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Bottlenose dolphins ‘smile’ at each other while playing, research shows

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Bottlenose dolphins ‘smile’ at each other while playing, research shows


Bottlenose dolphins "smile" at each other while playing
Open mouth smile. Credit: ZooMarine, Italy

Dolphins are extremely playful, but little is known about how they—and other marine mammals—communicate during playtime. New research published October 2 in the journal iScience shows that bottlenose dolphins (Tursiops truncates) use the “open mouth” facial expression—analogous to a smile—to communicate during social play.

The dolphins almost always use the facial expression when they are in their playmate’s field of view, and when playmates perceived a “smile,” they responded in kind 33% of the time.

“We’ve uncovered the presence of a distinct facial display, the open mouth, in bottlenose dolphins, and we showed that dolphins are also able to mirror others’ facial expression,” says senior author and evolutionary biologist Elisabetta Palagi of the University of Pisa.

“Open-mouth signals and rapid mimicry appear repeatedly across the mammal family tree, which suggests that visual communication has played a crucial role in shaping complex social interactions, not only in dolphins but in many species over time.”

Dolphin play can include acrobatics, surfing, playing with objects, chasing, and playfighting, and it’s important that these activities aren’t misinterpreted as aggression. Other mammals use facial expressions to communicate playfulness, but whether marine mammals also use facial expressions to signal playtime hasn’t been previously explored.

“The open mouth gesture likely evolved from the biting action, breaking down the biting sequence to leave only the ‘intention to bite’ without contact,” says Palagi. “The relaxed open mouth, seen in social carnivores, monkeys’ play faces, and even human laughter, is a universal sign of playfulness, helping animals—and us—signal fun and avoid conflict.”

To investigate whether dolphins visually communicate playfulness, the researchers recorded captive bottlenose dolphins while they were playing in pairs and while they were playing freely with their human trainers.

They showed that dolphins frequently use the open mouth expression when playing with other dolphins, but they don’t seem to use it when playing with humans or when they’re playing by themselves.

While only one open mouth event was recorded during solitary play, the researchers recorded a total of 1,288 open mouth events during social play sessions, and 92% of these events occurred during dolphin-dolphin play sessions.

Dolphins were also more likely to assume the open mouth expression when their faces were in the field of view of their playmate—89% of recorded open mouth expressions were emitted in this context—and when this “smile” was perceived, the playmate smiled back 33% of the time.

“Some may argue that dolphins are merely mimicking each other’s open mouth expressions by chance, given they’re often involved in the same activity or context, but this doesn’t explain why the probability of mimicking another dolphin’s open mouth within 1 second is 13 times higher when the receiver actually sees the original expression,” says Palagi.

“This rate of mimicry in dolphins is consistent with what’s been observed in certain carnivores, such as meerkats and sun bears.”

The researchers didn’t record the dolphins’ acoustic signals during playtime, and they say that future studies should investigate the possible role of vocalizations and tactile signals during playful interactions.

“Future research should dive into eye-tracking to explore how dolphins see their world and utilize acoustic signals in their multimodal communication during play,” says corresponding author and zoologist Livio Favaro.

“Dolphins have developed one of the most intricate vocal systems in the animal world, but sound can also expose them to predators or eavesdroppers. When dolphins play together, a mix of whistling and visual cues helps them cooperate and achieve goals, a strategy particularly useful during social play when they’re less on guard for predators.”

More information:
Smiling underwater: exploring playful signals and rapid mimicry in bottlenose dolphins, iScience (2024). DOI: 10.1016/j.isci.2024.110966. www.cell.com/iscience/fulltext … 2589-0042(24)02191-6

Citation:
Bottlenose dolphins ‘smile’ at each other while playing, research shows (2024, October 2)
retrieved 2 October 2024
from https://phys.org/news/2024-10-bottlenose-dolphins-playing.html

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Climate shocks associated with higher rates of intimate partner violence against women

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Climate shocks associated with higher rates of intimate partner violence against women


partner violence
Credit: Alex Green from Pexels

Countries affected by severe climate change may also have a higher prevalence of violence against women, finds a new study led by UCL researchers.

