How Alaskan bears help plants


This video about Alaska is called The Land of Giant Bears.

From Oregon State University in the USA:

Great scat! Bears — not birds — are the chief seed dispersers in Alaska

January 16, 2018

It’s a story of bears, birds and berries.

In southeastern Alaska, brown and black bears are plentiful because of salmon. Their abundance also means they are the primary seed dispersers of berry-producing shrubs, according to an Oregon State University study.

The OSU team used motion-triggered cameras to record bears, birds and small mammals eating red berries of devil’s club, and retrieved DNA in saliva left on berry stalks to identify the species and sex of the bears. Researchers found that bears, while foraging, can disperse through their scat about 200,000 devil’s club seeds per square kilometer per hour. Rodents then scatter and hoard those seeds, much like squirrels hoard acorns.

The study was published today in the journal Ecosphere.

In most ecosystems, birds generally are thought of as chief dispersers of seeds in berries, said Taal Levi, an ecologist in OSU’s College of Agricultural Sciences and co-author on the study. The researchers found that birds accounted for only a small fraction of seed dispersal.

This is the first instance of a temperate plant being primarily dispersed by mammals through their gut, and suggests that bears may influence plant composition in the Pacific Northwest.

It was well-known that bears were dispersing seeds through their scat, Levi said, but it was not known that they were dispersing more seeds than birds, or the relative contribution of brown and black bears to seed dispersal, or whether the two species bears were eating berries at different times of the year.

“Devil’s club is extremely abundant in northern southeast Alaska, so it didn’t seem plausible that birds were dispersing all this fruit”, Levi said. “Bears are essentially like farmers. By planting seeds everywhere, they promote a vegetation community that feeds them.”

The researchers found that in the study area along the Chilkat and Klehini rivers in southeastern Alaska, brown bears dispersed the most seeds, particularly before salmon became widely available. They also found that after the brown bears switched from eating berries to salmon later in the season, black bears moved in and took over the role as principal seed dispersers. Black bears are subordinate to brown bears and avoid them.

The fruit on a devil’s club stalk is clustered into a cone containing berries. The researchers observed through the camera recordings that brown bears can swallow an estimated 350 to 400 berries in a single mouthful. Birds, on the other hand, consumed on average 76 berries per plant that they visited.

“That’s pretty remarkable,” Levi said. “When birds visit these shrubs, they take a few berries and fly off. They don’t eradicate the cones like a bear.”

Laurie Harrer, Levi’s co-author, swabbed devil’s club to retrieve environmental DNA from residual saliva left by animals and birds that ate the berries. Harrer, a master’s student in OSU’s Department of Fisheries and Wildlife, analyzed the samples to determine that female brown bears ate more berries than male brown bears, female black bears ate more than male black bears and brown bears ate more than black bears.

Brown bears, also known as grizzlies, are extinct in Oregon and California and are nearly extinct in Washington.

“The indirect effect of salmon is that they support abundant bear populations that then disperse a lot of fruit”, Levi said. “We’ve lost the salmon-bear ecosystem that once dominated the Pacific Coast. That has implications for the plant community. These seed dispersal pathways through brown bears are all but eliminated. The degree to which black bears can fulfill that role is not clear.”

Advertisements

Ancient fossil bear discovery in Canada


This video says about itself:

18 December 2017

Paddington‘s prehistoric ancestor, a primitive bear with a sweet tooth, has been discovered in the Arctic. Researchers identified the remains of a 3.5-million-year-old bear from a fossil-rich site in Canada’s High Arctic. The findings show that the animal is a close relative of the ancestor of modern bears, and that it also had a taste for sweet treats – shown by cavities in its teeth. They say the ancient bear may have got his bad teeth from munching on berries, rather than Paddington’s preferred sweet treat of marmalade sandwiches.

From the Natural History Museum of Los Angeles County in the USA:

Primitive fossil bear with a sweet tooth identified from Canada’s High Arctic

December 18, 2017

Researchers from the Canadian Museum of Nature and the Natural History Museum of Los Angeles County have identified remains of a 3.5-million-year-old bear from a fossil-rich site in Canada’s High Arctic. Their study shows not only that the animal is a close relative of the ancestor of modern bears — tracing its ancestry to extinct bears of similar age from East Asia — but that it also had a sweet tooth, as determined by cavities in the teeth.

