Red panda, two, not one, species?


This 2018 video is called World’s Weirdest Animals: Red Panda.

From New Scientist:

Red panda genes suggest there are actually two different species

26 February 2020

By Gege Li

We now have the strongest indicator yet that there are two separate species of red panda: the Chinese red panda (Ailurus styani) and the Himalayan red panda (Ailurus fulgens). Previously, these were classified as subspecies based on the pandas’ physical characteristics and location, but this has been contested due to a lack of genetic evidence.

To address this gap, Yibo Hu at the Chinese Academy of Sciences in Beijing, and his colleagues sequenced the whole genomes of 65 red pandas by extracting DNA from blood, muscle and skin samples taken from museum specimens and red pandas in captivity.

These red pandas came from wild populations living in the Himalayas in Nepal and India, or the Qionglai mountains in China’s Sichuan province.

Using data from 49 red pandas, the team compared their haplotypes, variations in DNA inherited from a single parent – for example, their mitochondrial DNA, which is inherited from the mother, and Y chromosomes, which are inherited from the father.

Compared to Chinese red pandas, the Himalayan red pandas had 50 per cent fewer mutations in the single letters, or bases, that make up DNA across their whole genomes . Hu’s team also found that the haplotypes clustered together in different regions of the genomes of Himalayan and Chinese red pandas, and there were no shared Y chromosome variants between red pandas from the eastern Himalayas and those from Sichuan.

Hu says this shows that they genetically diverged from each other, with minimal transfer of genetic variation between the populations, resulting in the two species. This divergence happened about 200,000 years ago, he says.

Physical differences between the two populations supported the classification – the Chinese red panda has redder fur on its face and more prominent tail rings, for example.

Though there is clearly genetic differentiation between the sampled populations, no red pandas were sampled in Bhutan and northern India where the animals are also found, says Jon Slate at the University of Sheffield in the UK. “Without having sampled pandas there, it’s harder to really confidently say there are two distinct species here,” he says.

The genome analyses also showed that the Himalayan red panda underwent a drastic reduction in population three times, with the most recent decline taking place 90,000 years ago. This has resulted in a low genetic diversity and small population size in today’s Himalayan species.

In comparison, the Chinese red panda experienced a population drop twice – most likely due to glacial periods – but managed to recover after each event.

However, both species’ numbers are dwindling due to habitat loss and climate change, though it isn’t clear how many individuals are left in the wild. “To conserve the genetic uniqueness of the two species, we should avoid their interbreeding in captivity,” says Hu.

How pandas climb trees, new research


This video from China is about giant panda Mao Sun climbing a tree.

By Susan Milius in the USA, 28 January 2020:

How pandas use their heads as a kind of extra limb for climbing

Short legs on a chubby body demand a work-around when it comes to getting up a tree

AUSTIN, Texas — Pandas really use their heads to climb.

As the pudgy, short-legged bear climbs, it presses its head briefly against the tree trunk again and again, physicist Andrew Schulz said January 4 at the annual meeting of the Society for Integrative and Comparative Biology. The head serves as a make-do extra paw, first pressed against one side of the tree and then against the other. This extra pressure helps the bear hold on as it releases and raises an actual paw. Schulz knows of similar behavior only in newborn kangaroos, which use their heads to help haul themselves to their mother’s pouch for the first time.

Head moves make sense for panda proportions, said Schulz, speaking for a research collaboration between his university, Georgia Tech in Atlanta, and China’s Chengdu Research Base of Giant Panda Breeding. Pandas have the shortest leg-to-body ratio among the world’s eight living bear species. “I like to call them Corgi bears,” he says.

How pandas, or any other big mammals, climb hasn’t gotten the analytic attention that techniques of squirrels and other small animals have, Schulz said. Yet rushing up a tree trunk can be a lifesaving move in the wild for pandas attacked by feral dogs. Chengdu researcher James Ayala conceived the climbing study to get the first quantitative data on emergency escape skills in captive-bred youngsters. Such information helps the Chengdu researchers judge young pandas’ chances of surviving in the wild.

