This is the second youngster of this species that we have seen in the garden recently. How many actually survive to this age I do not know though I am sure many perish before attaining this age.
One pair of Wood Pigeons at least, nest each year in the tall conifer behind our garden but I think the nests are usually predated by cats, magpies and maybe even the squirrels. We rarely see young that survive to fledging.
Note that the young birds do not yet have the white markings that is so noticeable on the adult birds, that will come with the next moult.