Birds and an animal with a funny nose (7)
I believe the answer is:
'birds' is the definition.
(pigeon is a kind of bird)
'an animal with a funny nose' is the wordplay.
'an animal' becomes 'pig' (pigs are animals).
'with' says to put letters next to each other.
'a funny' indicates anagramming the letters.
'nose' with letters rearranged gives 'eons'.
'and' acts as a link.
(Other definitions for pigeons that I've seen before include "Town birds" , "Cooing birds" , "Spin ego around the birds" , "Columbiform birds" , "traditional pie filling" .)