For this study, the Chengdu staff built a panda climbing gym: four bark-stripped tree trunks, each a different diameter, holding up a high platform. Researchers videotaped eight young pandas, all at least a year old. The animals had grown beyond the waddling fluffball stage and were basically young teenagers with a bit of growing, and sometimes a lot of learning, left to do.

Some youngsters just didn’t get the tree thing. “No controlled ascent or descent — it was kind of madness every single time,” Schulz said of one young bear.

Others caught on, for instance reaching the pole top in eight of 10 attempts. The most successful climbers moved their heads roughly four times more than those who flubbed the poles, Schulz said. Even one female born without claws made it up the pole. The head press improves the panda grip and keeps panda weight safely balanced close to the tree.

Head-climbing looks familiar to Nicole MacCorkle, a giant panda keeper at Smithsonian’s National Zoo in Washington, D.C. She wasn’t at the meeting, but she has seen video from the Chengdu climbing tests. The zoo pandas tackle trees this way too, she says.

Although for cubs, sometimes heading up is the easy part. “They’ll climb up fairly quickly into a tree, but it seems like they can’t quite figure out how to get back down,” MacCorkle says. If cubs stay stuck too long, a keeper will come to the rescue, but, “typically they work it out for themselves.”

Why are giant panda babies so small?


This 2016 video says about itself:

Newborn Panda Reunited With Mother | Panda Babies | BBC Earth

After precautionary checks, the newborn panda is reunited with mum.

From Duke University in the USA:

Why are giant pandas born so tiny?

New clues from bones put an old theory to the test

December 13, 2019

Born pink, blind, and helpless, giant pandas typically weigh about 100 grams at birth — the equivalent of a stick of butter. Their mothers are 900 times more massive than that.

This unusual size difference has left researchers puzzled for years. With a few exceptions among animals such as echidnas and kangaroos, no other mammal newborns are so tiny relative to their mothers. No one knows why, but a Duke University study of bones across 10 species of bears and other animals finds that some of the current theories don’t hold up.

Duke biology professor Kathleen Smith and her former student Peishu Li published their findings this month in the Journal of Anatomy.

Baby panda skeletons are hard to come by, but the researchers were able to study the preserved remains of baby pandas born at the Smithsonian’s National Zoo in Washington, D.C.

The National Zoo’s first panda couple, Ling-Ling and Hsing-Hsing, had five full-term cubs in the 1980s, but none of them survived long after birth.

The researchers took micro-CT scans of two of those cubs, along with newborn grizzlies,
sloth bears, polar bears, dogs, a fox, and other closely related animals from the Smithsonian National Museum of Natural History and the North Carolina State College of Veterinary Medicine.

They used the scans to create 3-D digital models of each baby’s bony interior at birth.

As a baby animal grows and develops inside the womb, its bones and teeth do, too. The researchers examined the degree of ossification, or how much the skeleton has formed by the time of birth. They looked at whether the teeth had started to calcify or erupt, and the degree of fusion between the bony plates that make up the skull.

The panda may be an extreme example, but all bears have disproportionately small babies, Li said. A newborn polar bear’s birthweight as a fraction of mom’s is less than 1:400, or less than one-half of one percent of her body mass. For the vast majority of baby mammals, including humans, the average is closer to 1:26.

One decades-old idea links low birthweights in bears to the fact that, for some species, pregnancy overlaps with winter hibernation. Pregnant females don’t eat or drink during this time, relying mostly on their fat reserves to survive, but also breaking down muscle to supply protein to the fetus.

The thinking is that, energetically, females can only afford to nourish their babies this way for so long before this tissue breakdown threatens their health. By cutting pregnancy short and giving birth to small, immature babies, bears would shift more of their growth to outside the womb, where babies can live off their mother’s fat-rich milk instead of depleting her muscles.

Proponents of the theory concede that not all bears — including pandas — hibernate during the winter. But the idea is that small birthweight is ‘locked in’ to the bear family tree, preventing non-hibernating relatives from evolving bigger babies too.

“It’s certainly an appealing hypothesis,” Smith said.

But the Duke team’s research shows this scenario is unlikely. The researchers didn’t find any significant differences in bone growth between hibernating bears and their counterparts that stay active year-round and don’t fast during pregnancy.

