Scientists reveal controlling factors of water and heat exchanges over the Zoige wetland

Peer-Reviewed Publication

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

 

IMAGE: THE ZOIGE PLATEAU WETLAND DURING THE SUMMER. view more 

CREDIT: XIANYU YANG

The Qinghai–Tibet Plateau (QTP) is composed of complex and diverse topographic features, as well as many significant differences in water, heat, and momentum flux exchange under different underlying surfaces. Alpine, or high elevation wetlands are a common type of underlying surface on the QTP. Because of the unique features of this critical water source and ecosystem, scientists are striving to know more about the mechanisms behind water and heat exchanges within high elevation wetlands and how these processes affect the climate of the region.

“The alpine wetland is very sensitive to temperature and precipitation.” said Associate Professor Xianyu Yang with Chengdu University of Information Technology.

His recent study, just published in Advances in Atmospheric Sciences, investigated the characteristics of hydrometeorological factors throughout alpine wetlands in the warm season (June–August) and cold season (December–February). Dr. Yang used in situ observations from the Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences' Zoige Plateau Wetland Ecosystem Research Station to examine water and heat exchange mechanisms within the nearby wetland.

The Zoige Alpine wetland is the largest plateau marsh wetland in the world with an area that covers about 7,080 km2. It is located on the eastern margin of the QTP, with an average elevation of approximately 3,500 m. Yang evaluated the region's atmospheric contributions and new surface parameters using the Community Land Model (CLM) 5, which is capable of determining water and heat transfers among soil, alpine wetland surface, and the atmosphere, using in situ observations as its input data.

After examining CLM5 data, Dr. Yang and his team found that the depth of frozen soil averages between 20 cm and 40 cm throughout the alpine wetland. The sensible heat flux before 16:00 (local time), or approximately solar noon, was greater in the cold season than in the warm season, while the diurnal latent heat flux was always greater in the warm season.

Compared with other atmospheric factors, longwave radiation had a greater influence on heat fluxes at night, as heat radiates away from the surface. That said, during the daytime, temperature and longwave radiation were both control factors for sensible heat flux. For latent heat flux, temperature and air pressure were control factors, but these atmospheric influences were negligible in the cold season.

"This research advances our understanding of the land surface processes over the alpine wetland on the QTP." said Yang. "For future study, the results are sufficient and significant for parameterization scheme optimization in the CLM5 model, hopefully aiding future research."

According to Yang, the next step is to carry out more situ observation experiments over the Zoige Plateau Wetland and improve the parameterization schemes of CLM5.

Some scientists have also investigated the control factors and influencing parameters for water and heat exchanges, with results showing that controlling factors vary amongst the different underlying surfaces. Observation data and CLM5 model limitations still constrain even these robust results from this and similar studies. 

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JOURNAL

Advances in Atmospheric Sciences

DOI

10.1007/s00376-022-1443-5 

ARTICLE TITLE

The Characteristics and Controlling Factors of Water and Heat Exchanges over the Alpine Wetland in the East of the Qinghai-Tibet Plateau

ARTICLE PUBLICATION DATE

10-Dec-2022

Scientists develop a new way to verify forecasts of where typhoons hit land

Peer-Reviewed Publication

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

 

IMAGE: THE NEW VERIFICATION APPROACH CAN HELP IDENTIFY “NEAR MISS” CASES IN FORECASTS OF A TYPHOON’S LANDFALL POSITION. view more 

CREDIT: DAOSHENG XU

Landfalling typhoons can cause widespread damage, so accurately forecasting them is crucial. More specifically, the errors associated with a typhoon's landfall position are often more important than those related to the timing of landfall. However, the most widely used method to verify typhoon tracks (the traditional “point-to-point matching” approach) can be easily affected by the predicted moving speed of the typhoon. Consequently, a large track error can sometimes be obtained even if the predicted landfall position is close to the observed one.

To address this issue, Dr. Banglin Zhang and colleagues from the Guangzhou Institute of Tropical and Marine Meteorology have proposed a simple method to evaluate landfalling typhoon track forecasts. Their findings, recently published in Advances in Atmospheric Sciences, reveal that this new approach can lessen the timing errors when verifying a predicted landfalling typhoon track.

