Females were aged based on feather colour: brown females were assigned to second-year class (SY) and blue-green females to after second-year class (ASY) (Hussell 1983).
Twi the Humble Feather The three classical guitarists who make up Twi the Humble Feather, based in Brooklyn, include their unconventional tuning in the credits of their debut EP, "Music for Spaceships and Forests" (Friendly Ghost).
This line was selected for eight generations for increased feather pecking behaviour based on a social feather pecking test, but the hens showed no difference in aggressive pecking behaviour when compared to the low feather pecking line [ 27].
While this is perhaps not a surprising conclusion based on how feathers (and especially long flight feathers) are attached to the body of birds, it is an important confirmation of this point.
Further, measures among four ventral regions are also highly repeatable for this species [17] suggesting that our assessment of color in one region is fairly representative of color across the entire ventral surface of melanin-based feather coloration.
This feather microstructure does not quite line up with existing models for the evolution of feathers (based on Prum, 1999).
Using a microscope, she could then pinpoint minute structural characteristics and identify the bird species or family based on the feathers.
From trains, modelled on kingfishers to improve energy efficiency, to carpet tiles, based on birds' feathers and geckos to reduce the use of adhesive, Benyus is building up a portfolio of successful green designs created by imitating nature, a process called biomimicry.
"The bottom line is that until we understand how the fossilisation process affects these colour-producing chemicals and structures, and until we know how to look for evidence of these in fossils, there's really no point in attempting to reconstruct colour of feathers based on melanosomes alone," McNamara wrote in an email.
However, their measurements were based on the feathers as seen and did not include their putative extension into the halo.
They provide compelling evidence that the highly divergent ecotypes based on which feathers the lice exploit - body, head, wing or generalist - have evolved over and over again as new hosts with multiple vacant niches are colonized.