The research, published in PLOS Climate, examined how climate shocks—such as storms, landslides and floods—might be linked to higher rates of intimate partner violence in the two years following the event.

The researchers gathered data on intimate partner violence from 363 surveys conducted in 156 countries between 1993 and 2019, focusing on women who currently had a partner. Intimate partner violence was defined as any physical and/or sexual violence in the past year.

The team also gathered data on climate shocks from 1920 to 2022 in 190 countries. They then analyzed the relationship between climate shocks and intimate partner violence, while also considering the country’s economic status.

They found that there was a significant link between intimate partner violence and certain climate shocks (including storms, landslides and floods). Meanwhile, other types of climate shocks (such as earthquakes and wildfires) didn’t show a clear connection to intimate partner violence.

Countries with higher GDP had lower rates of intimate partner violence.

Lead author, Professor Jenevieve Mannell (UCL Institute for Global Health), said, “Existing evidence has found that when a woman experiences a climate-related event, she is more likely to experience violence in some countries and for some types of violence, but not others.

“We set out to explore what was happening at a national level to help inform international climate change policy.”

The researchers were unable to assess why different climate shocks have more of an impact on intimate partner violence. However, they believe that different shocks may take different amounts of time to have an effect on violence and this may not have been captured in the two-year window studied, due to data availability.

As a result, they are calling for more regular data collection by countries on measures of violence against women.

Professor Mannell added, “A small body of evidence shows that heat and humidity increases aggressive behaviors, including violence. Climate-related disasters increase stress and food insecurity in families in ways that can lead to increases in violence. They also reduce the social services often available for dealing with partner violence, such as police and civil society, who are more focused on the disaster.

“At the same time, governments may put in place shelters for disaster relief which are often overcrowded and unsafe, without thinking about the risks of sexual violence.

“All of this happens more often and with increased severity in countries that have patriarchal gender norms and where the use of violence against women is widely accepted as normal behavior.”

Importantly, the researchers believe that climate mitigation and adaptation efforts can and should play an important role in reducing violence against women.

This could include mentioning “violence against women” in Nationally Determined Contributions (the climate change commitments countries make) and allocating finances to address it, or developing Climate Change Gender Action Plans. Samoa and Fiji are two countries which have already done this.

The researchers also advise that violence against women needs to be a consideration in countries’ disaster planning processes.

More information:
The impact of environmental shocks due to climate change on intimate partner violence: A structural equation model of data from 156 countries, PLOS Climate (2024). DOI: 10.1371/journal.pclm.0000478

Citation:
Climate shocks associated with higher rates of intimate partner violence against women (2024, October 2)
retrieved 2 October 2024
from https://phys.org/news/2024-10-climate-higher-intimate-partner-violence.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





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Scientists use tiny ‘backpacks’ on turtle hatchlings to observe their movements

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Scientists use tiny ‘backpacks’ on turtle hatchlings to observe their movements


Scientists use tiny 'backpacks' on turtle hatchlings to observe their movements
Using lightweight accelerometers has enabled the team to study turtles when visibility of them is limited. Credit: Mr. Davey Dor.

New research suggests that green turtle hatchlings ‘swim’ to the surface of the sand, rather than ‘dig,’ in the period between hatching and emergence. The findings have important implications for conserving a declining turtle population globally.

In a study published in Proceedings of the Royal Society B: Biological Sciences, scientists from UNSW’s School of Biological, Earth and Environmental Sciences used a small device, known as an accelerometer, to uncover novel findings into the behaviors of hatchlings as they emerge from their nests.

Sea turtle eggs are buried in nests 30–80cm deep. Once hatched, the newborn turtles make their way to the surface of the sand over three to seven days. But because this all happens underground, we have very little understanding of the first few days of a hatchling‘s life.

