Hummingbirds’ unique sideways flutter gets them through small apertures
An Anna’s hummingbird (Calypte anna) navigating an aperture too small for its wingspan by sidling through while flapping its wings. Credit: Marc Badger, UC Berkeley Most birds that flit through dense, leafy forests have a strategy for maneuvering through tight windows in the vegetation—they bend their wings at the wrist or elbow and barrel through.