Showing posts sorted by relevance for query MINK ARE WEASELS. Sort by date Show all posts
Showing posts sorted by relevance for query MINK ARE WEASELS. Sort by date Show all posts

Sunday, November 29, 2020

WEASAL FAMILY
Corona virus mutates rapidly in mink and ferrets. Should we be afraid?

By Matthew Rozsa, Salon- Commentary
November 29, 2020
  
Ferret outdoors. (Shutterstock)

2020 has been an unpredictable year, but it’s safe to say that even the most cynical doomsday preppers didn’t anticipate checking off “dead, coronavirus-infected mink rising from their graves” from their figurative 2020 bingo cards.

This article first appeared in Salon.

Yet that is precisely what has happened in Denmark, as thousands of mink have been killed and buried in shallow graves to halt the spread of SARS-CoV-2, according to The Guardian. Thankfully the mink did not rise up because they had been resurrected; the more innocuous, though still disgusting, explanation is that their bodies were bloated with decomposition gases and rose to the surface naturally because they had been buried en masse just below the surface.

This is not to say that the deceased mink — or their living counterparts — are not potentially disease vectors. Earlier this month Danish Prime Minister Mette Frederiksen was compelled to announce the mass killing of mink, and an end to mink farming for the foreseeable future, after health officials in that country discovered a cluster of SARS-CoV-2 mutations among both farmed mink and people. Scientists have long held concerns that mutations in the virus could limit the effectiveness of any potential coronavirus vaccine.

Less than two weeks later, Danish scientists revealed that they had taken genetic and experimental data on the mutations and found no evidence that they enabled the virus to be transmitted more easily among human beings. They also said that the data also did not indicate that the virus would be more deadly.


Despite these findings, however, scientists still determined that a mass culling of mink was necessary because the virus has been so prevalent among mink farms, with a resulting increase in the number of COVID-19 diagnoses in regions with mink farms.

Denmark is the world’s largest producer of mink pelts, but mink and other mustelidae like ferrets are renowned for their abilities as virus mutation factories. Because ferrets are the animals most like humans in terms of how their immune systems respond to influenza, scientists have experimented with them to make existing viruses more deadly, a biowarfare concept known as “gain of function” research. As The New York Times reported in 2012, “Working with ferrets, the animal that is most like humans in responding to influenza, researchers found that a mere five genetic mutations allowed the virus to spread through the air from one ferret to another while maintaining its lethality.”

It added, “A separate study at the University of Wisconsin, about which little is known publicly, produced a virus that is thought to be less virulent.”

Specifically, virologist Ron Fouchier of the Erasmus Medical Center in Rotterdam, revealed in 2011 that he was able to take an influenza virus that did not seem to be transmitted by air, and infected enough ferrets with it that it mutated to the point where it could be airborne. As Science Magazine reported at the time, “The virus is an H5N1 avian influenza strain that has been genetically altered and is now easily transmissible between ferrets, the animals that most closely mimic the human response to flu. Scientists believe it’s likely that the pathogen, if it emerged in nature or were released, would trigger an influenza pandemic, quite possibly with many millions of deaths.”

There was some less ominous news this week involving a study led by University College London researchers of virus genomes from more than 46,000 people with COVID-19 from 99 countries. As revealed in the scientific journal Nature Communications, scientists found that the mutations which have occurred so far in the novel coronavirus have not made COVID-19 spread more rapidly.

A weasel / ˈwiːzəl / is a mammal of the genus Mustela of the family Mustelidae. The genus Mustela includes the least weasels, polecats, stoats, ferrets and mink. Members of this genus are small, active predators, with long and slender bodies and short legs.

SEE  

Thursday, July 06, 2023

American mink regrow their brains in a rare reversal of the domestication process

New research by the Max Planck Institute of Animal Behavior (MPI-AB) suggests that loss of brain size is not permanent in domesticated animals

Peer-Reviewed Publication

MAX-PLANCK-GESELLSCHAFT

American mink 

IMAGE: NATIVE TO NORTH AMERICA, THE AMERICAN MINK HAS BECOME FERAL THROUGHOUT EUROPE. view more 

CREDIT: KAROL ZUB




Farm animals look different from their wild counterparts in many ways, and one difference is consistent: their brains are smaller than those of their ancestors. From sheep to pigs to cows, domesticated animals have smaller relative brain sizes compared to their wild counterparts—a phenomenon known as the domestication effect. Now, a study by the Max Planck Institute of Animal Behavior (MPI-AB) has discovered a rare reversal of the domestication effect. Over the course of captive breeding, the American mink has undergone a reduction in relative brain size, but populations that escaped from captivity were able to regain almost the full ancestral brain size within 50 generations. The study is published today in the Royal Society Open Science.

