NTU Singapore scientists develop device to 'communicate' with plants using electrical signals

NANYANG TECHNOLOGICAL UNIVERSITY

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VIDEO: PLANT TALK: A TEAM OF SCIENTISTS LED BY #NTUSG? HAS DEVELOPED A DEVICE THAT CAN 'COMMUNICATE' WITH PLANTS BY DELIVERING ELECTRICAL SIGNALS TO AND FROM PLANTS. POTENTIAL USES OF THE... view more 

CREDIT: NTU SINGAPORE

A team of scientists led by Nanyang Technological University, Singapore (NTU Singapore) has developed a device that can deliver electrical signals to and from plants, opening the door to new technologies that make use of plants.

The NTU team developed their plant 'communication' device by attaching a conformable electrode (a piece of conductive material) on the surface of a Venus flytrap plant using a soft and sticky adhesive known as hydrogel. With the electrode attached to the surface of the flytrap, researchers can achieve two things: pick up electrical signals to monitor how the plant responds to its environment, and transmit electrical signals to the plant, to cause it to close its leaves.

Scientists have known for decades that plants emit electrical signals to sense and respond to their environment. The NTU research team believe that developing the ability to measure the electrical signals of plants could create opportunities for a range of useful applications, such as plant-based robots that can help to pick up fragile objects, or to help enhance food security by detecting diseases in crops early.

However, plants' electrical signals are very weak, and can only be detected when the electrode makes good contact with plant surfaces. The hairy, waxy, and irregular surfaces of plants make it difficult for any thin-film electronic device to attach and achieve reliable signal transmission.

To overcome this challenge, the NTU team drew inspiration from the electrocardiogram (ECG), which is used to detect heart abnormalities by measuring the electrical activity generated by the organ.

Transmitting electrical signals to create an on demand plant-based robot

As a proof-of concept, the scientists took their plant 'communication' device and attached it to the surface of a Venus flytrap - a carnivorous plant with hairy leaf-lobes that close over insects when triggered.

The device has a diameter of 3 mm and is harmless to the plant. It does not affect the plant's ability to perform photosynthesis while successfully detecting electrical signals from the plant. Using a smartphone to transmit electric pulses to the device at a specific frequency, the team elicited the Venus flytrap to close its leaves on demand, in 1.3 seconds.

The researchers have also attached the Venus flytrap to a robotic arm and, through the smartphone and the 'communication' device, stimulated its leaf to close and pick up a piece of wire half a millimetre in diameter.

Their findings, published in the scientific journal Nature Electronics in January, demonstrate the prospects for the future design of plant-based technological systems, say the research team. Their approach could lead to the creation of more sensitive robot grippers to pick up fragile objects that may be harmed by current rigid ones.

Picking up electrical signals to monitor crop health monitoring

The research team envisions a future where farmers can take preventive steps to protect their crops, using the plant 'communication' device they have developed.

Lead author of the study, Chen Xiaodong, President's Chair Professor in Materials Science and Engineering at NTU Singapore said: "Climate change is threatening food security around the world. By monitoring the plants' electrical signals, we may be able to detect possible distress signals and abnormalities. When used for agriculture purpose, farmers may find out when a disease is in progress, even before full?blown symptoms appear on the crops, such as yellowed leaves. This may provide us the opportunity to act quickly to maximise crop yield for the population."

Prof Chen, who is also Director of the Innovative Centre for Flexible Devices (iFLEX) at NTU, added that the development of the 'communication' device for plants monitoring exemplifies the NTU Smart Campus vision which aims to develop technologically advanced solutions for a sustainable future.

Next generation improvement: Liquid glue with stronger adhesive strength

Seeking to improve the performance of their plant 'communication' device, the NTU scientists also collaborated with researchers at the Institute of Materials Research and Engineering (IMRE), a unit of Singapore's Agency for Science, Technology and Research (A*STAR).

Results from this separate study, published in the scientific journal Advanced Materials in March, found that by using a type of hydrogel called thermogel - which gradually transforms from liquid to a stretchable gel at room temperature - it is possible to attach their plant 'communication' device to a greater variety of plants (with various surface textures) and achieve higher quality signal detection, despite plants moving and growing in response to the environment.

