USC study reveals the key reason why fake news spreads on social media

The USC-led study of more than 2,400 Facebook users suggests that platforms — more than individual users — have a larger role to play in stopping the spread of misinformation online.

Peer-Reviewed Publication

UNIVERSITY OF SOUTHERN CALIFORNIA

USC researchers may have found the biggest influencer in the spread of fake news: social platforms’ structure of rewarding users for habitually sharing information.

The team’s findings, published Tuesday by Proceedings of the National Academy of Sciences, upend popular misconceptions that misinformation spreads because users lack the critical thinking skills necessary for discerning truth from falsehood or because their strong political beliefs skew their judgment.

Just 15% of the most habitual news sharers in the research were responsible for spreading about 30% to 40% of the fake news.

The research team from the USC Marshall School of Business and the USC Dornsife College of Letters, Arts and Sciences wondered: What motivates these users? As it turns out, much like any video game, social media has a rewards system that encourages users to stay on their accounts and keep posting and sharing. Users who post and share frequently, especially sensational, eye-catching information, are likely to attract attention.

“Due to the reward-based learning systems on social media, users form habits of sharing information that gets recognition from others,” the researchers wrote. “Once habits form, information sharing is automatically activated by cues on the platform without users considering critical response outcomes, such as spreading misinformation.”

Posting, sharing and engaging with others on social media can, therefore, become a habit.

“Our findings show that misinformation isn’t spread through a deficit of users. It’s really a function of the structure of the social media sites themselves,” said Wendy Wood, an expert on habits and USC emerita Provost Professor of psychology and business.

“The habits of social media users are a bigger driver of misinformation spread than individual attributes. We know from prior research that some people don’t process information critically, and others form opinions based on political biases, which also affects their ability to recognize false stories online,” said Gizem Ceylan, who led the study during her doctorate at USC Marshall and is now a postdoctoral researcher at the Yale School of Management. “However, we show that the reward structure of social media platforms plays a bigger role when it comes to misinformation spread.”

In a novel approach, Ceylan and her co-authors sought to understand how the reward structure of social media sites drives users to develop habits of posting misinformation on social media.

Why fake news spreads: behind the social network

Overall, the study involved 2,476 active Facebook users ranging in age from 18 to 89 who volunteered in response to online advertising to participate. They were compensated to complete a “decision-making” survey approximately seven minutes long.

Surprisingly, the researchers found that users’ social media habits doubled and, in some cases, tripled the amount of fake news they shared. Their habits were more influential in sharing fake news than other factors, including political beliefs and lack of critical reasoning.

Frequent, habitual users forwarded six times more fake news than occasional or new users.

“This type of behavior has been rewarded in the past by algorithms that prioritize engagement when selecting which posts users see in their news feed, and by the structure and design of the sites themselves,” said second author Ian A. Anderson, a behavioral scientist and doctoral candidate at USC Dornsife. “Understanding the dynamics behind misinformation spread is important given its political, health and social consequences.”

Experimenting with different scenarios to see why fake news spreads

In the first experiment, the researchers found that habitual users of social media share both true and fake news.

In another experiment, the researchers found that habitual sharing of misinformation is part of a broader pattern of insensitivity to the information being shared. In fact, habitual users shared politically discordant news — news that challenged their political beliefs — as much as concordant news that they endorsed.

Lastly, the team tested whether social media reward structures could be devised to promote sharing of true over false information. They showed that incentives for accuracy rather than popularity (as is currently the case on social media sites) doubled the amount of accurate news that users share on social platforms.

The study’s conclusions:

• Habitual sharing of misinformation is not inevitable.
• Users could be incentivized to build sharing habits that make them more sensitive to sharing truthful content.
• Effectively reducing misinformation would require restructuring the online environments that promote and support its sharing.

These findings suggest that social media platforms can take a more active step than moderating what information is posted and instead pursue structural changes in their reward structure to limit the spread of misinformation.

 

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2216614120 

METHOD OF RESEARCH

Survey

ARTICLE TITLE

Sharing of misinformation is habitual, not just lazy or biased

ARTICLE PUBLICATION DATE

17-Jan-2023

Team conducts reanalyses assessment of mean and extreme climates over West Africa

Study looks to aid decision-making in critical sectors like agriculture and water resources.

