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Cats have driven many species to extinction. Experts share tactics for reducing feline destruction

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Sunday, November 26, 2023

Cat owners and cat admirers alike tend to be intrigued by their enigmatic companions. When we see an intrepid feline carefully stalking its prey or happily playing with other cats, we ponder the mysteries of its mind and the depths of its soul. What manic misadventures do cats engage in when we're not around? "A free-roaming cat is not filling an ecological niche, or reverting to its ancestral form. It is merely a run-away pet that needs to be brought back inside." Unfortunately, the real world of cats differs significantly from the innocent, whimsical versions depicted in movies like "Cats" and "The Aristocats." In fact, when domesticated cats are allowed to roam freely, they often leave a trail of ecological destruction in their wake. Many species have gone extinct due to domesticated cats being allowed to roam outdoors, and many other animals are suffering immensely because of it. To understand why, it is first important to recognize that domesticated cats can never be "wild," whether they are owned by humans or "feral," meaning a domesticated cat that has no owner. Of course, wild cats exist — not only tigers, but also bobcats and literal wild cats, from which these favored pets evolved. But these cats are native, not invasive and don't spread wherever humans do. By definition, just like cows and chickens, a domesticated cat is biologically incapable of being a natural part of the wilderness. "Just like a stray dog doesn’t become a wolf, a feral cat doesn’t become a wild cat," explained Daniel Joseph Herrera, a PhD student studying urban ecology at the University of Maryland–College Park who has co-authored a 2022 study on domesticated cats being an invasive species. "A free-roaming cat is not filling an ecological niche, or reverting to its ancestral form. It is merely a run-away pet that needs to be brought back inside." "The species most detrimentally impacted by outdoor cats are island species [that] are often naïve to or ill-equipped to handle the enormous threat posed by cats." Herrera said people often confuse the term "feral" with the term "wild" and use this confusion to justify the cat’s continued outdoor life. But it's quite clear that domesticated cats can be dangerous to ecosystems. The question is how dangerous. According to Grant Sizemore, the Director of Invasive Species Programs at the American Bird Conservancy, outdoor cats can negatively impact a wide variety of species from a diverse range of environments around the world, from backyards to oceans. "Those impacts include direct predation, parasite and disease transmission, and indirect effects (e.g., competition)," Sizemore wrote to Salon. "Generally, however, the species most detrimentally impacted by outdoor cats are island species [that] are often naïve to or ill-equipped to handle the enormous threat posed by cats and often have smaller populations than continental wildlife." Sizemore said that this is particularly true of species that are either only as big as cats or slightly smaller, such as the endangered Newell’s Shearwater, "which has nested in burrows in the secluded mountains of Kauaʻi for eons." Outdoor cats are also responsible for the extinction of the Stephen’s Island Wren (or Lyall’s Wren), with Sizemore adding this may be the most famous example of a species now extinct because of cats. "These birds have been ravaged by outdoor cats, even more so than other introduced predators, because cats not only kill the young in the nest but also kill adults, eliminating the chance for that adult bird, which has already survived the trials of youth, to breed again in subsequent years," Sizemore explained. "Sadly, whether on islands or elsewhere, the impacts of cats adds up, and cats have now contributed to the extinction of at least 63 species of birds, mammals and reptiles worldwide." Outdoor cats have a particularly devastating impact on birds, ranking as "the top source of direct, human-caused bird mortality in the United States, killing an estimated 2.4 billion birds every year." Want more health and science stories in your inbox? Subscribe to Salon's weekly newsletter Lab Notes. "In Australia, feral cats were most likely the principal cause of extinction of the pig-footed bandicoot, central hare-wallaby, desert bandicoot, lesser bilby and long-tailed hopping-mouse, amongst others." As Herrera pointed out, bird species are hardly alone in being targeted by outdoor cats. "Free-roaming cats are known for their predation on bird populations, but research has found that cats actually prey on small mammals more than they do birds," Herrera explained. This can include chipmunks, moles, voles, mice and squirrels, which are easier to catch than birds since they cannot fly away. "Additionally, these species may prove a more reliable source of prey since they do not migrate annually like many species of bird do." Although cats are traditionally known for preying on non-native rodents like brown rats, Herrera said "they prefer smaller and easier-to-handle prey such as native small mammals and birds. Previous research has found that cats do not reduce the number of rats in an area, and my own research has found cats and rats to live in relative harmony where people leave cat food outside." Even when cats are not destroying native species through hunting, they can do so through by spreading infections. "In those parts of the world without a long evolutionary history of cats, cats also spread some cat-dependent diseases (such as toxoplasmosis) to many native birds and mammals," explained John C.Z. Woinarski, a professor at the NESP Threatened Species Recovery Hub at Charles Darwin University, in an email to Salon. He added that "in Australia, there would be no toxo were it not for cats" and that "Australia's fauna has been particularly affected by cats, with cats implicated in the extinction of many native mammal species, and the ongoing decline of many threatened birds and mammals." If there is any good news here, it is that humans can solve the problem they helped create. According to Arie Trouwborst, a professor of nature conservation law at Tilburg University, "the only effective way to protect vulnerable wildlife from cats is for people to keep their cats indoors or otherwise within their control — just as we expect pet owners to do with any other animal." He cited the Australian city of Canberra as an example of a government that has done this effectively. "A sympathetic way to work towards a landscape without free-roaming cats, already employed by the Australian authorities in Canberra, is to gradually phase them out," Trouwborst wrote to Salon. "Whereas current outdoor cats may keep roaming the rest of their lives, each newly acquired cat must from now on be kept indoors from the start." He added, "Feral cats are a different category. As cats are one of the world's worst invasive alien species, biodiversity conservation laws and policies require efforts to remove them from the landscape." Woinarski offered suggestions for cat owners who want to protect the environment including de-sexing, registration and preventing cats from roaming, strategies which can be strengthened by government regulation. While the problem of dealing with feral cats is more complicated, he suggested actions like banning the importation of domesticated cats to islands that do not already have them, eradicating cats from the islands that do have them, regulating other threats to species susceptible to cat predation, creating predator-proof enclosures for species particularly threatened by cat predation (which is being heavily done in Australia) and "intensive baiting and other cat control programs at sites of conservation significance." While these measures may seem extreme, Woinarski pointed out that "in Australia, feral cats were most likely the principal cause of extinction of the pig-footed bandicoot, central hare-wallaby, desert bandicoot, lesser bilby and long-tailed hopping-mouse, amongst others." Dr. Sarah Crowley, a senior lecturer at the University of Exeter's Centre for Geography and Environmental Science, argued that there are "several techniques that could help people reduce the amount of wildlife killed by owned domestic cats. The most successful were feeding a meat-rich, complete diet and playing with cats in a way that simulates hunting behaviors (e.g. with a feather wand) for 5-10 minutes a day." It is not merely the wildlife that suffers when outdoor cats are given free rein to roam. As Sizemore observed, "cats are the top source of rabies among domestic animals in the United States and disproportionately expose more people to this disease than wildlife." The animals which roam outdoors "are also about three times more likely to be infected with parasites, which can then be spread to people. Furthermore, cats are a definitive host for the parasite Toxoplasma gondii that causes toxoplasmosis. The parasite can only complete its life cycle in a cat’s digestive tract and is then excreted via feces into the environment, where it can subsequently infect any bird or mammal." These parasites "can cause miscarriages, fetal deformities, blindness, organ failure and death and has been associated with neurodegenerative diseases (e.g., schizophrenia)," Sizemore said. "The risk of toxoplasmosis by cats is an often overlooked but potentially serious consequence of cats roaming the landscape." Read more about invasive species

