Friday, April 21, 2023

Study shows human tendency to help others is universal

People of diverse cultures are more similar than previously thought

UNIVERSITY OF SYDNEY

Professor Nick Enfield — IMAGE: PROFESSOR NICK ENFIELD, UNIVERSITY OF SYDNEY view more
CREDIT: UNIVERSITY OF SYDNEY

A new study on the human capacity for cooperation suggests that, deep down, people of diverse cultures are more similar than you might expect. The study, published in Nature Scientific Reports, shows that from the towns of England, Italy, Poland, and Russia to the villages of rural Ecuador, Ghana, Laos, and Aboriginal Australia, at the micro scale of our daily interaction, people everywhere tend to help others when needed. Our reliance on each other for help is constant: The study finds that, in everyday life, someone will signal a need for assistance (e.g., to pass a utensil) once every 2 minutes and 17 seconds on average. Across cultures, these small requests for assistance are complied with seven times more often than they are declined. And on the rare occasions when people do decline, they explain why. This human tendency to help others when needed—and to explain when such help can’t be given—transcends other cultural differences.

The findings help solve a puzzle generated by prior anthropological and economic research, which has emphasized differences among people of diverse cultures in how resources are shared. For example, while whale hunters of Lamalera in Indonesia follow distributional norms when sharing out a large catch, Hadza foragers of Tanzania share food more for fear of generating negative gossip; or while wealthier Orma villagers in Kenya are expected to pay for public goods such as road projects, such offers among the Gnau of Papua New Guinea are likely to be rejected as they would create an awkward obligation to reciprocate. Cultural differences like these present a challenge for our understanding of cooperation and helping in our species: Are our decisions about sharing and helping shaped by the culture we grew up with? Or are humans equally generous and giving by nature? This new global study finds that, while special occasions and high-cost exchange may attract cultural diversity, when we zoom in on the micro-level of social interaction, cultural difference mostly goes away, and our species’ tendency to give help when needed becomes universally visible.

This study was coordinated by Giovanni Rossi (UCLA) and Nick Enfield (University of Sydney), director of the European Research Council grant ‘Human Sociality and Systems of Language Use’. See below for full list of team members.

Figure 1. Locations of data collection.

Shared cross-cultural principles underlie human prosocial behavior at the smallest scale: Scientific Reports

Talking points

Small requests for assistance (e.g., to pass a utensil) occur on average once every 2 minutes and 17 seconds in everyday life around the world. Small requests are low-cost decisions about sharing items for everyday use or assisting others with tasks around the house or village. Such decisions are many orders more frequent than high-cost decisions such as sharing the spoils of a successful whale hunt or contributing to the construction of a village road, the sort of decisions that have been found to be significantly influenced by culture.
The frequency of small requests varies by the type of activity people are engaged in. Small requests are most frequent in task-focused activities (e.g., cooking), with an average of one request per 1 minute and 42 seconds, and least frequent in talk-focused activities (conversation for its own sake), with an average of one request per 7 minutes and 42 seconds.
Small requests for assistance are complied with, on average, seven times more often than they are declined; six times more often than they are ignored; and nearly three times more often than they are either declined or ignored. This preference for compliance is cross-culturally shared and unaffected by whether the interaction is among family or non-family.
A cross-cultural preference for compliance with small requests is not predicted by prior research on resource-sharing and cooperation, which instead suggest that culture should cause prosocial behavior to vary in appreciable ways due to local norms, values, and adaptations to the natural, technological, and socio-economic environment. These and other factors could in principle make it easier for people to say “No” to small requests, but this is not what we find.
Interacting among family or non-family does not have an impact on the frequency of small requests, nor on rates of compliance. This is surprising in light of established theories predicting that relatedness between individuals should increase both the frequency and degree of resource-sharing/cooperation.
People do sometimes reject or ignore small requests, but a lot less frequently than they comply. The average rates of rejection (10%) and ignoring (11%) are much lower than the average rate of compliance (79%).
Members of some cultures (e.g., Murrinhpatha speakers of northern Australia) ignore small requests more than others, but only up to about one quarter of the time (26%). A relatively higher tolerance for ignoring small requests may be a culturally evolved solution to dealing with “humbug”—pressure to comply with persistent demands for goods and services. Still, Murrinhpatha speakers regularly comply with small requests (64%) and rarely reject them (10%).
When people provide assistance, this is done without explanation, but when they decline, they normally give an explicit reason (74% of the time). Theses norms of rationalization suggest that while people decline giving help “conditionally”, that is, only for reason, they give help “unconditionally”, that is, without needing to explain why they are doing it.
When people decline assistance, they tend to avoid saying “No”, often letting the rejection being inferred solely from the reason they provide for not complying. Saying “No” is never found in more than one third of rejections. The majority of rejections (63%) consist instead of simply giving a reason for non-compliance.