Peer-Reviewed Publication

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

 

IMAGE: IN THE MAJORITY OF WEST AFRICAN NATIONS, WHERE SUBSISTENCE AGRICULTURE IS PREDOMINANTLY PRACTICED, CLIMATE CHANGE HAS BEEN NOTED AS AN INCREASING THREAT TO FOOD SECURITY AND INADEQUATE NUTRITION. THESE NATIONS HAVE LIMITED CAPACITY FOR ADAPTATION AND ARE SUBJECT TO HARSH WEATHER. THIS EMPHASIZES THE SIGNIFICANCE OF GATHERING ACCURATE CLIMATIC DATA TO FULLY COMPREHEND CURRENT AND FUTURE VULNERABILITIES IN ORDER TO BUILD THE BEST METHODS FOR COPING WITH CLIMATE CHANGE. REANALYSES ARE ALTERNATE DATASETS FOR CLIMATE STUDIES AND OPERATIONAL USE BECAUSE STATION OBSERVATIONS ARE DIFFICULT TO GET AND SPATIOTEMPORALLY INCONSISTENT IN WEST AFRICA. REANALYSES PRODUCE ESTIMATES OF THE ATMOSPHERIC FIELDS THAT ARE PHYSICALLY CONSISTENT, ALLOWING FOR PROCESS-BASED ANALYSIS OF VARIABLES LIKE TEMPERATURE AND PRECIPITATION VARIABILITY AND LONG-TERM TRENDS, AS WELL AS CLIMATE EXTREMES. view more 

CREDIT: ADVANCES IN ATMOSPHERIC SCIENCES

An international team of scientists has reviewed the effectiveness of reanalysis data products for studying the climate over West Africa. Reanalysis data provides scientists with a blend of observations combining past weather forecasts rerun with modern forecasting models. These reanalysis datasets are beneficial alternatives that can be used to investigate climate conditions of any given geographic location where no sufficient observational datasets exist. The team set out to assess the accuracy of the existing reanalysis products in examining the West African climate.

Their findings are published in the journal Advances in Atmospheric Sciences on Jan 17.

The team assessed two reanalysis products – ERA5 and ERA-interim. ERA5 is the fifth-generation atmospheric reanalysis product, produced by an intergovernmental research institute, the European Centre for Medium-Range Weather Forecasts. ERA5 provides global climate data covering the period from January 1950 to the present. ERA-interim was the predecessor to ERA5. Knowing that these two products perform with varying degrees of quality and accuracy, the team undertook to assess these products to better understand their shortcomings and strengths before using them to study the West Africa climate.

The team investigated the performance of the ERA5 and ERA-interim products in representing the mean and extreme climates over West Africa for the period from 1981 to 2018. They used the Climate Research Unit (CRU) and Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) observational datasets to conduct their study.

The team was interested in studying West Africa because with its extreme weather conditions, this region is susceptible to global warming. Looking ahead, scientists expect the climate in West Africa to change because of rising temperatures and unpredictable rainfall patterns. Added to that, the population of West Africa is expected to grow faster than the global average. Because this region was already vulnerable to extreme weather such as floods and droughts, climate change can have a significant impact on their ability to grow the crops they need for food. “Understanding the climate conditions is critical for identifying present and future vulnerabilities and developing climate change adaption strategies,” said Imoleayo Ezekiel Gbode, a climate scientist at the Federal University of Technology Akure.

Weather stations and the observational datasets that can be obtained from them are sparse over Africa. The data obtained from reanalysis datasets is a possible alternate solution in this region where observational data is so limited. However, previous studies have shown that the accuracy of reanalysis data varies significantly in some regions, especially where the observations are limited or the terrain is remote and complex. So the team undertook their study focusing on the spatial pattern and temporal variability of both mean and extreme climate conditions in West Africa for the period from 1981 to 2018. They used the CRU and CHIPRS data as reference datasets.

From their study, the team learned that the ERA5 product has achieved considerable progress compared to its predecessor, ERA-interim, in terms of reduced precipitation and temperature biases and improved representation of inter-annual variability in much of western Africa. They also discovered that ERA5 reproduces precipitation extremes better than ERA-interim, although both reanalyses underestimate the intensity and frequency of heavy precipitation and overestimate the number of wet days.