The results provided through this novel method revealed that buried hatchlings maintained a head-up orientation and unexpectedly, moved vertically through the sand by rocking forwards and backwards rather than tipping side-to-side as expected with digging.

“When I visualize a hatchling that has just come out of its egg, it is completely in the dark in its surroundings. There’s no sign to point which way is up toward the surface—yet, they will orientate themselves and move upwards regardless,” says Mr. Davey Dor, who led the study as part of his Ph.D. “Our initial findings and ‘proof’ of this new methodology opens the door for so many new questions in sea turtle ecology.”

How can you study something underground?

The image of newly hatched baby turtles moving enthusiastically across the sand and into the ocean is somewhat familiar. But what happens before then?

Once they emerge from their eggs, hatchlings move through the sand column and eventually emerge on the surface.

“It was about 64 years ago that the period of turtles hatching from their eggs and coming up to the surface was first observed,” says Mr. Dor. “And since then, people have tried different techniques to observe this phase, such as using a glass viewing pane to watch the hatchlings, or using microphones to listen to their movement.”

Each of these previous techniques has come with limitations which means it has remained difficult to study the first few days of life for turtle hatchlings.

“You just don’t think about how much work it takes for these tiny hatchlings to swim through the sand in the dark, with almost no oxygen,” says Associate Professor Lisa Schwanz. “It happens right under everyone’s feet, but we haven’t had the technology to really understand what is happening during this time.”

So Mr. Dor, A/Prof. Lisa Schwanz and Dr. David Booth, from the University of Queensland, set out to explore new ways to observe and research this obscure, little-known process.

Miniature accelerometer backpacks

Accelerometers, which measure changes in speed or direction, have previously been used to study animal movement, behaviors and physiology.

“The simple principle of the type of accelerometer we used is that it measures acceleration from three different angles,” says Mr. Dor. “So it can measure a change in velocity in a forwards and backwards motion, an up and down motion and a side to side motion.”

But until now, an accelerometer hadn’t been used in this context.

This research took place on Heron Island, a long-term monitoring nesting site for green turtles in the southern Great Barrier Reef, where nesting season typically runs from December to March.

“After locating the nests, we waited for approximately 60 days for the eggs to develop,” says Mr. Dor. “Three days before they hatched, we put a device called a hatch detector next to 10 different nests. This unique instrument measures voltage at the nest site and lets us know when the hatchlings had hatched out of their eggs.”

As soon as the team became aware that the eggs had hatched, they carefully dug down into the nest, selected the hatchling closest to the surface and attached a light-weight, miniature accelerometer onto the baby turtle, before placing it back. “We then gently layered the sand back in the way it was found,” says Mr. Dor.

It was then a waiting game to see when the hatchlings emerged. “We checked the nest site every three hours and when they did finally emerge, we retrieved the accelerometer from the hatchling carrying it.”

The accelerometer provided new data on the direction, speed and time it took for the ten hatchlings to emerge. “We analyzed the data and found that hatchlings show amazingly consistent head-up orientation—despite being in the complete dark, surrounded by sand,” says Mr. Dor.

“We found that their movement and resting periods are generally quite short, that they move as if they were swimming rather than digging, and that as they approach the surface of the sand, they restrict their movement to nighttime,” says Mr. Dor.

Conservation and nest intervention

Sea turtle populations are in decline in many parts of the world, with several species listed as endangered. The nesting phase is a major vulnerability for turtle populations and as a result, conservation management often focuses on nest intervention, including relocation, shading and watering.

Nest relocation has been used widely around the world for many years and the practice is expected to continue as the effects of climate change and rising sea levels are affecting turtle nesting. However, factors such as moisture and temperatures in the nest, which can vary when a nest is moved, can impact important performance traits of hatchlings, including their speed and movement.

“Altering nest characteristics, such as substrate moisture and depth, could have consequences for hatchlings that we currently don’t understand,” says Mr. Dor.

“This means knowledge of hatchling behavior in the sand column—and its links to offspring success—is key to future conservation practices.”

