a building of rooks Book of St Albans ConfidencehighAttestationhistorical-source, wikipedia-citedAlso spelledbuyldynge (1486) 3 sourcesWikipedia - List of animal namesOxford Dictionaries - What do you call a group of ...?Book of Saint Albans (1486) - The companyes of bestys & foules
a parliament of rooks A gathering of birds, especially rooks or owls. ConfidencehighAttestationwikipedia-cited, wiktionary-attestedAlso used forowls 4 sourcesWikipedia - List of animal namesOxford Dictionaries - What do you call a group of ...?Wiktionary - parliamentWiktionary - Appendix:English collective nouns