"With the traditional method for verifying typhoon track forecasts, the error in the typhoon track may derive from the error in the typhoon's moving speed error rather than its position error," explains Dr. Daosheng Xu, first author of the study. "However, the neighborhood strategy upon which our method is based verifies the forecast within a time window around each grid point, hence reduces influences of the timing error."

As mentioned above, the traditional point-to-point method for evaluating typhoon tracks is sometimes sensitive to timing errors and/or typhoon moving-speed errors. Hence, Dr. Xu and his colleagues proposed this "time neighborhood method" to solve the problem. By comparing the properties of this new method to those of the traditional approach by forecasting 12 landfalling typhoon cases, they found that the new method is not sensitive to the timing errors and that the difference between the new and traditional method is more apparent when the typhoon has a moderate movement speed (between 15 and 30 km h−1). There is hope, therefore, that this method might be able to provide meteorologists with more intuitive evaluations of typhoon track forecasts, which will be of broader benefit to the government and the general public.

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JOURNAL

Advances in Atmospheric Sciences

DOI

10.1007/s00376-022-1398-6 

ARTICLE TITLE

A Time Neighborhood Method for the Verification of Landfalling Typhoon Track Forecast

ARTICLE PUBLICATION DATE

10-Dec-2022

Signals from the ionosphere could improve tsunami forecasts

Peer-Reviewed Publication

UNIVERSITY OF WASHINGTON

 

IMAGE: A SERIES OF GOES-17 SATELLITE IMAGES CAUGHT THE UMBRELLA CLOUD GENERATED BY THE UNDERWATER ERUPTION OF THE HUNGA TONGA-HUNGA HA’APAI VOLCANO ON JAN. 15, 2022. view more 

CREDIT: NASA

Research from the University of Washington shows that signals from the upper atmosphere could improve tsunami forecasting and, someday, help track ash plumes and other impacts after a volcanic eruption.

A new study analyzed the Hunga Tonga-Hunga Ha’apai eruption in the South Pacific earlier this year. The Jan. 15, 2022, volcanic eruption was the largest to be recorded by modern equipment. Ash blanketed the region. A tsunami wave caused damage and killed at least three people on the island of Tonga. It also had unexpected distant effects.

No volcanic eruption in more than a century has produced a global-scale tsunami. The tsunami wave from the underwater eruption was first predicted as only a regional hazard. Instead, the wave reached as far as Peru, where two people drowned.

Results of the new study, published this fall in Geophysical Research Letters, uses evidence from the ionosphere to help explain why the tsunami wave grew larger and traveled faster than models predicted.

“This was the most powerful volcanic eruption since the 1883 eruption of Krakatau, and a lot of aspects of it were unexpected,” said lead author Jessica Ghent, a UW doctoral student in Earth and space sciences. “We used a new monitoring technique to understand what happened here and learn how we could monitor future natural hazards.”

She will present the work in a poster Wednesday, Dec. 14, at the American Geophysical Union annual meeting in Chicago and she will present the work at the meeting that afternoon.

Tsunamis are rare enough occurrences that forecast models, relying on a limited number of tide gauges and ocean sensors, are still being perfected. This study is part of an emerging area of research exploring the use of GPS signals traveling through the atmosphere to track events on the ground.

A big earthquake, or in this case a huge volcanic eruption, generates pressure waves in the atmosphere. As these pressure waves pass through the zone from about 50 to 400 miles altitude where electrons and ions float freely, known as the ionosphere, the particles are disturbed. GPS satellites beaming coordinates back down to Earth transmit a slightly altered radio signal that tracks the disturbance.

“Other groups have been looking at the ionosphere to monitor tsunamis. We are interested in applying it for volcanology,” said co-author Brendan Crowell, a UW research scientist in Earth and space sciences. “This Tonga eruption kicked our research into overdrive. There was a big volcanic eruption and a tsunami — normally you’d study one or the other.”

