pterylosis

pterylosis (plural pteryloses)

1. (ornithology) The particular arrangement of feathers on a bird.
   • 2006, Ted R. Anderson, Biology of the Ubiquitous House Sparrow‎:

     In a detailed study of the pterylosis of the genus Passer (with special emphasis on the house sparrow), Clench (1970) identified nine feather tracts: dorsal, scapulohumeral, femoral, ventral, lateral neck, capital, alar, crural, and caudal.

Pterylosis refers to the arrangement of feathers and how they are implanted in the skin, while ptilosis refers to the properties of the feathers themselves.

• ptilosis

• pterolysis