Synonyms for Squawk (same or very similar meaning)
WordNet sense 1 (informal terms for objecting):
beef, gripe, kickWordNet sense 2 (utter a harsh abrupt scream):
screech, screak, skreak, skreighWordNet sense 3 (complain):
bellyache, crab, grouse, hollerFrom the ODE community, based on WordNetadd/edit