For the new study, the researchers analyzed 818 ground stations in the Global Navigation Satellite System, the global network that include GPS and other satellites, around the South Pacific to measure the atmospheric disturbance in the hours following the eruption. Results support the hypothesis that the sonic boom generated by the volcanic explosion made the tsunami wave bigger and faster. The ocean wave got an extra push from the atmospheric pressure wave created by the eruption. This extra push wasn’t included in the initial tsunami forecasts, researchers said, because volcano-triggered tsunamis are so rare.

“Tsunamis typically can travel in the open ocean at 220 meters per second, or 500 miles per hour. Based on our data, this tsunami wave was moving at 310 meters per second, or 700 miles per hour,” Ghent said.

The authors were able to separate out different aspects of the eruption – the acoustic sound wave, the ocean wave and other types of pressure waves – and check their accuracy against ground-based observation stations.

“The separation of these signals, from the acoustic sound wave to the tsunami, was what we had set out to find,” Ghent said. “From a hazards-monitoring perspective, it validates our hope for what we can use the ionosphere for. This unusual event gives us confidence that we might someday use the ionosphere to monitor hazards in real time.”

While the Tonga eruption didn’t eject much ash for the size of the event, Ghent and Crowell say the Global Navigation Satellite System signals could be used in other ways to accurately track volcanic ash plumes.

Looking upward to monitor volcanoes and tsunamis is appealing because ground-based monitoring has challenges in the Pacific Northwest and other areas. Sensors must be maintained and repaired, snow and ice can block signals or cause damage, accessing the monitoring stations may be difficult.

What’s more, “the wild mountain goats can eat the cables of the ground instruments because the goats like salt,” Ghent said.

“If you have a way to monitor an area without actually being there, you’re really opening the door to being able to monitor it all year long and help keep people safe around the world.”

This research was funded by NASA and the National Science Foundation.

###

 

For more information, contact Ghent at jghent@uw.edu and Crowell at crowellb@uw.edu.

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JOURNAL

Geophysical Research Letters

DOI

10.1029/2022GL100145 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Spectral Characteristics of Ionospheric Disturbances Over the Southwestern Pacific From the 15 January 2022 Tonga Eruption and Tsunami

Eco-friendly paint most effective against fouling on ships and boats

Peer-Reviewed Publication

CHALMERS UNIVERSITY OF TECHNOLOGY

 

IMAGE: A CHALMERS-LED STUDY SHOWS THAT AN ENVIRONMENTALLY FRIENDLY ANTIFOULING PAINT IS MORE EFFECTIVE AGAINST FOULING THAN A TRADITIONAL COPPER-BASED PAINT. THE BLACK SURFACES ARE COATED WITH BIOCIDE-FREE SILICONE-BASED PAINT, THE RED SURFACES ARE COATED WITH COPPER-BASED PAINT AND THE WHITE SURFACES HAVE NO ANTIFOULING TREATMENT. THE PICTURE WAS TAKEN AFTER TWO YEARS OF EXPOSURE IN THE SEA. view more 

CREDIT: IVL | ANNA-LISA WRANGE

Emissions from copper-based antifouling paints are a well-known environmental problem. As much as 40 percent of copper inputs to the Baltic Sea come from antifouling paints on ships and leisure boats. According to a new study from Chalmers University of Technology, Sweden, this is completely unnecessary. When the researchers compared copper-based antifouling paint with biocide-free silicone-based paint, they found that the environmentally friendly alternative was best at keeping the fouling at bay. 

‘This means that we now have a great opportunity to drastically reduce the release of the heavy metal into our sensitive sea. This is the first independent scientific study to show that silicone paint is more effective than copper-based paint in the Baltic Sea region,’ says Maria Lagerström, researcher in marine environmental science at Chalmers.

Together with colleagues at the University of Gothenburg, the Swedish Environmental Institute IVL and Chalmers, Maria Lagerström investigated whether biocide-free silicone paints on the hulls of ships and leisure boats are a viable alternative to copper-based bottom paints to combat fouling. The study was carried out over a year at three sites in the Baltic Sea region and the Skagerrak and the results have been published in the scientific journal Marine Pollution Bulletin.