The scientists identify the bear as Protarctos abstrusus, which was previously only known from a tooth found in Idaho. Showing its transitional nature, the animal was slightly smaller than a modern black bear, with a flatter head and a combination of primitive and advanced dental characters. The results are published today in the journal Scientific Reports.

“This is evidence of the most northerly record for primitive bears, and provides an idea of what the ancestor of modern bears may have looked like,” says Dr. Xiaoming Wang, lead author of the study and Head of Vertebrate Paleontology at the Natural History Museum of Los Angeles County (NHMLA). “Just as interesting is the presence of dental caries, showing that oral infections have a long evolutionary history in the animals, which can tell us about their sugary diet, presumably from berries. This is the first and earliest documented occurrence of high-calorie diet in basal bears, likely related to fat storage in preparation for the harsh Arctic winters.”

The research team, which included co-author Dr. Natalia Rybczynski, a Research Associate and paleontologist with the Canadian Museum of Nature, were able to study recovered bones from the skull, jaws and teeth, as well as parts of the skeleton from two individuals.

The bones were discovered over a 20-year period by Canadian Museum of Nature scientists, including Dr. Rybczynski, at a fossil locality on Ellesmere Island known as the Beaver Pond site. The peat deposits include fossilized plants indicative of a boreal-type wetland forest, and have yielded other fossils, including fish, beaver, small carnivores, deerlets, and a three-toed horse.

The findings show that the Ellesmere Protarctos lived in a northern boreal-type forest habitat, where there would have been 24-hour darkness in winter, as well as about six months of ice and snow.

“It is a significant find, in part because all other ancient fossil ursine bears, and even some modern bear species like the sloth bear and sun bear, are associated with lower-latitude, milder habitats,” says co-author Dr. Rybczynski. “So, the Ellesmere bear is important because it suggests that the capacity to exploit the harshest, most northern forests on the planet is not an innovation of modern grizzlies and black bears, but may have characterized the ursine lineage from its beginning.”

Dr. Wang analyzed characteristics of fossil bear remains from around the world to identify the Ellesmere remains as Protarctos and to establish its evolutionary lineage in relation to other bears. Modern bears are wide-ranging, found from equatorial to polar regions. Their ancestors, mainly found in Eurasia, date to about 5 million years ago.

Fossil records of ursine bears (all living bears plus their ancestors, except the giant panda, which is an early offshoot) are poor and their early evolution controversial. The new fossil represents one of the early immigrations from Asia to North America but it is probably not a direct ancestor to the modern American black bear.

Of further significance is that the teeth of both Protarctos individuals show signs of well-developed dental cavities, which were identified following CT scans by Stuart White, a retired professor with the UCLA School of Dentistry. The cavities underline that these ancient bears consumed large amounts of sugary foods such as berries. Indeed, berry plants are found preserved in the same Ellesmere deposits as the bear remains.

“We know that modern bears consume sugary fruits in the fall to promote fat accumulation that allows for winter survival via hibernation. The dental cavities in Protarctos suggest that consumption of sugar-rich foods like berries, in preparation for winter hibernation, developed early in the evolution of bears as a survival strategy,” explains Rybczynski.

‘Yetis’ are Asian bears


This video says about itself:

Yeti, Bigfoot debunked: DNA reveals the bear facts

2 July 2014

An international team of researchers working on the Oxford-Lausanne Collateral Hominid Project has analyzed DNA evidence from samples of hair sent to them as possible evidence of the creature commonly referred to as Bigfoot.

Cryptozoology is the study of animals that people claim exist, but haven’t yet been proven to be real, like Bigfoot, which pops up in various forms among different cultures around the world.

This study has debunked all of the samples from across the United States, Russia, and other countries after comparing them with DNA sequences cataloged by GenBank.

Animals that matched the samples included cows, horses, bears, sheep, porcupine, deer, canidae like coyotes, wolves or dogs, a serow, a human, and a raccoon which was found in Russia, significantly outside of the animal’s supposed natural range.