While we know that in the scramble across the sand to the water, hatchlings are at great risk from predators, “it’s also true that some hatchlings don’t even make it to that point,” says A/Prof. Schwanz. “We have so little knowledge of what makes one hatchling successfully emerge while another doesn’t, so it’s really important that we figure out what might contribute to this.”

Opening the door to further research

The latest publication confirms that using accelerometers to monitor hatchlings provides many benefits, including data of movement and behaviors, and crucially, the ability to study turtles when our visibility of them is limited.

These findings have also provided new insights and changed previous assumptions about hatchlings’ earliest days in the sand.

“There are lots of factors that we don’t really understand because we haven’t been able to observe this stage of their lives, but we hope this will change as a result of this new method, particularly in answering questions about best conservation practices,” says Mr. Dor.

The following summer, Mr. Dor returned to Heron Island to put accelerometers on multiple hatchlings in a single nest.

“So, using the next year’s data, we’ll get a sense of how coordinated the nests are, because there is a theory about whether the turtles coordinate their movements, or if they have a division of labor,” says A/Prof. Schwanz.

More information:
David Dor et al, Swimming through sand: using accelerometers to observe the cryptic, pre-emergence life-stage of sea turtle hatchlings, Proceedings of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rspb.2024.1702

Citation:
Scientists use tiny ‘backpacks’ on turtle hatchlings to observe their movements (2024, October 2)
retrieved 2 October 2024
from https://phys.org/news/2024-10-scientists-tiny-backpacks-turtle-hatchlings.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





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How do ‘double skeptics’ affect government policy on climate and vaccination?

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How do ‘double skeptics’ affect government policy on climate and vaccination?


skeptical
Credit: Pixabay/CC0 Public Domain

Governments and other policymakers around the world wrestle with how to deal with people who are skeptical of official positions and guidelines, such as climate skeptics and antivaxxers.

Earlier research has linked such skepticism to distrust of scientists among members of the public, while other studies have shown that it is difficult to erode skeptical attitudes that are psychologically motivated by factors such as bias against elite institutions or a conservative world view.

New research from the University of Cambridge, reported in the journal PLOS ONE, suggests a more tailored approach could help dispel some of this skepticism, which could have implications for the way governments deal with skepticism among their constituents.

“The research shows that there are other approaches than addressing these issues in a one-size-fits-all manner,” said study co-author Dr. Zeynep Clulow from Cambridge Judge Business School. “There are different types of skeptics, so this requires different strategies aimed at dispelling skepticism.”

“These findings can help policymakers develop more targeted strategies and focus more attention on groups that are persuadable, rather than being resigned to considering every skeptic to be some consistent conspiracist on every issue,” said co-author Professor David Reiner, also from Cambridge Judge Business School.

The research analyzed the drivers of skepticism toward climate change and COVID-19 vaccination, based on a survey taken in early 2021 by polling firm Ipsos Mori, when most countries had been through the first wave of the pandemic and begun rolling out vaccination programs. Nationally-representative samples of 2,000 people were polled in each of eight countries: Australia, Brazil, China, India, Japan, South Africa, the UK and the US.

The study found that while the vast majority of people support COVID-19 vaccinations and recognize the threats posed by climate change, there were small groups who are skeptical of either climate change or COVID-19 vaccination, and an even smaller group who were skeptical of both.

For this smaller group of “double skeptics,” their attitudes were motivated by an underlying skeptical mindset, which was distrustful of institutions in general, including scientists and mainstream media.

Single-issue skeptics, in contrast, were primarily distrustful of scientists. The research found that people who completely distrust scientists were approximately four times more likely to be antivaxxers and five times more likely to be climate skeptics than double skeptics.

According to the researchers, this distinction suggests that efforts to overcome isolated predictors of skepticism—such as building trust in scientists, economic support and information campaigns—are more likely to boost support for policies designed to create societal responses to global challenges.

The same is not true for double skeptics: such strategies are likely to be ineffective or even counter-productive for people whose skepticism is associated with a more generalized skeptical worldview.

