When electrons slowly vanish during cooling

Researchers observe an effect in the quantum world that does not exist in the macrocosm

Peer-Reviewed Publication

UNIVERSITY OF BONN

 

IMAGE: COMPOSED OF LOCALIZED AND MOBILE ELECTRONS, HERE BROKEN UP BY AN ULTRASHORT LIGHT PULSE. view more 

CREDIT: IMAGE: UNIVERSITY OF BONN

Many substances change their properties when they are cooled below a certain critical temperature. Such a phase transition occurs, for example, when water freezes. However, in certain metals there are phase transitions that do not exist in the macrocosm. They arise because of the special laws of quantum mechanics that apply in the realm of nature’s smallest building blocks. It is thought that the concept of electrons as carriers of quantized electric charge no longer applies near these exotic phase transitions. Researchers at the University of Bonn and ETH Zurich have now found a way to prove this directly. Their findings allow new insights into the exotic world of quantum physics. The publication has now been released in the journal Nature Physics.

If you cool water below zero degrees Celsius, it solidifies into ice. In the process, it abruptly changes its properties. As ice, for example, it has a much lower density than in a liquid state - which is why icebergs float. In physics, this is referred to as a phase transition.

But there are also phase transitions in which characteristic features of a substance change gradually. If, for example, an iron magnet is heated up to 760 degrees Celsius, it loses its attraction to other pieces of metal - it is then no longer ferromagnetic, but paramagnetic. However, this does not happen abruptly, but continuously: The iron atoms behave like tiny magnets. At low temperatures, they are oriented parallel to each other. When heated, they fluctuate more and more around this rest position until they are completely randomly aligned, and the material loses its magnetism completely. So while the metal is being heated, it can be both somewhat ferromagnetic and somewhat paramagnetic.

Matter particles cannot be destroyed

The phase transition thus takes place gradually, so to speak, until finally all the iron is paramagnetic. Along the way, the transition slows down more and more. This behavior is characteristic of all continuous phase transitions. “We call it ‘critical slowing down,’“ explains Prof. Dr. Hans Kroha of the Bethe Center for Theoretical Physics at the University of Bonn. “The reason is that with continuous transitions, the two phases get energetically closer and closer together.” It is similar to placing a ball on a ramp: It then rolls downhill, but the smaller the difference in altitude, the more slowly it rolls. When iron is heated, the energy difference between the phases decreases more and more, in part because the magnetization disappears progressively during the transition.

Such a “slowing down” is typical for phase transitions based on the excitation of bosons. Bosons are particles that “generate” interactions (on which, for example, magnetism is based). Matter, on the other hand, is not made up of bosons but of fermions. Electrons, for example, belong to the fermions.

Phase transitions are based on the fact that particles (or also the phenomena triggered by them) disappear. This means that the magnetism in iron becomes smaller and smaller as fewer atoms are aligned in parallel. “Fermions, however, cannot be destroyed due to fundamental laws of nature and therefore cannot disappear,” Kroha explains. “That’s why normally they are never involved in phase transitions.”

Electrons turn into quasi-particles

Electrons can be bound in atoms; they then have a fixed place which they cannot leave. Some electrons in metals, on the other hand, are freely mobile - which is why these metals can also conduct electricity. In certain exotic quantum materials, both varieties of electrons can form a superposition state. This produces what are known as quasiparticles. They are, in a sense, immobile and mobile at the same timetime – a feature that is only possible in the quantum world. These quasiparticles - unlike “normal” electrons - can be destroyed during a phase transition. This means that the properties of a continuous phase transition can also be observed there, in particular, critical slowing down.

So far, this effect could be observed only indirectly in experiments. Researchers led by theoretical physicist Hans Kroha and Manfred Fiebig’s experimental group at ETH Zurich have now developed a new method, which allows direct identification of the collapse of quasiparticles at a phase transition, in particular the associated critical slowing down.