From the University at Buffalo in the USA:

Abominable Snowman? Nope — study ties DNA samples from purported Yetis to Asian bears

New paper shows how science can explore the roots of folklore

November 28, 2017

Summary: The Yeti or Abominable Snowman — a mysterious, ape-like creature said to inhabit the high mountains of Asia — looms large in the mythology of Nepal and Tibet. Now, a new DNA study of purported Yeti samples from museums and private collections is providing insight into the origins of this Himalayan legend.

The Yeti or Abominable Snowman — a mysterious, ape-like creature said to inhabit the high mountains of Asia — looms large in the mythology of Nepal and Tibet.

Sightings have been reported for centuries. Footprints have been spotted. Stories have been passed down from generation to generation.

Now, a new DNA study of purported Yeti samples from museums and private collections is providing insight into the origins of this Himalayan legend.

The research, which will be published in Proceedings of the Royal Society B, analyzed nine “Yeti” specimens, including bone, tooth, skin, hair and fecal samples collected in the Himalayas and Tibetan Plateau. Of those, one turned out to be from a dog. The other eight were from Asian black bears, Himalayan brown bears or Tibetan brown bears.

“Our findings strongly suggest that the biological underpinnings of the Yeti legend can be found in local bears, and our study demonstrates that genetics should be able to unravel other, similar mysteries,” says lead scientist Charlotte Lindqvist, PhD, an associate professor of biological sciences in the University at Buffalo College of Arts and Sciences, and a visiting associate professor at Nanyang Technological University, Singapore (NTU Singapore).

Lindqvist’s team is not the first to research “Yeti” DNA, but past projects ran simpler genetic analyses, which left important questions unresolved, she says.

“This study represents the most rigorous analysis to date of samples suspected to derive from anomalous or mythical ‘hominid‘-like creatures,” Lindqvist and her co-authors write in their new paper. The team included Tianying Lan and Stephanie Gill from UB; Eva Bellemain from SPYGEN in France; Richard Bischof from the Norwegian University of Life Sciences; and Muhammad Ali Nawaz from Quaid-i-Azam University in Pakistan and the Snow Leopard Trust Pakistan program.

The science behind folklore

Lindqvist says science can be a useful tool in exploring the roots of myths about large and mysterious creatures.

She notes that in Africa, the longstanding Western legend of an “African unicorn” was explained in the early 20th century by British researchers, who found and described the flesh-and-blood okapi, a giraffe relative that looks like a mix between that animal and a zebra and a horse.

And in Australia — where people and oversized animals may have coexisted thousands of years ago — some scholars have speculated that references to enormous animal-like creatures in Australia’s Aboriginal “Dreamtime” mythology may have drawn from ancient encounters with real megafauna or their remains, known today from Australia’s fossil record.

But while such connections remain uncertain, Lindqvist’s work — like the discovery of the okapi — is direct: “Clearly, a big part of the Yeti legend has to do with bears”, she says.

She and colleagues investigated samples such as a scrap of skin from the hand or paw of a “Yeti” — part of a monastic relic — and a fragment of femur bone from a decayed “Yeti” found in a cave on the Tibetan Plateau. The skin sample turned out to be from an Asian black bear, and the bone from a Tibetan brown bear.

The “Yeti” samples that Lindqvist examined were provided to her by British production company Icon Films, which featured her in the 2016 Animal Planet special “YETI OR NOT,” which explored the origins of the fabled being.

Solving a scientific mystery, too: How enigmatic bears evolved

Besides tracing the origins of the Yeti legend, Lindqvist’s work is uncovering information about the evolutionary history of Asian bears.

“Bears in this region are either vulnerable or critically endangered from a conservation perspective, but not much is known about their past history,” she says. “The Himalayan brown bears, for example, are highly endangered. Clarifying population structure and genetic diversity can help in estimating population sizes and crafting management strategies.”

The scientists sequenced the mitochondrial DNA of 23 Asian bears (including the purported Yetis), and compared this genetic data to that of other bears worldwide.

This analysis showed that while Tibetan brown bears share a close common ancestry with their North American and Eurasian kin, Himalayan brown bears belong to a distinct evolutionary lineage that diverged early on from all other brown bears.

The split occurred about 650,000 years ago, during a period of glaciation, according to the scientists. The timing suggests that expanding glaciers and the region’s mountainous geography may have caused the Himalayan bears to become separated from others, leading to a prolonged period of isolation and an independent evolutionary path.