Environmentally friendly paints are rarely used

The use of copper in antifouling paints is a known and widespread environmental problem for aquatic plants and organisms in the Baltic Sea. The heavy metal does not degrade in the environment and it is therefore common for water, sediment and soil in marinas, ports and shipyards to be contaminated and exceed environmental guideline values for copper. An earlier study from Chalmers shows that antifouling paints account for as much as 40 per cent of the total copper inputs to the Baltic Sea.

‘As the Baltic Sea is an inland sea, it takes 25–30 years for the water to be exchanged. This means that the heavy metal remains for a very long time. It is therefore important to be aware of the substances we release,’ says Maria Lagerström.

Despite the negative impact of heavy metals on the marine environment, the antifouling paint market for ships and recreational boats is completely dominated by copper-based paints. The market share of silicone-based paints for the shipping sector was 1 percent in 2009 and increased to 10 percent in 2014. For the recreational boating sector, the proportion of boats painted with silicone paint is estimated to be significantly lower. And although there are more environmentally friendly options on the market, change seems to be hard to bring about.

‘Both the shipbuilding industry and the leisure boating sector have one thing in common: they are highly traditional. People like to use the products they are used to, and they are also sceptical as to whether non-toxic alternative solutions really work,’ says Maria Lagerström.

Effective even over a longer period of time

Although the study of the different antifouling paints was completed after twelve months, the results were found to persist over time.

‘We actually left our test panels at one of the test sites. These have now been under the surface for over two years. We can see that the silicone paint still works well and, more importantly, works better than the copper paint,’ says Maria Lagerström.

More on the research and antifouling paints

• The scientific paper ‘Are silicone foul-release coatings a viable and environmentally sustainable alternative to biocidal antifouling coatings in the Baltic Sea region?’ has been published in the journal Marine Pollution Bulletin.
   
• The study is led by Maria Lagerström, Anna-Lisa Wrange, Dinis Reis Oliveira, Lena Granhag, Ann I. Larsson and Erik Ytreberg. The researchers are based at Chalmers University of Technology, the University of Gothenburg and the Swedish Environmental Institute IVL.
   
• Traditional antifouling paints inhibit fouling by continuously leaching copper and/or other toxic substances that are poisonous to marine organisms. For silicone paints, it is instead its smooth surface properties that make it difficult for fouling to stick to the hull. The paints are also self-cleaning, which means that any fouling that has managed to stick is removed as the hull moves through the water.

• Silicone paint is based on the substance silicone, which is produced using silicone oxide extracted from sand. The scientific paper’s collection of ecotoxicological studies shows that silicone paints are significantly less harmful to the environment than copper paints. But some silicone paints contain highly fluorinated substances, known as PFAS, which are very resistant to biodegradation in the environment. However, the silicone paint tested in the study was fluorine-free.    
   
• The research was funded primarily by the Swedish Transport Administration, within the framework of the Lighthouse Swedish Maritime Competence Centre and the Sustainable Shipping project.        

For more information, please contact:

Maria Lagerström
Researcher, Department of Mechanics and Maritime Sciences, Chalmers University of Technology
+46 31 772 46 23, maria.lagerstrom@chalmers.se

 

Caption: A Chalmers-led study shows that an environmentally friendly antifouling paint is more effective against fouling than a traditional copper-based paint. The black surfaces are coated with biocide-free silicone-based paint, the red surfaces are coated with copper-based paint and the white surfaces have no antifouling treatment. The picture was taken after two years of exposure in the sea.

Photo: IVL | Anna-Lisa Wrange 

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JOURNAL

Marine Pollution Bulletin

DOI

10.1016/j.marpolbul.2022.114102 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Are silicone foul-release coatings a viable and environmentally sustainable alternative to biocidal antifouling coatings in the Baltic Sea region?’

UK

New index shows regions in the north have higher risk of food insecurity

Peer-Reviewed Publication

UNIVERSITY OF SOUTHAMPTON

 

IMAGE: FOOD INSECURITY RISK RANKS COMPOSITION IN ENGLAND view more 

CREDIT: UNIVERSITY OF SOUTHAMPTON

A new index developed by researchers at the University of Southampton reveals neighbourhoods in the north of England have the highest risk of food insecurity.