In fact, despite being small, the researchers found that most bear skeletons are just as mature at birth as their close animal cousins.

The panda bear is the one exception to this rule, results show. Even in a full-term baby panda, the bones look a lot like those of a beagle puppy delivered several weeks premature.

“That would be like a 28-week human fetus” at the beginning of the third trimester, Smith said.

Other factors might have pushed panda babies toward smaller sizes over time — some researchers blame their bamboo-only diet — but data are scarce, Li said. The researchers say the panda bear’s embryonic appearance likely has to do with a quirk of panda pregnancy.

All bears experience what’s called “delayed implantation.” After the egg is fertilized, the future fetus enters a state of suspended animation, floating in the womb for several months before implanting in the uterine wall to resume its development and get ready for birth.

But while other bears gestate for two months after implantation, giant pandas are done in a month.

“They’re basically undercooked,” said Li, now a Ph.D. student at the University of Chicago.

The researchers say they only looked at skeletons in this study, and it could be that other organs like the brain tell a different story. But the new study suggests that baby pandas follow the same trajectory as other mammal relatives — their bones mature in the same sequence and at similar rates — but on a truncated timetable.

“Development is just cut short,” Smith said.

Scientists are still searching for a complete explanation of why the panda’s peculiar size differential evolved over geological time, and how.

“We really need more information about their ecology and reproduction in the wild,” Smith said, and we may not have much time given their risk of extinction. But this study brings them one step closer to an answer.

This research was supported by a Shared Material Instrumentation Facility Undergraduate User Program grant, the Duke Department of Biology, and the Undergraduate Research Office at Duke.

White giant panda discovery in Sichuan, China


This January 2018 video is called Panda albino. However, this is not a real albino, as part of its fur is brown, not white; and its eyes are not red.

Translated from Dutch NOS TV today:

Completely white panda found in China

In China, conservationists have found a completely white panda. The characteristic black spots of its peers are missing.

The animal was caught in mid-April by a wildlife camera in a nature reserve in Sichuan province; where there are several nature reserves for the animal species. In the past, brown specimens have sometimes been found.

This 2017 video is about Qizai, the only brown panda in captivity.

Because the photo shows that the animal has red eyes, researchers think it is a unique albino specimen. Carriers of that genetic disorder have white fur and red eyes due to a lack of melanin pigment.

Extra cameras

According to the manager of the reserve, this is a young panda, one or two years old. The animal is in good health given its constant pace. The sex could not be determined based on the camera images.

The reserve will set up additional camera traps in the area to monitor the animal and to establish whether it has contact with other individuals in the area.

Giant pandas, vegetarians of carnivorous ancestry


This video from China is called Giant Panda SHU LAN eating bamboo (04/2017).

From ScienceDaily:

Giant panda‘s bamboo diet still looks surprisingly carnivorous

May 2, 2019

Giant pandas are unusual in being extremely specialized herbivores that feed almost exclusively on highly fibrous bamboo, despite belonging to a clade (Carnivora) of primarily flesh-eating carnivores. But a study reported in Current Biology on May 2 suggests that the switch to a restricted vegetarian diet wasn’t, in some respects, as big an evolutionary leap as it seems.

The study finds that the protein and carbohydrate content of the panda’s plant diet looks surprisingly like that of a hypercarnivore, animals that obtain more than 70 percent of their diet from other animals, they report. About 50 percent of the panda’s energy intake comes in the form of protein, placing them right alongside feral cats and wolves.

“As we know, the giant panda is a Carnivora species, yet extremely specialized on a plant food, the bamboo,” said Fuwen Wei of Chinese Academy of Sciences, Beijing. “Based on what they eat, they absolutely belong to the herbivores, but considering the macronutrient composition of the ingested and absorbed diets, they belong to the carnivores.”

The pandas do have traits in common with herbivores, including a skull, jaw musculature, and dentition that are adapted for fibrous diets, and a specialized “pseudo-thumb” used for handling bamboo. They’ve also lost the ability to taste umami, which is often associated with meat eating. On the other hand, giant pandas have a digestive tract, digestive enzymes, and gut microbes that resemble that of carnivores and not herbivores.

