Remember in last week’s column my warning never to try to
charge a nonrechargeable battery? OK, you’re right, there was
no such warning; however, there should have been. This week I
found in my October issue of Consumer Reports that a safety
alert has been issued for the HP Photosmart R707 digital camera.
If you put a nonrechargeable battery in the camera and put the
camera in its docking station, a glitch in the “firmware” may
result in charging of the battery. One case of a fire has been
reported. HP says an update to the firmware will remedy the
problem. (If you happen to own this camera, Consumer Reports
gives a number, 866-304-7117, to call for information.)
Speaking of batteries, the battery in my trusty 1997 Volkswagen
Jetta will have been in service precisely five years next Monday,
September 11. I remember the date well, having had the battery
installed between the times that the first and second planes hit the
World Trade Center. I’m impressed the battery has lived these
five years and wonder if I should be prudent and purchase a new
one before winter sets in. Guess I’ll opt to go for six years.
Perhaps it’s my age but long lives seem to have been a recurrent
theme recently. At our Old Guard meeting last week one
member was celebrating his 103rd birthday. Then I read that the
oldest person in the world, I believe she was in South America,
died at the age of 116. An article by Joe Treen in the
September/October AARP magazine discusses the science of
aging and cites Edward Rondthaler, 101, as a centenarian who
still writes songs, children’s books and a weekly letter to the
editor for his local newspaper. The article has a picture of a man
holding a turtle. I’m not sure if it’s Ed and, if so, why the turtle?
The picture reminded me that I had failed to note the death
within the past year of Harriet, at over 170 the world’s oldest
known living animal. Harriet was a Galapagos tortoise that may
have belonged to Charles Darwin at one time. She didn’t look a
day over 100.
In the AARP article, Treen compares old Ed Rondthaler with the
naked mole-rat. It seems that the naked mole-rat and Ed share
the longevity thing. The mole-rat lives to 20 –30 years, up to 10
times longer than mice of the same size and scientists are trying
to figure out why. Treen discusses various theories and studies
on the factors that enter into living long. We’ve discussed some
of these in earlier columns. For example, restricted diets and
gene manipulation are two approaches that have significantly
increased lifespans in various subjects ranging from mice to
I was going to expand on the aging theme but then I searched for
more on the naked mole-rat on the Web sites of the Smithsonian
National Zoological Park, Cornell University and Davidson
College. I found the naked mole-rat to be a fascinating critter
with a lifestyle more like that of the ant or the bee than any rat or
mole. Indeed, the naked mole-rat isn’t closely related to either a
mole or a rat. Its closest relatives are porcupines, chinchillas and
There are over 30 other species of animals known as mole-rats
that hardly resemble the naked mole-rat, which is the only mole-
rat that has virtually none of the typical rodent fur – hence, the
“naked”. Jill Locantore, in an article on the National Zoo Web
site, describes the naked mole-rat as resembling an “overcooked
hot dog with buck teeth”. The four buck teeth, two upper and
two lower, actually lie outside the mouth and are superbly
adapted for digging tunnels. The naked mole-rat’s mouth can
close behind the teeth so it doesn’t swallow dirt while digging.
The wrinkled skin reminds me of one of those crinkly dogs,
whose breed I’ve forgotten. The skin is so thin that you can see
through it and make out some of the naked mole-rat’s organs.
The animal itself can’t see worth a hoot. It has evolved in a
world of darkness living in its underground tunnels.
The naked mole-rat is found in the wild only in arid regions in
the horn of Africa in countries such as Ethiopia, Somalia and
Kenya. In this part of Africa there are plants having large
underground roots and tubers, some of which are the size of a
soccer ball. The wise naked mole-rat eats out the center but
leave the skin essentially intact. This lets the plant regenerate the
tuber, providing another succulent meal for the mole-rat, which
doesn’t drink water, getting all its water from the plants.
But it’s the social behavior of the naked mole-rat that is most
interesting. The organization of a naked mole-rat colony is more
like that of an ant or a bee colony than that of any other mammal.
The naked mole-rat colony, which may number between 20 and
300 mole-rats, has a queen that rules with an iron hand. The
queen has a harem, so to speak, of a few selected males. When
she’s in the mood to mate, she’s the one who initiates the
process. When she ascends to the throne, the queen becomes
significantly larger than the other members of the colony. She
needs this extra volume to handle the large number of offspring
she will produce.
Paul Sherman at Cornell and his colleagues observed one naked
mole-rat queen that gave birth to as many as 28 pups in one litter
and had a total of over 900 in her lifetime! Only 10 to 11 weeks
are required to bring a litter to term; thus a queen can produce 4
or 5 litters a year. My impression of the life of a bee queen is
that she mostly lolls around laying eggs and being attended by
her subjects. Not so the naked mole-rat queen. She takes an
active interest in the detailed workings of the colony and will
leave her nest to see how things are going. If she comes upon a
blocked tunnel or if the food supply is running low, she’ll nudge
and prod her subjects to get to work to remedy the situation.
She also actively discourages any hanky panky in the ranks by
breaking up prospective romantic encounters among her subjects.
Her strategy here seems to be to engage in a lot of nose-to-nose
pushing and shoving with those members of the colony that are
ready for sexual activity. The researchers don’t know how the
queen enforces celibacy among her subjects but speculate the
pushing and shoving create stress that may affect the hormone
balance in both males and females.
The diet of the naked mole-rats is primarily the roots and tubers.
When a tunnel-digging member of the colony finds a food
source, it will bite off a chunk and carry it back to the colony,
chirping and holding the food aloft for all to sniff. A stream of
colony members then sets off, apparently following a scent trail,
to bring back food for the colony. The mole-rats also have the
distressing habit of re-ingesting their feces, presumably to get the
maximum amounts of nutrients from their food. Also, if a pup
dies, they depart from their vegetarian diet and eat the dead pup.
What happens when the queen dies? Things get messy and the
high-ranking females, typically the soldier mole-rats, fight it out
with each other. Sometimes females die in these fights, which
may last weeks or months before one hardy female becomes the
clear winner and becomes queen. I was intrigued by a less
violent approach to becoming queen. It seems that occasionally
a relatively fat and lazy naked mole-rat will one night decide to
leave the colony and strike out on its own, searching for a
similarly inclined mole-rat of the opposite sex. The two mate
and start a new colony.
I think we may be having hot dogs tonight. I’ll try not to think of
them as naked mole-rats!
Allen F. Bortrum