Pair admitting strong affection for shore bird (6)
I believe the answer is:
plover
'shore bird' is the definition.
(plover is a kind of shore bird)
'pair admitting strong affection' is the wordplay.
'pair' becomes 'pr'.
'admitting' is an insertion indicator.
'strong affection' becomes 'love' (I've seen this before).
'pr' going around 'love' is 'PLOVER'.
'for' is the link.
(Other definitions for plover that I've seen before include "Wader" , "Shore bird with long pointed wings" , "Lapwing, for example" , "Wading bird, such as a peewit" , "Lapwing-like bird" .)