The team concludes that the overall remarkable performance of ERA5 in representing key climate features over Africa, together with its accessibility at a higher temporal and spatial resolution, makes it a suitable dataset for near-real-time climate monitoring, especially for the temperature over the region. However, the representation of long-term trends in West African precipitation remains a challenge for both reanalysis datasets. “We need improved datasets with better resolution and accuracy for climate impact assessment to guide decision-making processes in critical sectors like agriculture and water resources to ensure food security and sustainability,” said Gbode.

The research team with scientists from Nigeria, Canada, and Korea, includes Imoleayo Ezekiel Gbode from the Federal University of Technology Akure, Nigeria; Toju Esther Babalola from the Federal University Oye-Ekiti, Nigeria; Gulilat Tefera Diro from the University of Quebec at Montreal, Canada; and Joseph Daniel Intsiful from the Green Climate Fund, South Korea.

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JOURNAL

Advances in Atmospheric Sciences

DOI

10.1007/s00376-022-2161-8 

ARTICLE TITLE

Assessment of ERA5 and ERA-Interim in Reproducing Mean and Extreme Climates over West Africa

ARTICLE PUBLICATION DATE

17-Jan-2023

A new approach to sharing the burden of carbon dioxide removal

Peer-Reviewed Publication

INTERNATIONAL INSTITUTE FOR APPLIED SYSTEMS ANALYSIS

Carbon dioxide removal is key to meeting the climate goals outlined in the Paris Agreement. A new study analyzes what fair and equitable burden-sharing means for nature-based carbon dioxide removal in developing countries.

To have a chance to achieve the Paris Agreement’s goal of limiting global warming to 1.5–2°C compared to pre-industrial levels, it is clear that we will need to go beyond restricting emissions and actively focus on removing carbon dioxide from the atmosphere. Discussions and studies on how countries should share the burden of carbon dioxide removal are however limited, and so far, mostly only concerned developed countries and major emitters. To deliver the global targets we need to extend analysis and discussions to developing economies as well.

In a new IIASA-led study, an international team of researchers analyzed carbon dioxide removal quotas for developing countries, while considering issues of equity and fairness. The study, published in the journal Nature-Based Solutions, employs a diverse set of allocation methods on a range of global emissions scenarios to address equitability in sharing the burden of climate change mitigation.

The allocation methods were based on extended equity principles compared to previous studies, adding the Right to Development principle to other principles of Responsibility, Equality, and Capacity. Based on these methods, the team distilled the global climate targets into national quotas and assessed the implications for developing countries.

Carbon dioxide removal can be achieved by either using technology and engineering methods, or through natural climate solutions, such as conservation, restoration, and improved land management. Given the large potential for natural climate solutions in tropical developing countries, the study focused on seven of these (Brazil, Colombia, Democratic Republic of Congo (DRC), India, Indonesia, Malaysia, and Mexico) which together cover ∼35% of global cost-effective natural climate solutions potential.

“The study is unique because it looks at the issue from the perspective of developing countries. Because of this, the study has a far more rigorous methodology in evaluating potential carbon dioxide removal requirements compared to previous studies,” says Bintang Yuwono, co-lead author of the study and a researcher in the IIASA Biodiversity and Natural Resources Program. “The conclusions of the study point to a paradigm shift in using top-down burden-sharing approaches to inform climate change mitigation.”

The researchers found that the potential for carbon dioxide removal quotas for these seven countries ranged between 0.1–29 gigatons of carbon dioxide across the allocation scenarios. The results also revealed inherent bias and strong heterogeneity of quotas between the allocation methods, making agreement on an ‘equitable’ quota unlikely.

Moreover, the researchers also warned that if ambitious quotas are implemented in countries with vast forest areas, it might lead to competition between natural and non-nature-based solutions, to the detriment of emissions reduction, biodiversity, and the benefits that people can derive from nature. Therefore, it is important to not use these quotas to inform climate targets, but instead use the results to foster higher ambition in voluntary cooperation mechanisms.

“The research shows that fairness is not just important from an ethical perspective, but also contribute to more effective recommendations that address emission reductions from sustainable land management,” says Ping Yowargana study co-lead author, and a researcher in the IIASA Biodiversity and Natural Resources Program. “Manifesting ambition should go from top-down target setting on superficial parameters such as tons of carbon dioxide towards detailed deliberation of policy measures to address more fundamental issues. This, unfortunately, still requires a lot of hard work.”

