Jonas, the world’s oldest known dwarf lemur, died this winter only a few months shy of his 30th birthday. Photo by David Haring/Duke Lemur Center
DURHAM, N.C., March 30 (UPI) -- The surprisingly long-living fat-tailed dwarf lemur reveals the secret of delayed aging -- hibernate, a lot.
Very few small mammals make it past the single-digit birthdays. Lab mice rarely live to be three. Small animal species, in general, live much shorter lives than their large-bodied relatives. Humans, the Galapagos tortoise and several types of whales can live 100-plus years.
There are, of course, exceptions to the rule. The fat-tailed dwarf lemur is one of those exceptions, capable of living to nearly 30 years old -- three to four times the lifespan of its miniature-sized peers.
And researchers at Duke University say the species' strategy for a lengthy lifespan offers several clues to the process of aging.
Biologists at the Duke Lemur Center analyzed several decades worth of medical records and lemur studies in order to get a better understanding of how they outlast their peers. Their work revealed the lemur's secret -- torpor.
For nearly three months every year, the fat-tailed dwarf lemur goes into a kind of semi-hibernation state called a torpor. Torpor is a state of decreased physiological activity. Hibernating lemurs can slow their heart rate down from 800 beats per minute to just eight. Their breathing and metabolic rate also slows, and they allow their internal body temperature to fluctuate with the outside temperature.
Scientists have previously suggested that hibernating animals live longer simply by avoiding predation. But the latest study found a correlation between the amount of time hibernating and average lifespan -- for both wild lemurs and those in captivity.
The results, researchers say, are proof that a lemur's torpor does more than allow it to avoid being eaten. It's likely protecting its cells for oxidation -- a byproduct of breathing and digesting.
"If your body is not 'working full time' metabolically-speaking, you will age more slowly and live longer," study co-author Marina Blanco explained in a press release.
Scientists are hopeful that lemurs -- who are more genetically similar to humans than most lab animals -- will help them identify anti-aging genes in humans.
The study was published this month in the Journal of Zoology.