Microscopic View of a Desert Cardinal Feather

A microscopic view of a Pyrrhuloxia feather. Visible is the central rachis (black) and branching barbs (red) with interlocking, hooked barbules (grey and pink).


We have two lovely cardinal species that reside in the Sky Island region, the Northern cardinal (Cardinalis cardinalis) and Pyrrhuloxia (Cadinalis sinuatus), also known as the desert cardinal. Pyrrhuloxia has a prominent crest on its head, distinctive yellow bill (in contrast to the darker reddish-orange bill of the Northern cardinal), and gray feathers tinged with light red. When in flight, the red tint to the wings is visible as these beautiful birds fly around and perch in Sonoran Desert shrubs.  

The elegant flight of Pyrrhuloxia and other bird species is made possible by the light and flexible structure of feathers. Composed of beta-keratin just like the bird’s bill, feathers form a blade with interlocking separate barbs that branch off the central rachis. Learn more about the remarkable bioengineering of bird feathers here. 

A Pyrrhuloxia takes flight with the aid of wing feathers composed of many branching and interlocking barbs.