Babies' random choices become their preferences

JOHNS HOPKINS UNIVERSITY

Research News

 

IMAGE: THE ACT OF MAKING A CHOICE CHANGES HOW WE FEEL ABOUT OUR OPTIONS. view more 

CREDIT: WILL KIRK/JOHNS HOPKINS UNIVERSITY

When a baby reaches for one stuffed animal in a room filled with others just like it, that seemingly random choice is very bad news for those unpicked toys: the baby has likely just decided she doesn't like what she didn't choose.

Though researchers have long known that adults build unconscious biases over a lifetime of making choices between things that are essentially the same, the new Johns Hopkins University finding that even babies engage in this phenomenon demonstrates that this way of justifying choice is intuitive and somehow fundamental to the human experience.

"The act of making a choice changes how we feel about our options," said co-author Alex Silver, a former Johns Hopkins undergraduate who's now a graduate student in cognitive psychology at the University of Pittsburgh. "Even infants who are really just at the start of making choices for themselves have this bias."

The findings are published today in the journal Psychological Science.

People assume they choose things that they like. But research suggests that's sometimes backwards: We like things because we choose them. And, we dislike things that we don't choose.

"I chose this, so I must like it. I didn't choose this other thing, so it must not be so good. Adults make these inferences unconsciously," said co-author Lisa Feigenson, a Johns Hopkins cognitive scientist specializing in child development. "We justify our choice after the fact."

This makes sense for adults in a consumer culture who must make arbitrary choices every day, between everything from toothpaste brands to makes of cars to styles of jeans. The question, for Feigenson and Silver, was when exactly people start doing this. So they turned to babies, who don't get many choices so, as Feigenson puts it, are "a perfect window into the origin of this tendency."

The team brought 10- to 20-month-old babies into the lab and gave them a choice of objects to play with: two equally bright and colorful soft blocks.

They set each block far apart, so the babies had to crawl to one or the other - a random choice.

After the baby chose one of the toys, the researchers took it away and came back with a new option. The babies could then pick from the toy they didn't play with the first time, or a brand new toy.

"The babies reliably chose to play with the new object rather than the one they had previously not chosen, as if they were saying, 'Hmm, I didn't choose that object last time, I guess I didn't like it very much,' " Feigenson said. "That is the core phenomenon. Adults will like less the thing they didn't choose, even if they had no real preference in the first place. And babies, just the same, dis-prefer the unchosen object."

In follow-up experiments, when the researchers instead chose which toy the baby would play with, the phenomenon disappeared entirely. If you take the element of choice away, Feigenson said, the phenomenon goes away.

"They are really not choosing based on novelty or intrinsic preference," Silver said. "I think it's really surprising. We wouldn't expect infants to be making such methodical choices."

To continue studying the evolution of choice in babies, the lab will next look at the idea of "choice overload." For adults, choice is good, but too many choices can be a problem, so the lab will try to determine if that is also true for babies.

Genetic tracing 'barcode' is rapidly revealing COVID-19's journey and evolution

Drexel researchers' method helps uncover patterns in SARS-CoV-2's genetic mutations

DREXEL UNIVERSITY

Research News

 

IMAGE: RESEARCHERS FROM DREXEL UNIVERSITY ARE USING A NEW TECHNIQUE FOR SPOTTING PATTERNS IN THE GENETIC SEQUENCE OF THE SARS-COV-2 CORONAVIRUS THAT CAN HELP SCIENTISTS TRACE THE PATH OF ITS TRANSMISSION... view more 

CREDIT: DREXEL UNIVERSITY

Drexel University researchers have reported a method to quickly identify and label mutated versions of the virus that causes COVID-19. Their analysis, using information from a global database of genetic information gleaned from coronavirus testing, suggests that there are at least 8 to 14 slightly different versions of the virus infecting people in America, some of which are either the same as, or have subsequently evolved from, strains directly from Asia, while others are the same as those found in Europe.

First developed as a way of parsing genetic samples to get a snapshot of the mix of bacteria, the genetic analysis tool teases out patterns from volumes of genetic information and can identify whether a virus has genetically changed. They can then use the pattern to categorize viruses with small genetic differences using tags called Informative Subtype Markers (ISM).

Applying the same method to process viral genetic data can quickly detect and categorize slight genetic variations in the SARS-CoV-2, the novel coronavirus that causes COVID-19, the group reported in a paper recently published in the journal, PLoS Computational Biology. The genetic analysis tool, designed by Drexel graduate researcher Zhengqiao Zhao, that generates these labels is publicly available for COVID-19 researchers on GitHub.