“This has enabled us to show for the first time directly that such a slowdown can also occur in fermions,” says Kroha, who is also a member of the Transdisciplinary Research Area “Matter” at the University of Bonn and the Cluster of Excellence “Matter and Light for Quantum Computing” of the German Research Foundation. The result contributes to a better understanding of phase transitions in the quantum world. On the long term, the findings might also be useful for applications in quantum information technology.

Participating institutions and funding:
The study was carried out in collaboration of ETH Zurich and the University of Bonn. The work was funded by the Swiss National Science Foundation (SNF) and the German Research Foundation (DFG).

Publication: Chia-Jung Yang, Kristin Kliemt, Cornelius Krellner, Johann Kroha, Manfred Fiebig and Shovon Pal: Critical slowing down near a magnetic quantum phase transition with fermionic breakdown. Nature Physics, DOI: 10.1038/s41567-023-02156-7; Internet: https://www.nature.com/articles/s41567-023-02156-7

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JOURNAL

Nature Physics

DOI

10.1038/s41567-023-02156-7 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Critical slowing down near a magnetic quantum phase transition with fermionic breakdown

ARTICLE PUBLICATION DATE

31-Jul-2023

Why you shouldn’t declaw tigers or other big cats

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

Declawing house cats to keep them from scratching people and furniture is controversial – and even banned in some countries and areas in the U.S. – but the practice is not limited to house cats. In a new study, researchers looked at the effects of declawing on larger cat species and found that declawing disproportionately impacts their muscular capabilities as compared to their smaller brethren.

While it is illegal in the U.S. to surgically modify an exotic animal, declawing is still done on large cats like lions and tigers, often in an effort to allow cubs to more safely be handled in photo opportunities or for entertainment purposes.

“What people might not realize is that declawing a cat is not like trimming our fingernails; rather, it is removing part or all of the last bone of each digit,” says Adam Hartstone-Rose, professor of biological sciences at North Carolina State University and corresponding author of the research. “Like us, each cat finger has three bones, and declawing is literally cutting that third bone off at the joint.”

The researchers looked at the muscular anatomy of over a dozen exotic cats – from smaller species including bobcats, servals and ocelots, to lions and tigers – to determine the effect of declawing on their forelimb musculature.

They measured muscle density and mass, and also examined muscle fibers from both clawed and declawed exotic cats. They found that for the larger species declawing resulted in 73% lighter musculature in the forearm’s digital flexors. These muscles are involved in unsheathing the claws. They also found that overall, forelimb strength decreased by 46% to 66%, depending on the size of the animal, and that other muscles in the forelimb did not compensate for these reductions.

“When you think about what declawing does functionally to a housecat, you hear about changes in scratching, walking or using the litter box,” says Lara Martens, NC State undergraduate student and lead author of the research. “But with big cats, there’s more force being put through the paws. So if you alter them, it is likely that the effects will be more extreme.”

This is because paw size and body mass don’t scale up at a 1:1 ratio. Paw area increases at a slower rate than does body mass (which is proportional to volume), so larger cats have smaller feet relative to their body size, and their paws must withstand more pressure.

“Additionally, big cats are more reliant on their forelimbs – they bear most of the weight, and these bigger cats use their forelimbs to grapple because they hunt much larger prey,” Martens says. “So biomechanically speaking, declawing has a more anatomically devastating effect in larger species.”

“As scientists, it is our job to objectively document the effects of this surgery on the animals,” Hartstone-Rose says, “but it is hard to ignore the cruelty of this practice. These are amazing animals, and we should not be allowed to cripple them, or any animals, in this way.”

The work appears in Animals. NC State undergraduates Sarah Piersanti, Arin Berger, and Nicole Kida, and Ph.D. student Ashley Deutsch, also contributed to the research. The work was done in partnership with colleagues from Carolina Tiger Rescue, a sanctuary that rescues exotic carnivores, especially big cats, who have often been neglected or mistreated.

-peake-

Note to editors: An abstract follows.