Elaborating on this study, co-lead author Professor Chen Xiaodong said, "The thermogel-based material behaves like water in its liquid state, meaning that the adhesive layer can conform to the shape of the plant before it turns into a gel. When tested on hairy stems of the sunflower for example, this improved version of the plant 'communication' device achieved four to five times the adhesive strength of common hydrogel and recorded significantly stronger signals and less background noise."

Co-lead author of the Advanced Materials study and Executive Director of IMRE, Professor Loh Xian Jun, said: "The device can now stick to more types of plant surfaces, and more securely so, marking an important step forward in the field of plant electrophysiology. It opens up new opportunities for plant-based technologies."

Moving forward, the NTU team is looking to devise other applications using the improved version of their plant 'communication' device

CAPTION

Members of the research team include (top L-R) NTU Prof Chen Xiaodong, A*STAR Prof Loh Xian Jun, PhD students from the NTU School of Materials Science and Engineering, (bottom L-R) Li Wenlong and Luo Yifei.

CREDIT

NTU Singapo

CAPTION

The plant 'communication' device is attached on the surface of a Venus flytrap plant.

CREDIT

NTU S

 

While drowning numbers soar, beach safety programs are largely unevaluated

Australia may be leading the way on coastal drowning research, but a study led by UNSW has identified the need for more evidence to support prevention strategies.

UNIVERSITY OF NEW SOUTH WALES

Research News

 

A global review of coastal drowning science has found there is only one study worldwide that has evaluated beach safety education programs in schools.

Researchers from UNSW's Beach Safety Research Group have conducted the first in-depth review specific to coastal drowning.

The study, published in PLOS ONE, reviewed 146 coastal drowning studies from around the world.

"We found that evaluation of coastal drowning prevention strategies is rare," said William Koon, the lead author of the study and a PhD candidate in the School of Biological, Earth and Environmental Sciences said.

"This means we simply don't have enough data showing what works and what doesn't work.

"There was only one study worldwide - involving a private primary school in Queensland - to see if beach safety education program is effective in schools."

Since the review, an additional school-based evaluation of water safety virtual reality programs in Victoria has been published.

Mr Koon said the review's findings are concerning as tens of thousands of Australian primary and secondary school students participate in beach or water safety programs from lifeguards and lifesavers every year.

"There is remarkably little information out there to say [firstly], does it work and [secondly], here's how it works best," Mr Koon said.

"We need to assess if programs function as intended, and continually refine them to improve effectiveness."

Researchers and UNSW Beach Safety Research Group founding members Dr Amy Peden, Dr Jaz Lawes and Professor Rob Brander were also involved in the study.

"I find it interesting that over the last 16 years we haven't really seen any improvement in the number of coastal drownings each year in Australia, despite lots of ongoing school and public education programs," Professor Brander said.

The study found that more than three-quarters (76.7%) of coastal drowning research was from high-income countries. Australia is leading the way with 49 studies, followed by the US (28 studies).

It also found that existing drowning prevention strategies are largely un-evaluated, with little research being done in low-income countries where a majority of drowning events occur.

Mr Koon said while there were 125 coastal drowning deaths in Australia last year, the World Health Organisation estimates that more than 90 percent of all drowning occurs in low-and middle-income countries.

He said to address this global health problem, researchers need to start looking to local data from lower-resourced settings to understand the coastal safety issues there and prioritise drowning prevention programs for different groups of people.

"Researchers like myself need to ask 'is what I learned from Australian coastal safety research applicable to a place like Ghana or Costa Rica or India, where similar hazards exist, but the cultural context is very different'," he said.

The researchers conducted the review to better understand the science driving safety initiatives and highlight gaps in the field of coastal drowning, in order to prioritise future studies and prevention initiatives that will ultimately save lives.

They focused on fatal unintentional coastal drowning that was unrelated to boating, disaster (ie cyclones) or occupational accidents (ie commercial fishermen or scuba divers).

They found studies inconsistently reported intentional, occupational and boating coastal drowning deaths, and the terminology used to describe coastal waters was also non-uniform.

"Reviews such as this one are so important as they highlight gaps in the current evidence base, identifying opportunities for future research to really make a difference, rather than more of the same," study co-author Dr Amy Peden, from the UNSW School of Population Health said.

