What is a nestling?

A nestling refers to a young bird that is still dependent on its parents and is living in the nest. At this stage of development, the nestling is typically unable to fly and relies on its parents for food and care, making this option the most accurate representation of the term. Nestlings are in an important phase of growth where they are developing the strength and feathers necessary for their eventual transition to fledging, which is when they leave the nest and begin to fly. The definition captures not only the age of the bird but also its current living situation, which is a key characteristic of a nestling.