“The effects of onychectomy (declawing) on antebrachial myology across the full body size range of exotic species of Felidae”

DOI: 10.3390/ani13152462

Authors: Lara L. Martens, Sarah Jessica Piersanti, Arin Berger, Nicole A. Kida, Ashley R. Deutsch, Adam Harstone-Rose, North Carolina State University; Kathryn Bertok, Lauren Humphries, Angela Lassiter, Carolina Tiger Rescue, Pittsboro, North Carolina
Published: July 30, 2023 in Animals

Abstract:
While people are familiar with the practice of declawing domestic cats, “onychectomy” is also performed on non-domesticated species, including pantherines to prolong their use in entertainment opportunities. Although the surgery (the partial or complete removal of the distal phalanx) has clear osteological implications, its myological effects have never been studied. Because the mass of an animal increases cubically as a product of its volume and, the areas of its paws only increase as a square, larger felids have higher foot pressures and therefore the surgery may have particularly substantial functional effects for larger cats. In this study, we evaluate the forearms of clawed and declawed non-domestic felid specimens spanning the body size range of the whole family to evaluate the effects of onychectomy on muscle fiber architecture. We found that the deep digital flexors (the muscles most directly affected by onychectomy) of declawed felids are significantly lighter (~73%) and less powerful (46-66%), and that other muscles do not make up for these reductions. Thus, onychectomy has a substantial effect on the myological capabilities of cats and because these deficiencies are not compensated for in biomechanical disadvantaged larger felids, it is probably functionally even more devastating for these species.

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JOURNAL

Animals

DOI

10.3390/ani13152462 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

The Effects of Onychectomy (Declawing) on Antebrachial Myology across the Full Body Size Range of Exotic Species of Felidae

ARTICLE PUBLICATION DATE

30-Jul-2023

COI STATEMENT

The authors declare no conflict of interest.

 

Researchers discover method to overcome antimicrobial resistance

Peer-Reviewed Publication

UNIVERSITY OF OKLAHOMA

The World Health Organization has labeled antimicrobial resistance a global threat because most clinical antibiotics are no longer effective against certain pathogenic bacteria. The Center for Antibiotic Discovery and Resistance at the University of Oklahoma, led by Helen Zgurskaya, Ph.D., and Valentin Rybenkov, Ph.D., is working on finding alternative therapeutic solutions.

Antibiotics work by targeting specific parts of a bacteria cell, such as the cell wall or its DNA. Bacteria can become resistant to antibiotics in a number of ways, including by developing efflux pumps – proteins that are located on the surface of the bacteria cell. When an antibiotic enters the cell, the efflux pump pumps it out of the cell before it can reach its target so that the antibiotic is never able to kill the bacteria.

However, OU researchers have contributed to a recent discovery published in the journal Nature Communications. The scientists found a new class of molecules that inhibit the efflux pump and make the antibiotic effective again.

The inhibitors have a novel mechanism of action, which until recently remained unclear. Zgurskaya’s team, in collaboration with teams at the Georgia Institute of Technology and King’s College London in the United Kingdom, have uncovered that these inhibitors work as a “molecular wedge” that targets the area between the inner and outer cell membranes and increases antibacterial activities of antibiotics. Understanding this mechanism can facilitate the discovery of new therapeutics for clinical applications.

“We already live in a post-antibiotic era, and things will get much worse unless new solutions are found for antibiotic resistance in clinics. The discoveries we’ve made will facilitate the development of new treatments to help mitigate an impending crisis,” Zgurskaya said.

Helen Zgurskaya is a George Lynn Cross Research Professor and Valentin Rybenkov is a professor of biochemistry, both in the Department of Chemistry and Biochemistry, Dodge Family College of Arts and Sciences at the University of Oklahoma. Learn more about their research at the Center for Antibiotic Discovery and Resistance.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-023-39615-x 

ARTICLE TITLE

Conformational restriction shapes the inhibition of a multidrug efflux adaptor protein

 

Researchers find little evidence of cheating with online, unsupervised exams

Peer-Reviewed Publication

IOWA STATE UNIVERSITY

 

IMAGE: STUDENTS WORK ON LAPTOPS ABOVE “GENE POOL,” A TILE MOSAIC BY ANDREW LEICESTER INSIDE THE MOLECULAR BIOLOGY BUILDING AT IOWA STATE UNIVERSITY. view more 

CREDIT: PHOTO BY CHRISTOPHER GANNON/IOWA STATE UNIVERSITY.

