Teeth, sex and testosterone reveal secrets of aging in wild mouse lemurs

PUBLIC RELEASE DATE:

29-Oct-2014

Contact: Megan McRainey megan.mcrainey@emory.edu 404-727-6167 Emory Health Sciences @emoryhealthsci

Mouse lemurs can live at least eight years in the wild twice as long as some previous estimates, a long-term longitudinal study finds.

PLOS ONE published the research on brown mouse lemurs (Microcebus rufus) led in Madagascar by biologist Sarah Zohdy, a post-doctoral fellow in Emory University's Department of Environmental Sciences and the Rollins School of Public Health. Zohdy conducted the research while she was a doctoral student at the University of Helsinki.

"It's surprising that these tiny, mouse-sized primates, living in a jungle full of predators that probably consider them a bite-sized snack, can live so long," Zohdy says. "And we found individuals up to eight years of age in the wild with no physical symptoms of senescence like some captive mouse lemurs start getting by the age of four."

It is likely that starvation, predation, disease and other environmental stressors reduce the observed rate of senescence in the wild, Zohdy notes, but a growing body of evidence also suggests that captive conditions may affect mental and physical function.

"We focused on wild mouse lemurs because we want to know what happens naturally when a primitive primate is exposed to all of the extrinsic and intrinsic mortality factors that shaped them as a species," Zohdy says. "Comparing longevity data of captive and wild mouse lemurs may help us understand how the physiological and behavioral demands of different environments affect the aging process in other primates, including humans."

The study determined ages of wild mouse lemurs in Madagascar's Ranomafana National Park through a dental mold method that had not previously been used with small mammals. In addition to the high-resolution tooth-wear analysis for aging, fecal samples underwent hormone analysis.

The researchers found no difference between the longevity of male and female mouse lemurs, unlike most vertebrates where males tend to die first.

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Teeth, sex and testosterone reveal secrets of aging in wild mouse lemurs

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