A secretive marsh bird faces existential threat from rising seas

Louisiana wetlands are eroding faster than almost anywhere in the world - and endangering the wildlife that call them home

Biologists crouched in the mud squint past their headlamps at the secretive marsh bird.

They have tramped through tall cordgrass for two hours, trying to stir the creature up by shaking cans of bolts and metal pellets. A few hundred feet away, the stretch of Louisiana marshland gives way to the Gulf of Mexico. Closer to their faces, mosquitoes swarm.