Data collection

Our research is based in extensive field work and on the analysis of video recordings of social interaction in everyday home/village life in a set of geographically, linguistically, and culturally diverse field sites (see the Table 1 and Figure 1 below).

We identified and analyzed over one thousand request events in domestic and informal settings on five continents. We extracted these events from video recordings of everyday life featuring more than 350 individuals—family, friends, neighbors—representing eight diverse languages and cultures: Cha’palaa (northern Ecuador), Lao (Laos), Murrinhpatha (northern Australia), Siwu (eastern Ghana), English (UK/US), Italian (Italy), Polish (Poland), and Russian (Russia).

Language	Language family	Location	Data collected by	Coding and analysis by
Cha’palaa	Barbacoan	Ecuador	Floyd	Floyd
English	IE (Germanic)	UK/US	Rossi	Kendrick
Italian	IE (Romance)	Italy	Rossi	Rossi
Lao	Tai	Laos	Enfield	Enfield
Murrinhpatha	Southern Daly	Australia	Blythe	Blythe
Polish	IE (Slavic)	Poland	Zinken	Zinken
Russian	IE (Slavic)	Russia	Baranova	Baranova
Siwu	Kwa	Ghana	Dingemanse	Dingemanse

Table 1. Languages included in this study and authors responsible for data collection and analysis. (IE = Indo-European).

Attached Figure 1. Locations of data collection. (This map is published with the paper and can be used under a Creative Commons license that attributes the source, citing the paper)

What did we NOT do?

We did NOT rely on introspection or second-hand reports about the cultures we studied. Reports about how people interact with one another (e.g., how often they ask for help, or what they say to refuse help) are often skewed by biased impressions. Our findings are instead based on direct observation of naturally occurring interactions captured on high-definition video and audio. We collected first-hand audio/video recordings from around the world, and systematically compared what we saw.
We did NOT make people play economic games. Much prior research on resource-sharing used economic games (e.g., Ultimatum Game, Dictator Game) to compare prosocial behavior across cultures. This experimental approach poses issues of ecological validity: does people’s behavior in the experiment reflect what they would do in the real world? To overcome this, we observed unconstrained, spontaneous interactions among people; interactions that would have occurred without our study taking place. Another issue with economic-game experiments is that they typically require at least one participant to be anonymous. This means that social relations are not (fully) invoked in, or affected by, the decision made. By contrast, our focus on helping/sharing events among social familiars, happening in public and repeatedly, allowed us to study interactions with clear implications for relationships and reputation.
We did NOT study requests in formal or institutional exchanges, such as when buying something at a store, or getting assistance from an employee. Exchanges in workplace, business, or religious settings are constrained by institutional obligations and goals. This not only restricts how participants conduct themselves but also makes interactions harder to compare across cultures. Our focus was instead on maximally informal interaction in the home or village among people who know each other well: family, friends, neighbors. Informal interactions of this kind represent the most basic and primary sphere of social life, providing a solid baseline for comparison across cultures.
We did NOT study requests among strangers. Our interest was specifically in cooperation among social familiars with close and enduring relationships. While encounters among strangers are common in large-scale, industrialized societies, in many communities around the world it is rare to interact with someone and not know who they are or how they are related to you. Also, helping/sharing events among social familiars have clear implications for reputation and reciprocity.
We did NOT study big requests (e.g., to share scarce resources, to borrow a large sum of money, etc.). Prior economic-game research focused on high-stakes helping/sharing decisions and found them to be shaped by striking cultural diversity. Such decisions are relatively infrequent, and more susceptible to the influence of local norms, values, and the socio-economic environment. By contrast, small, low-cost requests are pervasive, and often motivated by similar kinds of needs and practicalities that permeate mundane life in communities around the world: people everywhere need others to pass items, help to make food, move heavy objects, etc. Another reason for focusing on small requests is that, while the fulfillment of big requests is often deferred, small requests are typically fulfilled immediately, in the next few seconds or minutes. This allows us to capture these events on video, from start to end, and analyze them in their entirety.