Outdoor and feral cats can seriously harm native ecosystems. Here's how to fix it

Cat owners and cat admirers alike tend to be intrigued by their enigmatic companions. When we see an intrepid feline carefully stalking its prey or happily playing with other cats, we ponder the mysteries of its mind and the depths of its soul. What manic misadventures do cats engage in when we're not around?

"A free-roaming cat is not filling an ecological niche, or reverting to its ancestral form. It is merely a run-away pet that needs to be brought back inside."

Unfortunately, the real world of cats differs significantly from the innocent, whimsical versions depicted in movies like "Cats" and "The Aristocats." In fact, when domesticated cats are allowed to roam freely, they often leave a trail of ecological destruction in their wake. Many species have gone extinct due to domesticated cats being allowed to roam outdoors, and many other animals are suffering immensely because of it.

To understand why, it is first important to recognize that domesticated cats can never be "wild," whether they are owned by humans or "feral," meaning a domesticated cat that has no owner. Of course, wild cats exist — not only tigers, but also bobcats and literal wild cats, from which these favored pets evolved. But these cats are native, not invasive and don't spread wherever humans do. By definition, just like cows and chickens, a domesticated cat is biologically incapable of being a natural part of the wilderness.

"Just like a stray dog doesn’t become a wolf, a feral cat doesn’t become a wild cat," explained Daniel Joseph Herrera, a PhD student studying urban ecology at the University of Maryland–College Park who has co-authored a 2022 study on domesticated cats being an invasive species. "A free-roaming cat is not filling an ecological niche, or reverting to its ancestral form. It is merely a run-away pet that needs to be brought back inside."

"The species most detrimentally impacted by outdoor cats are island species [that] are often naïve to or ill-equipped to handle the enormous threat posed by cats."

Herrera said people often confuse the term "feral" with the term "wild" and use this confusion to justify the cat’s continued outdoor life. But it's quite clear that domesticated cats can be dangerous to ecosystems. The question is how dangerous. According to Grant Sizemore, the Director of Invasive Species Programs at the American Bird Conservancy, outdoor cats can negatively impact a wide variety of species from a diverse range of environments around the world, from backyards to oceans.

"Those impacts include direct predation, parasite and disease transmission, and indirect effects (e.g., competition)," Sizemore wrote to Salon. "Generally, however, the species most detrimentally impacted by outdoor cats are island species [that] are often naïve to or ill-equipped to handle the enormous threat posed by cats and often have smaller populations than continental wildlife."