"The types of SARS-CoV-2 viruses that we see in tests from Asia and Europe is different than the types we're seeing in America," said Gail Rosen, PhD, a professor in Drexel's College of Engineering, who led the development of the tool. "Identifying the variations allows us to see how the virus has changed as it has traveled from population to population. It can also show us the areas where social distancing has been successful at isolating COVID-19."

The ISM tool is particularly useful because it does not require analysis of the full genetic sequence of the virus to identify its mutations. In the case of SARS-CoV-2, this means reducing the 30,000-base-long genetic code of the virus to a subtype label 20 bases long.

The ISM tool also identified certain positions in the virus's genetic sequence that changed together as the virus spread. The researchers found that from early April to the end of the summer, three positions in the SARS-CoV-2 sequence mutated at the same time. Those positions are in different parts of the genetic sequence. One part is thought to be associated with cellular signaling and replication. Another portion is associated with formation of the protein spike - the part of the virus that enables its entry into healthy cells - changed in tandem with a third portion of code, which doesn't translate to protein.

While more investigation is needed on how these simultaneous mutations impact the transmission and severity of the virus, sites that change together can be used to consolidate the subtype label into 11 bases, which could make downstream analysis more efficient, according to the researchers.

"It's the equivalent of scanning a barcode instead of typing in the full product code number," Rosen said. "And right now, we're all trying to get through the grocery store a bit faster. For scientists this means being able to move to higher-level analysis much faster. For example, it can be a faster process in studying which virus versions could be affecting health outcomes. Or, public health officials can track whether new cases are the result of local transmission or coming from other regions of the United States or parts of the world."

While these genetic differences might not be enough to delineate a new strain of virus, Rosen's group suggests understanding these genetically significant "subtypes," where they're being found and how prevalent they are in these areas is data granular enough to be useful.

"This allows us to see the very specific fingerprint of COVID-19 from each region around the world, and to look closely at smaller regions to see how it is different," Rosen said. "Our preliminary analysis, using publicly available data from across the world, is showing that the combination of subtypes of virus found in New York is most similar to those found in Austria, France and Central Europe, but not Italy. And the subtype from Asia, that was detected here early in the pandemic has not spread very much, instead we are seeing a new subtype that only exists in America as the one most prevalent in Washington state and on the west coast."

In addition to helping scientists understand how the virus is changing and spreading, this method can also reveal the portion of its genetic code that appears to remain resistant to mutations - a discovery that could be exploited by treatments to combat the virus.

"We're seeing that the spike protein and the part of the virus responsible for packaging its genetic material have developed a few major mutations, but otherwise they are changing at a slower rate," said Bahrad Sokhansanj, PhD, a visiting scholar at Drexel. "Importantly, both are key targets for understanding the body's immune response, identifying antiviral therapeutics, and designing vaccines.

Rosen's Ecological and Evolutionary Signal-Processing and Informatics Laboratory will continue to analyze COVID-19 data as it is collected and to support public health researchers using the ISM process.

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Physicists build circuit that generates clean, limitless power from graphene

Researchers harnessed the atomic motion of graphene to generate an electrical current that could lead to a chip to replace batteries.

UNIVERSITY OF ARKANSAS

Research News

 

IMAGE: PAUL THIBADO, PROFESSOR OF PHYSICS, HOLDS PROTOTYPE ENERGY-HARVESTING CHIPS. view more 

CREDIT: RUSSELL COTHREN, UNIVERSITY OF ARKANSAS

FAYETTEVILLE, Ark. - A team of University of Arkansas physicists has successfully developed a circuit capable of capturing graphene's thermal motion and converting it into an electrical current.

"An energy-harvesting circuit based on graphene could be incorporated into a chip to provide clean, limitless, low-voltage power for small devices or sensors," said Paul Thibado, professor of physics and lead researcher in the discovery.

The findings, published in the journal Physical Review E, are proof of a theory the physicists developed at the U of A three years ago that freestanding graphene -- a single layer of carbon atoms -- ripples and buckles in a way that holds promise for energy harvesting.

The idea of harvesting energy from graphene is controversial because it refutes physicist Richard Feynman's well-known assertion that the thermal motion of atoms, known as Brownian motion, cannot do work. Thibado's team found that at room temperature the thermal motion of graphene does in fact induce an alternating current (AC) in a circuit, an achievement thought to be impossible.

In the 1950s, physicist Léon Brillouin published a landmark paper refuting the idea that adding a single diode, a one-way electrical gate, to a circuit is the solution to harvesting energy from Brownian motion. Knowing this, Thibado's group built their circuit with two diodes for converting AC into a direct current (DC). With the diodes in opposition allowing the current to flow both ways, they provide separate paths through the circuit, producing a pulsing DC current that performs work on a load resistor.

