On a street frequented by dozens of pigeons, you can go years without seeing a newborn. Yet young birds are growing nearby. They develop in nests that are often hidden high up and only join the places where we watch birds after several weeks. By then, their appearance has already changed considerably.
This gap between birth and first appearance explains an urban curiosity: we readily see adult pigeons walking, pecking and gathering, but rarely the earliest part of their lives. There is no need for a mysterious disappearance or exceptional birth rates to explain this impression.
A young pigeon starts life under cover
A young pigeon is called a squab. On hatching, its sparse down and still-visible skin make it look very different from the fully feathered pigeon in a public square. It depends on adults for food and stays in the nest. That is what the word “altricial” means: early development takes place in the nest, unlike that of a chick able to follow its mother soon after hatching.
Both parents take part in incubation and then in raising the young. The RSPCA gives a typical clutch as two eggs, with incubation lasting around eighteen days. These are biological guideposts, not a timetable for dating a young bird precisely from a photograph.
The same British organisation puts fledging at around twenty-five to twenty-nine days, with the birds progressing towards independence over the following weeks. Between four and six weeks, a bird may already be well feathered. So a young bird’s visibility and its complete independence do not necessarily begin on the same day: it may remain near its birthplace after leaving the nest.
Buildings extend a cliff-dwelling habitat
Urban pigeons are domesticated descendants of the rock dove, Columba livia. The RSPCA distinguishes these populations from woodpigeons and the various doves that can also be found. Not all birds familiarly called “pigeons” have the same way of life or are identified by the same criteria.
The rock dove is associated with cliffs and rocky sites. Ledges, the undersides of bridges, rooftops and cavities in buildings provide urban pigeons with high-up nesting opportunities. A passer-by may see adults heading towards a façade without being able to make out the nest it shelters.
This location explains much of the young birds’ invisibility. We look at birds on the ground, where they are easy to observe. Reproduction takes place in another space, sometimes only a few metres away, but outside our usual field of view. A large number of visible adults does not mean their nests are within sight.
A “milk” produced by both parents
Feeding very young pigeons has another distinctive feature. Both males and females produce a substance called crop milk. The crop is a pouch in the digestive tract, so this “milk” is not a mammary secretion like that of a mammal.
The RSPCA describes the role of this substance in the first days of life. Futura’s article then explains how softened seeds are gradually introduced into the diet. This transition accompanies the young bird’s growth, while the adults continue to provide its food.
The expression should not be taken as an invitation to replace this feeding with drinking milk. Observing and understanding an animal’s diet does not, by itself, provide a care protocol for a bird found by someone. A bird in distress needs a wildlife rescue centre or a qualified professional; do not improvise a meal based on the name of this substance.
By the time it leaves, a young bird already looks like the others
By its first flight, a squab no longer has the bare appearance of a newborn. Its size and plumage may make it look like an adult in a group. More subtle clues remain: less pronounced iridescence on the neck, often darker eyes and a less developed cere, the area at the base of the beak. These features should be considered together, taking account of variations in the plumage of urban pigeons.
Births are not restricted to one short, identical period everywhere. The RSPCA says that in towns and cities, available food can allow pigeons to breed beyond spring and summer. This possibility is neither a local count nor proof of a population increase in any particular city.
The paradox is therefore mainly down to the way we see things: the first days are spent in inconspicuous places, then the young become visible when they already look much like adults. To notice this hidden life, it is better to watch their movements from a distance than to try to reach or disturb a nest.
References
- You have probably never seen a baby pigeon. It exists, it has a name, and it only leaves the nest when almost an adult
- Pigeons in the UK: facts, behaviour and common myths - RSPCA - rspca.org.uk
A squab and an egg in a nest, in La Virgen del Camino, Spain. Illustrative photograph.
Photograph: Fernando Losada Rodríguez — Wikimedia Commons — CC BY-SA 4.0.