Over 100 different risk factors related to coastal drowning were identified, but the data sources, outcomes used, and analyses employed were variable.

"What we learned is that the consistency in reporting and analysing of these different scenarios was just all over the place," Mr Koon said. "Not every place in the world is recording drowning in the same way.

Studies were also published in a variety of journals representing different disciplines.

Many studies recommended prevention measures, most frequently related to education, lifeguards and signage.?

"Is that enough? Are these efforts working? How well? We don't have enough data to answer these questions," Mr Koon said.

There are limited resources for evaluations on water safety programs, he said.

"But someone with a long-term view should start to see that investment in monitoring and evaluation is a way to really make sure the work is doing what it's supposed to do," he said. He says it is important to continue to refine school water safety programs.

"There are probably different lessons to be learned, such as messaging at different ages, whether that's stopping to look for rips or putting on sunscreen, avoiding alcohol or avoiding jumping off rocks and cliffs.

He said there has been "remarkably little information" studying prevention measures.

"Research on danger signs on beaches has already told us that people don't really look at signs, and if they do, are not really influenced to change decisions or behaviour," he said.

"We're still in the stage where most programs are driven by expert opinion without much supporting data."

He said Australia continues to lead the world in drowning prevention and water safety research because organisations like Surf Life Saving Australia and Royal Life Saving Society - Australia maintain robust databases, with some of the most detailed drowning data in the world.

UNSW Beach Safety Research Group researchers are currently working with Lake Macquarie lifeguards to evaluate a beach safety program which they deliver to high school students.

"We hope to be able to offer some recommendations on how other people in the industry can move forward with evaluating some of their school and other beach safety education programs," he said.

"As our review has shown, the kind of information this evaluation will yield addresses a massive gap in our understanding of what's effective and what's not in the drowning prevention education space," Dr Peden said.

"Identifying what can improving safety and reduce young people's risk of drowning during adolescence can result in positive behaviours throughout adulthood."

Deforestation taking a heavy toll on international bird haven

UNIVERSITY OF QUEENSLAND

Research News

 

IMAGE: FORK-TAILED WOODNYMPH view more 

CREDIT: PABLO NEGRET

An analysis has found deforestation is severely affecting forest bird species in Colombia, home to the greatest number of bird species in the world.

University of Queensland-led research, steered by Dr Pablo Negret, analysed the impact of deforestation on 550 bird species, including 69 only found in the South American nation.

"Our study has shown an astonishing reduction in bird species habitat," Dr Negret said.

"One third of the forest bird species in Colombia have lost at least a third of their historical habitat, and that's just using the most recent data we have available - from 2015.

"Moreover, 18 per cent or 99 species have lost more than half of their historical habitat to date.

"By 2040, we expect this will increase to 38 per cent or 209 species.

"Sadly, many of those species are endemic to the country and are not currently classified as threatened by the International Union for Conservation of Nature, suggesting that there are many unlisted species that face an imminent extinction threat from ongoing habitat loss."

Dr Negret said the results were concerning but not surprising.

"Deforestation is one of the main drivers of habitat loss for many species in the tropics," he said.

"We know that deforestation affects thousands of species in these ecosystems, but our attention is usually focused on a tiny fraction - threatened and charismatic species.

"This study provides more data on species previously thought abundant that are actually dwindling - hopefully we can shine a light on them, so they can be recognised as under threat and don't fall through the cracks."

The researchers used historical and present satellite forest cover data, while collating spatial information on other variables associated with deforestation patterns.

UQ's Professor Martine Maron said the research would help predict future habitat loss for already-threatened species.

"This methodology, and the technologies behind it, allow us to identify places where future habitat loss is predicted.

"This means that we can reveal the locations where threatened species are most likely to lose precious habitat, and prioritise their protection.

"And, in a country with growing threats to rich bird diversity, it pays to be ahead of the game."

The authors hope the Colombian government and NGOs working in this space will use the research to guide conservation of Colombia's bird species.