Additionally, they discovered that their design increased the amount of power delivered. "We also found that the on-off, switch-like behavior of the diodes actually amplifies the power delivered, rather than reducing it, as previously thought," said Thibado. "The rate of change in resistance provided by the diodes adds an extra factor to the power."

The team used a relatively new field of physics to prove the diodes increased the circuit's power. "In proving this power enhancement, we drew from the emergent field of stochastic thermodynamics and extended the nearly century-old, celebrated theory of Nyquist," said coauthor Pradeep Kumar, associate professor of physics and coauthor.

According to Kumar, the graphene and circuit share a symbiotic relationship. Though the thermal environment is performing work on the load resistor, the graphene and circuit are at the same temperature and heat does not flow between the two.

That's an important distinction, said Thibado, because a temperature difference between the graphene and circuit, in a circuit producing power, would contradict the second law of thermodynamics. "This means that the second law of thermodynamics is not violated, nor is there any need to argue that 'Maxwell's Demon' is separating hot and cold electrons," Thibado said.

The team also discovered that the relatively slow motion of graphene induces current in the circuit at low frequencies, which is important from a technological perspective because electronics function more efficiently at lower frequencies.

"People may think that current flowing in a resistor causes it to heat up, but the Brownian current does not. In fact, if no current was flowing, the resistor would cool down," Thibado explained. "What we did was reroute the current in the circuit and transform it into something useful."

The team's next objective is to determine if the DC current can be stored in a capacitor for later use, a goal that requires miniaturizing the circuit and patterning it on a silicon wafer, or chip. If millions of these tiny circuits could be built on a 1-millimeter by 1-millimeter chip, they could serve as a low-power battery replacement.

The University of Arkansas holds several patents pending in the U.S. and international markets on the technology and has licensed it for commercial applications through the university's Technology Ventures division. Researchers Surendra Singh, University Professor of physics; ; Hugh Churchill, associate professor of physics; and Jeff Dix, assistant professor of engineering, contributed to the work, which was funded by the Chancellor's Commercialization Fund supported by the Walton Family Charitable Support Foundation.

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Laundry lint can cause significant tissue damage within marine mussels

UNIVERSITY OF PLYMOUTH

Research News

 

IMAGE: MARINE MUSSELS ARE COMMONLY USED TO MONITOR WATER QUALITY IN COASTAL AREAS. view more 

CREDIT: UNIVERSITY OF PLYMOUTH

Microscopic fibres created during the laundry cycle can cause damage to the gills, liver and DNA of marine species, according to new research.

Scientists at the University of Plymouth exposed the Mediterranean mussel (Mytilus galloprovincialis), found in various locations across the world, to differing quantities of tumble dryer lint.

They demonstrated that increasing the amount of lint resulted in significant abnormality within the mussels' gills, specifically leading to damage of tissues including deformity, extensive swelling and loss of cilia. In the liver, the presence of lint led to atrophy or deformities leading to loss of definition in digestive tubules.

The increasing concentration of fibres also led to a reduction in the mussels' ability to filter food particles from the seawater and a significant increase in DNA strand breaks in the blood cells.

Scientists say the precise causes of the effects are not wholly clear, but are likely to arise from the fibres themselves and chemicals present within them.

They say the findings are unlikely to solely apply to lint, as its properties are consistent with other textiles and fibres found commonly in waste water and throughout the marine environment.

The study, published in the journal Chemosphere, was conducted by academics in the School of Biological and Marine Sciences and School of Geography, Earth and Environmental Sciences.

Dr Andrew Turner, Associate Professor of Environmental Sciences, was the study's senior author and has previously conducted research highlighting the chemicals - including bromine, iron and zinc - found within lint.

He said: "The laundering of clothes and other textiles is among the most significant sources of synthetic microfibers within the environment. However, despite their known presence in a range of species, there have been very few studies looking in detail at their impact. This study shows for the first time what harm they can cause, and it is particularly interesting to consider that it is not just the fibres themselves which create issues but also the cocktail of more harmful chemicals which they can mobilise."

Co-author Awadhesh Jha, Professor in Genetic Toxicology and Ecotoxicology, added: "Mytilus species are commonly used to monitor water quality in coastal areas, and the damage shown to them in this study is a cause for significant concern. Given their genetic similarity to other species and the fact they are found all over the world, we can also assume these effects will be replicated in other shellfish and marine species. Damage to DNA and impairment of the filter feeding abilities would have potential impact on the health of the organisms and the ecosystem. That is particularly significant as we look in the future to increase our reliance on aquaculture as a global source of food."

