Blackbird chicks grow up and move out quite quickly. Often the parent birds kick them out of the nest because they have two clutches a year most often and need the nest free. I've watched blackbirds fledge and it's quite interesting. They hang out around the nest and are fed by the parents even as new eggs are being incubated.

I must look and see if I can spot the babies near the nest. I probably won't because there are so many places they could hide.

They will definitely try to hide in any nearby shrubbery.

I had to handle a frightened sparrow after a cat had played with it the other day.

You may well be able to get quite close to the tinybun, if you're sufficiently cautious - it's all a matter of not startling them, and approaching very slowly. For this shot, I wound up probably no more than 10' away, having edged up toward them over the course of a minute or two. It's quite a special feeling to be considered sufficiently non-threatening for multiple tinybuns to remain calm in such proximity. ^_^