Pretty Great Tits make for healthy offspring, study shows

Andrew E. may have gotten it wrong after all: a homely mate may be less prone to wander, but could result in less healthy children.

 

At least that's what a recent study seems to show for Great Tits, a species of yellow-bellied bird common to parts of Asia and Africa.

 

A paper published in the open access journal Frontiers in Zoology by BioMed Central reports that prettier birds tend to have chicks with higher birth weight, growth rate, and immune response.

 

Researchers Vladimír Remeš and Beata Matysioková from Palacky University in the Czech Republic observed that the appearance of a female Great Tit (Parus major) may be an indicator of the health and viability of her offspring.

 

Usually, the adult Great Tit female has a black stripe across the breast and white patches on her cheeks.

Experimental chick swapping  

In an experiment, Remeš and Matysioková took two mothers with different patterning and swapped their chicks.

 

They found a correlation between the size or width of the genetic mother’s black breast stripe and the infant’s weight at two weeks.

 

The strength of infants’ immunity was the same regardless of the purity of the white cheek patches of both the genetic and foster mother, whereas the body size of a chick corresponded with the body size of its genetic mother.

 

Great Tits are socially monogamous birds, with both males and females developing brightly-colored plumage in adulthood. It was observed, however, that the ornamentation of the males had no effect on the health of the offspring. Ornamentation signals fitness

 

Remeš and Matysioková explain the ornamentation could have resulted from the evolutionary principle of “survival of the fittest”. Bigger and healthier offspring ensure the survival of the species because they have a higher chance of surviving to adulthood. Since bright coloration uses up physical energy better directed toward reproduction or self-maintenance, the Great Tit females most probably developed ornamentation as a signal of reproductive fitness.

 

In short: beauty aids in the continuity of the species. — TJD, GMA News