This study is the latest research by the University in the field, with it being awarded a Queen's Anniversary Prize for Higher and Further Education in 2020 for its ground-breaking research and policy impact on microplastics pollution in the oceans.

That research has included work showing that washing clothes releases thousands of microplastic particles into environment, and that devices fitted to washing machines can reduce the fibres produced in laundry cycle by up to 80%. Scientists from the University have also showed that wearing clothes could release more microfibres to the environment than washing them.

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Woodpeckers' drumming: Conserved meaning despite different structure over the years

UNIVERSITY OF ZURICH

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IMAGE: GREAT SPOTTED WOODPECKER DURING THE FIELD EXPERIMENT. view more 

CREDIT: (PICTURE: ALAIN BLANC, ENES TEAM)

Animal acoustic signals are amazingly diverse. Researchers from the University of Zurich and the University of Saint-Etienne, together with French, American and Dutch collaborators, explored the function and diversification of animal acoustic signals and the mechanisms underlying the evolution of animal communication systems.

To this end, they used Shannon & Weaver's 'Mathematical Theory of Communication' originally ap-plied to telecommunications in 1949, which has transformed the scientific understanding of animal communication. This theory allows the amount of information in a signal to be quantified. The researchers were the first to use this framework within an evolutionary perspective to explore the bio-logical information encoded in an animal signal.

How drumming structure evolves over time

In deciding which biological model to choose, the researchers selected the woodpeckers' drumming as their ideal candidate. This bird family is known for rapidly striking their beaks on tree trunks to communicate. The team combined acoustic analyses of drumming from 92 species of woodpeckers, together with theoretic calculations, evolutionary reconstructions, investigations at the level of ecolog-ical communities as well as playback experiments in the field.

"We wanted to test whether drumming has evolved to enhance species-specific biological information, thereby promoting species recognition", says lead author Maxime Garcia of the UZH Department of Evolutionary Biology and Environmental Studies.

Constant amount of information for 22 million years

Results demonstrate the emergence of new drumming types during woodpeckers evolution. Yet, despite these changes in drumming structure, the amount of biological information about species identity has remained relatively constant for 22 million years. Selection towards increased biological infor-mation thus does not seem to represent a major evolutionary driver in this animal communication system. How then can biological information be concretely maintained in nature? Analyses of existing communities around the globe show that ecological arrangements facilitate the efficiency of drumming signals: Communities are composed of only a few species, which distribute their drumming strategies to avoid acoustic overlap. "The responses to different drumming structures seen in our experimental approach show the ability of individuals to recognize their own species based on acoustic cues about species identity found in drumming signals", says Garcia. This way, biological information about spe-cies identity can be maintained without necessarily inducing a strong evolutionary pressure on drum-ming signals.

The present study shows that random and unpredictable changes in the structure of communication signals over time can occur while maintaining the signals overall informative potential within and across species. This work leads the way to further investigate the evolution of meaning associated with communicating through multiple communication channels.

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Face masks unlikely to cause over-exposure to CO2, even in patients with lung disease

AMERICAN THORACIC SOCIETY

Research News

 

IMAGE: FACE MASKS DO NOT CONTRIBUTE TO CARBON DIOXIDE POISONING. FACE MASKS IS KEY TO PREVENTING COVID-19 INFECTION. view more 

CREDIT: ATS

New research findings contradict statements linking wearing face masks to carbon dioxide poisoning by trapping CO2. During the COVID-19 pandemic the wearing of face masks has become a highly political issue with some individuals falsely claiming that wearing face masks may be putting people's health at risk. The study published in the Annals of the American Thoracic Society shows otherwise.

In "Effect of Face Masks on Gas Exchange in Healthy Persons and Patients with COPD," Michael Campos, MD and co-authors assessed problems with gas exchange, that is, changes in oxygen level or carbon dioxide levels in healthy individuals as well as veterans with chronic obstructive pulmonary disease or COPD before and while using surgical masks. People with COPD, according to the ATS Patient Education Fact Sheet on the disease, "must work harder to breathe, which can lead to shortness of breath and/or feeling tired."

"We show that the effects are minimal at most even in people with very severe lung impairment," said Dr. Campos of the Miami Veterans Administration Medical Center and the Division of Pulmonary, Allergy, Critical Care and Sleep Medicine at the University of Miami.

As for the feeling of breathlessness that some healthy people may experience, Dr. Campos explained: "Dyspnea, the feeling of shortness of breath, felt with masks by some is not synonymous of alterations in gas exchange. It likely occurs from restriction of air flow with the mask in particular when higher ventilation is needed (on exertion)."

If you're walking briskly up an incline, for example, you may experience feelings of breathlessness. An overly tight mask may also increase the feeling of breathlessness. The solution is simply to slow down or remove the mask if you are at a safe distance from other people.

