The Fat-Tailed Dwarf Lemur

This little guy (Cheirogaleous medius) is native to the western coast of Madagascar. And he (let’s go with “he”) is typically quite small – as an adult weighing in at about a third of a pound. Lemurs are primates, and thus closely related to humans. The fat-tailed dwarf lemur is famous within the scientific community as the only primate known to hibernate for extended periods. This lemur will hibernate for up to 7 months – remarkable for any member of the animal kingdom. He will gorge for months during the wet season, feeding on fruits, flowers and bugs, storing fat in his tail, which may account for as much as 40% of his body weight. It doesn’t really get cold in Madagascar, but it gets pretty dry, and our lemur goes into hibernation. What scientists find intriguing about this hibernation is its length and the extent of torpor. Torpor is defined by decreased metabolism, heart rate and body temperature. While in torpor, the lemur’s heart rate will drop from about 180 beats per minute to four; breathing will decrease to one breath every ten to fifteen minutes; and body temperature will match that of the ambient temperature.

On the western coast of Madagascar the ambient temperature may drop to the low 40’s (Fahrenheit), taking with it the body temperature of the lemur (his usual body temperature matches that of ours).

Lemurs and Sleep

Humans enjoy two types of sleep; REM or rapid eye movement sleep, and non-REM sleep. We dream during REM sleep, while non-REM is restorative sleep. For humans, non-REM sleep is vital. But lemurs during hibernation seem only to experience REM sleep (no way to know if they dream), leaving scientists to wonder if they sleep at all. Animals deprived of non-REM sleep die over time; but not the fat-tailed dwarf lemur. It is a curiosity that is still being studied. Another curiosity is just how scientists are able to derive their data. They have to attach EEG sensors to the tiny foreheads of the lemurs. Similarly, they have had to implant sensors in a handful of the lemurs to measure body temperature. Gotta have small hands. Future occupation for a certain politician?

Does any of this matter?

Duke University is at the forefront of research into the behaviour of lemurs, especially how the brains of dwarf lemurs deal with hibernation. Could hibernation extend human life? For example, could a hibernate state be induced in patients waiting for the availability of an organ to be transplanted? Or could the metabolism of astronauts be managed to enable them to endure months of travel, absent the large quantities of nutrients necessary (as in the “Aliens” movies where Sigourney Weaver rises from an extended sleep, still looking quite fit and dishy)?

The CBC

I believe that taxpayers’ dollars are well spent on CBC Radio. Over the years I have enjoyed “This Country in the Morning” and “Morningside” with Peter Gzowski; “As It Happens” especially during the Barbara Frum years; and now “The Current” where the story about the fat-tailed dwarf lemur recently was broadcast. CBC Television? Love the news, but will pass on “Schitt’s Creek.” So thank you, CBC Radio for the lemur story.

Madagascar

Madagascar lies off the east coast of Africa and is the fourth largest island in the world – not that much smaller than the state of Texas. (If anyone asks; only Greenland, New Guinea and Borneo are larger islands).

From the air at least Madagascar is a gorgeous place. Having broken off from the Indian continent more than 80 millions years ago, its flora and fauna are unique. About 90% of its wildlife is found nowhere else. Lemurs, for example, are endemic to Madagascar. While lemurs are cute, there are a lot of things in Madagascar that are not. Lots of big bugs you would not want to meet. The hissing cockroach, below, is 2 to 3 inches long.

Spiders, scorpions, giant centipedes and malaria-causing mosquitoes abound. Plenty of snakes, none “overly dangerous to humans” (whatever that means). The good news? No lions, hippos, or crocs. But still not a place for me. Only four golf courses; just one an 18 holer.

My advice? Gather the grandkids and watch the movie.