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Sunday, October 27, 2024

DESANTISLAND HORROR SHOW

Florida biologists prove invasive Burmese pythons are swallowing deer, alligators whole

JULIA JACOBO
Fri 25 October 2024

The scale at which the Burmese python is able to decimate the native wildlife population in South Florida continues to astonish biologists studying to eradicate the invasive species.

Researchers in the region recently proved that Burmese pythons are able to stretch their jaws wide enough to swallow large prey -- such as fully grown deer and alligators -- whole, according to a paper published in the journal Reptiles & Amphibians.

"Knowing the size of prey that predators can consume facilitates understanding and predicting their ecological impact," the paper states.

PHOTO: In December 2022, biologists stumbled upon a gruesome scene of a nearly 15-foot female Burmese python eating a fully-grown white tail near on private property near Naples, Florida. (Conservancy of Southwest Florida)

A group of biologists stumbled upon a nearly 15-foot female Burmese python in December 2022 in the midst of devouring an adult white-tailed deer, Ian Bartoszek, a wildlife biologist and science coordinator at the Conservancy of Southwest Florida in Naples, told ABC News.

Bartoszek and his team use radio telemetry -- a technique that uses radio signals to track the movement and behavior of animals -- to understand the pythons' behavior. Trackers placed on males help researchers find the reproductive females, Bartoszek said.

MORE: Invasive ocean species detected in Florida waters, scientists say

By the time they got to the scene, the python had swallowed about half of the deer, and it took about 30 more minutes for it to consume the other half, Bartoszek said. Had the deer still been alive, the scientists would have intervened. Instead, they got a front-row seat to the intricacies of the food chain.

"For us biologists, this was the most intense thing we've ever seen on assignment," he said. "This was as primal as it gets."

PHOTO: In December 2022, biologists stumbled upon a gruesome scene of a nearly 15-foot female Burmese python eating a fully-grown white tail near on private property near Naples, Florida. (Conservancy of Southwest Florida)

The female python weighed about 115 pounds, while the deer weighed about 77 pounds -- representing 93% of the snake's maximal gape area, the size of their mouth opening, according to the paper.

MORE: Key Largo tree cactus becomes 1st-ever US species to become extinct due to rising sea levels

Burmese pythons can consume meals equivalent to 100% of their body mass, according to the Florida Fish and Wildlife Commission. While parts of tailed deer had been found in python necropsies before, this was the first time biologists had witnessed it in the wild, Bartoszek said.

"In this specific example, it feels like we caught the serial killer in action," Bartoszek said.

PHOTO: In December 2022, biologists stumbled upon a gruesome scene of a nearly 15-foot female Burmese python eating a fully-grown white tail near on private property near Naples, Florida. (Conservancy of Southwest Florida)

The large nonvenomous constrictor captures its prey by ambushing it before coiling around it. The snake then squeezes until the animal goes into cardiac arrest, Bartoszek said.

In the case they witnessed, the python had bitten the deer in the neck before coiling around it, he added.

"When you see their anatomy firsthand, they are amazingly designed," Bartoszek said. "Mother Nature did a very good job with the species."

MORE: How experts are trying to save the Florida panther

Had that python lived, it probably would have "used" the feed from the deer over the course of a week, Bartoszek said. But since they are opportunistic hunters, the snake could have very well captured its next prey before then, he added.

A variety of species have been found in the gut contents of Burmese pythons during necropsies, including mammals, birds, reptiles, as well as federally protected species such as the wood stork and the Key Largo woodrat, according to the FWC.

PHOTO: A python is seen as Robert Edman, with the Florida Fish and Wildlife Conservation Commission, gives a python-catching demonstration to potential snake hunters at the start of the Python Bowl 2020 on January 10, 2020 in Sunrise, Florida. (Joe Raedle/Getty Images)

Burmese pythons are one of the most concerning invasive species in the region, according to the U.S. Geological Survey (USGS).

The species, native to Africa, Asia and Australia, established a breeding population in South Florida through intentional and accidental release, according to the USGS.

MORE: Python farming could offer one of the most sustainable sources of meat in the world, according to a new study

Severe declines in mammal populations throughout Everglades National Park have been linked to the species, according to the USGS. A 2012 study found that populations of raccoons had declined 99.3%, opossum populations declined 98.9%, and bobcats 87.5% since 1997. Other mammals have "effectively disappeared" over time, such as marsh rabbits, cottontail rabbits and foxes, according to the USGS.

"Imagine just thousands and thousands of pythons eating their way through the Everglades," Bartoszek said.