“Further genetic research on these rare and elusive animals may help illuminate the environmental history of the region, as well as bear evolutionary history worldwide — and additional ‘Yeti’ samples could contribute to this work,” Lindqvist says.

Grizzly bears need overpasses to cross roads


This video from Canada says about itself:

13 June 2014

As you travel through Banff National Park animals are travelling too — over your roof and under your wheels. Wildlife crossing structures and highway fencing in Banff National Park have reduced large animal deaths by more than 80%. So which animals adopted crossing structures first? Who prefers overpasses versus underpasses? Find out here through the lens of a remote camera that captured five years of wildlife movement on an overpass in Banff National Park near Redearth Creek.

From the University of British Columbia Okanagan campus in Canada:

Family-friendly overpasses are needed to help grizzly bears, study suggests

Design of wildlife road crossings is crucial for protecting grizzlies

November 27, 2017

Researchers have determined how female grizzly bears keep their cubs safe while crossing the Trans-Canada Highway.

Adam Ford, Canada Research Chair in Wildlife Restoration Ecology at UBC‘s Okanagan campus, along with Montana State University‘s Tony Clevenger, studied the travel patterns of grizzlies in Banff National Park between 1997 and 2014. In most cases, a mother bear travelling with cubs opted to use a wildlife overpass instead of a tunnel to cross the highway.

“We used data from Canada’s longest and most detailed study of road-wildlife interactions,” explains Ford, an assistant professor of biology. “We found that grizzly bear females and cubs preferred to use overpasses to cross the highway.”

During the 17-year study period, bears not travelling in these family groups used both underpasses and overpasses. “You can’t just build a tunnel under a highway and expect to conserve bears,” says Ford. “Our work shows that the design of structures used to get bears across the road matters for reconnecting grizzly bear populations.”

The study looked at five different wildlife crossing structure designs distributed across 44 sites along a 100-km stretch of the Trans-Canada Highway. The structures are purpose-built bridges or tunnels to facilitate the safe movement of animals across roads. Tracking and motion-triggered cameras were used to monitor grizzly bear movement and Ford says all grizzly bears selected larger and more open structures like overpasses and open-span bridges, compared to tunnels and box culverts.

“Since adult females and cubs drive population growth, this research tells us that overpasses are needed to protect bears in roaded areas,” says Ford.

The study also documents the most cost-effective means to design highway mitigation. A common concern in conservation is how to allocate funding to bring the most effective gains for biodiversity. The researchers estimated the cost-effectiveness of structure designs and were surprised by the result.

“When we look at the population as a whole, there were a lot of passages made by males in box culverts, which is the cheapest type of structure to build,” explains Clevenger, stressing that a diversity of wildlife crossing structure designs along a highway is essential.

“It’s important to reduce the chances of adult males encountering cubs since the males will kill young bears,” Clevenger adds. “Creating both ‘bachelor’ and ‘family’-friendly designs will further help bear populations grow.”

This peer-reviewed study was published online this week in the Wildlife Society Bulletin.

Young black bear steals ball


This video from the USA says about itself:

17 August 2017

A young [black] bear searching for bird food on the deck can’t resist an Amazing Spider Man bounce ball – after all it says suitable for ages 3 and up! This young male bear is facing his first full summer on his own and is probably around 3 years old. He is still really a kid at heart after first ignoring the bounce ball he decides to take it after all. I found it later deflated with numerous tooth holes in it. Such a sweet bear, I hope he stays out of trouble.

Black bear at United States bird feeders


This video from the USA says about itself:

4 August 2017

Young male Black Bear now on his own makes a very rare daylight morning stop on the deck looking for food. Also a rare morning when the two trail cams are still running so we see the bear from three different cameras. Note the Eastern Towhees sounding the alarm callsBlue Jays are not a big presence here so the Towhees are sort of the Backyard Watchouts. I always put the bird food away at night and put it back up in morning – perhaps this bear is starting to figure that out. The fact that more bears have been showing up recently may mean that food is scarcer than usual up in the mountain forests. This should be berry-time!

Black bear cubs, other American animals


This camera trap video from North Carolina in the USA says about itself:

1 August 2017

A mother Black Bear and her two cubs visit Backyard North plus a guest visitor and a surprise close-up.