shared with us by Margaret Maire. While these two nests are fairly close, there are many situations where the nests are practically on top of each other, in the same or adjacent tree. 🦅🪺🪹😯😃👍