A bat from Siberia has set the world’s longevity record for small mammals, a feat that has grabbed the attention of scientists who study aging in humans. The male Brandt’s myotis is at least 41 years old.
Recently recaptured from the wild, the bat bore a numbered band that had been attached by researchers who captured and banded 1,544 bats near caves in the Siberian region of Russia in the 1960s.
The bat’s remarkable longevity was reported in the Journal of Gerontology by Andrej J. Podlutsky and Steven N. Austad of the University of Texas Health Science Center in San Antonio, and Alexander M. Khritankov and Nikolai D. Ovodov of the State Nature Researve Stolby in Krasnoyarsk, Russa.
The scientists said the bat lived 9.8 times longer that would have been expected based on its “longevity quotient” (age standardized by body size). That is the highest value ever reported for any mammal, including those maintained in captivity.
To survive so long in the wild, the researchers said, the bat’s physical functions must have been very well preserved. In other words, its ability to hear, echolocate and fly and maneuver rapidly had to remain at very high levels for this aging bat to capture prey and escape predators on a daily basis.
The general rule for mammals is that the smaller the species, the shorter the lifespan. “However,” the authors of the report said, “bats are a major exception to this pattern, with longevity of more than 20 years now documented for 22 bat species [and] more than 30 years for six species.” The Brandt’s myotis (Myotis brandtii) weighs just 6 to 6.7 grams before beginning hibernation.
Until Khritankov and Ovodov reported a 38-year-old Brandt’s myotis several years ago, the record had been at least 34 years, held by a little brown myotis (Myotis lucifugus) in the United States.
Why bats manage to live so long is a fascinating question that, the scientists said, “should make bats of special interest for researchers studying mechanisms of slow aging.”
One strong possibility is hibernation. Brandt’s myotis, for instance, hibernates from late September to the middle of June in Siberia. Hibernating bats, on average, live six years longer than those that do not hibernate. However, the authors note, even nonhibernating bats are unusually long-lived.
Possible mechanisms for bats’ longevity include – hypothetically – a possible resistance to oxidation damage, or DNA that is especially resistant to damage. Both are extremely speculative, but some research hints are pointing in those directions. “Our results at least suggest that bats might have exceptional defense mechanisms against cellular damage,” the researchers said.
BCI members can read the whole story on the amazing longevity of bats in the Summer 2006 issue of BATS Magazine.