Reference

Yuwono, B., Yowargana, P., Fuss, S., Griscom, B. W., Smith, P., & Kraxner, F. (2022). Doing burden-sharing right to deliver natural climate solutions for carbon dioxide removal. Nature-Based Solutions, 100048. DOI: 10.1016/j.nbsj.2022.100048

 

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. www.iiasa.ac.at

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JOURNAL

Nature-Based Solutions

DOI

10.1016/j.nbsj.2022.100048 

ARTICLE TITLE

Doing burden-sharing right to deliver natural climate solutions for carbon dioxide removal

A recent research on why and when to help firms keep workers in a crisis

Short time work programs, which allow firms to avoid layoffs, are suitable for facing temporary shocks, but not permanent ones, according to a study by Giulia Giupponi, Bocconi University, Milan

Peer-Reviewed Publication

BOCCONI UNIVERSITY

 

VIDEO: WITH SHORT-TIME WORK PROGRAMS, GOVERNMENTS ALLOW FIRMS EXPERIENCING TEMPORARY DEMAND OR PRODUCTIVITY SHOCKS TO REDUCE HOURS WORKED, WHILE PROVIDING INCOME SUPPORT TO THEIR EMPLOYEES FOR THE HOURS NOT WORKED. A NEW STUDY FINDS THAT SUCH POLICIES CAN IMPROVE EMPLOYMENT OUTCOMES FOR WORKERS DURING PERIODS OF CRISIS. BY PARTICIPATING IN THESE PROGRAMS, FIRMS ARE ABLE TO RETAIN MORE WORKERS AND ARE MORE LIKELY TO SURVIVE. IN THE EVENT OF PROLONGED ECONOMIC SHOCKS, HOWEVER, SHORT-TIME WORK PROGRAMS MAY IMPAIR EFFICIENT LABOR MARKET ALLOCATION. DURING PERIODS OF DIFFICULTY, DUE TO PRODUCTIVITY SHOCKS OR WIDESPREAD ECONOMIC CRISES, FIRMS MIGHT BE FORCED TO LAY OFF PART OF THEIR WORKFORCE AS A COST-CUTTING SOLUTION. THROUGH SHORT-TIME WORK (STW) PROGRAMS, GOVERNMENTS ACT TO PREVENT MASS LAYOFFS BY SUBSIDIZING COMPANIES TO RETAIN THEIR EMPLOYEES WHILE REDUCING INDIVIDUAL WORKING HOURS. SUCH MEASURES WERE ESPECIALLY POPULAR DURING THE COVID PANDEMIC, WHEN A THIRD OF THE EUROPEAN LABOR FORCE WAS UNDER A SHORT-TIME WORK SCHEME. TO UNDERSTAND THE EFFECTS OF STW ON FIRM AND EMPLOYEE OUTCOMES, IN A FORTHCOMING PAPER, PROFESSORS GIULIA GIUPPONI (BOCCONI UNIVERSITY, MILAN) AND CAMILLE LANDAIS (LONDON SCHOOL OF ECONOMICS) STUDY THE IMPACT OF SUCH PROGRAMS IN ITALY DURING THE GREAT RECESSION. USING DETAILED ADMINISTRATIVE DATA ON COMPANIES AND INDIVIDUAL WORKERS, THEY EXPLOIT VARIATION IN ELIGIBILITY ACROSS ITALIAN FIRMS FOR A STW PROGRAM, THE CASSA INTEGRAZIONE GUADAGNI STRAORDINARIA, TO SHED LIGHT ON THE EMPLOYMENT, PRODUCTIVITY, AND WELFARE EFFECTS OF THE POLICY. view more 

CREDIT: BOCCONI UNIVERSITY, MILAN

With short-time work programs, governments allow firms experiencing temporary demand or productivity shocks to reduce hours worked, while providing income support to their employees for the hours not worked. A new study finds that such policies can improve employment outcomes for workers during periods of crisis. By participating in these programs, firms are able to retain more workers and are more likely to survive. In the event of prolonged economic shocks, however, short-time work programs may impair efficient labor market allocation.
 
During periods of difficulty, due to productivity shocks or widespread economic crises, firms might be forced to lay off part of their workforce as a cost-cutting solution. Through short-time work (STW) programs, governments act to prevent mass layoffs by subsidizing companies to retain their employees while reducing individual working hours. Such measures were especially popular during the COVID pandemic, when a third of the European labor force was under a short-time work scheme.
 