PHOTO: A hypothetical prey pyramid shows the diet necessary for a Burmese python hatchling to reach a size of 15 feet. (Conservancy of Southwest Florida)

Burmese pythons were added to Florida's Prohibited Nonnative Species List in 2021. The state also pays bounty hunters to catch Burmese pythons through the FWC's Python Patrol program.

The species, with its efficient reproductive capabilities and voracious appetite, is creating a cascading effect of loss within the ecosystem of the Everglades and surrounding areas, Bartoszek said.

"We didn't want to alarm people," Bartoszek. "We just want to showcase what our native wildlife is up against across the greater Everglades ecosystem."

Florida biologists prove invasive Burmese pythons are swallowing deer, alligators whole originally appeared on abcnews.go.com

Wednesday, October 23, 2024

In Ontario, you can train hunting dogs by letting them chase penned animals. Is that fair?

NO!!

CBC
Tue, October 22, 2024

Ron Lounsbury, 80, currently has about 30 hound dogs, a breed known as the Trigg Foxhound. He says he brings them to a training facility near Smiths Falls, Ont., about once a week. (Submitted by Ron Lounsbury - image credit)

For the first time in more than 25 years, Ontario is accepting applications from operators who want to create new fenced-in training facilities stocked with coyotes, foxes, rabbits and hares — specifically designed to teach dogs to pursue live animals and also to host competitions.

"[The dogs] have a nose — they find the game, they flush the game and they keep the game moving," said hunter Ron Lounsbury, 80, who lives on a farm outside Brantford, Ont., and has been breeding and raising Trigg Foxhounds, a hound dog breed, for more than half his life.

He calls them his babies.

You don't need living beings to be bait for this kind of training. - Leslie Sampson, Coyote Watch

Lounsbury currently has 30 of his own dogs and regularly brings them to a training facility near Smiths Falls, Ont.

"It's a big, rugged, well-maintained, well-kept pen. The game's in great shape," he said.

In Ontario, it's still legal for hunters to train their dogs in these wildlife pens, but they've become increasingly controversial. Firearms are not permitted inside the facility.

"Contact between sporting dogs and wildlife is actively avoided and strict protections are in place to maintain safety," Lounsbury said.

There are now 33,000 members in the Ontario Sporting Dog Association, which lobbied the government over the past year on the training and trialing licenses.

There are now 33,000 members of the Ontario Sporting Dog Association, which lobbied the government over the past year on the training and trialling licences. (David McNew/The Associated Press)

Applications for new pens open

In 1997, then Ontario Conservative premier Mike Harris began phasing out "train and trial areas." The province stopped licensing new pens and didn't allow existing ones to be transferred to anyone else.

At the time, there were 60 facilities in Ontario. Today there are 22, according to the province, but that could soon change now that Ontario is accepting applications for new pens until Dec. 29. Non-residents can also apply.

People say it's a pen, a confined area — but it's a huge area. You don't know you're in a pen. - Ron Lounsbury, hunter

"Train and trial facilities prepare sporting dogs and their handlers for animal tracking and competitions while ensuring a safe environment that protects both dogs and wildlife from public areas," said Melissa Candelaria, senior communications adviser for Ontario's Ministry of Natural Resources.

The number of licences the province grants will depend on how much interest there is, she said.

"I think it's a good idea," said Lounsbury. "It's governed, it's controlled. They protect the game. The people who own them and run them are dedicated people and they work very hard at what they do."

Ron Lounsbury of Paris, Ont., is the president of the Canadian Trigg Association. He's been raising hound dogs for 50 years and regularly runs his dogs at a training facility in eastern Ontario.

Lounsbury is president of the Canadian Trigg Association. He's been raising hound dogs for 50 years and regularly runs his dogs at a training facility in eastern Ontario. (Submitted by Ron Lounsbury)

Facility operators must meet certain provincial standards before they can open. For instance, facilities housing coyotes must have a pen of at least 80 hectares for training purposes and 160 hectares if the pen is used to host competitions, which involve judges awards points to dogs for their ability to track and flush out animals.

"People say it's a pen, a confined area — but it's a huge area. You don't know you're in a pen," said Lounsbury.

The rules also lay out how many refuge areas must be included in each pen, including culverts, dens and brush piles; when dogs are allowed in the pen (only during months when there's sufficient foliage cover, for example); and how many dogs are allowed in each fenced-in area at once (it depends on the size of the pen and the prey, but dozens of dogs can be inside simultaneously).

A cyclist was bitten on the arm by a coyote, similar to the one seen in this stock photo, while on the Cabot Trail in Cape Breton Highlands National Park on Wednesday.

The pens are stocked with rabbits, hares, foxes and coyotes. One animal rights group says the coyotes are forced to run for hours at a time and are often injured or even killed by the dogs. (Harry Collins Pho/Shutterstock)

Pens 'sickening,' 'barbaric,' say animal rights groups

"We are dead against it," said Leslie Sampson, executive director of the animal advocacy group Coyote Watch. "We know what happens within the captive fenced-in areas."

