We witnessed this touching scene outside our kitchen window yesterday evening. The quality of the pictures isn't good because the light was fading fast but they show a fascinating aspect of pigeon behaviour.
These birds feed their young with a kind of 'milk' - a sweet, sticky liquid - secreted in their crop and the youngster has to push it's beak well down its parent's throat to reach it.
As the youngster grows the 'milk' is mixed with more of the bird's normal food, which is mostly vegetable matter - leaves and seeds. I suspect these birds have been responsible for nipping off my pea seedlings as soon as they've appeared through the soil.
These birds were clearly trying to wean their youngster away from dependence on the contents of its parents crop, by pecking at objects in the soil. it seemed to get the message because after they left it was clearly trying to forage for itself.
Top quality avian parenting skills!