Dr. Campos stressed the importance of wearing a face mask to prevent COVID-19 infection. If a surgical mask is not available, a cloth mask with at least two layers is recommended by the CDC. Patients with lung disease, in particular, should avoid getting infected and should wear a face mask, which, along with handwashing and social distancing, is proven to reduce the risk of COVID-19 infection.

The impetus for the study came after reports of a public hearing in Florida where individuals made inflammatory comments, namely that wearing masks were putting lives at risk and finding out that no data on the effects of surgical masks on gas exchange was available.

"We acknowledge that our observations may be limited by sample size, however our population offers a clear signal on the nil effect of surgical masks on relevant physiological changes in gas exchange under routine circumstances (prolonged rest, brief walking)," wrote the authors. "It is important to inform the public that the discomfort associated with mask use should not lead to unsubstantiated safety concerns as this may attenuate the application of a practice proven to improve public health."

"The public should not believe that masks kill," added Dr. Campos.

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About the Annals of the American Thoracic Society

The AnnalsATS is a peer-reviewed journal published by the American Thoracic Society. The Journal delivers up-to-date and authoritative coverage of adult and pediatric pulmonary and respiratory sleep medicine and adult critical care. The scope of the Journal encompasses content that is applicable to clinical practice, the formative and continuing education of clinical specialists and the advancement of public health. The journal's impact factor is 4.836.

Editor: Colin Cooke, MD, MS, associate professor in the department of internal medicine at the University of Michigan.

About the American Thoracic Society

Founded in 1905, the American Thoracic Society is the world's leading medical association dedicated to advancing pulmonary, critical care and sleep medicine. The Society's more than 16,000 members prevent and fight respiratory disease around the globe through research, education, patient care and advocacy. The ATS publishes four journals, the American Journal of Respiratory and Critical Care Medicine, the American Journal of Respiratory Cell and Molecular Biology, the Annals of the American Thoracic Society and ATS Scholar.

Bright light bars big-eyed birds from human-altered landscapes

FLORIDA MUSEUM OF NATURAL HISTORY

Research News

 

IMAGE: IN A STUDY OF 240 BIRD SPECIES, FLORIDA MUSEUM OF NATURAL HISTORY RESEARCHERS FOUND STRONG LINKS BETWEEN EYE SIZE, LIGHT AND HABITAT USE. THE FINDINGS SUGGEST EYE SIZE COULD BE... view more 

CREDIT: IAN AUSPREY/FLORIDA MUSEUM

GAINESVILLE, Fla. --- New research shows the glaring light in human-altered landscapes, such as livestock pastures and crop fields, can act as a barrier to big-eyed birds, potentially contributing to their decline.

Florida Museum of Natural History researchers found strong links between bird eye size, habitat and foraging technique. Birds that kept to the shade of the forest had larger eyes than those that inhabited the canopy, and birds with relatively small eyes were more numerous in agricultural settings.

The findings suggest eye size is an overlooked, but important trait in determining birds' vulnerability to changes in their habitat and could help inform future research on their sensitivity to other bright environments, such as cities.

"Many bird species literally disappear from highly disturbed, anthropogenic habitats such as agricultural landscapes," said lead author Ian Ausprey, a Ph.D. student in the Florida Museum's Ordway Lab of Ecosystem Conservation and a National Geographic Explorer. "That's probably due to many reasons, but this paper suggests light could be part of that."

Despite numerous studies on how light influences the makeup of plant communities, little research has focused on how it drives the ecology of vertebrates. Ausprey said while some of the study's results may seem like "a no-brainer," it is the first to document the relationships between light, eye size and how birds navigate their world.

Light is especially key for birds, which use their vision to detect food. Big eyes house more photoreceptors and are a common feature in birds of prey such as owls and raptors, enabling them to resolve images at longer distances and in darker settings.

But large eyes can also be susceptible to overexposure and glare in bright environments. Previous research has shown too much light can overwhelm birds, causing them to alter their feeding behavior and diminish their alertness to threats.

For four years, Ausprey and fellow University of Florida Ph.D. student Felicity Newell, a study co-author, surveyed birds in the cloud forests of northern Peru, part of the tropical Andes, a global biodiversity hotspot. In these forests, light is structured on a vertical gradient, powerful at the canopy and increasingly weaker as it filters down to the darkest parts of the understory. Gaps in the canopy open up patches of startling brightness, changing light intensity "over infinitesimally small scales," Ausprey said. "You can go from being very dark to very bright within inches."

The swift, dramatic changes in the landscape are mirrored in its variety of birds: A difference of 1,000 feet in elevation can uncover a completely distinct avian community.