Sampson said the coyotes are forced to run for hours at a time and are often injured or even killed by the dogs.

"The government has completely ignored what Ontarians want and don't want," she said. "They have basically bent to a small extremist group of individuals that want to have access to these really sickening, barbaric ways of making money. "

According to the province, operators can source wildlife by purchasing animals from licensed trappers. They can also be bred in captivity.

"It's wildlife trafficking in Ontario," said Sampson.

There are other ways to train a hunting dog, she said.

"You don't need living beings to be bait for this kind of training," she said. "There's lots of ways to train animals, but it's not as exciting for the dog handlers and the money that they're making."

Sampson also worries the province doesn't have the means to ensure the operators are following all the rules. "What they have in there — it all looks fancy on paper, but to actually enforce all of this, there's not enough conservation officers."

Lounsbury admits there are some unethical hunters out there, but he doesn't support them — and he said the pen operators want nothing more than to protect the wildlife inside its fences.

"For the guy that owns the facility, the most expensive thing for him is his game," he said. "The last thing he wants is it killed."

Ron Lounsbury's dogs relax after running in a training facility. He says some of them will run nearly 50km in five hours.

Lounsbury's dogs relax after running at a training facility. He says some of them will run nearly 50 kilometres in five hours. (Submitted by Ron Lounsbury)

Concerns over spreading disease

When dogs interact with coyotes, foxes and other wildlife inside a fenced area, there are other things to consider.

The coyotes may be carrying tapeworms such as echinococcus multilocularis, said Jan Hajek, infectious diseases doctor at Vancouver General Hospital.

"Coyotes can defecate and when the animals are chasing them, they can come in contact with the defecation," he said.

The dog might pick up the tapeworm as a result.

"That dog could transmit that parasite from their stool to other humans, other dogs, other environments," warned Hajek.

Saturday, October 12, 2024

From chaos to structure

How a bunch of seemingly disorganized cells go on to form a robust embryo

Peer-Reviewed Publication

Institute of Science and Technology Austria

Pipetting liquids into tiny test tubes, analyzing huge datasets, poring over research publications—all these tasks are part of being a scientist. But breaking this routine is essential. Time away from the usual work environment can spark creative ideas. Lab retreats, for instance, offer a great setting where researchers can engage with other peers, often leading to new collaborations.

The latter was true for Bernat Corominas-Murtra and Edouard Hannezo from the Institute of Science and Technology Austria (ISTA). Fascinated by a dataset showcased during a poster session at a collaborative retreat research group in Spain, Corominas-Murtra started a lively discussion with fellow researcher Dimitri Fabrèges, a postdoc from the research group of Professor Takashi Hiiragi at the Hubrecht Institute in Utrecht, The Netherlands. What started as a conversation has now turned into a publication in Science.

The international team of researchers has built a comprehensive atlas of early mammalian morphogenesis—the process of an organism developing shape and structure—analyzing how mouse, rabbit, and monkey embryos develop in space and time. Based on this atlas, they see that individual events such as cell divisions and movements are highly chaotic, yet the embryos as a whole end up looking very similar to one another. With this dataset, they propose a physical model that explains how a mammalian embryo builds structure from chaos.

From one to many

In animals, embryonic development starts when an egg cell is fertilized. This event triggers an array of consecutive cell divisions, known as cleavages. In a nutshell, a single cell divides into two, then two become four, four become eight, and so forth. Eventually, the bulk of cells form into a very organized structure called the blastocyst, from which all future organs and tissues develop. The entire process is termed morphogenesis.

“These early steps of embryonic development are key, as they set the stage for all subsequent developmental processes,” explains Edouard Hannezo. In some animals, for instance, in C. elegans—a transparent roundworm and one of the most studied model organisms by developmental biologists—the divisions in the early embryo are extremely well regulated and orientated the same way across different embryos, giving rise to organisms that all have the same number of cells. In mammalian species, however, it seems like divisions are much more random, both in timing and orientation. This raises the question of how reproducible mammalian embryonic development proceeds despite this disorder.

A detailed embryo map

To address this question, the Hiiragi group set out to image and quantitatively analyze many different embryos, to compare their similarities both within and between different mammalian species, from mice to rabbits and monkeys. Dimitri Fabrèges and colleagues created a so-called ‘morphomap’—a map to visualize high-dimensional morphological data. “It’s an imaging analysis pipeline showing how embryos behave in time and space—a precise atlas of an embryo’s morphogenesis,” explains Hannezo.