Who are the authors of this study?

Corresponding authors:

Giovanni Rossi (project coordinator and lead author)

N. J. Enfield (project leader and corresponding author)

Co-authors:

Mark Dingemanse

https://markdingemanse.net/

Julija Baranova

https://www.researchgate.net/profile/Julija-Baranova

Joe Blythe

Simeon Floyd (project coordinator)

Kobin H. Kendrick

Jörg Zinken

Related studies by the same research team

Gratitude goes without saying

https://royalsocietypublishing.org/doi/10.1098/rsos.180391

Getting others to do things

https://langsci-press.org/catalog/book/263

Universal principles in the repair of communication problems

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0136100

JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-30580-5

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Shared cross-cultural principles underlie human prosocial behavior at the smallest scale

ARTICLE PUBLICATION DATE

19-Apr-2023

COI STATEMENT

This study received funding from the European Research Council, the Australian Research Council, the Dutch Research Council, the Max Planck Society, the Academy of Finland, and the University of Sydney.

Disclaimer: AAAS and EurekAlert!

'Awesome' solar eclipse wows viewers in Australia, Indonesia

JAKARTA, Indonesia (AP) — Under a cloudless sky, 20,000 eclipse chasers crowded a tiny outpost to watch a rare solar eclipse plunge part of Australia's northwest coast into brief midday darkness Thursday while temporarily cooling the tropical heat.

The remote tourist town of Exmouth, with fewer than 3,000 residents, was promoted as one of the best vantage points in Australia to see the eclipse that also crossed remote parts of Indonesia and East Timor.

An international crowd had been gathering for days, camping in tents and trailers on a red, dusty plain on the edge of town with cameras and other viewing equipment pointed skyward.

NASA astronomer Henry Throop was among those at Exmouth cheering loudly in the darkness.

“Isn’t it incredible? This is so fantastic. It was mind-blowing. It was so sharp and it was so bright. You could see the corona around the sun there,” the visibly excited Washington resident said.

“It’s only a minute long, but it really felt like a long time. There’s nothing else you can see which looks like that. It was just awesome. Spectacular. And then you could see Jupiter and Mercury and to be able to see those at the same time during the day — even seeing Mercury at all is pretty rare. So that was just awesome,” Throop added.

First-time eclipse chaser Julie Copson, who traveled more than 1,000 kilometers (600 miles) north from the Australian west-coast port city of Fremantle to Exmouth, said the phenomenon left her skin tingling.

“I feel so emotional, like I could cry. The color changed and seeing the corona and sun flares …,” Copson said.

“It was very strong and the temperature dropped so much,” she added, referring to a sudden 5-degree-Celsius (9-degree-Fahrenheit) fall in temperature from 29 degrees Celsius (84 Fahrenheit) when the moon’s shadow enveloped the region.

It was the fifth eclipse for Detroit resident Shane Varrti, who began planning his trip to Exmouth a year ago.

“It’s very exciting. All this effort has come to fruition,” Varrti said.

In Indonesia's capital, hundreds came to the Jakarta Planetarium to see the partial eclipse that was obscured by clouds.

