Spring is coming to North America and scientists are quietly excited. Small dwarf lemurs wake up after months of hibernation; the first time these furry fat-tailed animals have spent a long hibernation in captivity.
New research, which recreated seasonal conditions to convince dwarf lemurs in captivity to hibernate as their wild relatives do in western Madagascar, suggests that these animals may return to their wild hibernation form after decades of breeding in captive care.
“We have been able to reproduce their wild conditions well enough to get them to replicate their natural [hibernation] patterns, ”said Erin Ehmke, a primate biologist at the Duke Lemur Center where the study was conducted.
The results of the study should not only help improve the care of dwarf lemurs in captivity, but also offer scientists new ways to study the biological trick that hibernating animals use to cope with environmental extremes.
(Lydia Greene)
Fat-tailed dwarf lemurs are the main hibernators, spending up to seven months wintering each year depending on conditions. It is an extreme survival tactic used by many mammals for 250 million years.
Dwarf lemurs, which use fat in their tails to last the Malagasy winter, are actually our most hibernating primate relative. To save energy in hibernation, the heart rate is almost flat, body temperature plummets and respiration decreases to the point where scientists have observed that a hibernating lemur spends 21 minutes between breaths.
Studying hibernating animals is more than an enviable curiosity for scientists, as it could one day improve human health. While it remains in the realm of science fiction for now, researchers are studying hibernation science to find ways to help people survive long-distance spaceflight, make surgery safer, and even and all, prevent disease.
In this study, the research team monitored eight dwarf lemurs, descendants of wild animals brought to the Duke Lemur Center decades ago, during an artificial winter months to see if these animals could hibernate similar to their wild counterparts.
“Hibernation is literally in their DNA,” said Marina Blanco, a primate biologist at Duke University.
Although, despite their efforts to care for animals in captivity, they tend to behave differently from their wild friends, especially when it comes to hibernation, something scientists have known for quite some time, and which is most likely due to unnatural conditions in a zoo habitat climate with abundant food.
Studies have shown that dwarf lemurs in captivity, for example, fall into much shorter hibernation episodes, called torpor, than wild lemurs, with these energy-saving dreams that rarely last more than 24 hours in captivity.
It is still a mystery whether this is just a temporary disruption of hibernation patterns or why captive lemurs have lost their physiological ability to hibernate.
The researchers showed that dwarf lemurs are able to maintain hibernation for months during captivity, supporting the idea that hibernation is biologically connected to these animals and can be reactivated under the right conditions.
Before settling in, the animals were equipped with radio transmitters to measure heart rate and skin temperature and were housed in temperature-controlled enclosures with wooden boxes designed to mimic tree gaps.
The researchers gradually adjusted the lights to match the brief winter-like hours in Madagascar, turned the thermostat dial to 10 degrees Celsius (50 degrees Fahrenheit) and limited the animals’ food, then looked and waited. .
From October to February, lemurs spent nearly three-quarters of their time in metabolic slow motion: rolled up, fresh to the touch, barely moving, or breathing for up to 11 days in a stretch, showing little interest in food.
Surprisingly, few previous studies have experimented with restricting food to captive animals, although hibernation is an extreme energy-saving strategy that animals use to survive when food is scarce.
“Let males feed more often, express short episodes of torpor more often, and stay awkward in fewer hours than females in general (although the size of our sample is too small to be conclusive)[s] that food may have affected to some extent the dynamics of clumsiness, ”the researchers wrote in their method paper.
Lemurs, which have been waking up from their sleep for months, appear healthy, the researchers said, with a heart rate of animals ranging from 8 beats per minute (ppm) to about 200 ppm, and with that, the their appetites.
With the recovery of the animals, researchers are looking to plan more studies before next year’s winter, as long-lived lemurs can also harbor secrets for proper aging.
“Until now, if you wanted to study hibernation in these primates, you had to go to Madagascar to find them on the spot,” Blanco said. “We can now study hibernation here [in captivity] and follow up more closely “.
The research was published in Scientific reports.