AMES, IA — When Iowa State University switched from in-person to remote learning halfway through the spring semester of 2020, psychology professor Jason Chan was worried. Would unsupervised, online exams unleash rampant cheating?

His initial reaction flipped to surprise as test results rolled in. Individual student scores were slightly higher but consistent with their results from in-person, proctored exams. Those receiving B’s before the COVID-19 lockdown were still pulling in B’s when the tests were online and unsupervised. This pattern held true for students up and down the grading scale.

“The fact that the student rankings stayed mostly the same regardless of whether they were taking in-person or online exams indicated that cheating was either not prevalent or that it was ineffective at significantly boosting scores,” says Chan.

To know if this was happening at a broader level, Chan and Dahwi Ahn, a Ph.D. candidate in psychology, analyzed test score data from nearly 2,000 students across 18 classes during the spring 2020 semester. Their sample ranged from large, lecture-style courses with high enrollment, like introduction to statistics, to advanced courses in engineering and veterinary medicine.

Across different academic disciplines, class sizes, course levels and test styles (i.e., predominantly multiple choice or short answer), the researchers found the same results. Unsupervised, online exams produced scores very similar to in-person, proctored exams, indicating they can provide a valid and reliable assessment of student learning.

The research findings were recently published in Proceedings of the National Academy of Sciences.

“Before conducting this research, I had doubts about online and unproctored exams, and I was quite hesitant to use them if there was an option to have them in-person. But after seeing the data, I feel more confident and hope other instructors will, as well,” says Ahn.

Both researchers say they’ve continued to give exams online, even for in-person classes. Chan says this format provides more flexibility for students who have part-time jobs or travel for sports and extra-curriculars. It also expands options for teaching remote classes. Ahn led her first  online course over the summer.

Why might cheating have had a minimal effect on test scores?

The researchers say students more likely to cheat might be underperforming in the class and anxious about failing. Perhaps they’ve skipped lectures, fallen behind with studying or feel uncomfortable asking for help. Even with the option of searching Google during an unmonitored exam, students may struggle to find the correct answer if they don’t understand the content. In their paper, the researchers point to evidence from previous studies comparing test scores from open-book and close-book exams.

Another factor that may deter cheating is academic integrity or a sense of fairness, something many students value, says Chan. Those who have studied hard and take pride in their grades may be more inclined to protect their exam answers from students they view as freeloaders.

Still, the researchers say instructors should be aware of potential weak spots with unsupervised, online exams. For example, some platforms have the option of showing students the correct answer immediately after they select a multiple-choice option. This makes it much easier for students to share answers in a group text.

To counter this and other forms of cheating, instructors can:

• Wait to release exam answers until the test window closes.
• Use larger, randomized question banks.
• Add more options in multiple-choice questions and making the right choice less obvious.
• Adjust grade cutoffs.

COVID-19 and ChatGPT

Chan and Ahn say the spring 2020 semester provided a unique opportunity to research the validity of online exams for student evaluations. However, there were some limitations. For example, it wasn’t clear what role stress and other COVID-19-related impacts may have played on students, faculty and teaching assistants. Perhaps instructors were more lenient with grading or gave longer windows of time to complete exams.

The researchers said another limitation was not knowing if the 18 classes in the sample normally get easier or harder as the semester progresses. In an ideal experiment, half of the students would have taken online exams for the first half of the semester and in-person exams for the second half.

They attempted to account for these two concerns by looking at older test score data from a subset of the 18 classes during semesters when they were fully in-person. The researchers found the distribution of grades in each class was consistent with the spring 2020 semester and concluded that the materials covered in the first and second halves of the semester did not differ in their difficulty.

At the time of data collection for this study, ChatGPT wasn’t available to students. But the researchers acknowledge AI writing tools are a gamechanger in education and could make it much harder for instructors to evaluate their students. Understanding how instructors should approach online exams with the advent of ChatGPT is something Ahn intends to research.