To understand the effects of STW on firm and employee outcomes, in a forthcoming paper, Professors Giulia Giupponi (Bocconi University, Milan) and Camille Landais (London School of Economics) study the impact of such programs in Italy during the Great Recession. Using detailed administrative data on companies and individual workers, they exploit variation in eligibility across Italian firms for a STW program, the Cassa Integrazione Guadagni Straordinaria, to shed light on the employment, productivity, and welfare effects of the policy.

Even though during the Recession employment levels decreased across the board, companies that used STW ended up having on average a 45% higher level of employment than the rest. The effect derives from their ability to retain a greater number of workers by reducing individual hours worked and thus their overall wage bill cost. Government subsidies ensure that workers’ overall compensation decreases by substantially less than what would be implied by the reduction in hours.
 
The researchers find that the take-up of STW was particularly high among firms with low liquidity or a high risk of large reductions in their labor force. Since the fundamental premise of STW programs is to aid firms unable to efficiently hoard labor during crises, these findings indicate that the program was successful in reaching its primary targets. Overall, the policy is estimated to have increased the probability of survival of firms by 10%.
 
“The key result of the paper is that short time work works. It helps saving employment in firms that use the program and offers a substantial degree of short-term insurance to workers against the cost of hour reductions and job loss,” stated Prof. Giupponi.
 
The paper also investigates the dynamic effects of STW after the program ends. “Once the subsidy ends, the positive effects on employment at the firm level dissipate, as does the insurance value that the program offers to workers,” said the author. In the medium and long run, workers who participated in STW programs fared only marginally better in terms of employment outcomes than those laid-off before the crisis.
 
“There is a risk that – when the shock is permanent – short-time work might end up subsidizing low-productivity jobs,” added Prof. Giupponi. Specifically, the researchers find that – in the Italian context during the Great Recession – low-productivity firms had a high propensity to use the policy, even though they had limited prospects of growth once the program ended. One may worry that, by subsidizing work in low-productivity firms, short-time work may prevent workers from moving to high-productivity companies, with negative consequences for aggregate productivity.
 
To shed light on the overall impact of the policy on the economy, the researchers exploit exogenous variation in the intensity of short-time work utilization across Italian local labor markets to understand whether a more intense use of the program translated into poorer economic outcomes. Results suggest that areas with higher STW utilization experienced slower employment growth and total factor productivity growth, even though these effects are of modest size.
 
The authors provide compelling evidence that STW programs were effective in preventing a surge in unemployment during the Great Recession and can be an important tool to mitigate the impact of economic crises. However, the program is best employed in the face of temporary rather than permanent shocks: when shocks become persistent, short-time work can hinder the reallocation of workers to other firms and limit economic growth.
 
To guarantee that the program’s benefits are maximized, the authors propose to introduce mechanisms – such as a co-payment by firms – to attract into the program those who are willing to bear part of the cost. “This is one way by which we can improve the selection of firms and reduce the likelihood of these potential reallocation effects,” Prof. Giupponi concluded.
 
Giulia Giupponi, Camille Landais, “Subsidizing Labor Hoarding in Recessions: The Employment & Welfare Effects of Short Time Work.” Forthcoming in The Review of Economic Studies.

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JOURNAL

The Review of Economic Studies

DOI

10.1093/restud/rdac069 

ARTICLE TITLE

Subsidizing Labour Hoarding in Recessions: The Employment and Welfare Effects of Short-time Work

Can Iceland feed Europe?

Peer-Reviewed Publication

REICHMAN UNIVERSITY

 

IMAGE: DR. ASAF TZACHOR, SCHOOL OF SUSTAINABILITY AT REICHMAN UNIVERSITY view more 

CREDIT: GILAD KAVALERCHIK

Can Iceland feed Europe?

According to a new study led by Dr. Asaf Tzachor at Reichman University’s School of Sustainability, the small country of Iceland can play a pivotal role in European food security, providing over 40 million Europeans with a safe, sustainable, and locally-produced protein source over the next decade, while mitigating over 700 million tons of CO2 emissions.