The region is also home to small-scale farms with livestock pastures and vegetable fields, often interspersed with islands of remaining forest. The broad range of ambient light, from the deep, dark forest interior to wide open country, made an ideal model system for measuring birds' use of light, Newell said.

Ausprey and Newell measured eye size relative to body size in 240 species that make up the cloud forest bird community of Amazonas, their study region.

They found the largest-eyed insect-eating birds were "far-sighted" species, those that nab prey on the wing, such as flycatchers. Eye size in "near-sighted" species that hunt in the dimly lit understory increased the closer to the ground they lived. One such big-eyed species is the rufous-vented tapaculo, Scytalopus femoralis, a bird only found in Peru. Ausprey said the species behaves much like a mouse, scuttling across the forest floor in search of insects in mossy logs and under tree roots.

For bird groups that eat fruit, seeds and nectar - food items that don't require capture - eye size did not vary based on which part of the forest they inhabited.

The researchers also attached tiny light-sensing backpacks to 71 birds representing 15 focal species. The sensors tracked the intensity of light the birds encountered over a period of days, providing a first look at their light "micro-environments."

Of these 15 species, the bird that inhabited the darkest environment was the rusty-tinged antpitta, Grallaria przewalskii, another species exclusive to Peru, which spends much of its life walking along the forest floor. The blue-capped tanager, Thraupis cyanocephala, lived in the brightest environments.

The researchers also found that eye size was correlated with the abundance of a species in agricultural settings, with smaller-eyed birds being more common, suggesting that birds better adapted to the dark forest understory would struggle to adjust to the flood of light in a field, Ausprey said.

Preliminary results from subsequent research suggest these patterns hold at a global scale. The trend might also carry over into urban areas, which "are basically extreme forms of agricultural landscapes in some ways," he said.

In fact, the rufous-collared sparrow, Zonotrichia capensis, the bird most commonly found in agricultural fields, is also the most abundant species in Latin American cities, Newell said.

The study is the first to emerge from Ausprey and Newell's project, which examined how climate and land use influence cloud forest birds.

"This study makes excellent use of emerging technologies to answer one of the major questions in ecology - how do light levels affect the niches of birds and their vulnerability to habitat modification," said Scott Robinson, Ordway Eminent Scholar at the Florida Museum.

But the technology required a bit of MacGyvering: The light sensors don't directly transmit data, meaning Ausprey had to figure out a way to get them back. The solution was to superglue a radio tag to the delicate sensor and use a surgical adhesive to attach the packet to a bird's back, sticking long enough to get meaningful information, but detaching after a few days. Ausprey would then clamber over steep ridges and through thick shrubs and bamboo, antenna in hand, to retrieve it.

They also had to select the bird species that would cooperate: Large tanagers, toucans and woodcreepers were excluded due to their strong bills and proclivity for aggressive behavior. Even so, three of the expensive, imported sensors wound up chewed and destroyed.

"When you work with technology in the field, you have to have a strong stomach for tragedy," Ausprey said.

Ausprey and Newell expressed thanks to the large team - about 100 people - of field assistants, hosts, nature reserve staff and community members that contributed to the project.

Ausprey is also a fellow with the UF Biodiversity Institute.

 

Researchers hear more crickets and katydids 'singing in the suburbs'

PENN STATE

Research News

 

IMAGE: COLLECTION METHODS USED TO MONITOR POPULATIONS OF KATYDIDS, SUCH AS THIS RATTLER ROUND-WINGED KATYDID, CAN BE CHALLENGING BECAUSE MANY KATYDID SPECIES LIVE HIGH IN TREES, ACCORDING TO D.J. MCNEIL, THE... view more 

CREDIT: D.J. MCNEIL, PENN STATE

UNIVERSITY PARK, Pa. -- The songs that crickets and katydids sing at night to attract mates can help in monitoring and mapping their populations, according to Penn State researchers, whose study of Orthoptera species in central Pennsylvania also shed light on these insects' habitat preferences.

"We were surprised to find more species in suburban areas than in either urban or rural areas," said the study's lead researcher, D.J. McNeil, postdoctoral fellow in Penn State's Insect Biodiversity Center and the Department of Entomology.

The study was the first to show that the use of aural point count surveys -- a method commonly used by wildlife biologists to study birds and other vertebrates by listening to their songs -- can be effective in exploring the population dynamics of night-singing insect species, the researchers said.

"Insect populations are showing declines globally, and several studies have indicated that Orthopterans, such as grasshoppers, crickets and katydids, are among the most threatened insect groups," said study co-author Christina Grozinger, Publius Vergilius Maro Professor of Entomology, Penn State College of Agricultural Sciences. "Having a nondestructive way to monitor and map these species is vital for understanding how to conserve and expand their populations."

