Giant pandas living in zoos may be suffering from ‘jet lag’, says study

Giant pandas living in captivity can suffer from “jet lag” if their biological clocks don’t match their environment, scientists say. This could have a significant impact on the well-being and behavior of endangered species, according to a new study published this Monday (18) in the journal Frontiers in Psychology.

Like all animals, pandas have a circadian clock — an internal biological clock that works in cycles of approximately 24 hours — and is regulated by environmental signals. But problems arise when the signals they are exposed to in captivity do not match those in their natural environment, the study concluded.

This can be very significant when 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 study lead author Kristine Gandia, a PhD student at the University of Stirling in Scotland, in a press release.

“When internal clocks are not synchronized with external signals such as light and temperature, animals experience adverse effects. In humans, this can range from jet lag to metabolic problems and seasonal affective disorders,” Gandia said.

Gandia and a team of observers decided to understand how the “jet lag” of living in latitudes where animals did not evolve could affect them. “This is definitely a concept that can be applied to all animals in captivity,” Gandia told CNN.

Giant pandas were chosen as the focus of the study in part because they live highly seasonal lives. Migrations occur in the spring, because 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 many who have ‘panda cams’ (webcams of the animal enclosures), so we can see how their behavior changes at different latitudes.”

These cameras allowed scientists to monitor the pandas’ behavior over a 24-hour period. However, other factors, such as regular visits from zookeepers, can also affect animals’ circadian clocks.

Gandia explained to CNN that the latitudinal range of giant pandas is between 26 and 42 degrees north. Corresponding latitudes could also be considered between 26 and 42 degrees south, she said, as they reflect temperature and lighting conditions.

A team of 13 observers, led by Gandia, monitored 11 giant pandas in six different zoos, all born in captivity. The zoos were not identified, but were roughly divided between the animals’ natural latitudes and those outside that area.

Those that matched were at latitudes equivalent to their natural habitat in China, but could be in other countries. 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 essentially recorded the entire repertoire of giant panda behavior, trying to explain behaviors that are positive, neutral and negative indicators of well-being. Therefore, this would include behaviors such as playing, grooming, and sexual behaviors as positive behaviors, and drinking and urinating/defecating as neutral maintenance behaviors, and various abnormal/stereotypical behaviors as negative behaviors, being the most common rhythm. Daylight and temperature were considered important cues for pandas.

Gandia explained the comparison with jetlag, telling CNN:

‘Jet lag’ does not refer to the acute inability to sleep at appropriate times resulting from moving quickly between different time zones, but rather to the potential lack of ability to fully adapt to environmental conditions. Conditions and signs at latitudes that pandas did not evolve to live in. Therefore, this can result in certain internal clocks or behaviors becoming desynchronized with the environment or with each other.

The captive animals showed three peaks of activity over a 24-hour period — one of which was at night — just as they would in their natural habitat.

Sexual behavior has only been recorded during the day in adult pandas, which could be an easier time for them to find mates in the wild.

Those living in captivity outside their native latitude were found to be less active, which may have been because daylight and temperature cues were different from those in their natural environment.

“When giant pandas are housed at higher latitudes — meaning they experience more extreme seasons than those in which they evolved — this alters their overall activity levels and abnormal behavior,” Gandia said.