Sizemore said that this is particularly true of species that are either only as big as cats or slightly smaller, such as the endangered Newell’s Shearwater, "which has nested in burrows in the secluded mountains of Kauaʻi for eons." Outdoor cats are also responsible for the extinction of the Stephen’s Island Wren (or Lyall’s Wren), with Sizemore adding this may be the most famous example of a species now extinct because of cats.

"These birds have been ravaged by outdoor cats, even more so than other introduced predators, because cats not only kill the young in the nest but also kill adults, eliminating the chance for that adult bird, which has already survived the trials of youth, to breed again in subsequent years," Sizemore explained. "Sadly, whether on islands or elsewhere, the impacts of cats adds up, and cats have now contributed to the extinction of at least 63 species of birds, mammals and reptiles worldwide." Outdoor cats have a particularly devastating impact on birds, ranking as "the top source of direct, human-caused bird mortality in the United States, killing an estimated 2.4 billion birds every year."


Want more health and science stories in your inbox? Subscribe to Salon's weekly newsletter Lab Notes.


"In Australia, feral cats were most likely the principal cause of extinction of the pig-footed bandicoot, central hare-wallaby, desert bandicoot, lesser bilby and long-tailed hopping-mouse, amongst others."

As Herrera pointed out, bird species are hardly alone in being targeted by outdoor cats.

"Free-roaming cats are known for their predation on bird populations, but research has found that cats actually prey on small mammals more than they do birds," Herrera explained. This can include chipmunks, moles, voles, mice and squirrels, which are easier to catch than birds since they cannot fly away. "Additionally, these species may prove a more reliable source of prey since they do not migrate annually like many species of bird do."

Although cats are traditionally known for preying on non-native rodents like brown rats, Herrera said "they prefer smaller and easier-to-handle prey such as native small mammals and birds. Previous research has found that cats do not reduce the number of rats in an area, and my own research has found cats and rats to live in relative harmony where people leave cat food outside."

Even when cats are not destroying native species through hunting, they can do so through by spreading infections.

"In those parts of the world without a long evolutionary history of cats, cats also spread some cat-dependent diseases (such as toxoplasmosis) to many native birds and mammals," explained John C.Z. Woinarski, a professor at the NESP Threatened Species Recovery Hub at Charles Darwin University, in an email to Salon. He added that "in Australia, there would be no toxo were it not for cats" and that "Australia's fauna has been particularly affected by cats, with cats implicated in the extinction of many native mammal species, and the ongoing decline of many threatened birds and mammals."

If there is any good news here, it is that humans can solve the problem they helped create. According to Arie Trouwborst, a professor of nature conservation law at Tilburg University, "the only effective way to protect vulnerable wildlife from cats is for people to keep their cats indoors or otherwise within their control — just as we expect pet owners to do with any other animal." He cited the Australian city of Canberra as an example of a government that has done this effectively.

"A sympathetic way to work towards a landscape without free-roaming cats, already employed by the Australian authorities in Canberra, is to gradually phase them out," Trouwborst wrote to Salon. "Whereas current outdoor cats may keep roaming the rest of their lives, each newly acquired cat must from now on be kept indoors from the start."

He added, "Feral cats are a different category. As cats are one of the world's worst invasive alien species, biodiversity conservation laws and policies require efforts to remove them from the landscape."

Woinarski offered suggestions for cat owners who want to protect the environment including de-sexing, registration and preventing cats from roaming, strategies which can be strengthened by government regulation. While the problem of dealing with feral cats is more complicated, he suggested actions like banning the importation of domesticated cats to islands that do not already have them, eradicating cats from the islands that do have them, regulating other threats to species susceptible to cat predation, creating predator-proof enclosures for species particularly threatened by cat predation (which is being heavily done in Australia) and "intensive baiting and other cat control programs at sites of conservation significance."

While these measures may seem extreme, Woinarski pointed out that "in Australia, feral cats were most likely the principal cause of extinction of the pig-footed bandicoot, central hare-wallaby, desert bandicoot, lesser bilby and long-tailed hopping-mouse, amongst others."

Dr. Sarah Crowley, a senior lecturer at the University of Exeter's Centre for Geography and Environmental Science, argued that there are "several techniques that could help people reduce the amount of wildlife killed by owned domestic cats. The most successful were feeding a meat-rich, complete diet and playing with cats in a way that simulates hunting behaviors (e.g. with a feather wand) for 5-10 minutes a day."

It is not merely the wildlife that suffers when outdoor cats are given free rein to roam. As Sizemore observed, "cats are the top source of rabies among domestic animals in the United States and disproportionately expose more people to this disease than wildlife." The animals which roam outdoors "are also about three times more likely to be infected with parasites, which can then be spread to people. Furthermore, cats are a definitive host for the parasite Toxoplasma gondii that causes toxoplasmosis. The parasite can only complete its life cycle in a cat’s digestive tract and is then excreted via feces into the environment, where it can subsequently infect any bird or mammal."

These parasites "can cause miscarriages, fetal deformities, blindness, organ failure and death and has been associated with neurodegenerative diseases (e.g., schizophrenia)," Sizemore said. "The risk of toxoplasmosis by cats is an often overlooked but potentially serious consequence of cats roaming the landscape."