McNeil explained that Orthoptera species -- such as those in suborder Ensifera, which consists of crickets and katydids -- are known to be highly sensitive to variation in habitat conditions. Since they feed on plants, these species also can be affected negatively when insecticides and herbicides are applied to vegetation.

McNeil noted that few efficient, standardized monitoring protocols exist for Ensifera, and many involve lethal trapping or time-intensive collection efforts such as mark-recapture. In addition, other collection methods such as sweep-netting are challenging in densely vegetated habitats, especially for katydid species, many of which live high in trees. The researchers pointed out that the conspicuous stridulations, or mating calls, produced by singing Ensifera make them excellent candidates for aural population surveys.

"Although researchers have used acoustic sampling methods for crickets and katydids in the past, these methods often require specialized audio gear and complex machine-learning algorithms to disentangle the insects' calls from the background noise," McNeil said. "This is very expensive, and it requires a very high-tech skill set. Developing a simple and efficient monitoring protocol can greatly improve our ability to study and understand Ensifera population ecology."

To address this need, McNeil drew on his background in ornithology -- his doctoral research focused on birds -- to develop a protocol that required only a human being to conduct aural point count surveys.

"You can identify birds by their calls really easily, and I came to realize that this was true for crickets and katydids," he said. "For example, one cricket species makes a particular type of chirp, and another one has a different pattern. So, over the course of a few years, I've taught myself the different breeding calls of the crickets and katydids, and I've reached the point where I can confidently identify a large portion of the species that we have in this region."

The researchers defined the study area by selecting a central point in downtown State College, Pennsylvania, and plotting four transects extending 10 kilometers east, west, north and south. Along each transect, they selected 10 points, about 1 km apart, as survey locations. The resulting 41 roadside sampling points encompassed deciduous forest, row-crop agricultural fields, pastures, and varying degrees of urban and suburban cover types.

"That allowed us not only to get different habitat types, but to capture a smooth gradient across the entire spectrum of what a cricket might experience," McNeil said.

McNeil conducted all of the surveys by standing stationary for three minutes at each location and using a checklist to record the number of Ensifera species detected. Because the study focused on crickets and katydids that sing mostly after dark, sampling was performed between sunset and midnight, and each location was sampled five times from July to November in 2019, a time of year that includes the seasonal singing periods for most local Ensifera. He then used occupancy modeling approaches to map the species distributions across the urban-to-rural gradient.

The findings, reported Sept. 29 in the Journal of Insect Conservation, provided the first quantitative glimpse into the habitat needs for a variety of night-singing Orthoptera in eastern North America, the researchers said. For example, some species preferred agriculturally dominated landscapes, some preferred urban habitats, and others were found across all areas surveyed.

"We found that intermediate levels of urbanization, such as what you'd find in suburban areas, hosted the highest number of species, perhaps because areas with intermediate levels of disturbance host the greatest number of habitat niches and can support more species than heavily disturbed or totally undisturbed ecosystems," McNeil said.

"We hope that this study inspires people to listen carefully to the diverse insect songs in their backyards at night and think about ways to improve the habitat for these important species," Grozinger said.

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Tips on how to support insect biodiversity can be found on the Insect Biodiversity Center website.

Penn State funding for the Insect Biodiversity Center supported this work.

 

Ice discharge in the North Pacific set off series of climate events during last ice age

OREGON STATE UNIVERSITY

Research News

 

IMAGE: THE JOIDES RESOLUTION, A RESEARCH VESSEL THAT DRILLS INTO THE OCEAN FLOOR TO COLLECT AND STUDY CORE SAMPLES IS SEEN AT THE PORT OF VALDEZ. THE JR IS A PART... view more 

CREDIT: BILL MILLS, IODP/TAMU [PHOTO ID: EXP346_003]

CORVALLIS, Ore. - Repeated catastrophic ice discharges from western North America into the North Pacific contributed to, and perhaps triggered, hemispheric-scale changes in the Earth's climate during the last ice age, new research published online today in Science reveals.

The discovery provides new insight into the impact rapidly melting ice flowing into the North Pacific may have on the climate across the planet, said Maureen Walczak, a paleoclimatologist in Oregon State University's College of Earth, Ocean, and Atmospheric Sciences and the study's lead author.

"Understanding how the ocean has interacted with glacial ice in the past helps us predict what could happen next," Walczak said.