The map allowed the scientists to quantitatively analyze the developmental process by addressing questions such as the inter-embryo variability of development. With this dataset, the scientists were able to define what ‘normal’ morphogenesis looks like.

Fabrèges presented the morphomap at the lab retreat in Spain. The data showed that the first divisions after fertilization were not regulated across mice, rabbits, and monkeys. The cells divided randomly until they reached the 8-cell stage, a stage where all embryos suddenly started to look the same. “After looking very different in the first stages, embryos seemed to converge toward each other’s shape at the end of the 8-cell stage,” Hannezo continues. But how come? What brings structure to this chaos?

An embryonal Rubik’s cube—cell cluster optimizes its packing

Corominas-Murtra and Hannezo, both theoretical physicists, were fascinated by this dataset and set out to understand this process from a theoretical standpoint.

However, an embryo’s shape is highly complex, making it difficult to determine what it means for two embryos to be similar or different. The scientists discovered that they could effectively approximate the full complexity of the structure of an embryo simply by studying the configurations of the cell-to-cell contacts. “We think that we can derive most of the important details about the morphology of an embryo by understanding the arrangements of cells or knowing which cells are physically connected—similar to connections in a social network. This approach significantly simplifies data analysis and comparisons between different embryos,” says Corominas-Murtra.

Using this information, the scientists created a simple physical model for how embryos converge to a reproducible shape. The model shows that physical laws drive embryos to form a specific morphology shared among mammals.

By destabilizing most cell arrangements except a few selective ones that lower the surface energy of the embryo, physical interactions between cells can guide the formation toward a defined shape. In other words, cells tend to stick more and more together and this seemingly simple process actually drives the embryo through successive rearrangements to the most optimal packing. It’s like embryos solve their own Rubik’s cube.

No chaos, no structure

The results provide a detailed look at how the development of mammalian embryos is governed by variability and robustness. Without chaos, there is no structure; one needs the other. Both are essential parts of what constitutes ‘normal’ development. “We’re finally starting to have tools to analyze the variability of morphogenesis, which is crucial to understanding the mechanisms of developmental robustness,” Hannezo summarizes. Randomness seems to be a primary force in the generation of complexity in the living world.

By gaining more knowledge of what normal looks like, scientists also gain insights into abnormalities. This can be very helpful in areas, such as disease research, regenerative medicine, or fertility treatments. In the future, this knowledge can assist in selecting the healthiest embryo for in vitro fertilization (IVF), thereby improving the implantation success rate.

The schematic shows that the 4-cell stage embryo gives rise to many different shapes. At the beginning of the 8-cell stage, the embryos are driven toward the most optimal packing due to simple physical laws.

Credit

Fabrèges & Corominas Murtra et al. / Science

Journal

Science

DOI

10.1126/science.adh1145

Method of Research

Computational simulation/modeling

Subject of Research

Cells

Article Title

Temporal variability and cell mechanics control robustness in mammalian embryogenesis

Article Publication Date

11-Oct-2024

Friday, October 04, 2024

Elephants evacuated, animals stranded in floods in Thailand

Agence France-Presse
October 4, 2024

More than 100 elephants had to be evacuated from a sanctuary in Thailand due to rising flood waters (AFP)

More than 100 elephants in northern Thailand have been moved to higher ground to escape rapidly rising flood waters, local media reported, but many other animals were still stuck as their sanctuary struggled to evacuate them on Friday.

Saengduean Chailert, director of the Elephant Nature Park in Chiang Mai province, had posted a video of the panic-stricken elephants splashing through muddy waters and asked the government to send "urgent help".

"The water is flooding worse than before. The entire area is flooded. The whole village is flooded... Right now, we have nowhere to go," she wrote on social media.

Photos and videos showed brown water rushing through the Elephant Nature Park as staff and volunteers carried dogs in blankets and placed cages on rubber tyres to transport animals to safety.

The park falls under the remit of the Save the Elephant Foundation, one of Thailand's biggest elephant conservation NGOs.

One of the foundation's officers told AFP that aside from 126 elephants, there were around 5,000 animals –- including dogs, cats, cows, pigs and rabbits -- stuck in the floods.

Local media reported that more than 100 staff and volunteers were able to safely transport 117 of the elephants to higher ground.

Major inundations have struck parts of northern Thailand as recent heavy downpours caused the Ping River to reach "critical" levels on Thursday, according to the district office.

Thailand's northern provinces have been hit by large floods since Typhoon Yagi struck the region in early September, with one district reporting its worst inundations in 80 years.

Thai Elephant Alliance says there are around 3,800 captive elephants in the country, and there are more than 4,000 individuals living in the wild, according to the Thailand Environment Institute.

