a siege of bitterns Book of St Albans ConfidencehighAttestationhistorical-source, wiktionary-wordlist-onlyAlso used forcranes, heronsAlso spelledsege (Middle English) 3 sourcesWiktionary - siegeWiktionary - Appendix:English collective nounsBook of Saint Albans (1486) - The companyes of bestys & foules
a sedge of bitterns Fanciful / unverified ConfidencelowAttestationwiktionary-wordlist-onlyAlso used forcranes, herons 2 sourcesWiktionary - sedgeWiktionary - Appendix:English collective nouns