“Our results show that loss of brain size is not permanent in domesticated animals,” says Ann-Kathrin Pohle, a Master’s student at MPI-AB and first author on the paper. “This finding deepens our understanding of how domestication has changed the brains of animals, and how these changes might be affecting animals when they return to the wild.”

Understanding the feral brain

When animals lose brain size through the course of domestication, it’s mostly considered to be a one-way street. Animals almost never seem to regain the relative brain sizes of their ancestral forms, even in feral populations that have been living in the wild for generations. “Once animals loose parts of their body, such as certain brain regions, over the course of evolution, they are gone and cannot simply be regained,” says Dina Dechmann, senior author on the paper, and a group leader at MPI-AB.

Studying whether or not feral animals can regain the relative brain sizes of their wild counterparts is also difficult methodologically. To properly do so, Dechmann says, “you would need to find an animal with separate wild and feral populations to reduce the chance that the groups had mixed. And, you would need to find an animal that could be studied through sufficient brain and skull measurements.” You would need an animal, in other words, like the American mink.

Native to North America, the American mink has been domesticated for the fur trade for over a century. After they were bred in Europe for fur farming, captive animals escaped to form feral populations that have spread throughout Europe. This natural history thus provided the separated populations that Dechmann and her team needed: wild mink from North America, domesticated mink from European fur farms, and feral mink from Europe.

To explore changes in brain size, the team turned to a proxy: skulls. “Braincase size is a good proxy for brain size in mink, and this allows us to take measurements from existing skull collections without the need for living animals,” says Pohle. A museum collection from Cornell University was used to study skulls of wild American mink while European fur farms provided skulls of domesticated animals. For the feral population, Dechmann  and Pohl collaborated with Andrzej Zalewski at the Polish Mammal Research Centre who had a collection of skulls obtained from an eradication program of feral mink. “Usually, the difficulty with skull studies is finding big enough collections to work with,” says Dechmann. “We were incredibly fortunate to work with multiple organizations to obtain the population samples we needed.”

The team took measurements from skulls to calculate relative brain size of the animals. They found that, according to the well-documented domestication process, the brains of captive-bred mink had shrunk by 25% compared to their wild ancestors. But, in contrast to expectations, the brains of feral mink grew almost back to wild size within 50 generations.

Flexible brains

Dechmann suspects she knows why this animal, in particular, has achieved what was thought to be unlikely. American mink belong to a family of small mammals with a remarkable ability to seasonally change their brain size in a process known as Dehnel’s phenomenon. Dechmann, an expert on this process, has documented Dehnel’s in shrews, moles, and weasels.

“While other domesticated animals seem to lose brain size permanently, it’s possible that mink can regain their ancestral brain sizes because they have flexible brain size built into their system,” she says.

This flexibility could have offered advantages to the mink that re-entered the wild. “If you escape from captivity back to nature, you would want a fully capable brain to navigate the challenges of living in the wild. Animals with flexible brains, like the mink, could restore their brains even if they had shrunk it during an earlier time.”

The results don’t reveal if the brains of feral mink function the same as wild type mink. To find that out, the team would have to examine the brains of animals, which is a step for a future study.

 

Monday, August 21, 2023

END FUR FARMING
Animal rights activists released 3,000 minks from a Wisconsin farm during a late-night heist

Story by khawkinson@insider.com (Katie Hawkinson ) 

Vasily Fedosenko/Reuters© Provided by INSIDER

Animal rights activists broke in to a Wisconsin farm and released 3,000 minks into the wild.

They took responsibility via anonymous message on a site run by the Animal Liberation Front.

Police told a local outlet that 90% of the minks had been recovered in five days.

Thousands of minks ran wild in western Wisconsin after animal rights activists held a late-night heist to bust them out of a fur farm.


The activists released 3,000 minks from Olsen Fur Farm in Independence, Wisconsin, last week by cutting a hole in a chain-link fence and opening cages, The Star Tribune reported. The owner did not discover the damage until the next morning, the paper reported.

While the Trempealeau County Sheriff's Office has not released information on any suspects, an anonymous group took responsibility for the act by sending a message to the North American Animal Liberation Press Office, a site run by the Animal Liberation Front, which the FBI has previously labeled as an extremist group



"It's operational for now, but maybe releasing several hundred mink has a chance to close it for good," the message reads. "We hope many of the mink enjoy their freedom in the wild and that this farm will be unable to breed thousands upon thousands of them in future years.

