Once a feral pigeon has chosen a mate they will find a nesting site and jointly build a nest in which to lay their first eggs.
Feral pigeons usually lay two eggs but a very small number will lay a single egg and an even smaller number (0.5%) have been observed to lay 3 eggs.
The eggs are laid around 41 hours apart.
The first egg is usually (but not always) laid in the afternoon and is more often male. The second egg is more often female.
Both eggs will be a slightly different shape.
Parents don't feed the chicks as soon as they hatch , but the chicks receive their first meal from the parent bird within 4 to 6 hours of hatching.
When they are very young the parents only recognise their chicks by the exact location of the nest. Moving the nest 20 to 30 cm from the original site is enough to make the parents ignore it.
At around 4 to 7 days squabs will be aware enough of their surroundings to crouch down in the nest when observed by "intruders".
When the chicks are around 7 days old they will move backwards to the side of the nest to poop.
By the time they are 10-12 days old the chicks in the nest will attempt to hide from intruders.
By day 12-17 squabs can walk and may try to escape from the nest if they are disturbed. They are good at escaping from the nest by the time they are 20 days old.
By the time they are two weeks old chicks will snap their beaks and peck at intruders.
By day 15 co-ordinated flapping becomes possible.
By the time they are 20 days old squabs can walk and run and will wander from the nest, returning to be fed when the parents arrive. By this time the parents will recognise them outside the nest.
At around 20 days old the nestlings start pecking for food around the nest site.
When they are 25 - 28 days old the youngsters start to fly short distances.
By day 30 they will be attempting proper flight. and will leave the nest frequently but return to roost. At that age they will still beg from food and water from their parents.
They can fledge as early as 25 days or as late as 42 days.
Parental care will continue,usually to about 45 days but has been known to continue as long as 57 days.
The first (post juvenile moult) starts around 50 days after hatching.
Their eye colour changes from sludgy to the bright adult colour between 50 and 70 days old.
The cere enlarges and begins to change from soft and pink to white between 51 and 70 days of age.
At about 8 weeks their voice breaks, initially the squeak changes to a noise that sounds a bit like a quack or a honk.
The facts about the development of the feral pigeon have been gleaned from the observations recorded in the book "feral Pigeons" by Richard F Johnston and Marian Janiga.