The study was supported by a National Science Foundation Science of Learning and Augmented Intelligence Grant.

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2302020120 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Unproctored online exams provide meaningful assessment of student learning

That’s funny – but AI models don’t get the joke

Reports and Proceedings

CORNELL UNIVERSITY

ITHACA, N.Y. -- Large neural networks, a form of artificial intelligence, can generate thousands of jokes along the lines of “Why did the chicken cross the road?” But do they understand why they’re funny?

Using hundreds of entries from the New Yorker magazine’s Cartoon Caption Contest as a testbed, researchers challenged AI models and humans with three tasks: matching a joke to a cartoon; identifying a winning caption; and explaining why a winning caption is funny. 

In all tasks, humans performed demonstrably better than machines, even as AI advances such as ChatGPT have closed the performance gap. So are machines beginning to “understand” humor? In short, they’re making some progress, but aren’t quite there yet.

“The way people challenge AI models for understanding is to build tests for them – multiple choice tests or other evaluations with an accuracy score,” said Jack Hessel, Ph.D. ’20, research scientist at the Allen Institute for AI (AI2). “And if a model eventually surpasses whatever humans get at this test, you think, ‘OK, does this mean it truly understands?’ It’s a defensible position to say that no machine can truly `understand’ because understanding is a human thing. But, whether the machine understands or not, it’s still impressive how well they do on these tasks.”

Hessel is lead author of “Do Androids Laugh at Electric Sheep? Humor ‘Understanding’ Benchmarks from The New Yorker Caption Contest,” which won a best-paper award at the 61st annual meeting of the Association for Computational Linguistics, held July 9-14 in Toronto.

Lillian Lee ’93, the Charles Roy Davis Professor in the Cornell Ann S. Bowers College of Computing and Information Science, and Yejin Choi, Ph.D. ’10, professor in the Paul G. Allen School of Computer Science and Engineering at the University of Washington, and the senior director of common-sense intelligence research at AI2, are also co-authors on the paper.

For their study, the researchers compiled 14 years’ worth of New Yorker caption contests – more than 700 in all. Each contest included: a captionless cartoon; that week’s entries; the three finalists selected by New Yorker editors; and, for some contests, crowd quality estimates for each submission.  

For each contest, the researchers tested two kinds of AI – “from pixels” (computer vision) and “from description” (analysis of human summaries of cartoons) – for the three tasks.

“There are datasets of photos from Flickr with captions like, ‘This is my dog,’” Hessel said. “The interesting thing about the New Yorker case is that the relationships between the images and the captions are indirect, playful, and reference lots of real-world entities and norms. And so the task of ‘understanding’ the relationship between these things requires a bit more sophistication.”

In the experiment, matching required AI models to select the finalist caption for the given cartoon from among “distractors” that were finalists but for other contests; quality ranking required models to differentiate a finalist caption from a nonfinalist; and explanation required models to generate free text saying how a high-quality caption relates to the cartoon.

Hessel penned the majority of human-generated explanations himself, after crowdsourcing the task proved unsatisfactory. He generated 60-word explanations for more than 650 cartoons.

“A number like 650 doesn’t seem very big in a machine-learning context, where you often have thousands or millions of data points,” Hessel said, “until you start writing them out.”

This study revealed a significant gap between AI- and human-level “understanding” of why a cartoon is funny. The best AI performance in a multiple choice test of matching cartoon to caption was only 62% accuracy, far behind humans’ 94% in the same setting. And when it came to comparing human- vs. AI-generated explanations, humans’ were preferred roughly 2-to-1.

While AI might not be able to “understand” humor yet, the authors wrote, it could be a collaborative tool humorists could use to brainstorm ideas.

Other contributors include Ana Marasovic, assistant professor at the University of Utah School of Computing; Jena D. Hwang, research scientist at AI2; Jeff Da, research assistant at the University of Washington Rowan Zellers, researcher at OpenAI; and humorist Robert Mankoff, president of Cartoon Collections and long-time cartoon editor at the New Yorker.