Challis Hobbs, president of the Fur Commission USA, said the break-in may have done more harm than good for the mink.

"They basically just die because there's nothing to eat, and they don't have burrows to find security from predator attacks," Hobbs told the Star Tribune. "It messes with the ecosystem."

Around 90% of the minks have been recovered as of Wednesday, a spokesperson for the Trempealeau County Sheriff's Office told the Star Tribune. The escapees constituted three quarters of the farm's 4,000 mink population.

When contacted for updates by Insider, the Trempealeau County Sheriff's Office said they could not give comment outside of business hours.

MINK ARE WEASELS
FRANK ZAPPA WEASELS RIPPED MY FLESH 1970


Saturday, November 05, 2022

Carnivore gut microbes offer insight into health of wild ecosystems

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

Carnivore Gut Microbes Offer Insight Into Health of Wild Ecosystems 

IMAGE: A NEW STUDY FINDS THE MICROBIAL ECOSYSTEM IN THE GUTS OF WILD MARTEN (MARTES AMERICANA) THAT LIVE IN RELATIVELY PRISTINE NATURAL HABITAT -- LIKE THE ONE PICTURED HERE -- IS DISTINCT FROM THE GUT MICROBIOME OF WILD MARTEN THAT LIVE IN AREAS THAT ARE MORE HEAVILY IMPACTED BY HUMAN ACTIVITY. THE FINDING HIGHLIGHTS AN EMERGING TOOL THAT WILL ALLOW RESEARCHERS AND WILDLIFE MANAGERS TO ASSESS THE HEALTH OF WILD ECOSYSTEMS. view more 

CREDIT: RYLEE JENSEN


A new study finds the microbial ecosystem in the guts of wild marten (Martes americana) that live in relatively pristine natural habitat is distinct from the gut microbiome of wild marten that live in areas that are more heavily impacted by human activity. The finding highlights an emerging tool that will allow researchers and wildlife managers to assess the health of wild ecosystems.

“Specifically, we found that wild marten in relatively undisturbed environments have more carnivorous diets than martens in human-affected areas,” says Erin McKenney, co-lead author of a paper on the work and an assistant professor of applied ecology at North Carolina State University. Marten are small mammals, related to weasels, ferrets and mink.

“In conjunction with our other work on carnivore microbiomes, this finding tells us the microbial ecosystems in carnivore guts can vary significantly, reflecting a carnivore’s environment,” McKenney says. “Among other things, this means we can tell how much humans are impacting an area by assessing the gut microbiomes of carnivores that live in that area – which can be done by testing wild animal feces. In practical terms, this work is revealing a valuable tool for assessing the health of wild ecosystems.”

“Our goal here was to determine how, if at all, human disturbance of a landscape affects the gut microbiome of American marten that live in that landscape,” says Diana Lafferty, co-lead author of the paper and an assistant professor of biology at Northern Michigan University. “And the answers here were pretty clear.”

For the study, researchers collected gut microbiome data from 21 marten. Sixteen marten were harvested during a legal trapping season. The remaining five were trapped safely and released in the Huron Mountain Club, which is located in Michigan’s Upper Peninsula.

“The Huron Mountain Club is particularly important for this study, because it’s relatively pristine – one of the largest, primeval forests in the eastern United States,” Lafferty says. “That makes it an excellent juxtaposition to the 16 marten that were harvested, since those were collected in regions that are more impacted by human activity.”

The researchers found that the gut microbiomes of marten in the pristine forest of the Huron Mountain Club were clearly distinct from the marten harvested in other areas.

“This reflects the fact that marten in relatively pristine forest are able to forage at a higher trophic level, meaning they occupy a higher place in the food web,” Lafferty says. “In other words, the marten in relatively pristine forest have a more carnivorous diet, whereas marten in areas where there are more people were more omnivorous. Basically, the findings tell us a disturbed landscape results in a significantly different diet, which is reflected in their gut microbiomes.”

“It’s also worth noting that we were able to trap and release the marten in Huron Mountain Club during the dead of winter because we designed and built custom box traps to protect them from the elements,”  says Chris Kailing, a co-author of the paper who worked on the project while at Northern Michigan University. “That’s of interest because it makes winter sampling possible for future wildlife research even in harsh winter conditions.”

“This is the latest chapter in an ongoing body of research that is helping us understand carnivore gut microbiomes,” McKenney says. “Carnivore gut microbiomes are inherently more variable than the gut microbiomes of other animals. This study lends nuance to the emerging picture that all of this variability is not just noise. Rather, this variability stems from the nutritional landscape carnivores have access to – and that, in turn, reflects the health of the ecosystem carnivores inhabit. And that means that monitoring the gut microbiome of wild carnivores can offer us real insight into the ecosystems those carnivores live in.”