A new study, led by Dr. Asaf Tzachor at Reichman University’s School of Sustainability, in partnership with environmental and nutritional scientists from Iceland, Denmark and the UK, shows that by allocating renewable energy from hydroelectric and geothermal sources to advanced, biological reactors cultivating cyanobacteria, Iceland can play a critical role in Europe's protein self-sufficiency aspirations.

Iceland could produce hundreds of thousands of tonnes of sustainable, high-protein biomass, to become fully protein self-sufficient, as well as a net-exporter of proteins to feed other Northern European countries.

The new study assesses the technical feasibility of different energy allocation scenarios to novel food production systems. In the most conservative scenario, with an allocation of 15% of it currently installed capacity, Iceland could be protein self-sufficient providing its projected 2030 population of 390,000 people with their protein requirements, and become a net-exporter of high-quality proteins.

In the most ambitious biomass production scenario, Iceland could support itself and contribute significantly to food security in Denmark, Finland, Lithuania, Latvia, Estonia, Jersey, Isle of Man, Guernsey and Faroe Islands, feeding millions per year, and tens of millions over the course of the coming decade.

At the moment, the European Union depend heavily on importation of protein-rich feed crops, such as soybean, to meet domestic demand. According to the EU, member countries must import 75% of their protein requirements, including 95% of soy cake consumption.

Dependency on third parties exposes European countries to protein supply chain disruptions, including institutional disturbances such as those experienced during the COVID-19 pandemic, as well as various risk factors, including plant pests, pathogens and alternations in weather patterns.

This renders European food security vulnerable, particularly to the cascading, acute and chronic impacts of climate change.

These concerns have moved the topic of protein self-sufficiency higher up the policy agenda in Europe, with initiatives such as the EU Protein Plan aiming to incentivize and accelerate the development of alternative protein sources, that are locally produced.

The new study shows the untapped, and considerable potential of Iceland to contribute to European protein self-sufficiency plans.

The study also emphasizes the additional environmental benefit, with each kg of high-protein biomass consumed from the Icelandic reactors instead of beef saving 0.315 tonnes of CO2 emissions.

Under the most ambitious scenario, production of alternative proteins in Iceland could save over 75 million tonnes of CO2 emissions, which equals 7.3% of Europe’s cross-sector quarterly GHG emissions.

Dr. Asaf Tzachor, lead author of the study notes, "our intention was to stimulate thought, and stimulate action at the intersection of these consequential topics of food security, protein self-sufficiency, and climate action, highlighting one potent, readily available approach to achieve all three".

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JOURNAL

Foods

DOI

10.3390/foods12010038 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The Potential Role of Iceland in Northern Europe’s Protein Self-Sufficiency: Feasibility Study of Large-Scale Production of Spirulina in a Novel Energy-Food System

Flower patterns make bumblebees more efficient

Peer-Reviewed Publication

UNIVERSITY OF WÜRZBURG

 

IMAGE: THE INTERACTION OF BUMBLEBEES WITH FLOWERS BECOMES MUCH MORE EFFICIENT WHEN THE FLOWERS ARE PATTERNED. LEFT A MALE INDIVIDUAL OF THE WHITE-TAILED BUMBLEBEE, RIGHT A FORAGER OF THE BUFF-TAILED BUMBLEBEE. view more 

CREDIT: ANNA STOECKL / JOHANNES SPAETHE

Be it mallow, foxglove or forget-me-not: many flowers bear colourful patterns, which are known as nectar guides in biology. They are assumed to show the pollinating insects the shortest way to the nectary. This guiding function could increase the efficiency of the insects in their search for food, and at the same time improve the pollen dispersal of the plant.

A team from the Biocenter of Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, has now deciphered the individual steps through which flower patterns increase the efficiency of terrestrial bumblebees (Bombus terrestris) for the first time. They demonstrate that nectar guides reduce the time needed for the bee’s entire interaction with a flower by up to 30 percent – from approach to finding the nectar to departure.

What the flower patterns do

Surprisingly, flower patterns do not shorten the actual nectar search: After landing on a patterned flower, the bumblebees did not find the nectar any faster than on a flower without a pattern. However, the flower patterns shortened the approach flight time and ensured a strategically favourable landing position. Thus, they act like markings on a runway and help the bumblebees to coordinate their approach, reports the team led by Anna Stöckl and Johannes Spaethe in the journal Functional Ecology.