The authors wrote this paper in the spirit of the subject matter, with playful comments and footnotes throughout.

“This three or four years of research wasn’t always super fun,” Lee said, “but something we try to do in our work, or at least in our writing, is to encourage more of a spirit of fun.”

This work was funded in part by the Defense Advanced Research Projects Agency; AI2; and a Google Focused Research Award.

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Fascination of Science: 60 Encounters with Pioneering Researchers of Our Time

An intimate collection of portraits of internationally renowned scientists and Nobel Prize winners, paired with interviews and personal stories

Book Announcement

THE MIT PRESS

 

IMAGE: COVER ART TO "FASCINATION OF SCIENCE" view more 

CREDIT: THE MIT PRESS, 2023.

What makes a brilliant scientist? Who are the people behind the greatest discoveries of our time? Connecting art and science, photographer Herlinde Koelbl seeks the answers in this English translation of the German book Fascination of Science, an indelible collection of portraits of and interviews with sixty pioneering scientists of the twenty-first century. Koelbl's approach is intimate and accessible, and her highly personal interviews with her subjects reveal the forces (as well as the personal quirks) that motivate the scientists' work; for example, one wakes up at 3 am because her mind is calm then, another says his best ideas come to him in the shower. These glimpses into the scientists' lives and thinking add untold texture in this up-to-the-minute survey of the activities and progress that are currently taking place in the broad field of the natural sciences.

Koelbl's interview subjects include Nobel Prize winners Dan Shechtman, Frances Arnold, Carolyn Bertozzi, and cover scientific fields from astronomy, biochemistry, and quantum physics to stem-cell research and AI. Beautifully bringing together art, science, and the written word, Fascination of Science is an inspiring read that shows how creativity, obsession, persistence, and passion drive the pioneering researchers of our time.

Herlinde Koelbl is a German photographic artist, author, and documentary filmmaker. She has published more than a dozen photography books, including Jewish Portraits, Targets, and Angela Merkel Portraits 1991–2021. She has received numerous awards for her work, including the Dr. Erich Salomon Prize in 2001. You can learn more about her at www.herlindekoelbl.com.

“True to its title, this is a fascinating collection of interviews. Herlinde Koelbl's insightful questions and the candid responses of her subjects offer a matchless window into the personal histories and thinking of some of the world's most successful scientists."

-- John P. Holdren, Research Professor, Harvard University; President Obama's Science Advisor, January 2009 to January 2017

 

Contact: Head of UK and EU Publicity, Katie Lewis, The MIT Press,  (lewisk@mit.edu)

 

Scientists vacuum animal DNA from air in a Danish forest

Peer-Reviewed Publication

UNIVERSITY OF COPENHAGEN - THE FACULTY OF HEALTH AND MEDICAL SCIENCES

It is an early autumn morning. Three researchers from the Globe Institute at the University of Copenhagen venture into a Danish forest carrying plastic boxes with DNA air samplers. Wearing latex gloves and face masks, the researchers strap the samplers to tree trunks and attach air filters. They then turn on the power. A faint hum reveals that the collection of airborne particles is in progress.

During the following three days, the researchers returned to the forest to change the air filters several times.

“We saw relatively few animals in the short time we spent in the forest when we changed the air filters. A squirrel, the sound of a woodpecker, a pheasant squawking and a white-tailed eagle flying above us one day", says Postdoc Christina Lynggaard.

What the researchers did not notice in the forest, they saw when they sequenced the airborne DNA particles collected on the filters. In just three days of ‘vacuuming’ in an area of ​​the forest roughly the size of a football field, the researchers found DNA traces from 64 animal species. Some of them were domestic animals such as cow, pig, sheep, chicken and dog and exotic pets such as parakeet and peacock. But in addition, the researchers recorded around 50 terrestrial wild animals.

The wild animals spanned small and large animals and animals with different lifestyles - red deer, roe deer, Eurasian badger, white-tailed eagle, red fox, different vole species, robin, Eurasian red squirrel, common toad, smooth newt, great crested newt, crane, great spotted woodpecker, nuthatch, grey heron, marsh tit, woodcock - and many more.

