When young birds emerge from their nests, they enter the fledgling stage. This period marks a key step in their development, as they begin to explore the world outside their birthplace. Though they have left the nest, fledglings remain dependent on their parents, gradually learning the skills for independent survival.
From Hatchling to Fledgling
A bird’s life begins as a hatchling, often naked or with sparse down, and eyes closed. At this stage, they rely entirely on parents for warmth and nourishment. Hatchlings quickly develop into nestlings, characterized by open eyes and emerging pin feathers still encased in sheaths. Nestlings remain in the nest, unable to fly or stand proficiently, continually fed by adult caregivers.
Inside the nest, young birds undergo rapid physical changes to prepare for departure. Their true feathers, especially flight feathers, grow and develop. They stretch and flap their wings, strengthening muscles for flight. Most songbirds, classified as altricial species, spend an extended period in the nest, allowing for extensive development before fledging.
The Great Departure
The timing of fledging varies considerably among bird species, but it typically occurs when young birds are between 12 and 21 days old. For example, Northern Cardinals fledge as early as 7 to 13 days, while House Sparrows take 15 to 17 days, and larger birds like crows may remain in the nest for around 40 days. This departure is largely driven by instinct, as nestlings begin to exercise their flight muscles and move to the edge of the nest when they are ready. Remaining in the nest for too long increases their vulnerability to predators, making the outside world a comparatively safer option.
A fledgling’s first ventures outside the nest are often clumsy, involving short, awkward flights or even falls to the ground. This is a normal part of their learning process, and they may spend several days on the ground or in low vegetation. Parents sometimes encourage this departure by reducing food provisioning or by calling to their young from outside the nest. For many songbird species, all the young from a single brood typically fledge within a 24-hour window, emptying the nest quite suddenly.
Beyond the Nest
Once out of the nest, fledglings remain dependent on parental care. Parents stay close, providing food for their offspring, often for several weeks after fledging. This continued feeding ensures fledglings receive necessary nutrition for growth and development, even as they begin to experiment with foraging.
During this post-fledging period, parents teach essential survival skills. They demonstrate how to find food, guide them to safe roosting locations, and instruct them on evading predators. Parents issue alarm calls to warn of dangers and may actively defend their young. The transition to independence is gradual, with parental support slowly diminishing as fledglings become more proficient in flight and self-sufficiency.
Observing Fledglings Safely
When encountering a young bird outside its nest, it is helpful to distinguish between a nestling and a fledgling. A nestling is typically sparsely feathered or bare, unable to stand or perch, and needs intervention if found out of the nest. A fledgling, in contrast, is mostly or fully feathered, though it may appear somewhat disheveled, and can hop or flutter. These young birds are often found on the ground or in low branches, vocalizing loudly for their parents.
Finding a fledgling on the ground is a normal part of their development, and parents are usually nearby, continuing to care for them. However, it is generally best to observe from a distance and avoid intervention. If a fledgling exhibits clear signs of injury, such as bleeding, inability to stand, or a drooping wing, or if it has been attacked by a predator, then it may require assistance. In such cases, contacting a local wildlife rehabilitation center is the appropriate course of action.