Double-deck nesting by Carolina wren and northern cardinal

Abstract

Herewith, I report a Carolina Wren’s (Thryothorus ludovicianus) nest in a hanging basket flowerpot, which subsequently had a Northern Cardinal’s (Cardinalis cardinalis) nest built upon it. There was no interspecies aggression. Both species worked cooperatively to scare off a squirrel. The Carolina Wren and Northern Cardinal each fledged two young.