In a short time, the researchers found almost a quarter of the land-living animals previously recorded in and around the area.

“It's absolutely crazy! Although we have worked hard to optimise the method, we did not dare to hope for such good results. We didn't think we would succeed so well in the very first attempt in nature," says Associate Professor Kristine Bohmann.

Animal DNA in the air around us

The DNA that the researchers vacuumed from the air is the so-called environmental DNA.

“Animals secrete DNA into their surrounding environment all the time. It could be in the form of fragments of hair, feathers and skin cells. If they are airborne, we can vacuum them and use DNA analyses to find out which animals they came from", says Christina Lynggaard.

The new results follow the researchers' ground-breaking study from last year where they showed that animal DNA can be vacuumed from the air in a zoo. They used it to map the presence of many of the animals in Copenhagen ZOO.

"There is quite a difference between a zoo and nature," says Kristine Bohmann and continues: "In a zoo, the animals are present in large numbers in a relatively small area, while in nature they are much less concentrated. Therefore, we were unsure how well we could make the method work in nature. And that is where we have to get it to work if we want to use it to monitor biodiversity.”

A valuable tool

"We are in a biodiversity crisis, and tools are needed to understand how ecosystems change as a result of human impacts, to guide management strategies and to assess the risk of the spread of diseases in areas where animals can come into contact with people," says Christina Lynggaard.

The researchers' first results from vacuuming in nature show that airborne environmental DNA can be an effective method for mapping the presence of wild animals.

“As with all new methods, we have a lot of work ahead of us. But this study makes us hopeful. It demonstrates a sensitive method for mapping the presence of animals without having to see or disturb them," says Kristine Bohmann.

In the study, the researchers work with airborne environmental DNA in very small quantities. And because this is the first study to demonstrate the use of air filtration to detect the presence of a wide range of wildlife, the researchers went to great lengths to verify the findings.

"When we first detected DNA from peacocks, we were afraid that it might be a mistake. I therefore called around to find out if anyone who lived near the collection site had knowledge of peacocks in the area. Fortunately, they said that they had sometimes come across a peacock when they went for a walk", says Kristine Bohmann, who in this way was able to verify the otherwise somewhat unusual DNA find.

The study has just been published in Molecular Ecology Resources. 

The new research is primarily supported by the VILLUM Foundation in their research program "VILLUM Experiment", which supports research projects out of the ordinary that challenge the norm and have the potential to change fundamentally the way we approach important topics. The research is also supported by the VILLUM Foundation with a grant to Christina Lynggaard in their research program 'VILLUM International Postdoc', which supports the advancement of talented postdoc women in their research careers. The research is also supported by the Carlsberg Foundation with a grant to Kristine Bohmann in their research programme 'Semper Ardens: Accelerate'. This grant has enabled her to establish a research group focused on developing methods to use airborne environmental DNA to monitor birds and mammals.

 

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JOURNAL

Molecular Ecology Resources

DOI

10.1111/1755-0998.13840 

ARTICLE TITLE

Airborne environmental DNA captures terrestrial vertebrate diversity in nature

ARTICLE PUBLICATION DATE

27-Jul-2023

COI STATEMENT

M.S.J. is Chief Science Officer at DevLabs. The current study is not of direct commercial value to DevLabs. The remaining authors declare that they have no competing interests.

Cities no place for Australian eagles but smaller raptors are adapting

Peer-Reviewed Publication

FLINDERS UNIVERSITY

 

IMAGE: FLINDERS UNIVERSITY PHD CANDIDATE TAYLOR HEADLAND IS STUDYING THE BEHAVIOUR OF NANKEEN KESTRELS IN URBAN ENVIRONMENTS. view more 

CREDIT: COURTESY: PETRA SUMASGUTNER (UNIVERSITY OF VIENNA)

Increasing urbanisation is reducing biodiversity with cities proving harsh places for many of Australia’s native wildlife to live – not least magnificent birds of prey which face lack of habitat, high buildings and disturbance by car noise and night lights.   

