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Giant pandas living in captivity could be suffering from “jet lag” if their body clocks don’t match their environments, scientists say.
This could have a significant impact on the well-being and behavior of the endangered species, according to a new study published Monday in the journal Frontiers in Psychology.
Like all animals, pandas have a circadian clock — an internal body clock that runs in approximately 24-hour cycles — and it is regulated by cues from their environment. But problems arise when the cues they’re exposed to in captivity do not match the ones of their natural environment, the study found.
This could be very significant to considering the welfare of animals in captivity, many of which are at high risk of extinction in the wild — including giant pandas.
“Animals, including humans, have evolved rhythms to synchronize their internal environment with the external environment,” said lead study author Kristine Gandia, a PhD student at the University of Stirling in Scotland, in a news release.
“When internal clocks are not synchronized with external cues like light and temperature, animals experience adverse effects. In humans, this can range from jet lag to metabolic issues and seasonal affective disorder,” Gandia said.
Gandia and a team of observers set out to understand how the “jet lag” of living in latitudes that animals did not evolve in can affect them.
“This is definitely a concept that could apply to all captive animals,” Gandia told CNN.
Giant pandas were chosen as the focus for the study partly because they live highly seasonal lives. Migrations occur in spring because the pandas eat a certain species of bamboo and go in search of new shoots. Spring is also mating season.
Their treatment in captivity also lent itself well to the study, Gandia added.
“Pandas are very good animals to focus on,” she said. “They are very popular in zoos and there are a lot which have ‘panda cams’ (webcams from the animals’ enclosures), so we can see how their behavior changes across different latitudes.”
These cameras enabled the scientists to monitor the pandas’ behavior across a 24-hour period. Meanwhile, other factors such as regular visits by zookeepers could also affect the animals’ circadian clocks.
Gandia explained to CNN that the latitudinal range for giant pandas is between 26 and 42 degrees north. Matching latitudes could also be considered between 26 and 42 degrees south, she said, as these mirror the temperature and lighting conditions.
A team of 13 observers, led by Gandia, monitored 11 giant pandas at six different zoos, all of which were born in captivity. The zoos have not been identified but they were roughly split between the animals’ natural latitudes and those outside that range. Those that matched were in latitudes equivalent to their natural habitat in China, but could have been in other countries.
The observers studied the pandas every month for a year, taking regular readings to see how their behavior changed.
In an email to CNN, Gandia explained: “We recorded essentially the entire repertoire of giant panda behavior, trying to account for behaviors that are positive, neutral and negative indicators for welfare. So, this would include behaviors like play, grooming, and the sexual-related behaviors as positive behaviors, and drinking and urinating/defecating as neutral maintenance behaviors, and several abnormal/stereotypic behaviors as negative behaviors, with pacing being the most common.”
Daylight and temperature were both found to be important cues for the pandas.
Gandia explained the comparison with jetlag, telling CNN: “The ‘jet lag’ does not refer to the acute inability to sleep at proper times resulting from quickly moving between different time zones, but rather to the potential lack of ability to fully adapt to environmental conditions and cues at latitudes that the pandas have not evolved to live in. Therefore, it could result in certain internal clocks or behaviors being desynchronised with the environment or with each other.”
The captive animals displayed three peaks of activity during a 24-hour period — one of which was at night — just as they would in their natural habitat. Sexual behavior was only recorded during the daytime in adult pandas, which could be an easier time for them to find mates in the wild.
Those living in captivity outside of their home latitude were found to be less active, which may have been because the daylight and temperature cues differed from those in their natural environment.
“When giant pandas are housed at higher latitudes — meaning they experience more extreme seasons than they evolved with — this changes their levels of general activity and abnormal behavior,” Gandia said.
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