Read more

about invasive species

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The Extinction of the Giant Ape: Scientists Solve Long-Standing Mystery

In the karst landscapes of southern China, giant apes, known as Gigantopithecus blacki, once traversed the terrain. These massive creatures, standing three meters tall and...

An artist’s impression of a group of G. blacki within a forest in southern China. Credit: Garcia/Joannes-Boyau (Southern Cross University)In the karst landscapes of southern China, giant apes, known as Gigantopithecus blacki, once traversed the terrain. These massive creatures, standing three meters tall and weighing about 250 kilograms, are considered distant relatives of humans. Although they vanished before humans settled in the area, the reasons for their extinction remain largely a mystery. The only evidence of their former presence consists of approximately 2000 fossilized teeth and four jawbones.New evidence from this region published in Nature, uncovered by a team of Chinese, Australian, and US researchers, demonstrates beyond doubt that the largest primate to walk the earth went extinct between 295,000 and 215,000 years ago, unable to adapt its food preferences and behaviors, and vulnerable to the changing climates which sealed its fate.“The story of G. blacki is an enigma in paleontology – how could such a mighty creature go extinct at a time when other primates were adapting and surviving? The unresolved cause of its disappearance has become the Holy Grail in this discipline,” says paleontologist and co-lead author Professor Yingqi Zhang, from the Institute of Vertebrate Palaeontology and Palaeoanthropology at the Chinese Academy of Sciences (IVPP). “The IVPP has been excavating for G. blacki evidence in this region for over 10 years but without solid dating and a consistent environmental analysis, the cause of its extinction had eluded us.”Extensive Research ProjectDefinitive evidence revealing the story of the giant ape’s extinction has come from a large-scale project collecting evidence from 22 cave sites spread across a wide region of Guangxi Province in southern China. The foundation of this study was the dating.“It’s a major feat to present a defined cause for the extinction of a species, but establishing the exact time when a species disappears from the fossil record gives us a target timeframe for an environmental reconstruction and behavior assessment,” says co-lead author, Macquarie University geochronologist Associate Professor Kira Westaway.Digging into the hard cemented cave sediments containing a wealth of fossils and evidence of G. blacki. Credit: Kira Westaway (Macquarie University)“Without robust dating, you are simply looking for clues in the wrong places.”Six Australian universities contributed to the project. Macquarie University, Southern Cross University, Wollongong University and the University of Queensland used multiple techniques to date samples. Southern Cross also mapped G. blacki teeth to extract information on the apes’ behaviors. ANU and Flinders University studied the pollen and fossil-bearing sediments in the cave respectively, to reconstruct the environments in which G. blacki thrived and then disappeared.Dating Techniques and Environmental AnalysisSix different dating techniques were applied to the cave sediments and fossils, producing 157 radiometric ages. These were combined with eight sources of environmental and behavioral evidence, and applied to 11 caves containing evidence of G blacki, and also to 11 caves of a similar age range where no G. blacki evidence was found.The location of many caves including two G. blacki bearing caves. Credit: Yingqi Zhang (IVPP- CAS)Luminescence dating, which measures a light-sensitive signal found in the burial sediments that encased the G. blacki fossils, was the primary technique, supported by uranium-series (US) and electron-spin resonance (US-ESR) dating of the G. blacki teeth themselves.“By direct-dating the fossil remains, we confirmed their age aligns with the luminescence sequence in the sediments where they were found, giving us a comprehensive and reliable chronology for the extinction of G. blacki,” says Southern Cross University geochronologist Associate Professor Renaud Joannes-Boyau.Insights from Dental AnalysisUsing detailed pollen analysis, fauna reconstructions, stable isotope analysis of the teeth, and a detailed analysis of the cave sediments at a micro level, the team established the environmental conditions leading up to when G blacki went extinct. Then, using trace element and dental microwear textural analysis (DMTA) of the apes’ teeth, the team modeled G. blacki’s behavior while it was flourishing, compared to during the species’ demise.The G. blacki bearing cave of Zhang Wang lies 150 m above the valley floor making for a tough climb every day to conduct excavations. Credit: Kira Westaway (Macquarie University)“Teeth provide a staggering insight into the behavior of the species indicating stress, diversity of food sources, and repeated behaviors,” says Associate Professor Joannes-BoyauThe findings show G.blacki went extinct between 295,000 and 215,000 years ago, much earlier than previously assumed. Before this time, G. blacki flourished in a rich and diverse forest.Environmental Changes and Comparative AdaptationBy 700,000 to 600,000 years ago, the environment became more variable due to the increase in the strength of the seasons, causing a change in the structure of the forest communities.Orangutans (genus Pongo) – a close relative of G. blacki – adapted their size, behavior, and habitat preferences as conditions changed. In comparison, G. blacki relied on a less nutritious backup food source when its preferences were unavailable, decreasing the diversity of its food. The ape became less mobile, had a reduced geographic range for foraging, and faced chronic stress and dwindling numbers.“G. blacki was the ultimate specialist, compared to the more agile adapters like orangutans, and this ultimately led to its demise,” says Professor Zhang.Associate Professor Westaway says: “With the threat of a sixth mass extinction event looming over us, there is an urgent need to understand why species go extinct.“Exploring the reasons for past unresolved extinctions gives us a good starting point to understand primate resilience and the fate of other large animals, in the past and future.”Reference: “The demise of the giant ape Gigantopithecus blacki” by Yingqi Zhang, Kira E. Westaway, Simon Haberle, Juliën K. Lubeek, Marian Bailey, Russell Ciochon, Mike W. Morley, Patrick Roberts, Jian-xin Zhao, Mathieu Duval, Anthony Dosseto, Yue Pan, Sue Rule, Wei Liao, Grant A. Gully, Mary Lucas, Jinyou Mo, Liyun Yang, Yanjun Cai, Wei Wang and Renaud Joannes-Boyau, 10 January 2024, Nature.DOI: 10.1038/s41586-023-06900-0