The Asian elephant is classified as endangered by the IUCN, and contact and conflict between humans and the species is common in Thailand.

© Agence France-Presse

Thursday, September 19, 2024

FROM THE MARKET NOT THE LAB

Scientists again link covid pandemic origin to Wuhan market animals

Genetic evidence from a new report suggests the coronavirus pandemic most likely spilled over from animals in the Wuhan market.

By Joel Achenbach
September 19, 2024

An international team of scientists published a peer-reviewed paper Thursday saying genetic evidence indicates the coronavirus pandemic most likely originated with a natural spillover from an animal or animals sold in a market in Wuhan, China, where many of the first human cases of covid-19 were identified.

The paper, which appears in the journal Cell, does not claim to prove conclusively that the pandemic began in the Huanan Seafood Wholesale Market, and it is unlikely to end the acrimonious and politicized debate over the coronavirus’s origin.

For more than four years, researchers, intelligence agencies, journalists and amateur sleuths have tussled over the two main scenarios for the pandemic’s origin: a natural spillover from animals or some kind of leak from a laboratory experimenting on coronaviruses.

The new report bolsters the natural spillover theory, but it does not rule out other origins. A key limitation of the research is that the genetic data, obtained by Chinese investigators in the early days of the pandemic after the market was closed, cannot reveal whether any animal was actually infected with the virus.

“The results we see are consistent with infected animals, but we cannot prove that they were,” said Florence Débarre, an evolutionary biologist at the French National Center for Scientific Research and a co-author of the new paper.

Much of the report is familiar territory. Many of the 23 authors of the paper are known to have long supported a market origin for the virus. In an informal report in March 2023, they presented a central feature of the genetic data — the confirmation that animals potentially capable of triggering a pandemic were in the market.

That early report, which was not peer-reviewed or published in a journal, had a scientifically awkward provenance. It was written over the course of about 10 days, Débarre said, after she noticed that Chinese researchers had posted some of their genetic data from the market on GISAID, a public database regularly scanned by pandemic researchers.

The Chinese researchers had submitted a report to the journal Nature, and, after peer review, it was published in April 2023. The Nature paper from the Chinese scientists describes the genetic data as inconclusive about the origin of the pandemic, including that there is no proof any animals were infected with the virus.

“Furthermore, even if the animals were infected, our study does not rule out human-to-animal transmission, as the sampling was carried out after the human infection within the market,” the Nature paper states. “Thus, the possibility of potential introduction of the virus to the market through infected humans, or cold-chain products, cannot yet be ruled out.”

The new paper in Cell is longer, more comprehensive, probes a broader range of questions, and includes more data from the market and early-patient cases than the international team’s informal 2023 report, Débarre said.

Both the earlier and the new reports document that traces of the virus were found clustered in a section of the Huanan Seafood Wholesale Market where genetic traces of animals were also found. Several of those species — raccoon dogs, rabbits and dogs — are known to be susceptible to infection with SARS-CoV-2, the virus that causes covid. Raccoon dogs have also been shown experimentally to be capable of transmitting the virus.

A significant element of the new paper is an analysis of when the pandemic began. Scientists can study mutations of the coronavirus, which evolves at a relatively steady rate, to estimate when the millions of genomes deposited in databases had the most recent common ancestor. That genetic evidence points to mid-November 2019 as the most likely time the virus spilled into humans and began spreading, and there could have been two or more spillover events, the researchers said.

“The timing of the origin of the market outbreak is genetically indistinguishable from the timing of the origin of the pandemic as a whole,” the report states.

There are many independent lines of evidence pointing to the market as the epicenter of the pandemic, said Kristian Andersen, an infectious-disease researcher at Scripps Research in La Jolla, Calif., and a co-author of the report in Cell. No previous virus spillover has been so well-documented, he said.

“Of any previous outbreak, pandemic, you name it, we don’t have this level of granularity,” he said. “We can narrow it down to a single market, and narrow it down to a section in that market, and maybe even narrow it down to a single stall in that market. That is mind-boggling.”

Early in the outbreak, as word spread of an unusual respiratory illness in Wuhan, officials closed the Huanan market. It was cleaned and all animals were removed.

Finding the specific animals that could have caused a spillover of the virus may be impossible, said Michael Worobey, a University of Arizona evolutionary biologist and co-author of the report.

“Immediately, you have a needle-in-a-haystack situation, but then you incinerate all the haystacks and burn up all the needles,” Worobey said.

The genetic evidence, the new report contends, supports the hypothesis that SARS-CoV-2 emerged in the same way that SARS-CoV-1 — which sickened people in 2002-2003 but was extinguished before it could cause a full-blown pandemic — is widely believed to have started, from animals sold in a market. The authors contend the world needs to take more aggressive action to shut down the illegal trade in wildlife to lower the risk of another catastrophic pandemic.

