Spring is coming to North America and scientists are excited about it. Little dwarf lemurs wake up after months of hibernation – the first time these fur-tailed animals with fur have gone into long hibernation in captivity.
New research, which has recreated seasonal conditions to convince hibernating dwarf lemurs into hibernation, as do their wild relatives in western Madagascar, suggests that these animals may return to their wild hibernation modes after decades of captive breeding.
“We managed to reproduce their wild conditions well enough to make them reproduce their nature [hibernation] “said Erin Ehmke, a lead biologist at the Duke Lemur Center where the study was conducted.
The results of the study should not only help improve care for dwarf lemurs in captivity, but also provide scientists with new ways to study the biological deception that hibernating animals use to cope with environmental extremes.
(Lydia Greene)
Fat-tailed dwarf lemurs are master hibernators, spending up to seven months hibernating each year, depending on conditions. It is an extreme survival tactic used by many mammals for 250 million years.
Dwarf lemurs, which use tail fat deposits to last the winter in Madagascar, are in fact the closest relative of the hibernating primate. To save energy during hibernation, the heart rate is almost linear, body temperature drops and breathing slows to the point where scientists have observed that a hibernating lemur walks 21 minutes between breaths.
Studying hibernating animals is more than an envious curiosity for scientists, because it could one day improve human health. Although it remains a science fiction for the time being, researchers are looking at the science of hibernation to find ways to help people survive long-distance spaceflight, make the operation safer, and possibly prevent disease.
In this study, the research team monitored eight dwarf lemurs, the offspring of several wild animals brought to the Duke Lemur Center a few decades ago, for a few months of artificial winter to see if these animals could hibernate similar to their counterparts. their savages.
“Hibernation is literally in their DNA,” said Marina Blanco, a primate biologist at Duke University.
However, despite their efforts to care for captive animals, they tend to behave differently from their wild friends, especially when it comes to hibernation – something scientists have known for some time and most likely are due to. unnatural conditions in climatically controlled habitats of the zoo with abundant food.
Studies have shown that captive dwarf lemurs, for example, fall into much shorter periods of shallow hibernation, called torpor, than do wild lemurs, with these energy-saving sleeps, which rarely last more than 24 hours in captivity.
Whether this is just a temporary interruption of hibernation patterns or why captive lemurs have lost their physiological ability to hibernate remains a bit mysterious.
The researchers showed that dwarf lemurs are indeed able to withstand hibernation for months in captivity, supporting the idea that hibernation is biologically wired to these animals and can be reactivated under the right conditions.
Before breeding, the animals were equipped with radio transmitters to measure their heart rate and skin temperature and housed in comfortable, temperature-controlled enclosures with wooden boxes designed to mimic tree holes.
The researchers gradually adjusted the lights to suit Madagascar’s short winter hours, reduced the thermostat dial to 10 degrees Celsius (50 degrees Fahrenheit) and limited animal feed – then watched and waited.
From October to February, lemurs spent almost three-quarters of their time in slow metabolic motion: squatting, cool to the touch, barely moving or breathing for up to 11 days in a stretch, showing little interest in food.
Remarkably, few studies before this have experimented with restricting food to captive animals – even though hibernation is an extreme energy-saving strategy that animals use to survive when food becomes scarce.
“That males fed several times, expressed shorter torpor attacks more often and remained in torpor for fewer hours in general than females (although the size of our sample is too small to be conclusive)[s] that feeding could have affected the dynamics of the torpedoes to some extent, “the researchers wrote in their paper on methods.
Lemurs, who have been waking up from their sleep for several months, look healthy, the researchers said, with the animals’ heart rate hovering from 8 beats per minute (bpm) to about 200 bpm – and with it their appetite.
Once the animals recover well, researchers are looking to plan more studies before next winter, as long-lived lemurs could also keep secrets to age well.
“Until now, if you wanted to study hibernation in these primates, you had to go to Madagascar to find them in the act,” Blanco said. “Now we can study hibernation here [in captivity] and do more careful monitoring. “
The research was published in Scientific reports.