Birds and fish-eating mammals devouring rejected haul (8)

'birds' is the definition.
(seagull is a kind of bird)

'fish-eating mammals devouring rejected haul' is the wordplay.
'fish-eating mammals' becomes 'seals' (seals eat fish).
'devouring' is an insertion indicator.
'rejected' says the letters should be written backwards.
'haul' becomes 'lug' (I've seen this before).
'lug' back-to-front is 'gul'.
'seals' going around 'gul' is 'SEAGULLS'.

'and' is the link.