Mother birds give a nutritional leg up to chicks with unattractive fathers

September 25, 2006

Mother birds deposit variable amounts of antioxidants into egg yolks, and it has long been theorized that females invest more in offspring sired by better quality males. However, a study from the November/December 2006 issue of Physiological and Biochemical Zoology shows that even ugly birds get their day. Providing new insight into the strategic basis behind resource allocation in eggs, the researchers found that female house finches deposit significantly more antioxidants, which protect the embryo during the developmental process, into eggs sired by less attractive fathers.

"For female birds, an important aspect of parental investment is the resources allocated to eggs," writes Dr. Kristen J. Navara (Auburn University and Ohio State University) and her coauthors. "The resources available to any female for reproduction and self-maintenance will be finite and she will inevitably be faced with decisions regarding how much resource to invest in each egg in each clutch she lays."

Male house finches display nutrition-linked plumage ranging in color from bright red to drab yellow. The researchers found that eggs sired by unattractive males (those with less brilliant feathers) had more total antioxidants, including 2.5 times the vitamin E levels, than eggs sired by males with redder, more saturated plumage. Thus, they explain, the deposition of more nutrients could represent compensation for the disadvantages experienced by an offspring from a lower quality male, allowing females to supersede limitations of a suboptimal pairing on her own reproductive success.

"For house finches, a species in which individuals are short-lived [and] present a high risk of death, a focus on the immediate reproductive attempts may be the only viable strategy," write the researchers. "By depositing antioxidants in a compensatory manner, females can maximize the reproductive output from the current nesting effort."
-end-
Since 1928, Physiological and Biochemical Zoology has presented original, current research in environmental, adaptational, and comparative physiology and biochemistry.

Kristen J. Navara, Alexander V. Badyaev, Mary T. Mendonca, and Geoffrey E. Hill. "Yolk antioxidants vary with male attractiveness and female condition in the house finch (Carpodacus mexicanus)." Physiological and Biochemical Zoology 79:6.

University of Chicago Press Journals

Related Eggs Articles from Brightsurf:

Chromosome defects seen from over-exchange of DNA in sperm and eggs
The exchange of DNA between chromosomes during the early formation of sperm and egg cells normally is limited to assure fertility.

First dinosaur eggs were soft like a turtle's
New research suggests that the first dinosaurs laid soft-shelled eggs -- a finding that contradicts established thought.

Neutron source enables a look inside dino eggs
Did the chicks of dinosaurs from the group oviraptorid hatch from their eggs at the same time?

Mosquitoes more likely to lay eggs in closely spaced habitats
Patches of standing water that are close together are more likely to be used by mosquitoes to lay eggs in than patches that are farther apart.

Northern white rhino eggs successfully fertilized
After successfully harvesting 10 eggs from the world's last two northern white rhinos, Najin and Fatu, on August 22nd in Kenya, the international consortium of scientists and conservationists announces that 7 out of the 10 eggs (4 from Fatu and 3 from Najin) were successfully matured and artificially inseminated.

A solarium for hens? How to increase the vitamin D content of eggs
Many people suffer from a vitamin D deficiency. This can result in brittle bones and an increased risk of respiratory diseases.

Put eggs all in one basket, or spread them around? Birds know best
A species of Central American cuckoo, the greater ani, forms groups of two or three females that nest communally to protect their eggs from predators, but sometimes a female will go outside the communal group and lay an egg in an outsider's nest.

Antarctic flies protect fragile eggs with 'antifreeze'
A molecular analysis by the University of Cincinnati found that wingless flies protected their eggs with a temperature-resistant gel to help them withstand freezing and thawing in Antarctica.

Why house sparrows lay both big and small eggs
Bigger isn't always better, as biologists who spent six years looking at the egg sizes of an insular population of house sparrows on Hestmannoy in Norway discovered.

Campylobacter -- the germ on chicken eggs
Eggs are a popular food. In fact, Germans consumed almost 20 billion of them in 2016, which equates to a per capita consumption of 235 eggs.

Read More: Eggs News and Eggs Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.