Survivors of the Ice Age: How Did the Brown Bear Beat Extinction?

The brown bear is one of the largest terrestrial carnivores alive today, with a broad distribution throughout the Northern Hemisphere. In contrast to numerous other...

The study of ancient brown bear genomes reveals that their survival through the last Ice Age involved significant losses in range and genetic diversity, underscoring the importance of historical genetic studies in conservation efforts and future wildlife management. Credit: SciTechDaily.comThe brown bear is one of the largest terrestrial carnivores alive today, with a broad distribution throughout the Northern Hemisphere. In contrast to numerous other large carnivores that faced extinction by the end of the last Ice Age (cave bear, sabretoothed cats, cave hyena), the brown bear is one of the lucky survivors that made it through to the present. The question has puzzled biologists for close to a century – how was this so?Brown bears are ecologically flexible and have a broad dietary range. While they are carnivores, their diets can also consist primarily of plant matter making them adaptable to environmental changes. However, brown bears also experienced extensive range reductions and regional extinctions during the last Ice Age. Brown bears used to occupy a much wider range including Ireland, Honshu, the largest island of Japan, and Quebec (Canada).Did the decline or disappearance of bear populations in certain areas happen because bears left those places for better ones that they still currently live, or did unique groups of bears with distinct genes inhabit those areas and go extinct, leading to a loss in the overall diversity of the species? Genetic Studies and InsightsBy studying the genomes of ancient brown bears dated to between 3,800 and 60,000 years old, including several individuals from outside their current range, researchers from the University of Copenhagen, Denmark, and the University of Yamanashi, Japan sought to address this question by investigating the evolutionary relationships between brown bears across space and time.Their study showed that brown bears did not simply move with the shifting environment, but populations went extinct. “Our analyses showed that ancient brown bears represent genetic diversity absent in today’s populations,” says Takahiro Segawa, lead author of the study. “While brown bears survived global extinction, they suffered considerable losses of their historical range and genetic diversity.” This new perspective highlights a crucial period in the brown bear’s history and that they also faced challenges during and after the last Ice Age.“As we continue to grapple with the challenges of coexistence between humans and wildlife, insights from the deep past are invaluable in shaping a sustainable future,” adds Michael Westbury, the senior author of the study. “Although studying recent specimens can provide some insights, by including samples from the past and from areas a species no longer exists, we can better quantify how patterns of current diversity arose, and inform predictions about how they may respond to future environmental change.”Reference: “The origins and diversification of Holarctic brown bear populations inferred from genomes of past and present populations” by Takahiro Segawa, Alba Rey-Iglesia, Eline D. Lorenzen and Michael V. Westbury, 24 January 2024, Proceedings of the Royal Society B.DOI: 10.1098/rspb.2023.2411

Inner ear of extinct ape species is overlooked aspect of human bipedal evolution, study finds

Described by scientists as a "bony labyrinth," the inner ear provides many clues as to the origin of our species