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Azka Azzahra, 21, came with her sister and friends to get a closer look by using the telescopes with hundreds of other visitors.

“I am still happy to come even though it is cloudy. It is happy to see how people with high enthusiasm come here to see the eclipse, because it is rare,” Azzahra said.

The call to prayer resounded from the city's mosques when the eclipse phase began as Muslims in the country with the world’s largest Muslim population said eclipse prayers as a reminder of God’s greatness.

In East Timor, people gathered around the beach in Lautem municipality, waiting to witness the rare solar eclipse through their eclipse glasses. Some of them came from other countries and gathered with locals to have a clear view of the eclipse.

“Timor Leste is one of the unique countries where the experience is less humid, less cloudy, so we are expecting a clear sky, that’s why many international astronomers wish to converge here. We are hoping that there is going to be a clear sky,” Zahri Bin Ahmad, astrophile from the South East Asia Astronomy Network of Brunei said as they waited Thursday.

People cheered as the sun and moon reached maximum eclipse.

“This is a very new natural phenomenon for Timor Leste. It is very important for us to be able to watch and experience it firsthand,” said Martinho Fatima, a civil protection authority officer.

The hybrid solar eclipse tracked from the Indian Ocean to the Pacific Ocean and was mostly over water. The lucky few people in its path either saw the darkness of a total eclipse or a “ring of fire” as the sun peeked from behind the new moon.

Such celestial events happen about once every decade: The last one was in 2013 and the next one isn’t until 2031. They occur when Earth is in the “sweet spot” so the moon and the sun are almost the exact same size in the sky, said NASA solar expert Michael Kirk.

At some points, the moon is a little closer and blocks out the sun in a total eclipse. But when the moon is a little farther away, it lets some of the sun’s light peek out in an annular eclipse.

“It’s a crazy phenomenon,” Kirk said. “You’re actually watching the moon get larger in the sky.”

Several other upcoming solar eclipses will be easier to catch. An annular eclipse in mid-October and a total eclipse in April 2024 will both cross over millions of people in the Americas.

___

Burakoff reported from New York. Associated Press journalist Rod McGuirk in Canberra, Australia, contributed to this report.

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.

Edna Tarigan And Maddie Burakoff, The Associated Press

Ridgecrest faults increasingly sensitive to solid Earth tides before earthquakes

Reports and Proceedings

SEISMOLOGICAL SOCIETY OF AMERICA

Faults in the Ridgecrest, California area were very sensitive to solid earth tidal stresses in the year and a half before the July 2019 Ridgecrest earthquake sequence, researchers reported at the Seismological Society of America (SSA)’s 2023 Annual Meeting.

“The signal of tidal modulation becomes extremely strong” after 2018, said Eric Beauce of Lamont-Doherty Earth Observatory, who noted that the signal was identified with seismicity that occurred around the faults that broke in the 2019 magnitude 7.1 earthquake.

The link does not mean that tidal stresses—which are very small compared to other tectonic stresses—triggered the earthquake, however.

“We don’t know if something started to happen in the fault zone, something that is an indicator of the upcoming earthquake,” Beauce said. “Maybe that process changed the properties of the crust in a way that made the crust be more sensitive to tidal stresses.”

Pulled by the same gravitational forces of sun and moon that create ocean tides, the solid earth also deforms in the same periodic way. People can’t feel the changes, but the ground deforms between 10 to 20 centimeters a day.

These solid tides “induce very, very small stress changes in the crust,” Beauce explains, “which can induce stress changes in all the faults within the crust.”

Although researchers have known about these tiny stress changes for more than a century, it has been difficult to extract their signal from the seismic record, and to determine whether they modulate seismicity.

In the past ten years, however, better earthquake detection and analysis techniques have made it possible to search through earthquake catalogs to find the signal of tidal stresses, Beauce said.

He and his colleagues built a rich, high-resolution earthquake catalog, using machine learning algorithms along with other techniques, for the past decade of microseismicity in the Ridgecrest area. (Microseismicity usually refers to earthquakes of magnitude 2.0 or smaller).