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The study is published in Biological Conservation DOI: 10.1016/j.biocon.2021.109

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Golden-collared toucanet

CREDIT

Pablo Negret

 

Roof-tiles in imperial China: Creating Ximing Temple's lotus-pattern tile ends

Researchers from Kanazawa University and the Chinese Academy of Social Sciences cast light on the production of roof tiles during the Tang dynasty through a study of variations in lotus-pattern tile ends recovered from the Ximing Temple in Xi'an

KANAZAWA UNIVERSITY

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IMAGE: BASIC INFORMATION ABOUT TILE ENDS AND IMBRICES. THE FIGURE SHOWS THE STRUCTURE OF A TILE END AND HOW TILE ENDS AND IMBRICES ARE USED. view more 

CREDIT: KANAZAWA UNIVERSITY

Kanazawa, Japan -- Any visitor to China will have noticed the spectacular roofs on buildings dating from imperial times. However, the question of how these roof tiles were produced has attracted relatively little attention from archaeologists. Now, a team of researchers has conducted a major study of tile ends unearthed at the Ximing Temple in Xi'an, yielding exciting insights into their production.

In a study published in Archaeological Research in Asia, researchers from Kanazawa University and the Chinese Academy of Social Sciences have revealed the significance of minute variations in the tile ends used in the roof of the famous Ximing Temple in Xi'an, built during the Tang dynasty (618-907 AD) when Xi'an (then known as Chang'an) was the imperial capital.

The researchers conducted an investigation of 449 tile ends with lotus patterns from various periods during the Tang dynasty that had been recovered from the Ximing Temple. "We were interested in the variations in the tile ends, both those within the conscious control of the artisans who made the tiles, such as whether to use simple or complex lotus patterns, and those outside their control, such as the marks left by the deterioration of the molds used to make the tiles," says lead author of the study Meng Lyu.

"We discovered that the degree of minor variation in the tile ends increases significantly in the later samples," adds author Guoqiang Gong. "This suggests to us that there was a shift away from the centralized manufacturing of imperial building materials during the Early Tang period toward one in which small private artisans played an important role in the Late Tang period."

Intriguingly, the study has revealed traces of the coming together of two distinct cultural traditions. "We found that there were, in fact, two separate production systems at work to make the title ends," notes author Chunlin Li. "One produced tile ends with compound petal patterns and curved incisions, whereas the other made end tiles with simple petal patterns and scratched incisions." These two styles may ultimately have their origins during an earlier historical period when the Northern Wei dynasty was divided into two regimes on either side of the Taihang mountain range.

This study demonstrates that studying the roof tiles of China's grand imperial buildings can reveal a great deal about the circumstances of their production and yield insights into larger historical questions.

CAPTION

Shaping stage in production process of tile end. The shaping stage in tile-end production process is most likely to have followed this sequence: 1. Design; 2. Making first-level mold; 3. Making ceramic second-level mold; 4. Making tile end. The use of two different levels of mold enabled artisans to produce the needed numbers over a relatively short period of time.

CREDIT

Kanazawa University

CAPTION

Incisions on the back surfaces of tile ends and patterns on the front surfaces. Artisans firmly joined tile ends to imbrices through a process which left obvious traces on the back surfaces of the tile ends. Tile ends with simple petals mostly contain thin, radially oriented scratched incisions (Fig. 3.1), while those with compound petals usually contain wide, triangular-shaped curved incisions (Fig. 3.2). The correlation between pattern and processing technique identifies two production systems at the Ximing Temple workshop.

CREDIT

Kanazawa University

Consumption of added sugar doubles fat production

UNIVERSITY OF ZURICH

Research News

 

Sugar is added to many common foodstuffs, and people in Switzerland consume more than 100 grams of it every day. The high calorie content of sugar causes excessive weight and obesity, and the associated diseases. But does too much sugar have any other harmful effects if consumed regularly? And if so, which sugars in particular?

Even moderate amounts of sugar increase fat synthesis

Researchers at the University of Zurich (UZH) and the University Hospital Zurich (USZ) have been investigating these questions. Compared to previous studies, which mainly examined the consumption of very high amounts of sugar, their results show that even moderate amounts lead to a change in the metabolism of test participants. "Eighty grams of sugar daily, which is equivalent to about 0,8 liters of a normal soft drink, boosts fat production in the liver. And the overactive fat production continues for a longer period of time, even if no more sugar is consumed," says study leader Philipp Gerber of the Department of Endocrinology, Diabetology and Clinical Nutrition.