Flower patterns also shorten the time until take-off: the insects stayed significantly shorter on patterned flowers after collecting nectar. "Bumblebees very often run to the edge of the petals for take-off," explains Johannes Spaethe. They may find this take-off site more quickly if they can orient themselves to a pattern.

This study was conducted using video tracking. The bumblebees visits to artificial flowers were analysed in the laboratory. The artificial flowers presented different pattern types or none at all; all of them had nectar on them.

How the research continues

Next, the JMU team will investigate how the glossy surface that occurs on some flowers affects the interaction with pollinating insects.

This work is conducted in cooperation with Casper van der Kooi (https://www.uni-wuerzburg.de/aktuelles/einblick/single/news/the-paradox-of-the-shiny-flowers/), who is currently a Humboldt Foundation fellow at the JMU Biocenter. Anna Stöckl, who recently moved to the University of Konstanz and is setting up an Emmy Noether junior research group there, will also remain a cooperation partner.

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JOURNAL

Functional Ecology

DOI

10.1111/1365-2435.14262 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Flower patterns improve foraging efficiency in bumblebees by guiding approach flight and landing

The dark cost of being toxic

Sequestration of plant toxins by monarch butterflies leads to reduced warning signal conspicuousness

Peer-Reviewed Publication

MAX PLANCK INSTITUTE FOR CHEMICAL ECOLOGY

 

IMAGE: MONARCH BUTTERFLY (DANAUS PLEXIPPUS) ON A MILKWEED PLANT. THE HERBIVORES, WHICH ARE HOST PLANT SPECIALISTS, INGEST PLANT TOXINS AND STORE THEM IN THEIR BODIES. THEIR BRIGHT COLOURATION SIGNALS TO PREDATORS THAT THEY ARE TOXIC. HOWEVER, STORING PLANT TOXINS IS ALSO PHYSIOLOGICALLY COSTLY FOR THIS SPECIES. view more 

CREDIT: HANNAH ROWLAND

Aposematism in animals: the more toxic, the more striking the colour?

Monarch butterflies (Danaus plexippus) feed on milkweeds of the genus Asclepias when they are caterpillars, storing the plants’ cardenolide heart poisons in their bodies for their own defence. The combination of the toxins with the striking orange and black wings of the monarch is called aposematism (derived from the Greek terms apo = away and sema = signal). Hannah Rowland head of the Max Planck Research Group on Predators and Toxic Prey at the Max Planck Institute for Chemical Ecology explains: “aposematism works because predators learn that eye-catching prey are best avoided. Predators learn faster when the visual signal is always the same. Bright orange means “`’don’t eat me’. But other scientists and I have repeatedly found that aposematic animals can have varying degrees of warning signal strength, and we wondered what about pale orange, or deep orange? What does this mean, and what causes the difference?”

Rowland, together with her colleague Jonathan Blount from the University of Exeter, along with their international team of scientists, tested whether the storage of the plant’s toxins is costly to the butterfly’s body condition. Specifically, whether the storage of toxins causes oxidative stress, which happens when antioxidant levels are low. Because antioxidants can be used to make colourful pigments, they tested if the amount of toxins in the monarch is related to their conspicuousness and their oxidative state.

The researchers reared monarch caterpillars on four different milkweeds of the genus Asclepias that have different toxin levels. With this, they were able to manipulate the amount of toxins ingested to subsequently measure concentrations of cardenolides, determine oxidative state, and compare the resulting wing coloration.

“Monarch butterflies that sequestered higher concentrations of cardenolides experienced higher levels of oxidative damage than those that sequestered lower concentrations. Our results are among the first to show a potential physiological mechanism of oxidative damage as a cost of sequestration for these insects,” says Hannah Rowland. The scientists also found that the colour of the wings of male monarchs depended on how much cardenolides they sequestered, and how much oxidative damage this had resulted in. Males with the highest levels of oxidative damage showed decreasing colour intensity with increased toxin uptake, while males with the least oxidative damage were the most toxic and colour intense.

Plant toxins are even costly for specialized herbivores

“It is conventional wisdom that specialists are less impacted by plant defences than generalists, but our study provides compelling evidence that cardenolide sequestration is physiologically costly,” says Hannah Rowland. “Monarch butterflies are also often considered one of the main examples of aposematic animals, and our experiment shows that the conspicuousness of their warning signals depends to some extent on how much of the cardenolides they sequester and how costly this is for them. Together, this points to the fact that specialist herbivores must balance the benefits of toxic plant compounds as defences against their enemies with the burden that these same compounds impose.” Rowland plans to further investigate the role of predators in plant-herbivore-predator interactions. In particular, she is interested in investigating whether predators have an influence on the evolution of cardenolides.

