Meet the Tiniest Wing-Propelled Diver Most wing-propelled diving
birds are fairly large, ocean-going fellows. Not so for the
smallest species to adapt this strategy. Cinclidae are a very
special group of songbirds that hunt underwater for insect prey
in freshwater streams. These marvelous little birds are capable
of both “walking” along the bottom by gripping the substrate and
of propelling themselves through the water column with their
wings. Today, five species can be found. As a group these
species have spread throughout much of the world including North
America, Europe, Asia and Africa. Dippers look rather unassuming
when on land, and it would be easy to mistake them for catbirds
or other garden variety songbirds at a glance. However, detailed
studies have revealed many evolutionary novelties associated
with more efficient waterproofing of the feathers, modified wing
musculature to assist in the underwater “flight” stroke, and
physiological properties of blood haemoglobin that make them
very efficient at