American bitterns nest on the ground in Montana wetlands as a 28-inch migratory bird with a 42-inch wingspan. Males pump air into the esophagus then release it to generate a deep call that carries through thick marsh growth, marking territory and possibly attracting mates, while females utter a quieter similar note.

Threatened birds freeze motionless with bills aimed upward and eyes turned forward, their streaked brown-and-buff plumage matching cattails and bulrushes so they disappear. Habitat destruction, variable water management, people disturbing nests, abandoned fishing tackle, and avian influenza put this species of concern at risk, and more research must determine the impacts.