They found that “there is suggestive evidence that peak seismicity happens when tidal stresses are maximum,” Beauce said, “but this modulation is weak, and because it is weak, it is only suggested.”

Other researchers looking at the 2004 Indian Ocean and 2011 Tohoku megathrust earthquakes have detected an increase in modulation of seismicity connected to tidal stresses, decades before the earthquakes, said Beauce. And some scientists have been able to generate similar results in lab-created earthquake experiments.

The tidal findings do not have direct implications for earthquake forecasting, “as we do not know if we are looking at a general phenomenon or one specific to the Ridgecrest earthquake only, said Beauce, “but I see it as a way of getting new observational constraints on the physics of earthquakes, possibly the preparation and nucleation of earthquakes.”

METHOD OF RESEARCH

Observational study

When an earthquake strikes, how do Mexico city hospitals respond?

Reports and Proceedings

SEISMOLOGICAL SOCIETY OF AMERICA

Staff in public and private hospitals in Mexico City are likely to follow well-established and reinforced earthquake early warning (EEW) protocols for evacuation, according to an ongoing study.

Overall, staff are likely to follow the protocols especially when they are “reinforced with drills that help practice the correct protective action,” said Sandra Vaiciulyte of Universidad Nacional Autónoma de México. She discussed her research at the Seismological Society of America (SSA)’s 2023 Annual Meeting.

In the study, there have been “no accounts of injuries of patients and staff because of the particular reaction by staff,” Vaiciulyte said. “In general, the correct protective action—following the protocol—has great impact in safeguarding people from injuries and protecting lives in hazardous situations.”

Vaiciulyte and her colleagues wanted to learn more about how EEW protocols have impacted the vulnerable hospital population, since Mexico City introduced its public earthquake warning system in 1991.

The research team is carrying out in-depth interviews to find out what the existing EEW protocols are for hospitals and how staff and patient populations respond to these protocols and earthquakes.

Hospital EEW protocols can include a variety of protective actions, including sheltering in a secure place in a building, evacuation procedures, drop-cover-hold on behavior and turning off equipment where necessary.

A hospital’s specific protocols are shaped by several elements, said Vaiciulyte. “So far, the determining factor for the preparedness to respond to an earthquake or EEW has shown to depend on the individual hospital management capacity as well as the geographic location of the hospital, which determines to what extent the hospital is exposed to earthquake consequences” depending on their seismic micro-zones.

Other factors such as building structure, which can control how easy it is to evacuate, and the hospital’s purpose—whether it has a large intensive care unit population, for instance—affect a specific hospital’s protocols.

“These existing differences also affect the challenges with developing and maintaining the protocol,” Vaiciulyte said. “For example, for children’s hospitals ingress—entering the hospital from the outside—during an earthquake or EEW is more likely by the parents who are worried about their children.”

The study aims to include four hospitals, but “the hospital staff experiences are often more diverse, stemming beyond just one or several earthquake events within the specific studied hospital,” she noted. “That means that additional accounts of their experience in other hospitals are also taken into consideration.”

Obtaining permission to talk to staff can be challenging for some hospitals, so the research team is supplementing its survey with consultations with civil protection and EEW providers in Mexico.

The researchers did find some instances where staff members evacuated against protocol or raised their voices in an anxious or hysterical way, “which often has shown to be related to that individual staff member’s negative experience in an earthquake in the past, or a lower threshold of handling stressful situations,” said Vaiciulyte.

“These are anecdotal accounts, but nonetheless important in thinking about the potential strategies in helping hospital staff to deal with their own and patients’ reactions, especially when many individuals in Mexico City have been through several devastating earthquakes,” she added.

Vaiciulyte has also studied how people behave in fire events, noting some similarities like an initial hesitation about what to do, nervousness when cues like ground shaking or the smell of smoke occur, and the potential for injuries when evacuating. “In both situations, the response time is very limited before the effects of the hazard can be felt,” she said.

