Bulletins broadcast caws filling roosts (9)
I believe the answer is:
'bulletins' is the definition.
(I've seen this before)
'broadcast caws filling roosts' is the wordplay.
'broadcast' indicates an anagram (letters scattered or cast around).
'filling' is an insertion indicator.
'roosts' becomes 'nests' (I've seen this in another clue).
'caws' anagrammed gives 'wsca'.
'wsca' inserted inside 'nests' is 'NEWSCASTS'.
(Another definition for newscasts that I've seen is " Bulletins".)