Calls after elder, perhaps as they reveal age (4,5)

'as they reveal age' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'calls after elder' is the wordplay.
'calls' becomes 'rings' ('ring' can be a synonym of 'call').
'after' says to put letters next to each other.
'elder' becomes 'tree' (elder is a type of tree).
'rings' put after 'tree' is 'TREE RINGS'.

'perhaps' is the link.

Can you help me to learn more?