Mother and baby

(or Dad - I'm not knowledgable enough to know the difference)
This sparrow has built it's nest in the roof space of our garage. The chicks are the noisiest I have ever heard. For the last few weeks I have been able to hear them feeding whilst pottering around in the garden. Presumably  they are now getting used to being out of the nest.
BTW, how is the youngster managing to grip on to the quite steep slate roof tiles? A useful skill!