Lemur Babies with Older Moms are Less Likely to Get Hurt and Bitten

Lemur babies may have a leg up if their mothers are older. Scientists have discovered that infants born to older mothers are less likely to get hurt than those who are born to younger mothers.

In most animal societies, the males are the ones that are more aggressive. In lemurs, in contrast, females can also be bullies. In fact, female lemurs compete with one another for first dibs on food and chase away males at mealtimes, sometimes lunging or snapping at each other with sharp teeth.

In order to find out a bit more about parent care among lemurs, the researchers analyzed the detailed medical records for more than 240 ring-tailed lemurs. These lemurs were monitored daily from infancy to adulthood over a 35-year period. More specifically, the researchers combed the medical records in search of evidence of bite wounds.

So what did the scientists find? Of the 237 ring-tailed lemur babies born between 1971 and 2005, 15 were bitten before their first birthday. All of these lemurs died from their wounds. The scientists then investigated a bit further and found that the most significant impact on infant injury and survival rates was the age of the mother.

In fact, infants who avoided injury were born to mothers who were two years older on average than the mothers of infants that were badly bitten. These results held up even when the others were first-time moms.

While the records don't show exactly who the perpetrators were, it's likely that females--some of them related to the victims as sisters and aunts--were responsible for some of the biting. In addition, it's likely that the bites may have been meant for the mothers rather than for the infants, since researchers have found injured infants clinging to their mothers at the time of attack.

The findings reveal a little bit more about how female aggression takes its toll on infants. Currently, though, scientists plan to take a little bit of a better look at what exactly might instigate or cause these attacks.

The findings are published in the journal PLOS One.