The inner ear may not seem like a particularly bony place, but human ears in fact have three small bones (also known as ossicles): the malleus, the incus and the stapes. While most people would assume that these bones are necessary for hearing, one would not imagine that they relate much to how we walk. Yet according to Chinese and American scientists working together for a study in the journal The Innovation, the ear bones of ancient apes can teach us a lot not only about our primate ancestors, but also about ourselves. In a sense, the inner ear bones of the Lufengpithecus is a missing link in the evolutionary history of human locomotion. It all comes down to bipedalism, or the fact that humans walk on two legs. Because our various primate ancestors were often quadrupedal (walking on four legs), evolutionary scientists have often wondered how we made the shift from being a four-legged species to one that relies on two legs. The experts turned to the seemingly obvious places for answers: They studied the bones of ancient monkeys when they came from their limbs, pelvis, shoulders and spine. Yet in The Innovation study, the team of scientists looked instead to the inner ear. They specifically chose the remains of a Lufengpithecus, an ape from China that has been extinct for 7 to 8 million years. "The semicircular canals, located in the skull between our brain and the external ear, are critical for our sense of balance and position when we move, and they provide a fundamental component of our locomotion that most people are probably unaware of," Zhang Yinan, first author of the study and a Ph.D. student at the Institute of Vertebrate Paleontology and Paleoanthropology, said in a press statement. "The size and shape of the semicircular canals have mathematical correlation with how mammals, including apes and humans, move around their environment. Using modern imaging techniques, we are able to visualize the internal structure of fossil skulls and study the anatomical details of the semicircular canals to reveal how extinct mammals moved." After doing this, the scientists observed that the Lufengpithecus inner ear revealed an animal that moved in ways unlike anything previously known about ancient or modern primates. Instead, it is believed that the primate moved around by combining various motion types — clambering, climbing, bipedalism, quadrupedalism and forelimb suspension. The ancestors of the Lufengpithecus did not move anything like this — their locomotion was more analogous to what we see today among gibbons in Asia — and humans developed their bipedalism afterward. In a sense, the inner ear bones of the Lufengpithecus is a overlooked connection in the evolutionary history of human locomotion. As the authors of the study explain, it is because the inner ear bones yield information about the locomotion of primates that cannot be found through traditional methods. "The bony labyrinth of the inner ear of vertebrates houses the peripheral vestibular system comprised of three fluid-filled semicircular canals that are functionally tied to sense of balance, spatial orientation, posture, and body movements," the authors explain. "This, in turn, is linked to modes of locomotion among living and extinct taxa." Want more health and science stories in your inbox? Subscribe to Salon's weekly newsletter Lab Notes. "The dramatic increase in the average evolution rate of semicircular canals" within these apes may illuminate that "the rapid evolution of bipedalism in the human lineage in response to gradual global cooling." Interestingly, natural climate change may have also played a role in this ear evolution. After observing that evolutionary rates tend to slow down as global temperatures rise, the authors point out that "the dramatic increase in the average evolution rate of semicircular canals" within these apes may illuminate that "the rapid evolution of bipedalism in the human lineage in response to gradual global cooling." The Lufengpithecus lived during a warm period in the Pliocene era, one that "marks the beginning of Plio-Pleistocene continuous cooling and the onset of Northern Hemisphere alaciation. Against the backdrop of global cooling, the increase of grassy vegetation driven by regional-scale environmental factors may be the trigger for the accelerated evolution of" primates and humans walking on two legs in Africa. Studying our primate relatives has shed enormous light on our own evolution. A paper last year in the journal iScience studied chimpanzees and bonobos to determine if they possess a trait known as "vocal functional flexibility." Vocal functional flexibility refers to an animal's ability to produce complex sounds that form speech, as opposed to the more simple sounds that come forward from screaming, crying, laughing or making other basic sounds. Humans are not born with vocal functional flexibility but rather develop it over stages, and it is considered one of the prerequisites to creating actual speech. In their research, the authors of the iScience study discovered that grunting chimpanzees from newborns through to ten-year-old youths display vocal functional flexibility. "The logic is, if we find good evidence for something in humans and good evidence for something in chimpanzees, then we’re kind of justified in making the inference that this was also a trait that was held by the last common ancestor," Dr. Derry Taylor, the paper's corresponding author and a professor at the University of Portsmouth, told Salon at the time. "So we can say with a reasonable degree of confidence that whatever those vocal communication systems were like, they probably at least had this type of flexibility.” Another study — this one published last year in the journal Current Biology — involved scientists performing a magic trick known as the "French drop effect" in front of three types of monkeys: common marmosets, Humboldt's squirrel monkeys and yellow-breasted capuchin monkeys. The trick involves a scientist putting food in one hand, presenting it to the money and then putting their other hand over the treat while appearing to grab it. In fact, the scientists did not grab the treat with their second hand, therefore leading those monkeys that had opposable thumbs to be surprised when discovering it was still in the first hand. Yet the one species of monkey in the group that lacks opposable thumbs, the marmosets, were less likely to be fooled by the trick because they lacked the same digital frame of reference. "It tells us something about how we think without work," Dr. Nicky Clayton, a professor at the University of Cambridge and corresponding author on the paper — explained to Salon at the time. "We know this because we know . . . there's this massive power in this non-verbal communication. And then I think of seeing non-human animals respond in that way to these non-verbal stimuli. It creates all kinds of questions in your mind, doesn't it? Why is it so soothing to us? What does it mean for the animals that watch it?" Whether it is in shedding light on the origins of human locomotion and speech or helping us understand our very sense of selves, scientists who study primates both living and extinct continue to learn a lot more about human beings.

Costa Rica University Brings Bees and Farmers Together for Sustainability

Bees have long been at risk of extinction, posing a grave threat to global food production, which relies on them for pollination of approximately 75% of foodstuffs worldwide. Some analyses suggest that if bees were to vanish, life on Earth could be sustained for a mere five years longer. Recognizing the critical need to protect […] The post Costa Rica University Brings Bees and Farmers Together for Sustainability appeared first on The Tico Times | Costa Rica News | Travel | Real Estate.