The Cordilleran ice sheet once covered large portions of western North America from Alaska to Washington state and western Montana. Radiocarbon dating and analyses of the marine sediment record revealed that recurrent episodes of discharge from this ice sheet over the past 42,000 years were early events in a chain reaction of disturbances to the global climate. These disturbances triggered changes in deep ocean circulation and retreat of ice sheets in the North Atlantic.

The findings challenge theories that those massive, globally-reaching disturbances originated in the North Atlantic as rapid ice loss from the Laurentide ice sheet, another massive ice sheet that covered much of Canada and the northern United States, including the upper Midwest and Northeast. The Laurentide ice loss events are known as Heinrich Events.

"The outcome of this research was unexpected. The data irrevocably says that the Pacific ice goes first, with Heinrich Events and other changes following in a rhythm. The Pacific Ocean sets the drum beat," Walczak said. "This is a paradigm shift in our thinking about how these events are connected."

To gain insight into the climate history of the North Pacific, an international team of researchers collected and analyzed sediment cores from the northern Gulf of Alaska that were recovered by drilling as part of the International Ocean Discovery Program.

"Getting these new insights took years of work. We first mapped the seafloor and recovered short sediment cores in 2004, drilled longer cores in 2013 and had 16 years of painstaking laboratory work involving several Ph.D. students," said Alan Mix, the project's principal investigator and co-author of the paper.

"This was a virtually unknown area when we started, and now it offers among the most detailed and best-dated long records of ocean change on the planet during the ice age," said Mix, a distinguished professor in OSU's College of Earth, Ocean, and Atmospheric Sciences.

Researchers measured radioactive isotopes of carbon using two particle accelerators to establish the chronology of events and also added meticulous counts of small rocks dropped by icebergs known as ice-rafted debris.

The research team traced the source of the ice-rafted debris back to purges of massive ice streams emanating from the Cordilleran ice sheet, which covered northern Washington, most of British Columbia and southern Alaska from about 70,000 to 17,000 years ago.

Dirty icebergs broke off from surging ice streams and drifted northward in ocean currents, carrying and eventually dropping their load of sand, pebbles and gravel, leaving a record of rapid ice retreat buried in the deep sea like sunken treasure.

The authors of the study named these Alaskan iceberg dumps "Siku Events" after the Inuit word for ice. The big surprise, discovered by combining the record of glacial debris with the radiocarbon chronology, was that Siku Events immediately preceded Heinrich events, which are a similar type of ice purge in the North Atlantic.

Scientists have been aware of Heinrich Events, from similar evidence of ice-rafted debris in the North Atlantic, for more than 30 years but the trigger for those events has never been convincingly explained, the researchers said.

It makes sense for the Pacific Ocean to be involved in major planetary changes, Mix said. The Pacific Ocean is connected to the rest of the world by large-scale atmospheric circulation and physically around Antarctica, and during times of high sea level, through the Bering Strait and the Arctic Ocean to the North Atlantic.

"The Pacific Ocean is the largest exchangeable reservoir of heat and water and carbon dioxide on Earth, simply because of its massive size," he said. "It really is the 800-pound gorilla in the zoo of climate beasts."

Today the ice that remains along the coast of Alaska is mostly retreating and may be gone within this century as the climate warms. The melting ice will drain to the Pacific and the Arctic, contributing to sea level rise and impacting the balance of buoyant fresh and dense salty water in the ocean, much as it did in the past.

If the current ice melt follows patterns of the past, and happens quickly, it could contribute to the retreat of distant glacial systems in the North Atlantic and the Arctic.

"This is yet another reason that it is prudent to slow down warming by reducing our fossil-fuel use," Mix said.

"The new findings are likely to fuel increased interest in the North Pacific, an area that has not been as well-studied as other parts of the planet," Walczak said.

One thing that remains unclear is why the discharges from the Cordilleran ice sheet occurred. Researchers also would like to better understand the relationship between the discharges of the Cordilleran and the other climate events.

"Why did the other ice sheets respond to the retreat of the Cordilleran? How fast do the dominoes fall in this sequence of events?" Walczak asked. Those are among the questions the research team is continuing to investigate.

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Additional coauthors of the study include Andreas Schmittner, Joseph Stoner, Brian Haley; and June Padman, all of OSU's College of Earth, Ocean, and Atmospheric Sciences; Jianghui Du, who recently earned his doctorate at Oregon State; Jay Alder of OSU and the U.S. Geological Survey; Summer Praetorius, previously of OSU and now at the U.S. Geological Survey; Ellen Cowan of Appalachian State University; Stewart Fallon and L. Keith Fifield of Australian National University; and Sarah Zellers of University of Central Missouri.

The research was supported by the National Science Foundation, the Australian Research Council, the Australian-New Zealand IODP Commission and the American Australian Association.