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JOURNAL

Proceedings of the Royal Society B Biological Sciences

DOI

10.1098/rspb.2022.2068 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

The price of defence: toxins, visual signals and oxidative state in an aposematic butterfly

ARTICLE PUBLICATION DATE

18-Jan-2023

17-pound meteorite discovered in Antarctica

Reports and Proceedings

FIELD MUSEUM

 

IMAGE: THE RESEARCHERS WITH THEIR 16.7-POUND FIND. WHITE HELMET: MARIA SCHÖNBÄCHLER. GREEN HELMET: MARIA VALDES. BLACK HELMET: RYOGA MAEDA. ORANGE HELMET: VINCIANE DEBAILLE. PHOTO COURTESY OF MARIA VALDES. view more 

CREDIT: COURTESY OF MARIA VALDES

Antarctica is a tough place to work, for obvious reasons— it’s bitterly cold, remote, and wild. However, it’s one of the best places in the world to hunt for meteorites. That’s partly because Antarctica is a desert, and its dry climate limits the degree of weathering the meteorites experience. On top of the dry conditions, the landscape is ideal for meteorite hunting: the black space rocks stand out clearly against snowy fields. Even when meteorites sink into the ice, the glaciers’ churning motion against the rock below helps re-expose the meteorites near the surface of the continent’s blue ice fields.

An international team of researchers who just got back from Antarctica can attest to the continent’s meteorite-hunter-friendliness: they returned with five new meteorites, including one that weighs 16.7 pounds (7.6 kg).

Maria Valdes, a research scientist at the Field Museum and the University of Chicago, estimates that of the roughly 45,000 meteorites retrieved from Antarctica over the past century, only about a hundred or so are this size or larger. “Size doesn’t necessarily matter when it comes to meteorites, and even tiny micrometeorites can be incredibly scientifically valuable,” says Valdes, “but of course, finding a big meteorite like this one is rare, and really exciting.”

Valdes was one of four scientists on the mission, led by Vinciane Debaille of the Université Libre de Bruxelles (FNRS-ULB); the research team was rounded out by Maria Schönbächler (ETH-Zurich) and Ryoga Maeda (VUB-ULB). The researchers were the first to explore potential new meteorite sites mapped using satellite imagery by Veronica Tollenaar, a thesis student in glaciology at the ULB.

“Going on an adventure exploring unknown areas is exciting,” says Debaille, “but we also had to deal with the fact that the reality on the ground is much more difficult than the beauty of satellite images.” Despite timing their trip for Antarctica’s summertime in late December, temperatures hovered around 14° F (-10° C). Valdes notes that some days during their trip, it was actually colder in Chicago than it was in Antarctica, but spending days riding snowmobiles and trekking through ice fields and then sleeping in a tent made the Antarctic weather feel more extreme.

The 17-pound meteorite

The five meteorites recovered by the team will be analyzed at the Royal Belgian Institute of Natural Sciences; meanwhile, sediment potentially containing tiny micrometeorites was divided among the researchers for study at their institutions.

Valdes says she’s eager to see what the analyses of the meteorites reveal, because “studying meteorites helps us better understand our place in the universe. The bigger a sample size we have of meteorites, the better we can understand our Solar System, and the better we can understand ourselves.”

The team was guided by Manu Poudelet of the International Polar Guide Association and assisted by Alain Hubert. They were supported in part by the Belgian Science Policy. Valdes’s work is supported by the Field Museum’s Robert A. Pritzker Center for Meteoritics and Polar Studies, the TAWANI Foundation, and the Meeker family.

Rocks strewn across an ice field, with the scientists searching for meteorites in the background.

The team's tents when in the field.

 

A snowy field in Antarctica

The team hiking past rock formations in Antarctica.

PHOTOS Courtesy of Maria Valdes

"At the Mountains of Madness" by H. P. Lovecraft

      https://www.hplovecraft.com › writings › texts › fiction

Aug 20, 2009 — Distant mountains floated in the sky as enchanted cities,  

and often the whole white world would dissolve into a gold, silver, and scarlet land ...