High-maintenance mallards

Jun 17, 2011
A mallard displays the vivid colors of its speculum feathers. Credit: Rafael Maia.

The shimmery feathers of a male mallard might have a showy quality that appeals to prospective mates, but the water resistance and self-cleaning capabilities of iridescent feathers pale in comparison to those of noniridescent plumage.

"Those good looks come at a cost," says researcher Chad Eliason, a graduate student in The University of Akron Integrated Biosciences Ph.D. program. Eliason, along with principal investigator Dr. Matthew Shawkey, UA associate professor of biology, say mallards' patches of iridescent feathers have deficient .

The Journal of Experimental Biology selected Shawkey and Eliason’s research finding, "Decreased hydrophobicity of iridescent feathers: a potential cost of shiny plumage," as its Editors' Choice paper for the July 2011 issue of the journal.

Eliason explains that iridescent feathers achieve their color by light scattering from nanometer-scaled structures in the plumage. The flattened barbules of thesefeathers are twisted toward the plumage surface, causing them to reflect light in abundance, yet expose more surface area for water adhesion.

"The deeper the tone of the iridescent feather, the less its hydrophobicity," says Shawkey, adding that less water resistance not only results in damp, but also soiled feathers.

Pretty, not practical

Eliason and Shawkey exposed both dull brown and iridescent violet portions of feathers to water droplets and discovered that the brown plumage repelled water, which efficiently washed away dust. In contrast, vivid violet feathers retained more water, compromising their ability to self-clean.

The researchers add that their finding provides insight to the evolution and distribution of iridescent plumage in birds.

"Males may use iridescent colors to advertise to prospective mates their ability to survive despite potentially waterlogged feathers; then females could correctly choose high-quality males," says Shawkey. “These flattened barbules are found in iridescent of many species, so this could be a widespread pattern. We hope to find out if this is true in future research."

Explore further: World's first microbe 'zoo' opens in Amsterdam

Provided by University of Akron

4 /5 (1 vote)

Related Stories

The role of color in animal courtship uncovered

Dec 15, 2010

Researchers at UQ's Queensland Brain Institute are one step closer to unlocking the role of color in animal courtship rituals after identifying a unique feather structure in birds of paradise.

Recommended for you

World's first microbe 'zoo' opens in Amsterdam

3 hours ago

The world's first "interactive microbe zoo" opened in Amsterdam on Tuesday, shining new light on the tiny creatures that make up two-thirds of all living matter and are vital for our planet's future.

Study shows how chimpanzees share skills

4 hours ago

Evidence of new behaviour being adopted and transmitted socially from one individual to another within a wild chimpanzee community is publishing on September 30 in the open access journal PLOS Biology. This i ...

Little blue penguin back at sea after hospital stint

9 hours ago

Wildbase Recovery Community Trust ambassador and Rangitikei MP Ian McKelvie joined Massey University veterinary staff to release a little blue penguin back into the sea at Himatangi Beach this morning.

User comments : 0