Published in PLOS ONE, the Food Insecurity Risk Indices can identify risk to a smaller scale than ever before as it not only includes details about the geographical area, but also the characteristics of the population.

The Index showed a third of at-risk areas were in the north-west and 96 percent of those were urban areas including areas such as the Wirral, Blackpool, Stockport, Middlesborough and St Helens.

The researchers say the map and data can be used by local authorities to better target support and help those households most at risk, ensuring their limited budgets are spent in the areas that need it the most.

Dianna Smith, Associate Professor in Geography at the University of Southampton, said: “Food security for households is influenced by multiple factors, from individual circumstances to local access to affordable resources.

“We worked with local governments and charities to create a measure of food insecurity risk in neighbourhoods that captures these barriers. By creating a detailed picture of an area, local authorities and charities can be better informed of where they need to put their resources to help the people most in need. This is particularly important in rural areas where there are pockets of high deprivation amongst areas of affluence.”

The Index was developed for more than 30,000 neighbourhoods across England with populations between 1,000 to 3,000 people. The index calculates food insecurity risk for all areas based on benefits claimants and low-income at a household level, as well as data on mental health and adult educational attainment.

The study also created another index (structural risk) which included data on the obstacles people face when living in those areas, such as distance to large supermarkets where food is cheaper, broadband speed and public transport links. The researchers say this Structural Index is important to provide details of barriers in more rural areas alongside the main Index.

The researchers have made the maps and data freely available at https://www.mylocalmap.org.uk/iaahealth/ to encourage local authorities to be better prepared and provide targeted help and support.

Nisreen Alwan, Professor of Public Health at the University of Southampton who was also involved in the research, added: “Food insecurity in England is not a new social challenge, and while data has been collected about household food insecurity the detail of where more people experience food insecurity is lacking. Where people live is closely linked to their wellbeing and shapes health inequalities. Our work developing a food insecurity risk index for rural and urban settings in England, supported by the NIHR Applied Research Collaboration Wessex, gives local government and charities a tool to target resources and services to help those most at need particularly during this cost of living crisis.”

Ends
 

Notes to editors

1. The paper is published at: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0267260. A copy of the paper is available upon request. Interviews can be arranged with the researchers by emailing press@soton.ac.uk – Media Relations, University of Southampton.
    
2. The table below shows the main Food Insecurity Risk Index and the Structural Risk Index. The researchers say the Structural Risk Index should be used alongside the main risk measure in areas outside of cities. The structural risk measure includes distance to medium or large supermarkets, distance to employment centres of >100 employees, density of bus stops and digital access (download speed), all of which add to the individual risk of food insecurity reflected in the main measure.

 

LSOA Name	Food insecurity risk (Rank)	LSOA Name	Structural risk (Rank)
Wirral 016E	1	Carlisle 001D	1
Wirral 011C	2	Northumberland 019C	2
Blackpool 006A	3	Northumberland 003B	3
Wirral 027C	4	Eden 002D	4
Stockport 004B	5	Teignbridge 003C	5
Tendring 018A	6	Northumberland 007D	6
Middlesbrough 007E	6	Eden 001C	6
Stockport 004D	8	Herefordshire 020C	8
Wirral 008C	9	Allerdale 002D	9
Blackpool 010A	10	Eden 006C	10

 

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0267260 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Household food insecurity risk indices for English neighbourhoods: Measures to support local policy decisions

ARTICLE PUBLICATION DATE

9-Dec-2022

POST-CAPITALI$M

Scientists outline key policies for degrowth in the fight against climate change 

Leading researchers in ecological economics have published in Nature a strategic policy framework to ensure a just transition to post-growth economies.

Peer-Reviewed Publication

UNIVERSITAT AUTONOMA DE BARCELONA

Degrowth policies would be effective in fighting against climate breakdown and biodiversity loss and would secure human needs and well-being. Recent reports by the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES) suggest that this approach should be considered, but a just transition to a post-growth economic model poses several challenges. 

With the aim of facilitating this transition process, eight leading scientists in ecological economics have published today an article in Nature providing governments around the world with a strategic policy framework to enable wealthy countries to reduce materials and energy while improving social outcomes.

