10 Animals That Form Lifelong Bonds

9. Bald Eagles' Nests Get Bigger as Their Family Expands

Bald eagles are not only iconic symbols of strength and freedom, but also of enduring partnership. Once a pair of bald eagles forms a bond, they remain together for life, returning each breeding season to the same partner. This commitment is reflected in their shared effort to build and maintain large nests, which can become some of the biggest structures in the bird world. The process of nest building is a true team effort. Both eagles work together to gather large sticks, branches, and other materials, carefully constructing their nests high in trees, typically near water. These nests are incredibly durable, often reused and added to year after year, growing larger as the pair continues to strengthen their bond.