The pigeon, a familiar sight across sidewalks and city parks, is one of the most common birds in the world. Despite their prolific presence and year-round breeding cycle, the public rarely observes a baby pigeon. This absence creates a persistent mystery for many city dwellers. The life stage of a young pigeon is a carefully hidden process, governed by unique biology and a specific nesting strategy that keeps the vulnerable young out of sight until they are nearly adults.
The Name and the Mystery of Absence
The common name for a baby pigeon is a squab, and their disappearance from public view results from their highly secretive behavior. Descended from wild rock doves, these birds originally nested on cliff faces and in caves. Urban structures like bridges, rooftops, and window ledges mimic these ancestral environments, providing protected, high-up nesting locations inaccessible to most people.
Pigeons are altricial, meaning their young are born helpless and require an extended period of parental care within the nest. Unlike precocial birds, such as ducks or chickens, that leave the nest shortly after hatching, a squab remains hidden for an unusually long time. They typically stay confined to the nest for approximately four to six weeks, which is significantly longer than many other common bird species.
This extended nestling period is the primary reason the average person does not see them. By the time a squab is ready to fledge and venture out, it has reached nearly the size of an adult and is fully feathered. The juvenile bird is then easily mistaken for a mature pigeon, effectively blending into the flock upon its first appearance.
Exclusive Diet Pigeon Milk
The rapid growth that allows the squab to reach near-adult size before leaving the nest is fueled by a unique nutritional substance called crop milk. This secretion is not dairy milk, but a highly nutritious, semi-solid substance produced by both parent birds.
Crop milk is a cottage-cheese-like material composed of sloughed-off, fat-filled cells from the lining of the parents’ crop, an enlarged section of the esophagus. The production of this substance is regulated by the hormone prolactin, similar to lactation in mammals.
For the first week of life, crop milk is the squab’s sole source of food, delivered as the parent bird regurgitates the substance directly into the squab’s beak. This high-protein and high-fat diet allows the hatchling to grow at an accelerated rate. After the first week, the parents gradually introduce partially digested seeds and grains, slowly transitioning the squab to an adult diet.
From Hatchling to Fledgling
A newly hatched squab is a vulnerable creature with a distinct appearance that contrasts sharply with the familiar adult pigeon. The hatchling is born blind, with eyes remaining closed for about the first five days of its life. Its body is covered in sparse, yellowish, hair-like down rather than true feathers.
In their first few weeks, squabs have disproportionately large beaks and feet compared to their small bodies, making them appear awkward and undeveloped. They grow at an astonishing pace, transforming from a tiny, blind hatchling to a fully feathered bird in a matter of weeks.
The nestling phase involves a significant transformation, with pin feathers becoming visible on the wings and body around day ten. By the time the squab is four to six weeks old, it is ready to fledge, having developed its full set of contour feathers. While these fledglings are nearly adult-sized, a keen observer may still spot subtle differences, such as a duller pinkish-gray cere above the beak, which is whiter in adults.