1) Bird genus 2) Bitterns 3) Genus ixobrychus 
Ixobrychus is a genus of bitterns, a group of wading bird in the heron family Ardeidae. It has a single representative species in each of North America, South America, Eurasia and Australasia. The tropical species are largely resident, but the two northern species are partially migratory, with many birds moving south to warmer areas in winter. The...
(from the article `bittern`) Bitterns of the genus Ixobrychus are small (30 to 40 cm, or about 12 to 16 in.). The sexes are unlike in appearance and share in the nesting duties. ...
[n] - bitterns
genus Ixobrychus noun bitterns