Double skeptics tend to possess many of the typical skeptic characteristics, such as high distrust in social institutions and right-wing political orientation, which are collectively suggestive of an underlying skeptic mindset rather than a specific distrust of scientists.

Reasons why distrust in scientists might drive skepticism on climate change and COVID-19 vaccination include the complex nature of both issues that make it difficult for non-scientists to fully understand, and the financial and behavioral costs related to mitigation of these issues.

The surveys asked respondents to rate their trust in university scientists as part of a broader question that also probed trust in institutions and actors ranging from corporations to environmental NGOs to television news. They were also asked to rate trust in certain specific sources, including oil and gas companies, Greenpeace, Greta Thunberg, and social media.

While many respondents showed some degree of skepticism (35% did not consider climate change a major threat to their country, and 17% were unlikely to take a COVID-19 vaccine if offered one), only a very small minority (1.4%) chose the most skeptical response towards both issues.

Even in the United States, only 4% of respondents were skeptical towards both issues and that group was less than 2% of the sample in the other seven countries. Similarly, less than 5% of respondents in six countries completely dismissed the threat of climate change (Australia at 9% and the US at 14% were higher).

The research also found that skepticism is inversely related with education, science knowledge, and perceived responsibility for combating climate change. Skepticism was higher among men, people who distrust television, and those with right-wing political views.

The researchers also found that people who prioritized the economy over the mitigation of climate change or COVID-19, or both, were significantly more likely to distrust scientists.

The researchers note two important limitations of their study sample: respondents in emerging economies were recruited from urban centers, so the views of rural citizens may not be accurately reflected; and Chinese respondents were not asked about their political views.

The other caveat is that the survey was taken when almost no one had received the COVID-19 vaccine and when many countries were still under some form of lockdown.

“While acknowledging that this was a particularly unusual time, we expect the finding that double skeptics comprise a small fraction of total pool of skeptics to be robust and we would expect to see this finding extended to other topics,” said Clulow.

“Painting all skeptics as irredeemable conspiracists is both counterproductive and incorrect,” said Reiner.

“Most climate skeptics are not very concerned about taking a vaccine and vice versa. Most skeptics are single-issue skeptics and will need to be engaged on the specifics of the issue, which will, no doubt, be challenging, but they do not exhibit the more fundamental, all-encompassing skepticism we find among double-skeptics that extends to all societal institutions and media outlets.”

More information:
How to distinguish climate sceptics, antivaxxers, and persistent sceptics: Evidence from a multi-country survey of public attitudes, PLoS ONE (2024). www.jbs.cam.ac.uk/wp-content/u … 3/12/eprg-wp2205.pdf

Citation:
How do ‘double skeptics’ affect government policy on climate and vaccination? (2024, October 2)
retrieved 2 October 2024
from https://phys.org/news/2024-10-skeptics-affect-policy-climate-vaccination.html

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part may be reproduced without the written permission. The content is provided for information purposes only.





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Study traces wild cat eye color diversity to ancient ancestor

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Study traces wild cat eye color diversity to ancient ancestor


Blue, green, gold: Why eyes of wild cats vary in color
Credit: iScience (2024). DOI: 10.1016/j.isci.2024.110903

Fans of Clementine, the cat who recently captivated TikTok with her rare eye color, should take note. The piercing golden gaze of cheetahs, the striking blue stare of snow leopards, and the luminous green glare of leopards are all traits that can be traced to one ancestor, an ocelot-like feline progenitor that roamed Earth more than 30 million years ago.

In a new study published in iScience, Harvard researchers say this ancestral population likely featured felines with both brown and gray eyes, the latter paving the way for the rapid and wide diversification of iris color seen in cat species today.

“When I started this study I asked, ‘What do we know about eye color?’ And the truth is, very little, as there are basically almost no phylogenetic evolutionary studies on eye color,” said lead author Julius Tabin, a Griffin Graduate School of Arts and Sciences student in the Department of Organismic and Evolutionary Biology.