SAY NO TO SEA BED MINING

Scientists discover three new hydrothermal vent fields on Mid-Atlantic Ridge

Grant and Award Announcement

SCHMIDT OCEAN INSTITUTE

Newly Discovered Hydrothermal Vent Field on Puy des Folles Seamount in the Mid-Atlantic Ridge — IMAGE: THIS HIGH-TEMPERATURE HYDROTHERMAL VENT FIELD WAS DISCOVERED DURING THE EXPEDITION ON PUY DES FOLLES SEAMOUNT IN THE MID-ATLANTIC RIDGE, AT APPROXIMATELY 2000 METERS DEEP. view more
CREDIT: SCHMIDT OCEAN INSTITUTE

San Juan, Puerto Rico – Scientists have discovered three new hydrothermal vent fields over a 434-mile-long stretch of the Mid-Atlantic Ridge during the first scientific expedition aboard Schmidt Ocean Institute's recently launched research vessel Falkor (too).

The multidisciplinary science team representing 11 institutions from the United States, Canada, and France used advanced ocean technologies to make the discovery. Scientists used autonomous and remotely operated underwater vehicles resulting in 65 square miles (170 square kilometers) of seafloor mapped at one-meter scale resolution, an area approximately the size of Manhattan Island.

The discovery of the active hydrothermal vents is the first on this section of the world's longest underwater mountain range, the mid-Atlantic Ridge, in more than 40 years. One of the discovered vent fields was located at the Puy des Folles volcano and has five active sites over 6.95 square miles (18 square kilometers). High-temperature ‘black smoker’ vents were also found at the Grappe Deux vent system and Kane Fracture Zone.

“This cruise exceeded expectations with the discovery of so many amazing hydrothermal vents vibrant with life,” said Dr. Jyotika Virmani, executive director of Schmidt Ocean Institute. “We are delighted with the new capability that Falkor (too) brings to the ocean science community, including the ability to put multiple different types of technology in the water simultaneously. The dedication of the scientists and crew, along with the capabilities of the ship, was evident in the success of this expedition and we look forward to more.”

The Mid-Atlantic ridge is a target area for deep-sea mining and exists in international waters, also known as “The High Seas”. All mineral-resources-related activities in the area are regulated by the International Seabed Authority, established by the United Nations. The ISA is currently considering whether to allow deep sea mining.

Active hydrothermal vents are rich in metal sulfide deposits– mineral ore often affiliated with copper and zinc. In exploring the vents for the first time, scientists found rich biological communities. The vents were teeming with marine life including massive swarms of vent shrimp and a rare sighting of big fin squid. Many species found on vents live off chemical energy (chemosynthesis) instead of energy from sunlight, which doesn’t reach those depths.

Scientists are still learning about how these ecosystems function and the role they play for cycling carbon on our planet. The impacts deep-sea mining would have on hydrothermal vent ecosystems is unknown, and the discovery of active marine life underscores the need for more research to understand the effects.

“Regional Environmental Management Plans for regulating ocean mining require accurate scientific data on the presence of animal communities and an understanding of how sites are colonized,” said Chief Scientist, Dr. David Butterfield, Principal Research Scientist with the Cooperative Institute for Climate, Ocean, and Ecosystem Studies at the University of Washington and Group Leader for the Earth Ocean Interactions Program at NOAA Pacific Marine Environmental Lab in Seattle. “There is some agreement that sites with active venting and chemosynthetic vent fauna communities should be excluded from mining because of the very limited extent of hydrothermal vent habitat, which is restricted to a narrow band of activity on the global mid-ocean ridge system.”

The inaugural 40-day expedition on R/V Falkor (too) began in March. The new vessel will be utilized for global ocean exploration, focused on a new region of the world each year. The next expedition will begin April 17 exploring deep sea coral.

"Falkor (too)'s inaugural expedition has demonstrated all that's possible when you bring together scientists from around the world and give them access to the latest tools and technology, all aboard a collaborative floating laboratory," said Wendy Schmidt, co-founder and president of Schmidt Ocean Institute. "The discoveries on this expedition underscore how much we have yet to learn about deep sea ecosystems---and why, before marching ahead with mining or other potentially damaging activities, we need to learn more about our unknown ocean."

