Lizard moms may prepare their babies for a stressful world

Apr 19, 2012
Skink mothers under stress allocate more energy to self-preservation at the cost of their developing offspring. But the rough start may actually be a benefit to the babies once they're born. Credit: Erik Wapstra

Stressed out lizard moms tend to give their developing embryos short shrift, but the hardship may ultimately be a good thing for the babies once they're born, according to a study published in the journal Physiological and Biochemical Zoology.

Stress changes the way animals allocate energy. During predator attacks or food shortages, hormones are released that help the body to access stored energy. But for pregnant females there's a potential trade-off. could rob precious energy from developing embryos, leading to that aren't as healthy.

A research team led by Erik Wapstra of the University of Tasmania, Australia, tested the on southern grass skinks, which, unlike many lizards, give birth to live young rather than laying eggs.

In the lab, the researchers recreated the physiology of a by artificially raising levels of the stress hormone corticosterone in pregnant skins. Other skinks had their food intake limited, recreating the stress of a food shortage. The team then measured the health of the stressed mothers and their eventual offspring, and compared their state to mothers and offspring that weren't under stress.

The study found that stressed moms gave birth to smaller offspring that grew more slowly than those born to low-stress mothers. Stressed mothers themselves were found to be in better physical shape after giving birth than non-stressed mothers. That's a signal that when stressors are present, mothers tend to allocate energy to self-preservation first.

Despite seemingly getting the short end of the stick, the news wasn't all bad for offspring of stressed . "We found that small offspring had larger fat reserves relative to body size…, which may enhance offspring survival in a stressful post-natal environment," the researchers write. Previous studies have also shown that smaller juvenile lizards often do better when predator density is high or when food availability is low.

It appears that a mother's stress-induced selfishness may actually help to pre-adapt her babies for a stressful world.

Explore further: New planthopper species found in southern Spain

More information: Physiological and Biochemical Zoology, Vol. 85, No. 3 (May/June 2012), pp. 231-242. www.jstor.org/stable/10.1086/665567

add to favorites email to friend print save as pdf

Related Stories

Effects of prenatal stress passed across generations in mice

Aug 17, 2011

Sons of male mice exposed to prenatal stress are more sensitive to stress as adults, according to a study in the August 17 issue of The Journal of Neuroscience. These findings suggest experiences in the womb can lead to ind ...

Study: Crickets 'forewarn' unborn babies about spiders

Feb 17, 2010

Just because cricket moms abandon their eggs before they hatch doesn't mean they don't pass wisdom along to their babies. New research in the American Naturalist shows that crickets can warn their unborn babies about potent ...

Recommended for you

Bats use polarized light to navigate

11 minutes ago

Scientists have discovered that greater mouse-eared bats use polarisation patterns in the sky to navigate – the first mammal that's known to do this.

How fussy pandas maintain a balanced bamboo diet

4 hours ago

(Phys.org) —Pandas are famously fussy eaters, but new research suggests there is method to their madness, with the animals switching between different species and parts of bamboo plants to maintain a balanced ...

New planthopper species found in southern Spain

10 hours ago

Not much is known about the the genus of planthopper known as Conosimus, which now includes six species after a new one was recently discovered in the southern part of the Iberian Peninsula in the Spanish ...

How rockstars and peacocks attract the ladies

Jul 21, 2014

What is it that makes rockstars so attractive to the opposite sex? Turns out Charles Darwin had it pegged hundreds of years ago – and it has a lot to do with peacocks.

User comments : 0