Most studies focus on the distribution of eye colors in a species, or on the genes involved in making eye color in humans and domesticated animals. Studies on eye color in animal populations are rare due to the challenges of preservation and lack of diversity—most animals have brown eyes.

While eye color in humans is likely a result of sexual selection, and in domesticated animals a result of artificial selection, Tabin wondered what spurred the wide diversity in wild Felidae. Without fossil preservation to rely on, Tabin took a novel approach by analyzing digital images from sources such as iNaturalist to identify and categorize the varied eye colors in 52 felid taxa.

Tabin and co-author Katherine Chiasson, a Ph.D. candidate at Johns Hopkins University, created an algorithm to map iris colors onto a phylogenetic tree of Felidae.

“We found a lot of variability of color between species,” said Tabin, “but shockingly, we also found a lot of intraspecific variability. Most species have a singular eye color with no variation. So, it’s really surprising that once you get into the cats—lions, tigers, panthers, etc.— we see all these different eye colors. There are actually very few Felidae species that have only a singular eye color in their population.”

Equipped with the colors mapped onto the phylogenetic tree, the researchers set out to reconstruct the ancestral state. They found that early, pre-felid lineages (the ancestor of felids and their closest relatives, the linsangs) had brown eyes only. However, after the linsang species branched off, gray-eyed felines appeared alongside brown-eyed ones.

“It’s likely this happened due to a genetic mutation that drastically decreased the pigment in the eye,” Tabin said. Melanin can be either eumelanin, which is brown, or pheomelanin, which is yellow.

To go from a brown eye to a gray eye would require a decrease of eumelanin. That decrease would lead to an eye that is not fully brown and not fully gray, but a brownish gray color, which is what the researchers found.

Those gray-eyed felines opened the door to a burst of greens, yellows, and blues, providing an anchor between brown eyes and the new colors.

“Blue eyes require carefully balanced low levels of pigment and are likely recessive in felids. A wild population would probably not be able to maintain blue eyes in a population with only one blue-eyed individual among a sea of brown eyes.

“It’s probable that you would need something lighter than brown, but not as light as blue, to be the mediator. And that’s what you see: In every single cat species with blue eyes, they also have gray eyes,” said Tabin.

Tabin and Chiasson also observed that brown eyes and yellow eyes rarely coexist in a species. They said they were surprised to find a positive correlation between yellow eyes and round pupils, and a negative correlation between brown eyes and round pupils.

The researchers found no significant correlations for activity mode, zoogeographical region, habitat, and uniformity of eye color, which leaves the adaptive benefit of having varied eye colors an open question to pursue.

The researchers not only reconstructed the general eye color types present at each evolutionary node, but they were also able to predict the exact color of each ancestor’s eye.

“Being able to reconstruct color quantitatively is one of the paper’s greatest strengths, because it means we are the first animals to see the color of these eyes since these felids were alive millions of years ago,” Tabin said.

For Chiasson the study was special in part because all the resources they used are freely available online. “The fact that rigorous studies like ours can be done by anyone with an internet connection and some curiosity is indicative of a field-wide revolution that is increasing the accessibility of science around the world.”

The study opens an opportunity for more investigation of the evolutionary importance of gray eyes, as well as eye-color evolution in natural populations, Tabin said. “I’m still riding high on the excitement of knowing that the felid ancestor had both brown and gray eyes, because that’s something I didn’t go in expecting or even thinking about.”

More information:
Julius A. Tabin et al, Evolutionary insights into Felidae iris color through ancestral state reconstruction, iScience (2024). DOI: 10.1016/j.isci.2024.110903

Provided by
Harvard University


This story is published courtesy of the Harvard Gazette, Harvard University’s official newspaper. For additional university news, visit Harvard.edu.

Citation:
Study traces wild cat eye color diversity to ancient ancestor (2024, October 2)
retrieved 2 October 2024
from https://phys.org/news/2024-10-wild-cat-eye-diversity-ancient.html

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part may be reproduced without the written permission. The content is provided for information purposes only.





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