“All the data [on the origin of the pandemic] currently available point in the same direction, which is the wildlife trade in the Huanan market. Will it put the debate to an end? I’m afraid it’s unlikely,” Débarre said.

The natural spillover hypothesis has been challenged by proponents of the “lab leak theory,” an umbrella term for a suite of scenarios, many of them involving the Wuhan Institute of Virology. The sprawling institute conducted extensive research on coronaviruses, including SARS-CoV-1. Proponents of the lab leak theory argue the institute conducted research with lax biosafety protocols.

The debate over covid’s origins continues to be contentious and politicized. It is also entangled with geopolitical tensions and with a broader debate about biosafety practices and the regulatory oversight of laboratory experiments that seek to assess and understand the threat pathogens could pose.

The lab leak theory emerged early in 2020 and was embraced by President Donald Trump. It gained momentum in May 2021 when 18 scientists, including Worobey, wrote a letter to the journal Science saying all possible origins of the pandemic, including a lab leak, deserve investigation. President Joe Biden then asked his intelligence agencies to investigate.

They were unable to reach a consensus. Most favored a natural origin, but two agencies favored a lab origin. None claimed high confidence in their conclusions.

A report from Senate Republicans in 2022 said a “research-related accident” was the “most likely” origin of the pandemic, although it did not rule out a natural origin. “Critical corroborating evidence of a natural zoonotic spillover is missing,” the report said.

There is no evidence that the virus, or its progenitor, was inside a laboratory before the outbreak. Chinese officials have denied the virus came from a lab. But the Chinese government has limited outside investigations, and the lack of transparency has been an obstacle in the search to understand the origin of the virus.

Chinese officials have also dismissed the market origin, instead floating conjectures, generally dismissed by the global scientific community, that the virus came from outside China, possibly via packages of frozen seafood or from a military research facility in Maryland.

“To the question — Did it come from a lab or come from a market? — I think we already knew the answer to that,” Andersen said. “Yep, it’s the market. It’s natural, as we’ve previously seen happen.”

Thursday, September 05, 2024

The ecological impact of herbivore dung on plant communities

by Free University of Brussels

Xingzhao Sun of the research group Wildness, biodiversity and ecosystems under change of the Vrije Universiteit Brussel (VUB) explored the complex ecological interactions between herbivore dung and plant communities, providing new insights into the role of nutrients and microbial communities in ecosystems. The study is published in the journal Ecology and Evolution.

For her study, Dr. Sun collected dung samples from five herbivore species—European bison, horse, fallow deer, rabbit, and Scottish Highland cattle—during a field study conducted in Zuid-Kennemerland National Park in the Netherlands in early 2020. These samples were then analyzed in the lab for nutrient content, such as carbon, nitrogen, and phosphorus, as well as for microbial community composition. The research also included greenhouse and garden experiments to observe how different plant species responded to the various types of dung.

"One of our key findings is that the quality of dung varies significantly across different herbivore species." Dr. Sun explains. "Factors such as body size, digestive system type, and dietary preferences all contribute to these differences. For instance, rabbit dung is particularly high in nitrogen and has a unique microbial composition compared to other herbivore dung. Rabbits have a unique digestive process where they engage in coprophagy: they re-ingest their dung to maximize nutrient absorption. The high nitrogen content in their dung turns out to be especially beneficial for grass species in plant communities."

However, Dr. Sun emphasizes that no single type of dung can be deemed universally "best" for all plants, saying, "The impact of dung on plant communities depends on various factors, including species-specific plant-microbe symbiotic relationships and the specific nutrient needs of different plants.

"For example, legumes, known for their nitrogen-fixing ability, benefited more from dung with a lower nitrogen-to-phosphorus ratio, such as that from European bison or horses. The study not only advances our understanding of the ecological roles of herbivores but also highlights the complexity of their contribution to nutrient cycling in terrestrial ecosystems dung deposition."

More information: Xingzhao Sun et al, Microbial community composition in the dung of five sympatric European herbivore species, Ecology and Evolution (2024). DOI: 10.1002/ece3.11071

Journal information: Ecology and Evolution

Provid by Free University of Brussels Dung dynasty: The plant boosting powers of beetle recyclers

Dangerous new coronavirus is one of more than 30 pathogens found in new study of Chinese fur farms

By Sarah Newey
Daily Telegraph UK·
4 Sep, 2024

HKU5, a concerning new bat coronavirus, was discovered in the lungs and intestines of mink which had died from pneumonia. Photo / 123RF

A concerning new bat coronavirus is among 36 novel viruses detected among animals including racoon dogs, mink and guinea pigs in Chinese fur farms, scientists have warned.