The scientific group, which includes Jason Hickel and Giorgos Kallis of the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB), makes a series of recommendations that will enable governments to stabilise the economy in a post-growth transition, including universal public services such as health, education and housing, among others, as well as a job guarantee, working time reductions and a fairer distribution of income. The authors also identify five ways in which researchers can help develop science and policy to ensure a just transition.

The ecological crisis is being driven in large part by the pursuit of economic growth: ever-increasing levels of industrial production, measured in GDP. High-income economies – and the affluent classes and corporations that dominate them – are overwhelmingly responsible for this problem, as their use of energy and materials far exceeds sustainable levels.

As Jason Hickel, the lead author and professor at ICTA-UAB, explains, “in our existing economy, production is organized around the interests of capital accumulation rather than around human well-being. The result is a system that overuses resources and yet still fails to meet many basic human needs. It is failing both people and planet.”

The scientists argue that high-income nations should abandon aggregate growth as an objective and focus instead on securing human needs and well-being, while reducing less-necessary forms of production and the excess purchasing power of the rich.  This approach, known as degrowth, can enable rapid decarbonization and stop other forms of ecological breakdown.  

As Hickel puts it, "The dominant assumption in economics today is that every sector of the economy must grow, all the time, regardless of whether we actually need it. In the middle of an ecological emergency, this is dangerous and irrational. We should focus instead on producing what we know is necessary to achieve social and ecological goals – things like universal healthcare, affordable housing, public transit and renewable energy – while reducing destructive industries like SUVs, fast fashion and mass-produced beef.”

Giorgos Kallis, ICREA professor at ICTA-UAB, notes that there is solid evidence on the types of policies that can help countries move in a degrowth direction: working hour reductions, a green job guarantee, or a universal basic income. But there are still big unknowns regarding the ways in which systems and institutions are dependent on growth for their stability, and researchers can help identifying such dependencies and how they can be overcome. 

Co-author Julia Steinberger, professor at Lausanne University, says, “The growth-dependence of current economies is a danger to all of us, both for social and for ecological reasons. Degrowth research thus constitutes a vital lifeline: a robust way to consider radical alternatives for humanity to make it through the 21st century, flourishing within planetary boundaries."

The authors note that degrowth is a purposeful strategy to stabilize economies and achieve social and ecological goals, unlike recession, which is a chaotic and socially destabilizing event that occurs when growth-dependent economies fail to grow.

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JOURNAL

Nature

DOI

10.1038/d41586-022-04412-x 

METHOD OF RESEARCH

Commentary/editorial

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Degrowth can work — here’s how science can help

ARTICLE PUBLICATION DATE

12-Dec-2022

Reliance on moose as prey led to rare coyote attack on human

Study assesses animals’ diet, movement in Canadian park

Peer-Reviewed Publication

OHIO STATE UNIVERSITY

COLUMBUS, Ohio – Wildlife researchers have completed a study that may settle the question of why, in October 2009, a group of coyotes launched an unprovoked fatal attack on a young woman who was hiking in a Canadian park.

By analyzing coyote diets and their movement in Cape Breton Highlands National Park, where the attack occurred on a popular trail, the researchers concluded that the coyotes were forced to rely on moose instead of smaller mammals for the bulk of their diet – and as a result of adapting to that unusually large food source, perceived a lone hiker as potential prey.

The findings essentially ruled out the possibility that overexposure to people or attraction to human food could have been a factor in the attack – instead, heavy snowfall, high winds and extreme temperatures created conditions inhospitable to the small mammals that would normally make up most of their diet.

“The lines of evidence suggest that this was a resource-poor area with really extreme environments that forced these very adaptable animals to expand their behavior,” said lead author Stan Gehrt, a wildlife ecologist at The Ohio State University.

“We’re describing these animals expanding their niche to basically rely on moose. And we’re also taking a step forward and saying it’s not just scavenging that they were doing, but they were actually killing moose when they could. It’s hard for them to do that, but because they had very little if anything else to eat, that was their prey,” he said. “And that leads to conflicts with people that you wouldn’t normally see.”

The research is published in the Journal of Applied Ecology.

The death of 19-year-old folk singer Taylor Mitchell is the only fatality resulting from a coyote attack on a human adult ever documented in North America.