An international team of experts, led by Flinders University’s BirdLab and the University of Vienna, has evaluated the adaptability and ‘urban tolerance’ of 24 Australian raptor species and found 13 of the smaller birds of prey such as kites and falcons showing higher tolerance for living in urban areas than 11 of the larger bodied species. 

The species with the highest tolerance to urbanisation were the Eastern Barn Owl, Brahminy Kite and the Australian Hobby (Falco longipennis), while the Brown Falcon (Falco berigora) and the Wedge-tailed Eagle (Aquila audax) were the least tolerant raptor species to urban areas.  

Around the world, urban tolerance is generally higher in wildlife which have flexible behaviour to learn to live in closer proximity to humans, have high fertility and strong dispersal ability over various landscapes such as urban green spaces, parks, cemeteries or golf courses, say experts from South Australia, Europe, South Africa and the US in the new article in Nature Scientific Reports.  

The analysis of community science data sourced from eBird looked at raptors’ body mass, nest and habitat types, feeding and migratory status to assess their tolerance, says lead author University of Vienna raptor conservation researcher Dr Petra Sumasgutner. The worldwide decline in predator populations is contributing substantially to the biodiversity crisis. 

“As we see extensive cascading effects on ecosystems caused by human-dominated landscapes, we can find examples of predators which stay or return to ecosystems creating a buffer against biological invasion and disease transmission,” she says.  

“While some species of raptors are able to take advantage of human-dominated landscapes and urban areas, we are seeing a worrying population decline in many parts of the world.”     

Of more than 500 raptor species, 52% are in decline and 19% are currently classified as threatened with extinction.  

The study of Australian raptors was inspired by in-depth studies by Flinders University PhD Taylor Headland on the small-bodied Australian falcon – the Nankeen kestrel – which has shown adaptive techniques in both human-modified and natural landscapes alike. 

“As raptors are vital for ecosystem functioning, prioritising feeding and breeding habitat for urban-tolerated raptor species is essential to enable biodiverse urban landscapes,” says co-author Mr Headland, from the BirdLab research group at Flnders University’s College of Science and Engineering. 

 “While we see evidence of small Australian raptors persisting in urban environments, conservation management initiatives focusing on habitat protection and restoration of wilderness areas need also to focus on the needs of larger-bodied raptor species given the rise in urban expansion and their avoidance of city zones. 

 “We are concerned for the raptors of Australia and the Southern Hemisphere which are far less studied than those in the Northern Hemisphere so resources such as eBird life are invaluable.” 

Using 276,674 species observations of 24 raptors, the Whistling Kite (Haliastur sphenurus) was detected the most of any raptor in the study, amassing 45,787 observations, while the Eastern Barn Owl (Tyto alba) was observed the fewest times.  

The raptors observed in the area with the highest median radiance were the Brown Goshawk (Accipiter fasciatus) and Southern Boobook (Ninox boobook) in Docklands Park, in central Melbourne, Victoria.  

A Whistling Kite was sighted in the area with the lowest median radiance, which was at Lagoon Island, Lake Argyle, in north-eastern Western Australia. 

Since the Cornell Lab of Ornithology and US Audibon Society launched eBird more than a decade ago, more than 90 million checklists and 1.2 billion observations of birds have been submitted – making it one of the most successful community or citizen science projects to date.   

Read the article – Smaller Australian raptors have greater urban tolerance (2023) by T Headland, D Colombelli-Négrel, CT Callaghan, SC Sumasgutner, S Kleindorfer and P Sumasgutner – published in Scientific Reports DOI 10.10 38/s41598-023-38493-z.  

Coauthor Professor Sonia Kleindorfer examines a native Australian Nankeen kestrel.

CREDIT

Courtesy: Petra Sumasgutner (University of Vienna)

CAPTION

The Wedge-tailed Eagle (Aquila audax) is among the least tolerant raptor species to urban areas

CREDIT

Photo courtesy Mike Lee (Flinders / SA Museum)

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JOURNAL

Scientific Reports

DOI

10.1016/j.biocon.2021.109149 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Smaller Australian raptors have greater urban tolerance