Spring is coming to North America and scientists are quietly excited. Little dwarf nut wakes up after months in hibernation – the first time these hairy fat tails go into captivity in a long hibernation.
New research, which recreates seasonal conditions to lure dwarf lemurs into captive hibernation, just like their wild relatives in western Madagascar, suggests that these animals may return to their wild hibernation after decades of breeding in captivity.
‘We managed to repeat their wild conditions well enough so that they could repeat their natural version [hibernation] patterns, ”said Erin Ehmke, a primate biologist at the Duke Lemur Center, where the study was conducted.
The findings of the study should not only help to improve the care of dwarf lemurs in captivity, but also to give scientists new ways to study the biological tricks that hibernate that animals use to experience extremes in the environment.
(Lydia Greene)
Fat-tailed dwarf lemurs are master-hibernating, sleeping up to seven months annually, depending on the circumstances. It is an extreme survival tactic used by many mammals for 250 million years.
Dwarf walls, which use fat stores in their tails to keep the Madagascan winter, are actually our closest hibernation family member. To save energy in hibernation, their heart rate drops almost flat, lowering their body temperature and slowing down their breathing to the point where scientists have seen one dormant maki move between breaths for 21 minutes.
The study of animals that are in hibernation is more than a jealous curiosity for scientists, because it could one day improve human health. Although it currently remains in the field of science fiction, researchers are investigating the science of hibernation to find ways to help people survive long-haul flights, make surgery safer, and possibly even prevent disease.
In this study, the research team monitored eight dwarf lemurs, the descendants of some wild animals brought to the Duke Lemur Center decades ago, during an artificial winter for a month-long monitoring to see if these animals were similar to theirs. wild peers could sleep.
“Hibernation is literally in their DNA,” said primate biologist Marina Blanco of Duke University.
Despite the best efforts to care for animals in captivity, they tend to behave differently from their wild friends, especially when it comes to hibernation – something that scientists have known for some time, and are probably due to the unnatural conditions in climate-controlled. zoo habitats with enough food.
Studies have shown that dwarf lemurs in captivity, for example, fall into much shorter attacks of shallow hibernation, called torpor, than wild lemurs do, with this energy-saving sleep rarely lasting longer than 24 hours in captivity.
Whether this is just a temporary interruption of hibernation patterns, or because captive lemurs have lost the physiological ability to sleep, remains a bit of a mystery.
The researchers showed that dwarf lemurs are indeed capable of sustaining hibernation in captivity, supporting the idea that hibernation is biologically linked to these animals and can be reactivated under the right conditions.
Before the animals were knocked down, the radio transmitters were equipped to measure their heart rate and skin temperature, and they were housed in a tight temperature-controlled enclosure with wooden cabinets designed to mimic tree cavities.
The researchers gradually adjusted the lights to suit the short winter-like hours in Madagascar, turned the thermostat switch to 10 degrees Celsius (50 degrees Fahrenheit) and limited the animals’ food – then looked and waited.
From October to February, the lemurs spent almost three-quarters of their time in metabolic slow-motion: curled up, cool to the touch, barely moving, or breathing for up to 11 days in a row, showing little interest in food.
Strikingly, few studies have experimented with restricting food to captive animals – although hibernation is an extremely energy-saving strategy that animals use to survive when food becomes scarce.
‘That males fed more frequently, expressed a short torpedo attack more frequently, and generally stayed fewer hours than females did (although our sample size is too small to be conclusive)[s] that the nutrition may have had an effect on the dynamics of the body to some extent, ‘the researchers wrote in their methods.
The researchers reported that the lemurs, which are now recovering from their months-long dormancy, look healthy, with the heart rate of the animals jumping back from 8 beats per minute (beats per minute) to about 200 beats per minute – and with it their appetite .
Since the animals are recovering well, researchers want to plan more studies in the run-up to next year’s winter, as long-lived lemurs may also contain secrets to aging well.
“Until now, if you wanted to study hibernation in these primates, you had to go to Madagascar to find it,” Blanco said. ‘Now we can study hibernation here [in captivity] and do closer monitoring. “
The research was published in Scientific reports.