The paper, “The gut microbiome of wild American marten in the Upper Peninsula of Michigan,” will be published Nov. 3 in the open access journal PLOS ONE. The paper was co-authored by Sierra Gillman of the University of Washington; Miles Walimaa of Northern Michigan University; Macy Kailing of Virginia Tech University; and Brian Roell of the Michigan Department of Natural Resources.

The work was done with support from the Huron Mountain Wildlife Foundation.

A new study finds the microbial ecosystem in the guts of wild marten (Martes americana) that live in relatively pristine natural habitat -- like the one pictured here -- is distinct from the gut microbiome of wild marten that live in areas that are more heavily impacted by human activity. The finding highlights an emerging tool that will allow researchers and wildlife managers to assess the health of wild ecosystems.

CREDIT

Rylee Jensen

Saturday, April 08, 2023

Why are animal-to-human diseases on the rise?

Agence France-Presse
April 07, 2023

AFP
From Covid-19 to monkey pox, Mers, Ebola, avian flu, Zika and HIV, diseases transmitted from animals to humans have multiplied in recent years, raising fears of new pandemics.


What's a zoonosis?


A zoonosis (plural zoonoses) is a disease or infection transmitted from vertebrate animals to people, and vice versa. The pathogens involved can be bacteria, viruses or parasites.

These diseases are transmitted either directly during contact between an animal and a human, or indirectly through food or through a vector such as an insect, spider or mite.

Some diseases end up becoming specifically human, like Covid-19.

According to the World Organisation for Animal Health, 60 percent of human infectious diseases are zoonotic.

What types of diseases are involved?


The term "zoonoses" includes a wide variety of diseases.

Some affect the digestive system, such as salmonellosis, others the respiratory system, such as avian and swine flu as well as Covid, or the nervous system in the case of rabies.

The severity of these diseases in humans varies greatly depending on the disease and the pathogen's virulence, but also on the infected person, who may have a particular sensitivity to the pathogen.

What animals are involved?

Bats act as a reservoir for many viruses that affect humans.

Some have been known for a long time, such as the rabies virus, but many have emerged in recent decades, such as Ebola, the SARS coronavirus, Sars-CoV-2 (which causes Covid-19) or the Nipah virus, which appeared in Asia in 1998.

Badgers, ferrets, mink and weasels are often implicated in viral zoonoses, and in particular those caused by coronaviruses.

Other mammals, such as cattle, pigs, dogs, foxes, camels and rodents, also often play the role of intermediate host.

All the viruses responsible for major influenza pandemics had an avian origin, either direct or indirect.

Finally, insects such as ticks are vectors of many viral diseases that affect humans.

- Why has the frequency of zoonoses increased?


Having appeared thousands of years ago, zoonoses have multiplied over the past 20 or 30 years.

The growth of international travel has allowed them to spread more quickly.

By occupying increasingly large areas of the planet, humans also contribute to disrupting the ecosystem and promoting the transmission of viruses.

Industrial farming increases the risk of pathogens spreading between animals.

Trade in wild animals also increases human exposure to the microbes they may carry.

Deforestation increases the risk of contact between wildlife, domestic animals and human populations.

Should we fear another pandemic?

Climate change will push many animals to flee their ecosystems for more livable lands, a study published by the scientific journal Nature warned in 2022.

By mixing more, species will transmit their viruses more, which will promote the emergence of new diseases potentially transmissible to humans.

"Without preventative strategies, pandemics will emerge more often, spread more rapidly, kill more people, and affect the global economy with more devastating impact than ever before," the UN Biodiversity Expert Group warned in October 2020.

According to estimates published in the journal Science in 2018, there are 1.7 million unknown viruses in mammals and birds, 540,000 to 850,000 of them with the capacity to infect humans.

But above all, the expansion of human activities and increased interactions with wildlife increase the risk that viruses capable of infecting humans will "find" their host.

© 2023 AFP



Monday, February 06, 2023

‘Major Leap’ in Bird Virus Threatens Yet Another Pandemic

David Axe
Mon, February 6, 2023

Ritzau Scanpix/Mads Claus Rasmussen via Reuters

The same highly pathogenic bird-flu virus that’s killed tens of millions of chickens and other birds over the past year just got a lot closer to infecting people, too.