The results, published in Nature journal this week, reiterate the risk posed by small-scale fur farms, which continue to proliferate in China and Southeast Asia. It also expands the list of animals known to be susceptible to zoonotic pathogens, including novel coronaviruses, bird flu and Japanese encephalitis.

“Fur farms represent a far richer zoonotic soup than we thought,” said Professor Eddie Holmes, an evolutionary biologist and virologist at the University of Sydney. He co-authored the report alongside colleagues in China.

The researchers not only looked at commonly farmed and studied animals (such as mink, muskrats, foxes and raccoon dogs), but also species including guinea pigs and deer. These are less intensely farmed but remain commonplace in smaller backyard farms across China, and have rarely been the subject of disease surveillance efforts.

“What [the study] tells you is that these species are also full of viruses, and some of these viruses are jumping species boundaries … which is a real worry,” Holmes said. “I think that this [fur] trade is a roll of the dice. We’re exposing ourselves to viruses that come from wildlife, which is an obvious route [for the] next pandemic to occur.”

The team of researchers sequenced samples from 461 animals from fur farms, mostly in northeastern China. All had died after suffering from disease. The scientists identified 125 different virus species, including 36 new pathogens.

Of the viruses detected, 39 were deemed to have high spillover potential because they were “generalists” spotted in a diversity of animals.

The team also detected seven coronaviruses, with the original hosts traced to rodents, rabbits and canines. Though none were closely related to Sars-Cov-2, a concerning new bat coronavirus was discovered. Called HKU5, it was found in the lungs and intestines of mink which had died from a pneumonia outbreak on a fur farm

Denmark culled five million farmed mink in 2020 after the animals were found to harbour a mutated strain of Covid-19. Photo / 123RF

HKU5 ‘is a red flag’

“The question always is, can we work out what sorts of viruses we should worry most about, which are most likely to emerge [in humans]? It’s very hard to say, but if viruses are able to jump big evolutionary distances, it suggests they can replicate in different cell types. That is a risk,” said Dr Holmes.

“HKU5 needs to go on a watchlist immediately. It is absolutely a red flag,” he added, calling for more rigorous surveillance of fur farms inside China and across the globe.

Linfa Wang, director of the Emerging Infectious Diseases Research Programme at Singapore’s Duke-NUS Medical School, who was not involved in the study, said he agreed that HKU5 was a red flag, but that “we need more data from lab-based infection studies to corroborate this”.

Scientists have long been concerned that mink farms could provide fertile ground for viruses to mutate, as the animals are susceptible to many of the same viruses as humans.

In autumn 2020, Denmark culled its entire population of farmed mink – some five million animals – after a Covid-19 jumped from humans to mink, mutated, and then re-infected humans with a new strain. There was also alarm in Spain in 2022, when avian influenza was reported in a mink farm in the country’s northwest.

In the latest study, scientists also found mink infected with two H5N6 bird flu viruses – while guinea pigs had H1N2 and H6N2 was found in a muskrat.

“We know from European outbreaks that these [fur] farms can extremely easily get infected from wild birds,” said Dr Thomas Peacock, a virologist and fellow at the Pirbright Institute, who was not involved in the study but has previously called for the closure of fur farms worldwide.

“China, at least in recent history, has had a far greater diversity of avian influenza viruses which are considered to have pandemic potential than Europe, so any risk from Europe is multiplied by the situation in China.”

He added that the latest research reiterates the biosecurity risks posed by fur farms, and called for greater surveillance of the pathogens spreading inside them.

“This is very much a peeking under the lid of a massive industry,” Peacock told the Daily Telegraph. “The conclusions aren’t specifically ‘virus x was found in mink or raccoon dogs and therefore is a direct singular pandemic threat’, but more this practise seems to bring lots of divergent, unusual viruses together from wildlife/farmed sources which creates a mixing pot for virus evolution and emergence.”

JiaZhen Lim, a PhD student at the University of Hong Kong’s State Key Laboratory of Emerging Infectious Diseases who was not involved in the study, agreed: “I think the key takeaway is just that there are more viruses in the farmed animals than we previously knew, and some of [them] have the cross-species infection potential.”

The study did not put the findings in the context of the origins of Covid-19 – partly because the researchers did not find pathogens closely related to Sars-Cov-2, but also because the Chinese Government has largely blocked scientists in the country from exploring or discussing anything relating to how the pandemic may have started.

The debate about how Covid-19 first jumped to humans remains ongoing. Many scientists say available evidence points towards the pathogen jumping from bats to humans via an intermediate animal in the wildlife trade; others continue to speculate it leaked from a laboratory in Wuhan.