Ninety-four healthy young men took part in the study. Every day for a period of seven weeks, they consumed a drink sweetened with different types of sugar, while the control group did not. The drinks contained either fructose, glucose or sucrose (table sugar which is a combination of fructose and glucose). The researchers then used tracers (labeled substances that can be traced as they move through the body) to analyze the effect of the sugary drinks on the lipid metabolism.

Fructose and sucrose double fat production beyond food intake

Overall, the participants did not consume more calories than before the study, as the sugary drink increased satiety and they therefore reduced their calorie intake from other sources. Nevertheless, the researchers observed that fructose has a negative effect: "The body's own fat production in the liver was twice as high in the fructose group as in the glucose group or the control group - and this was still the case more than twelve hours after the last meal or sugar consumption," says Gerber. Particularly surprising was that the sugar we most commonly consume, sucrose, boosted fat synthesis slightly more than the same amount of fructose. Until now, it was thought that fructose was most likely to cause such changes.

Development of fatty liver or diabetes more likely

Increased fat production in the liver is a significant first step in the development of common diseases such as fatty liver and type-2 diabetes. From a health perspective, the World Health Organization recommends limiting daily sugar consumption to around 50 grams or, even better, 25 grams. "But we are far off that mark in Switzerland," says Philipp Gerber. "Our results are a critical step in researching the harmful effects of added sugars and will be very significant for future dietary recommendations."

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Sugar - Sidney Mintz

sidneymintz.net › sugar

I became awed by the power of a single taste, and the concentration of brains, energy, wealth and -- most of all, power -- that had led to its being supplied to so ..

UK variant spread rapidly in care homes in England

The UK variant of SARS-CoV-2 spread rapidly in care homes in England in November and December last year, broadly reflecting its spread in the general population, according to a study by UCL researchers

NOW SPREADING ACROSS ALBERTA, CANADA, AND USA

UNIVERSITY COLLEGE LONDON

Research News

 

The UK variant of SARS-CoV-2 spread rapidly in care homes in England in November and December last year, broadly reflecting its spread in the general population, according to a study by UCL researchers.

The study, published as a letter in the New England Journal of Medicine, looked at positive PCR tests of care home staff and residents between October and December. It found that, among the samples it had access to, the proportion of infections caused by the new variant rose from 12% in the week beginning 23 November to 60% of positive cases just two weeks later, in the week beginning 7 December.

In the south east of England, where the variant was most dominant, the proportion increased from 55% to 80% over the same period. In London, where the variant spread fastest, the proportion increased from 20% to 66%.

The researchers said the timing of infections suggested the new variant may have been passed from staff to residents, with positive cases among older people occurring later.

Senior author Dr Laura Shallcross (UCL Institute of Health Informatics) said: "Our findings suggest the UK variant spread just as quickly in care homes as it did in the general population. This shows the importance of public health measures to reduce transmission in the country as a whole."

Lead author Dr Maria Krutikov (UCL Institute of Health Informatics) said: "Our results are consistent with national trends, suggesting that the UK variant was present in care homes from early on, although our sample did not fully represent all care homes in England. As we carried out this work in December, we were able to inform public health decisions at the time.

"To see how viruses like Covid-19 are changing and to respond quickly and appropriately, it is really important we have an advanced surveillance system, with gene sequencing that can identify new variants as early as possible."

For the study, researchers analysed 4,442 positive PCR samples from care home staff and residents in England. These were all the positive tests of staff and residents processed from October to December at the Lighthouse laboratory in Milton Keynes, one of the UK's biggest coronavirus testing labs. Staff in care homes are tested every week, while residents are tested monthly.

PCR tests for SARS-CoV-2 are designed to detect three parts of the virus - the S gene, N gene, and ORF1ab. The UK variant, known as B.1.1.7., has changes in its S gene, or spike gene, which mean the tests do not detect this particular target.

This means researchers were able to identify the proportion of infections caused by the new variant by looking at the samples in which the other two targets, the N gene and ORF1b, were detected, but not the S gene.

