In the vast majority of cases an apparently abandoned baby bird is best left alone as the parents are very likely nearby and will soon return to feed it. It may be possible to help a genuinely abandoned or injured bird but expert advice should always be sought first. As a start read the advice on the RSPB website.
Experts in Berkshire that may be able to help include the RSPCA, which has branches in:
Other organisations include:
Renton Righelato - 13 June 2007