25 across
Some
birds
pecked
others
(8)
Some birds pecked others (8)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
The definition is Some birds, referring to bitterns (wading birds). The wordplay is a charade: BIT (pecked, in the past tense) + TERNS (other birds, i.e. "others") gives BITTERNS.