They also compared Ct values, which show how much of the virus is present, to check the samples did not miss the S gene because they were "weaker" positive tests, with less viral material.

Their analysis showed that in late November, the proportion of infections associated with B.1.1.7 increased sharply in several regions of England. In London, this was from 20% (week beginning 23 November) to 66% (week beginning 7 December). In the east of England, it rose from 35% to 64% over the same period, while in the south east the increase was from 55% to 80%. The data was predominantly drawn from London, the south east and east of England and the Midlands, with fewer positive test samples from the north of England and the south west.

Most samples were from people aged under 65, as staff are tested much more frequently than residents. However, among samples from those aged over 65, the proportion of infections caused by the new variant rose from 14% in the week beginning 23 November to 76% in the week beginning 7 December. (The number of total positive samples was low - just 21 and 157 respectively.)

The research was conducted as part of the Vivaldi study looking at Covid-19 infections in care homes. It received support and funding from the Department of Health and Social Care.

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Peer reviewed study / observational / people and cells

A new way to measure human wellbeing towards sustainability

INTERNATIONAL INSTITUTE FOR APPLIED SYSTEMS ANALYSIS

Research News

 

From science to implementation: How do we know if humankind is moving in the right direction towards global sustainability? The ambitious aim of the SDGs is a global call to action to end poverty, protect the planet, and ensure all people enjoy peace and prosperity by 2030. To monitor progress towards these goals, a set of over 220 indicators is used, but there is a danger that one can no longer see the forest for the trees. A single comprehensive indicator to assess the overall progress is needed. In a new paper published in the Proceedings of the National Academy of Sciences (PNAS), IIASA researchers and colleagues from the University of Vienna, the Vienna Institute of Demography (Austrian Academy of Sciences), and the Bocconi University present a bespoke indicator based on life expectancy and benchmarks of objective and subjective wellbeing: The Years of Good Life (YoGL) indicator.

"Many existing indicators of wellbeing do not consider the basic fact that being alive is a prerequisite for enjoying any quality of life. In addition, they often disregard the length of a life. Life expectancy has long been used as a very comprehensive indicator of human development, with avoiding premature death being a universally shared aspiration. However, mere survival is not enough to enjoy life and its qualities," explains lead author Wolfgang Lutz, Founding Director of the Wittgenstein Centre for Demography and Global Human Capital, a collaborative center of the Austrian Academy of Sciences (Vienna Institute of Demography), International Institute for Applied Systems Analysis, and University of Vienna. "The Years of Good Life indicator only counts a year as a good year if individuals are simultaneously not living in absolute poverty, free from cognitive and physical limitations, and report to be generally satisfied with their lives."

The results show that YoGL differs substantially between countries. While in most developed countries, 20-year-old women can expect to have more than 50 years of good life left (with a record of 58 years in Sweden), women in the least developed countries can expect less than 15 years (with a record low of 10 years for women in Yemen). While life expectancy is higher for women than for men in every country, female Years of Good Life are lower than those of males in most developing countries. This reveals a significant gender inequality in objective living conditions and subjective life satisfaction in most of these countries.

The paper - funded by an Advanced Grant to Lutz from the European Research Council - presents a first step in the great challenge to comprehensively assess sustainable human wellbeing that also considers feedbacks from environmental change. Unlike many other indicators, YoGL is not restricted to the national level but can be assessed for flexibly defined sub-populations and over long-time horizons because it has substantive meaning in its absolute value. It also has the potential to become a broadly used "currency" for measuring the benefits of certain actions, complementing assessments based on purely monetary units. For example, the social costs of carbon could potentially be evaluated in terms of Years of Good Life lost among future generations, rather than only in dollar terms - making it a key indicator to measure sustainable progress in an integrated and tangible way. Applying the same logic to the recent COVID-19 pandemic, study coauthor Erich Striessnig adds that YoGL also represents a major improvement over conventional indicators in assessing the long-term success of intervention measures.

"If we used YoGL as a currency to measure the long-term impacts of the ongoing crisis rather than GDP per capita or life expectancy, we would not only account for the material losses and the lost life years, but also for the losses in physical and cognitive wellbeing, as well as for the losses incurred by the younger generations in terms of their human capital resulting from school closures. Lack of consistent data that is needed to calculate YoGL does of course remain an issue. Political decision makers should, however, aim for improved data availability to make better informed decisions based on indicators such as YoGL," Striessnig concludes.

