Pandas are not picky eaters. Whichever meal, be it breakfast, lunch, or dinner, bamboo is always an option. What is really interesting is the fact that this might not have always been the case.
Scientists already knew that pandas had a much more varied diet before and that at one point in their evolution, they decided to switch to bamboo as their primary source of nutrition. In a report from January 31, a team of scientists revealed that they examined panda bones and teeth to determine where the panda’s reliance on bamboo comes from. What they found surprised them, as it seems that they made the switch to bamboo some 5,000 years ago. They previously believed that the switch was made more than 2 million years ago.
The analysis was made by comparing the abundance of various isotopes in modern animals with the isotopes in fossil animals. Animal diets usually contain varying amounts of isotopes of carbon, oxygen, and nitrogen which are then ingrained into bones, hair, and teeth. The ratios vary based on the type of diet and the location and climate where the animal is found. For example, carnivores have more heavy nitrogen-15 isotopes because of meat consumption. On the other hand, animals living in harsh, cold conditions consume vast amounts of oxygen-18 since that isotope does not evaporate from that sort of environment at the same speed it does in warmer and more humid conditions.
A team of scientists examined isotopes in the teeth of pandas that lived during the late Pliocene Epoch some 2.6 million years ago. The tests revealed that the animal had a much more significant variation in oxygen isotopes than they do now. This implies that the bears lived in more climates than only the cold ones they inhabit now. They did not inhabit just cold and moist habitats like they do today, but they also lived in hot and dry climates that were vastly different to their current forest homes.
Modern pandas have a much lower ratio of heavy-to-light nitrogen isotopes. This makes them pretty different from other present-day herbivores and carnivores. When it comes to the isotopes of pandas that date back to the mid-Holocene Epoch, the isotope levels are mostly indistinguishable from isotope levels found in other herbivores. This clearly signals to scientists that the panda diet was not as specialized then as it is today.
Given that pandas come from the bear family, it is not so surprising that their diet was as varied as testing suggests. One thing that is interesting is that scientists were able to detect high levels of diet variability in ancient species as they did.
Proxies like the isotopes that were used in these studies are crucial in determining an animal’s way of life. They can even easily identify what a specific animal was doing during its lifetime.
All these findings come from the Chinese Academy of Sciences’ Institute of Zoology in Beijing. All of the testing was conducted by a team led by Fuwen Wei and his team of wildlife ecologists.
It is still unknown what forced the popular bears to make this dietary switch. Their teeth are specialized for chewing through tough bamboo. They also developed a pseudo-thumb to make grasping bamboo stalks easier. There is still no clear information when and why these modifications occurred. Now, it is up to the scientists to determine what forced this evolutionary step, and when exactly it happened. Additional testing is underway, and the team of Chinese scientists hopes it might give us the information we are missing.
As her name suggests, Jenna Small stands little over 4ft tall. Being petite and blonde, many often underestimate her talent. As a result, she spent her entire life working twice as hard to prove that she was the best. Now an established geologist, she does not beat around the bush when it comes to her work. Her research has been published and used in schools throughout the region. She often states that her most significant accomplishment was choosing to better herself through a solid education. When she is not busy unearthing new findings, she volunteers as a motivational speaker to girls who have been victims of bullying, discrimination, or harassment.