But Wang, who played a key role in the work that traced Sars-1 back to bats, said the new research highlights the dangers of zoonotic spillover.

“These findings are significant and add further confirmation that animals are the most dangerous source of future viral disease emergence,” he told the Telegraph.

“Although the paper does not address the origin of SARS-CoV-2, it independently demonstrated that the risk of new viruses emerging from animal sources is MUCH higher than any other potential sources. Nature is much better in making new viruses of all kinds than humans.”

Holmes also said that fur farms present a “clear epidemic or pandemic risk”.

“In these locations, farmed animals act as a bridge [for diseases to spread] between wildlife to people or livestock,” he said. He added that “at the very least”, there needs to be “expanded surveillance of animals and humans working in this trade, and globally, not just in China”.

Saturday, August 24, 2024

From pets to pests: how domestic rabbits survive the wilderness

Uppsala University

How do rabbits go from fluffy pets to marauding invaders? Rabbits have colonized countries worldwide, often with dire economic and ecological consequences, but their secret has until now been a mystery. In a new study published in the journal Nature Ecology and Evolution, an international consortium led by scientists from BIOPOLIS-CIBIO (Portugal) and Uppsala University (Sweden) sequenced the genomes of nearly 300 rabbits from across three continents to unveil the key genetic changes that make these animals master colonizers.

Throughout history, people have taken animals under their care. Your dear pet - furry kitten, loyal dog, or colorful goldfish - is just part of an amazing variety of domestic forms. “Some changed so much from their wild ancestors, it is difficult to imagine they are related, like chihuahuas that descend from wolves” explains Dr Pedro Andrade, a researcher at BIOPOLIS-CIBIO and first author of the study. “Changes are often so drastic, that if you put your pet back in the wilderness, it will be very challenging for it to survive”.

But sometimes, they do rise to the challenge. When they do, we call them ferals, populations of a once domestic species that successfully readapted to the wild. Rabbits are a classic example. Through frequent and independent releases, rabbits have colonized locations worldwide. But despite years of research, a central question has eluded scientists: how can a domestic animal, optimized for thousands of years to live in captivity, not only survive but thrive when returned to the wild?

“In a previous study by our team, which looked at the colonization of Australia by rabbits, we found that multiple releases of domestic rabbits had taken place for several decades before a single introduction of 24 rabbits with wild ancestry in 1859, by Englishman Thomas Austin, triggered the explosive population growth of rabbits which caused one of the largest environmental disasters in history” says Dr. Joel Alves, a researcher at BIOPOLIS-CIBIO and the University of Oxford.

Could this be the key to explaining why rabbits so frequently establish these feral populations? To answer this, the international team of researchers sequenced the genomes of nearly 300 rabbits, including six feral populations from three continents – Europe, South America, and Oceania – as well as domestic and wild rabbits from the native range in Southwest Europe. Armed with this treasure trove of information, the largest genetic dataset of rabbits ever produced, researchers could now understand what makes these introduced rabbits unique.

“Domestic rabbits are so common, that our initial expectation was that these feral populations would be composed of domestic rabbits that somehow managed to re-adapt to the wild, but our findings point to a more complex scenario” explains Dr. Miguel Carneiro, one of the senior authors of the study. According to him, “despite looking at six largely independent colonizations, all these feral rabbits share a mixed domestic and wild origin.”

The team found that during re-adaptation to the wild, genetic variants linked to domestication are often eliminated because they are often deleterious in the wild making animals more vulnerable to predation a pattern that is more striking depending on how extreme the trait had become during domestication. “In these feral populations, you will typically not see an albino, or a fully black rabbit, even if these fancy coat colors are very common in domestic rabbits. However, you may very well encounter rabbits that carry the mutation for diluted coat color, a domestic variant that has minimal effect on camouflage.” adds Dr. Leif Andersson, professor at Uppsala University and another senior author of the study, who continues “This is a concrete example of natural selection in action”.

This purging of domestic traits didn’t just target fancy coat colors. The team found evidence for strong natural selection operating on genes linked to behavior and the development of the nervous system. “Tameness is crucial for domestic animals to live close to humans, but it will not help a rabbit that finds itself back in the wild survive, so natural selection removes the genetic variants linked to tameness” explains Dr Andrade.

The study has implications for understanding evolution and will be closely followed by lawmakers and practitioners on the frontlines of conservation. Feral rabbits often turn into invasive pests causing hundreds of millions of dollars in damages, and other domestic-turned-wild animals cause similar problems, like feral pigs or feral cats. “The best strategy to mitigate the impacts of invasive species is to prevent them from being introduced in the first place, so we hope our study provides important evidence to help evaluate and identify future invasion risks” concludes Dr. Carneiro.