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Reference

Lutz, W., Striessnig, E., Dimitrova, A., Ghislandi, W., Lijadi, A., Reiter, C., Spitzer, S., Yildiz, D. (2021). Years of Good Life (YoGL) is a wellbeing indicator designed to serve research on sustainability. Proceedings of the National Academy of Sciences (PNAS) DOI: 10.1073/pnas.1907351

About IIASA:

The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policymakers to shape the future of our changing world. IIASA is independent and funded by prestigious research funding agencies in Africa, the Americas, Asia, and Europe.
http://www.iiasa.ac.at

 

Study finds American mink to be main limiting factor of European mink

ESTONIAN RESEARCH COUNCIL

Research News 

IMAGE: RADIOTRACKING view more 

CREDIT: MADIS PÕDRA

The disappearance of the species from their natural habitat is a growing problem, which unfortunately means the need to intensive management, including ex situ conservation and translocations, is also growing. For the translocation to be successful, risk factors must be removed from the area. In the course of reestablishment, it is important to assess the adaptation of captive-bred animals into the wild in order to improve release strategies and methods.

The doctoral thesis of Madis Põdra focused on the translocation of captive-bred European mink. The efficiency of adaptation as well as the influence of American minks, the main threat, were evaluated. This was achieved by analysing the spread of the invasive species in Spain. The translocation of the European mink was assessed in two regions - the Salburua wetland in Northern Spain and Hiiumaa in Estonia. In Salburua, the abundance of the American mink was reduced before releasing the European mink; in Hiiumaa, the alien species was removed entirely. 27 European minks were released in Salburua wetland (2008-2010) and 172 in Hiiumaa (2000-2003). To monitor the process of adaptation of the released animals, radio-tracking as well as live trapping were used. The researchers studied the survival of the minks, the causes of their death, movements and their dietary acclimatization.

"My thesis confirms that the American mink is the main obstacle in reintroducing the European mink," explains Põdra. "If we want to reintroduce the European mink successfully, the alien species must be removed entirely. Captive-bred European mink are capable of adapting and surviving in the wild. The first month or month and a half is the most critical stage: at that time, the death rate of released animals is relatively high. Later, their behaviour starts to resemble that of wild minks."

This doctoral thesis is particularly interesting because the researchers managed to evaluate the efficiency of the adaptation in rather great detail. Similar studies have previously been researched on numerous occasions, but the majority of studies focus on the survival of the released animals, often leaving the question 'why' unanswered. In Spain, Madis Põdra proved that the American mink has significant influence on the translocation of the European mink even if the abundance of the alien species is low and the European mink has been well prepared for life in the wild. It is known that the European mink competes with the American mink for habitats, but with his research, Madis Põdra proved that the American mink is able to depredate on native species. The results obtained in Hiiumaa showed that captive-bred specimens are capable of adapting to life in the wild, but the process is influenced by multiple factors like the sex of the released animals and their living conditions in captivity. In addition, the tendency of the European mink to move to unsuitable habitats after release was discovered alongside their difficulties catching prey. This indirectly affects their survival - although bigger predators are the proximate causes of death, the ultimate causes may be a syndrome of mal-adaptations.

CAPTION

Madis Põdra, a doctoral student from the School of Natural Sciences and Health of Tallinn University,

CREDIT

Madis Põdra

The supervisors of the doctoral thesis are Tiit Maran, visiting lecturer from the Estonian University of Life Sciences, and Tiiu Koff, visiting professor and research track associate professor at Tallinn University. The opponents are Professor Asko Lõhmus from the University of Tartu and John G. Ewen, senior research fellow at the London Institute of Zoology.

The dissertation is available in the ETERA digital environment of TU Academic Library. https://www.etera.ee/zoom/110294/view?page=1&p=separate&p=separate&tool=info&tool=info&view=0,0,2067,2835https:%2F%2Fhttp://www.etera.ee%2Fzoom%2F110294%2Fview%3Fpage&view=0,0,2067,2835