In the new study, Wei teamed up with nutritional ecologist David Raubenheimer from the University of Sydney and colleagues to explore the macronutrient composition of their diet, including what the pandas ingest and what they absorb. Using an approach called nutritional geometry, the team showed that the macronutrient mix that giant pandas both eat and absorb is similar to carnivores, and unlike herbivores. The macronutrient composition of the panda’s milk also places it squarely among other carnivores.

The researchers say the findings can help resolve long-standing questions concerning the evolution of the giant panda, including the unusual transition to extreme specialized herbivory by a member of a carnivorous clade. “In fact”, they write, “the transition was likely more superficial than assumed, combining substantial adaptation to new food types with relatively smaller changes in macronutrient handling.”

The herbivorous diet led to evolutionary adaptations in their teeth, skull, and pseudo-thumb needed to process bamboo. But their gut and digestive system changed little, suggesting minimal evolutionary modification from their ancestral state was needed to deal with the macronutritional properties of bamboo. Their short gut, together with the abundance of bamboo, allows the panda to consume and process large amounts of bamboo, compensating for the low digestive efficiency of such a fibrous diet.

“There is also a broader message from this study,” says Raubenheimer. “It demonstrates the importance of considering both foods and nutrients in understanding the evolutionary ecology of animals. This is what nutritional geometry is designed to do.”

Wei says they will continue to study the evolution and adaptation of the giant panda. They’ll also apply that work to the panda’s conservation management as an endangered species.

Panda ancestors, what did they eat?


This 26 December 2018 video says about itself:

Two Captive-bred Giant Pandas Released into Wild in Southwest China

Two giant pandas, which will be released into the wild, received their final physical examinations on Wednesday at the China Conservation and Research Center for Giant Pandas in southwest China’s Sichuan Province.

From ScienceDaily:

Ancient pandas weren’t exclusive bamboo eaters, bone evidence suggests

January 31, 2019

The giant pandas we know and love today live only in the understory of particular mountains in southwestern China, where they subsist on bamboo alone. In support of their tough and fibrous bamboo diet, they’ve got distinctive teeth, skull, and muscle characteristics along with a special pseudo-thumb, the better to grasp and hold bamboo stems, leaves, and shoots with. But according to new evidence reported in Current Biology on January 31, extinct and ancient panda species most likely had a more varied and complex diet.

“It has been widely accepted that giant pandas have exclusively fed on bamboo for the last two million years”, says Fuwen Wei of Chinese Academy of Sciences. But, “our results showed the opposite.”

It’s impossible to know exactly what extinct animals ate. But researchers can get clues by analyzing the composition of stable isotopes (different forms of the same element that contain equal numbers of protons but different numbers of neutrons) in animal teeth, hair, and bones, including fossil remains. In the new study, the researchers first analyzed bone collagen of modern pandas (1970s-2000s) and other mammals from the same mountains.

The stable isotopic composition of carbon and nitrogen from modern panda and other modern mammal bone samples indicated three obvious groups: carnivores, herbivores, and giant pandas. The giant pandas were clearly unique, on account of their habit of eating bamboo. Next, Wei’s team measured bone collagen isotopes of 12 ancient pandas collected from seven archaeological sites in southern and southwestern China and compared them to the patterns they observed in modern giant pandas.

The data comparison showed that ancient and modern pandas are isotopically distinct from one another, suggesting differences in their dietary habits. There was also more variation among ancient panda species, suggesting that the niche they occupied was about three times wider than that of modern pandas. That is, ancient pandas most likely had a varied diet, similar to that of other mammalian species that lived alongside them. They were, the researchers write, “probably not exclusive bamboo feeders.”

The researchers suggest that pandas’ dietary habits have evolved in two phases. First, the pandas went from being meat eaters or omnivores to becoming dedicated plant eaters. Only later did they specialize on bamboo.

The researchers say they would now like to figure out when exactly pandas shifted to the specialized diet they have today. To find out, they plan to collect and study more panda samples from different historical times over the last 5,000 years.