Unit 19 - Birds (avian reptiles)

Feathers, forelimbs are modified into wings, furcula (fused clavicles), prominently keeled sternum, pneumatized bones, loss or fusion of digits, fusion of vertebrae, synsacrum, no teeth, no urinary bladder, one gonad often.

Down feathers - thermal insulation, Contour feathers - Flight feathers are a subtype of these, Filoplumes - Display or sensory.

Catch flying insects, forage over large areas, avoid some predators, migrate betwen feeding or breeding areas and away from extremely bad weather.

Bird lungs allow very efficient, one-way flow through respiratory channels called parabronchi.

4 main chambers, 2 atria and 2 ventricles due to a complete septum/wall.

Young that hatches ready to obtain food on their own.

Young that hatches and requires parental care for basic needs.

Cracking seeds open, eating small insects, spearing fish, tearing flesh.

Flightless, no sternal keel, most are very large, Ostrich, emu, cassowary, kiwi.

Wings are shaped like and used like flippers, all in southern hemisphere.

Perching birds and songbirds.

The voice box of birds. Located at the top of bronchi.