Gehrt, who leads the Urban Coyote Research Project that has monitored coyotes living in Chicago since 2000, was consulted by media for his expertise after the attack. In urban areas like Chicago, where thousands of coyotes live among millions of people, injuries from coyote-human encounters are very rare.

“We had been telling communities and cities that the relative risk that coyotes pose is pretty low, and even when you do have a conflict where a person is bitten, it’s pretty minor,” said Gehrt, a professor in Ohio State’s School of Environment and Natural Resources. “The fatality was tragic, and completely off the charts. I was shocked by it – just absolutely shocked.

“A lot of people began wondering if we were at the front edge of a new trend, and if coyotes were changing their behavior. And we didn’t have good answers.”

Gehrt expanded an initial investigation of the fatal attack – and a few dozen less severe human-coyote incidents in the park before and after Mitchell’s death – into a detailed field study. Between 2011 and 2013, he and colleagues captured 23 adult and juvenile coyotes living in the Cape Breton park and fitted them with devices to document their movement and use of space.

To obtain dietary information, the team also snipped whiskers from the live-captured coyotes and from the bodies of coyotes implicated in the fatal attack and in other human-coyote incidents. For comparison, the researchers collected fur from potential prey – southern red-backed voles, shrews, snowshoe hare, white-tailed deer and moose – and hair from local barbershops that served as a proxy for human food.

Seth Newsome, professor of biology at the University of New Mexico and corresponding author of the study, analyzed stable isotopes of carbon and nitrogen in these whisker and hair samples to determine what the coyotes had been eating in the months before they were captured or lethally removed from the population.

The analysis showed that, on average, moose constituted between half and two-thirds of the animals’ diets, followed by snowshoe hare, small mammals and deer.

“This dietary evidence was the critical piece to it,” Gehrt said. “Their diets changed because they’re taking advantage of whatever different food items are available at the time. We’re used to seeing big oscillations across the segments of whiskers depending on the season. But in this system, for these coyotes, we don’t see that – they flat line at the moose end, so there’s very little variation in their diet.”

Samples from the coyotes that were confirmed to have been involved in the fatal attack showed they had been eating only moose, “and their diet wasn’t changing,” he said. An analysis of coyote droppings confirmed the isotope findings. The researchers found only a few examples of individual animals having eaten human food.

Beyond the dietary analysis, Gehrt and colleagues did test for the possibility that coyotes were familiar with humans, and therefore not fearful around people. The movement patterns showed that while the coyotes’ space use was extensive – likely related to the need to search far and wide for prey – the animals largely avoided areas of the park frequented by people and were more active at night during periods when daytime human use was at its highest. Prohibition on hunting and trapping in the park also removed a human threat.

“It’s a big area for these coyotes to live in and never have a negative experience with a human – if they have any experience at all,” Gehrt said. “That also leads to the logical assumption that we’re making, which is that it’s not hard for these animals to test to see whether or not people are a potential prey item.”

In cities and most other wilderness areas where coyotes live, food of all types is plentiful – suggesting only areas low on natural prey, like islands and remote northern climates, would pose a similar risk for coyote-human interactions, Gehrt said. Their survival in Cape Breton, he said, is attributable to their remarkable ability to adjust to their environment.

“These coyotes are doing what coyotes do, which is, when their first or second choice of prey isn’t available, they’re going to explore and experiment, and change their search range,” he said.

“They’re adaptable, and that is the key to their success.”

This work was supported by Parks Canada, the Nova Scotia Department of Lands and Forestry, and the Max McGraw Wildlife Foundation.

Additional co-authors include Erich Muntz of Cape Breton Highlands National Park, Evan Wilson of Ohio State and Jason Power of the Nova Scotia Department of Lands and Forestry.

#

Contact: Stan Gehrt, Gehrt.1@osu.edu

Written by Emily Caldwell, Caldwell.151@osu.edu

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JOURNAL

Journal of Applied Ecology

DOI

10.1111/1365-2664.14333 

ARTICLE TITLE

Severe environmental conditions create severe conflicts: A novel ecological pathway to extreme coyote attacks on humans