This high-temperature hydrothermal vent field was discovered during the expedition in the Mid-Atlantic Ridge. Within hydrothermal vents, seawater chemically altered through water-rock interactions at high temperatures is expelled through geological formations called chimneys.

A mapping Autonomous Underwater Vehicle (AUV) is recovered to the Research Vessel Falkor(too) over the Mid-Atlantic Ridge. The AUV was equipped with multiple sensors to produce 1-meter-scale seafloor bathymetry maps and detect plume signals that indicate possible source areas for hydrothermal vents. The bathymetry and overlaid plume signals provided researchers with an indication of where the Remotely Operated Vehicle (ROV) dive could start. This strategy proved to be extremely successful, as the team discovered several new hydrothermal vent fields during the expedition.

CREDIT

Schmidt Ocean Institute

Whales stop by Gold Coast bay for day spa fix with full body scrubs

Peer-Reviewed Publication

GRIFFITH UNIVERSITY

Rolling humpback whales — IMAGE: BOTTOM CONTACT BEHAVIOUR DOCUMENTED WITH CATS CAMERA. SCREEN SHOTS SHOWING AN ACCOMPANYING WHALE ON ITS BACK DURING SAND ROLLING (A1) AND AN ACCOMPANYING WHALE MOVING ITS PECTORAL FIN OVER THE SUBSTRATE FROM TAG A (A2). SAND ROLLING PERFORMED BY AN ACCOMPANYING WHALE DURING DEPLOYMENT OF TAG (B) AND THE TAGGED INDIVIDUAL USING ITS PECTORAL FIN BEFORE ROLLING ON ITS BACK FROM TAG (C) view more
CREDIT: OLAF MEYNECKE

A new Griffith University study has found that humpback whales will use sandy, shallow bay areas to ‘roll’ around in sandy substrates to remove dead skin cells on their return journeys south to cooler waters.

Marine ecologist Dr Olaf Meynecke, from the Griffith-led Whales and Climate Research Program and Coastal and Marine Research Centre, used suction cup tags to track southward migrating whales between August 2021 and October 2022.

The CATS tags are fitted with integrated high-definition video, magnesium release system, a VHF transmitter for retrieval, magnetometers, a hydrophone and light, pressure, temperature and GPS sensors.

Using data and footage collected from the tags, whales were observed performing full and side rolls in up to 49m water depth on the sea floor that was lined with fine sand or rubble.

“On all occasions of sand rolling, the whales were observed on video to be slowly moving forward with their head first into the sand followed by rolling to one side or a full roll,” Dr Meynecke said.

“During the different deployments, the sand rolling was observed in the context of socialising. The behaviour was either following courtship, competition or other forms of socialising.

“So we believe that the whales exfoliate using the sand to assist with moulting and removal of ectoparasites such as barnacle and specifically select areas suitable for this behaviour.”

In tropical and subtropical waters, barnacles attach to the whales in their early life stages, and whales need to remove barnacles frequently to avoid excessive growth that leads to drag and energy loss.

“Humpback whales host diverse communities of skin bacteria that can pose a threat for open wounds if bacteria grow in large numbers,” Dr Meynecke said.

“Removing excess skin is likely a necessity to maintain a healthy bacterial skin community. Humpback whales can remove some barnacles and skin through surface activity such as breaches but not all.”

Skin from the whales was observed to be falling off during the process of all identified rolls, and fish such as juvenile silver trevally were seen to be actively feeding from the whales’ skin during this behaviour similar to cleaning stations are coral reefs.

The research Exfoliating Whales–Sandy Bottom Contact Behaviour of Humpback Whales has been published in Marine Science and Engineering.

This research was assisted by Sea World Research and Rescue Foundation and supported by funding to the Whales and Climate Research Program.

Footage of humpback whales 'ex [VIDEO] |