An unusual outbreak of the H5N1 virus in minks—relatives of weasels—at a Spanish fur farm last fall also exposed the farm’s staff to the virus. Swift action by health authorities helped prevent any human infections. This time.

But bird flu isn’t going away. And as H5N1 continues to circulate in domestic and wild birds, causing millions of animal deaths and tightening the supply of eggs, it’s also getting closer and closer to the human population. “This… avian influenza has the potential to become a major problem to humans,” Adel Talaat, a professor of pathobiological sciences at the University of Wisconsin-Madison, told The Daily Beast.

It might be a matter of time before H5N1 achieves large-scale “zoonosis” and makes the leap to the human species. If and when that happens, we could have yet another major viral crisis on our hands. On top of the COVID pandemic, worsening seasonal RSV, the occasional monkeypox flare-up and annual flu outbreaks.

Reports this week suggested that the current wave of bird flu could be crossing over into mammals with more regularity. Scientists found traces of bird flu in seals that died in a “mass mortality event” in the Caspian Sea in December, and the BBC reported this week that tests in Britain had found the virus in a range of mammals up and down the country. On Jan. 9, the World Health Organization was informed that a 9-year-old girl in Ecuador had tested positive.

Bird flu isn’t new. Scientists first identified the virus back in the 1870s. There’ve been dozens of major outbreaks over the years—and they’ve grown more frequent, and more severe, as the global population of domestic poultry has expanded in order to feed a growing human population.

H5N1, a more-severe “highly pathogenic avian influenza” virus—or HPAI—first appeared in China in the 1990s. It and other HPAIs have achieved zoonosis on a small scale, mostly in Asia. Several dozen people have died of bird flu in recent decades.

But so far, bird flu has mostly infected, well, birds. That makes it a huge problem for poultry farmers. And for people who buy eggs, of course. The current H5N1 outbreak has killed, or compelled farmers to cull, nearly 60 million chickens, turkeys, geese and ducks in the United States alone. The cullings drove up the price of eggs to nearly $5 per dozen at U.S. grocery stores last fall, according to the U.S. Department of Agriculture. That’s several times the long-term average price.

Bird Flu Taking the Leap


Higher egg prices will be the least of our problems if large-scale zoonosis ever triggers a human bird-flu pandemic. And that’s why scientists and health officials keep a close eye on H5N1 and related HPAIs as they spread and mutate. For epidemiologists, the bird-flu outbreak at the mink farm in northwestern Spain was a giant red flag. An ominous sign that major zoonosis might be getting more likely.

Spanish health officials first noticed the outbreak in early October, when the death rate among minks at a large farm in Galicia tripled. Biological samples from the farm’s 52,000 minks contained H5N1. It was the first time bird flu had infected farmed minks in Europe.

Authorities ordered the culling of all the minks at the affected farm. At the same time, they quarantined and tested the farm’s 11 workers. Luckily, none had caught the virus.

It was a close call. And all the more worrying because no one knows for sure what happened. “The source of the outbreak remains unknown,” a team led by virologist Montserrat Agüero reported in the latest issue of Eurosurveillance, an epidemiology journal. It’s possible wild birds spread the virus to the minks. It’s also possible the pathogen was present in the minks’ food, which contains raw chicken.

Equally troubling, the virus didn’t just spread from birds to minks. It may also have spread from minks to other minks, as well, Agüero’s team discovered. “This is suggested by the increasing number of infected animals identified after the confirmation of the disease.”

That post-zoonosis transmission within a new species is how an animal virus such as H5N1 could cause a new pandemic. It’s what happened with COVID, after the SARS-CoV-2 virus spread from bats or pangolins to people back in late 2019. It’s what happened with monkeypox, after that pathogen first leaped from monkeys and rodents to human beings, possibly decades ago.

“The ability to achieve sustained transmission in a mammal is a major leap for flu viruses, so the mink event is a big deal,” James Lawler, an infectious disease expert at the University of Nebraska Medical Center, told The Daily Beast. “It definitely increases the risk for [a] species-jump to humans.”

The Spanish bird-flu outbreak has a happy ending for all involved—except those 52,000 minks, of course. But the next outbreak might not end so neatly. Not if scientists are late noticing a zoonotic leap, or if viral transmission outpaces health officials’ ability to cull affected animals, quarantine exposed people and isolate the virus.

Bird flu more than many viruses demands constant vigilance. It’s infecting more birds than ever, jumping to mammals in more places and learning new genetic tricks that increase the risk to humans.

All that is to say, our bird-flu problem might get worse before it gets better. “The ongoing widespread outbreaks of HPAI are concerning across the board,” Lawler said.

The Daily Beast.