Stately bird - for example, one brought up in Dorset (7)
I believe the answer is:
Here is my best explanation:
'in dorset' is the definition.
(swanage is in dorset)
'stately bird for example one brought up' is the wordplay.
'stately bird' becomes 'swan'.
'for example' becomes 'eg' ('e.g.' can be a synonym of 'for example').
'one' becomes 'a'.
'brought up' says the letters should be written backwards (down clues only).
'ega' reversed gives 'age'.
(Another definition for swanage that I've seen is "Dorset seaside resort".)