Bees have long been at risk of extinction, posing a grave threat to global food production, which relies on them for pollination of approximately 75% of foodstuffs worldwide. Some analyses suggest that if bees were to vanish, life on Earth could be sustained for a mere five years longer. Recognizing the critical need to protect these vital insects and the benefits they bring to both flora and humanity, the Interdisciplinary Experimental Farm of Agroecological Models (Feima) at the Atlantic Campus of the University of Costa Rica (UCR), situated in Turrialba, has launched the Social Action Project: Establishment of Meliponariums. Meliponariums are structures constructed of wooden boxes where bees, specifically meliponas, build their hives. Notably, these boxes are crafted from entirely natural materials without any added chemicals and can be made from various types of wood readily available in the country, making their production straightforward. The primary goal of this initiative is twofold: to demonstrate that agricultural and human activities need not be detrimental to bees and to educate various stakeholders, including farm owners and institutions, about the management and vital contributions of these structures to bee preservation and environmental health. The bees housed at the Atlantic Campus are unique in that they belong to the meliponas species, which lack stingers and thus pose no threat to humans. While they typically produce minimal honey, they are exceptionally adept at generating propolis, a resin used by bees in nest construction. Notably, propolis possesses potent antibiotic and antiviral properties, making it a valuable resource in natural medicine for combating viruses, bacteria, and fungi. Dennis Barquero Bejarano, a researcher at the Atlantic Campus and agronomy instructor, elucidated the distinctive traits of meliponas and underscored the importance of preserving their habitat for their continued survival. The presence of bees hovering over crops heralds two pieces of good news: firstly, agricultural production benefits from their pollination, and secondly, it signifies the adoption of sound farming practices conducive to bee preservation. The meliponariums at the Atlantic Campus serve as indicators of environmentally friendly cultivation practices, particularly concerning meliponas. Professor Barquero highlighted practices such as abstaining from burning or using agrochemicals on weeds, as bees play a vital role in pollinating these plants. These spaces serve as valuable learning environments for students to acquire knowledge about sustainable agricultural practices. The impact of meliponariums extends beyond university grounds, reaching agricultural farms, environmental institutions, and local communities in Turrialba. Through outreach efforts such as workshops and the dissemination of agricultural best practices manuals, knowledge about bee conservation and sustainable farming techniques is shared and promoted in the region. The post Costa Rica University Brings Bees and Farmers Together for Sustainability appeared first on The Tico Times | Costa Rica News | Travel | Real Estate.

‘A frenzy of bodies in the chamber of death’: Italian fishers fight to preserve an ancient tradition

A sustainable technique for catching tuna that goes back thousands of years is on the verge of extinction in Italy – but not for a lack of fishOn an overcast morning, several miles off Sardinia’s east coast, four men jump into a net where 49 giant Atlantic bluefin tuna are fighting for their lives. For 30 minutes, the men struggle in a frenzy of nets, tails, fins and sleek silvery bodies before finally securing a metal hook through the gills of the nearest fish.From one of seven wooden boats framing this càmira dâ morti (“chamber of death”), Luigi Biggio yells for his men to pull.Death comes quickly, in a technique that, while bloody, may be more humane than suffocation in trawler nets. But the men in among them can end up in hospital from a whack of the thrashing fishes’ tails Continue reading...

