Hi Larry,
The details of ALL herons seem to be missing from the Gill 2nd edn list (they're certainly not listed underCICONIIFORMES were they would normally be) but in the other two they are there under CICONIIFORMES, although the authors differ in their use of subfamilies with Peters having a liberal approach:
ARDEIDAE(Ardeinae) Day Herons
ARDEIDAE(Nycticoracinae,Nycticoracini) Night Herons
ARDEIDAE(Nycticoracinae,Cochleariini) Boat-billed Heron
ARDEIDAE(Tigrisomatinae) Tiger Herons
ARDEIDAE(Botaurinae,Zebrilini) Zigzag Heron
ARDEIDAE(Botaurinae,Botaurini) Bitterns
And Sibley and Monroe a more conservative view:
ARDEIDAE Herons,Bitterns,Egrets
Looking at the individual case of Great Egret it appears that Gill 2nd edn follows a conservative route too:
Peters Family Name: ARDEIDAE(Ardeinae): Day Herons
Sibley-Monroe Family Name: ARDEIDAE:Herons,Bitterns,Egrets
Gill (2nd Ed.) Family Name: ARDEIDAE:Herons,Egrets,Bitterns
Must admit I always do a search based on individual species names.
Spud