Historical clue formulations

• Birds phonetically suggested by a feature of 17-, 27- and 51-Across — 2025-08-12
• Sam the Froot Loops mascot and others — 2020-01-14
• Ones who can't change large bills? — 2019-04-28
• They have substantial bills — 2008-08-31
• They have big bills — 2003-01-16