On an overcast morning, several miles off Sardinia’s east coast, four men jump into a net where 49 giant Atlantic bluefin tuna are fighting for their lives. For 30 minutes, the men struggle in a frenzy of nets, tails, fins and sleek silvery bodies before finally securing a metal hook through the gills of the nearest fish.From one of seven wooden boats framing this càmira dâ morti (“chamber of death”), Luigi Biggio yells for his men to pull.As 28 men look on, a majestic creature about three metres long, weighing 120kg (265lb), is raised from the water with a pulley. On the biggest boat, one man swiftly cuts its jugular and the vessel fills with blood.Biggio, 57, runs a tonnara, Italy’s version of an ancient Mediterrranean fishing custom, which traps and harvests bluefin tuna in the intimate, gruesome struggle known in Italian as the mattanza (“killing”). He comes from a long line of raís (from the Arabic for chief), almost sacred leaders of the hunt – a mantle passed from father to son in designated families.Death comes quickly, in a technique that, while bloody, may be more humane than suffocation in trawler nets. But the men in among them can end up in hospital from a whack of the thrashing fishes’ tails The harvest is violent and can seem barbaric, as the dying tuna are hooked, stabbed and hoisted on to boats. However, fisheries experts regard it as a rare sustainable method of catching bluefin tuna, one of the world’s most overfished species.Despite its merits, Italy’s tonnare face extinction. But they are not disappearing due to a lack of fish. While the practice was threatened in the early 2000s by a collapse in tuna populations due to commercial overfishing, EU regulations helped tuna numbers recover over the past decade.They fish tuna with Italian quotas and then sell the fish through Malta all over the world – except in Italy“We carry on a tradition that’s thousands of years old,” Biggio says. “We continue it with pride.”But Italy’s small-scale, traditional fishers have largely failed to secure permits under successive governments under the quota system, and are now struggling to compete with big fleets in the region.While in the 1920s, more than 50 groups fished this way across Italy, Giuliano Greco and his family, who own the tonnara that Biggio runs, also own half of the only other such fishery still active.“[The tonnara] is the only eco-friendly system for bluefin tuna fishing because it does not touch or disturb the rhythms and biorhythms of tuna stocks,” says Greco, who has been working with Sardinia’s Tonnara di Carloforte since the early 90s, taking over the business from his father.Unlike modern seine-net and trawler fishing vessels that catch everything in their paths, the tonnara nets are designed to catch only adult tuna, which ensures the fish return the next season. It also employs dozens of people in the community.With its swift harvest, the fish may suffer less compared with the slow suffocation in trawler nets. However, even the WWF – which considers the tonnara as sustainable – warned against making a spectacle of it.Italy’s tuna quotas are held by a few boats. “They fish tuna with Italian quotas and then sell the fish through Malta all over the world – except in Italy,” says Fabio Micalizzi, a Sicilian fighting for fairer distribution of quotas.Atlantic bluefin tuna are among the world’s most expensive and sought-after fish, occasionally selling for millions of dollars in Asia. In the 1960s, as global demand grew, large-scale fishing methods such as purse-seine fishing and longline fishing spread.Purse-seine fishing, the most common commercial method, involves dropping a cylindrical net around entire schools and closing it up at the bottom. This results in the highest bycatch of unwanted fish and other sealife.As a result, bluefin tuna populations in the Mediterranean plummeted to critical levels by the early 2000s.In an effort to stop overfishing, the EU implemented an extensive recovery plan in 2009. It allocated fishing quotas to member states, put limits on the number of boats allowed to fish and mandated a 30kg minimum weight for fished tuna.The ambitious plan seemingly paid off. Tuna populations rebounded so successfully that, since 2014, large boats “capture their yearly tuna quota in a day”, according to Alessandro Buzzi, of the WWF Mediterranean Marine Initiative.“Many newspapers still report today that tuna is an endangered species,” he says. “Luckily, the tuna can’t read the stupid things that humans write because otherwise it would get worried.”But the quotas that have helped fish numbers to recover have been “truly disastrous” for artisanal fishers, says Greco. The EU plan anticipated member states distributing quotas among local communities. But in Italy these became skewed toward larger companies.“If I could, I would sue the Italian government because of what it has forced us to lose in recent years,” Greco says, pointing out that, in 2023, Spain distributed 24% of its allotted fishing quotas among its tonnara, known there as almadraba, while the Italian government only managed 8%.As a result of the quota distribution, it is illegal for many small fishers in Italy to catch tuna. Even landing tuna as bycatch while fishing for other species can be penalised. “Whether you want it or not, the tuna jump into your boat,” says Micalizzi in Sicily. “If we professional fishermen catch it, we become killers and thieves.”In 2023, the Italian government redistributed a quota for 295 tonnes (roughly 1,200 adult tuna) out of 5,282 tonnes in total to small operators. But Micalizzi says that is far too little, especially since most of the Italian quota is allocated to a few seiners and longliners.Meanwhile, in Sicily, there have been multiple reports of people becoming sick with scombroid poisoning from eating badly conserved tuna, potentially fished without the right permits.“In these games who is the loser? The smallest,” says Antonio Di Natale, a UN expert on sustainable fisheries and former research director at the International Commission for the Conservation of Atlantic Tunas (ICCAT).In these last few years, the tuna have got bigger and bigger. So in that sense, the quota workedAs one of the oldest human industrial activities, according to Di Natale, the tonnara should be protected as a Unesco “intangible cultural heritage”. It is also invaluable as a sustainable fishing practice as it so easily controlled and highly selective, he adds.Today, much of the wild tuna caught in Italy is slowly transported in large floating cages to Malta, Spain and Croatia. There, they are fattened for up to six months to appease lucrative markets such as Japan that prize large and fatty fish.“There is nothing illegal in this practice,” Buzzi says. “But the impact of farming a tuna in a cage is not even comparable to the environmental impact of catching a wild tuna.”This year, before the harvest, Greco’s team released a shoal of 1,200 young tuna from their nets because they were too small. “What other fishing system allows for such selection?” he asks. But running a tonnara is neither quick nor cheap.While a big seine boat can go out with a small crew and catch the entire year’s quota in a week, the preparation of the tonnara takes about six months. The multi-chambered nets spanning 3km (and 40 metres deep) take two months to prepare and two days to mount at sea using 122 anchors.Greco says he invests €1.5m a year in the tonnara, and employs about 50 people. However, to fund what is one of Italy’s last two tonnara, he reluctantly sells 75% of his trapped fish to large-scale tuna cagers.“I don’t like fattening them,” says Greco. “It certainly doesn’t create first-rate fish and it pollutes … I would have declared cages illegal.”But Greco is also hopeful. His tonnara is open to tourists who want to learn about the ancient practice – and it helps that they buy his premium-quality tinned tuna for €25 a pop.Fausto Siddi takes a break between sessions of pulling the nets as they wait for the tuna shoal to swim further within the tonnara trap. Renato Calabró, exhausted from a morning of work and the final, straining tuna mattanza, has been working at the tonnara for the past decade At sea, the harvest is done, and one of the fishers calls for silence. “May the holy sacrament be thanked. In the name of Saint Anthony, let go,” he says. The others respond: “Aoooohh!” Most of Biggio’s team return to shore with their 49 giants, weighing six tonnes in total.But one boat stays behind. On it, several exhausted fishers sip local Ichnusa beer and bask in the sun.“In these last few years, the tuna have got bigger and bigger,” muses Stefano Sanna, a tonnara fisher for 25 years. “So in that sense, the quota worked.”

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