Exposing chicks to maternal stress leads to long-term reproductive success

October 21, 2008
Male and female nestling starlings face different developmental costs as they compete for access to the limited resources provided by a low quality mother. Credit: Oliver P. Love

Do mothers purposely expose their offspring to their own stress? If so, why?

The question arises because it is widely accepted that exposure to maternal stress during pre-natal development can have negative impacts on offspring following birth. To examine why a stressed mother would allow this to happen, evolutionary physiologists Oliver Love and Tony Williams examined how offspring exposure to the maternally-derived stress hormone corticosterone affect maternal fitness in free-living European starlings (Sturnus vulgaris).

They experimentally increased yolk levels of corticosterone to mimic the "signal" offspring receive indicating they have a low quality mother. They then paired corticosterone-exposed hatchlings with experimentally manipulated low quality mothers to examine how these mothers fared in raising stress-exposed young compared with "normal" young.

Finally, they followed mothers within and across years to determine the long-term effects of the original manipulation on future reproductive success and maternal survival.

Their results provide the first evidence that low quality mothers benefit in the long-term from exposing offspring to their own stress: corticosterone exposure better "matches" offspring demand to a mother's immediate offspring-rearing capability. Corticosterone-exposed sons were of lower quality at hatching and when paired with a low-quality mother these sons experienced increased mortality.

However, because these mothers now had fewer mouths to feed, and of the smaller, less-demanding sex (daughters), the offspring that survived were of better quality. More importantly, by reducing investment in their current reproductive attempt, these "matched" mothers began second broods in better condition, had increased future reproductive output, and increased survival compared to "mis-matched" mothers (low-quality mothers that raised "normal'" offspring).

In the long-term, natural selection therefore appears to favor low-quality mothers that expose offspring to quality-mediated stress.

Citation: "The adaptive value of stress-induced phenotypes: effects of maternally-derived corticosterone on sex-biased investment, cost of reproduction and maternal fitness" by Oliver P. Love and Tony D. Williams. American Naturalist (2008) 172:E135–E149 DOI: 10.1086/590959

Source: University of Chicago

Explore further: Newborn panda twins vocal, 'very, very active': National Zoo

Related Stories

Recommended for you

How wind sculpted Earth's largest dust deposit

September 1, 2015

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists.

Brazilian wasp venom kills cancer cells by opening them up

September 1, 2015

The social wasp Polybia paulista protects itself against predators by producing venom known to contain a powerful cancer-fighting ingredient. A Biophysical Journal study published September 1 reveals exactly how the venom's ...

ATLAS and CMS experiments shed light on Higgs properties

September 1, 2015

Three years after the announcement of the discovery of a new particle, the so-called Higgs boson, the ATLAS and CMS Collaborations present for the first time combined measurements of many of its properties, at the third annual ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.