@Great Argus Doesn't San Diego still have any left? AZA should try to bring in White-Bellied Herons (Ardea insignis) or Great-Billed Herons (Ardea sumatrana) as the former is critically endangered and really needs help and the latter would look great in Southeast Asian/Indonesian exhibits.
@drill I also remember seeing them in Cincinnati in 2003 thinking "But they're endemic to the US. Why not bring in an exotic species?" There are others just as striking such as the Purple Heron, Black-Headed Heron or Pacific Heron that Sylvan Heights could choose.
I know these herons and egrets are kept here: American bittern?, Green-backed heron, Great egret, Black-crowned night-heron, Black heron, Boat-billed heron (also Honduran and Panamanian subspecies), Cattle egret, Great blue heron, Javan pond-heron, Little blue heron, Snowy egret, Tri-colored heron, and Yellow-crowned night-heron. I don't know of any Reddish egrets kept here, but I hope and wouldn't be surprise if there are.