Killer whales use seaweed as tools to groom each other
June 24 (Reuters) - Killer whales are known for exceptional intelligence, displaying complex social structures and sophisticated communication. New research provides fresh evidence for this, documenting how these marine mammals use stalks of seaweed as tools to groom each other - as in, "You scratch my back and I'll scratch yours."
Using drones to observe a population of killer whales in the Salish Sea, part of the Pacific Ocean between Washington state and British Columbia, researchers noticed that these predators engaged in a behavior they named "allokelping," one of the few known examples of tool use by marine mammals.
The killer whales find large stalks of a type of seaweed called bull kelp, either attached to the seabed or floating at the surface. They then bite off the end of the stalk, position it between themselves and another killer whale and roll the kelp between their bodies.
The researchers hypothesize that the behavior promotes skin health while strengthening social bonds. Other populations of killer whales have been observed rubbing their bodies on smooth stone beaches, possibly to remove dead skin.
"Most examples of tool use in animals involve solving ecological problems, such as gaining access to food. For example, chimpanzees use sticks to fish for termites. What's remarkable about this discovery is that the tool - the kelp - is used not to obtain food but to facilitate social interaction," said marine biologist Darren Croft of the University of Exeter in England, co-author of the study published this week in the journal Current Biology, opens new tab.
"This kind of socially motivated tool use is extremely rare in non-human animals and has previously only been observed in a small number of primates, usually in captivity," added Croft, executive director of the Center for Whale Research, a scientific organization based in Washington state that has studied this population of killer whales since the 1970s.
The researchers documented the behavior among both male and female killer whales of all ages. It likely plays an important role in their social lives, Croft said.
There are some other examples of tool use among marine mammals. Sea otters use rocks and other hard objects to crack open shells to get at the meat inside. And certain dolphins use marine sponges to protect their snouts and stir up the seabed while foraging. The researchers said the behavior by the killer whales goes one step further because they modify an object for use as a tool.
"While this is not the first documented case of cetacean or marine mammal tool use, it is - as far as we know - the first case of cetacean tool manufacturing with tool use. The whales are not just finding perfect lengths of kelp in the environment, but rather actively modifying larger intact stalks of kelp to create the pieces they are using for allokelping," said study co-author Rachel John, a University of Exeter graduate student studying killer whale behavior.
"Another key part of what makes this behavior so unique is the fact that they are manipulating the kelp cooperatively with a partner without the use of hands or any hand-like appendages. They use their mouth to position the kelp initially, but after that they only use the momentum and pressure of the core of their bodies to maintain contact with each other and the kelp between them," John added.
The behavior is known only among this killer whale population.
"We found that individuals with more visible peeling skin were more likely to engage in allokelping, suggesting that the behavior may serve a skin-care function. Brown seaweeds like kelp are known to have antibacterial properties, so it's plausible that rubbing with kelp helps improve skin health," Croft said.
"Second, we think this behavior likely plays a role in maintaining social bonds. Physical contact is known to be important for social cohesion in many species, including humans. Just as we might hug a friend we haven't seen in a while, it's possible that allokelping serves to reinforce social relationships among whales," Croft added.
This kelp grows in cold and nutrient-rich coastal and intertidal waters and thrives off the western coast of North America, which includes the home range of these killer whales.
This population is at grave risk of extinction, Croft said, with only 73 individuals counted in the latest census. They are highly specialized salmon hunters, particularly reliant on Chinook salmon. As salmon populations have declined, in part due to dam-building on spawning rivers, the whales have struggled to find enough food.
"In short, they are starving," Croft said.
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The Guardian
19 hours ago
- The Guardian
‘Positive cascades could help accelerate change': social tipping points expert on fixing climate crisis
Timothy Lenton is a professor of climate change and Earth system science at the University of Exeter. He started working on tipping points in the 1990s, making him one of the first scientists in the world to study this form of planetary risk. In an upcoming book, Positive Tipping Points: How to Fix the Climate Crisis, he argues the Earth has entered an 'unstable period' but humanity can still prevail if we can trigger positive social and economic tipping points to reverse the damage that has already been done. On 30 June, he will host a global conference on tipping points. How do you define a tipping point?A tipping point is where change becomes self-propelling within a system, meaning it will shift from one state to another. That can happen because the balance of feedback in the system switches from damping feedback to amplifying feedback. The result can look very rapid and irreversible. How has our understanding of these risks changed?We first published a map of climate tipping elements in 2008, Since then, we have added much more than we have subtracted from that map. And, unfortunately, in the intervening 17 years, the evidence suggests we're much closer to some of these tipping points than we thought. Which tipping points might we have passed?Things are undoubtedly happening faster than anticipated. The tipping points of greatest concern include the West Antarctic ice sheet, where the loss of a significant chunk of the ice sheet is self-propelling, which could raise the world's sea levels by about 1.2 metres. There is also the Greenland ice sheet, which is losing mass at an accelerating rate. Then we have the permafrost, parts of which are already passing localised tipping points – and that's adding methane and carbon dioxide to the atmosphere. Then there's the unprecedented bleaching and dieback of coral reefs, which hundreds of millions of people depend on for their livelihoods. And which are close?There's a tipping point in the circulation of the north Atlantic Ocean, when deep water stops forming in the middle of the subpolar gyre south-west of Greenland. That system seems quite volatile, and a tipping point there is like a small version of a bigger tipping point of the Atlantic meridional overturning circulation (Amoc), which studies suggest is at much greater risk than we thought even a few years ago. That in turn could trigger monsoon tipping points in west Africa and India. I'd also note the risk of tipping Amazon rainforest dieback from a mixture of climate change and direct human disruption. Unfortunately, I could reel off quite a few more. How accurate are the predictions?If anything, we have underestimated the risks. When we did our first assessment in 2008, we thought Greenland was close to a big tipping point. We haven't changed that judgment, but we thought West Antarctica would need at least 3C of warming [above pre-industrial levels]. Unfortunately, everything that's been observed since suggests we were way too optimistic. As a rule, the more we learn, the closer we think the tipping points are – and meanwhile we've been warming the planet up. It's like running faster into a sea that is rising to drown us. Why has it taken so long for the world to talk about these catastrophic threats?In the climate science community, we have tended to concentrate on assessing what's the most likely thing to happen, but the more important question is: what's the worst thing that could happen? That's the difference between a scientific assessment and a risk assessment. I would argue we've not been treating climate change as a risk assessment. That is also because a lot of well-funded entities have been systematically undermining the knowledge consensus on climate change, which has forced the scientific community to defend what's in effect 19th-century physics. That hasn't put us in a great position to emphasise tipping point risks, which inherently have more uncertainty around them. Why do we need to talk about them now?Because tipping point risks are real and potentially existential. If we have a tipping point in the Atlantic Ocean – the so-called Amoc – we could lose more than half the area for growing staple crops worldwide. It would cause water security crises and severely disrupt the monsoons in west Africa and India, which would affect billions of people. We have to level up to those risks, better understand them and how close they are, and what things we can do in response. Even if we can't stop the events happening, we can do things that reduce the vulnerability of people exposed to the risks. That is why we are drawing attention to tipping points. This is not as a council of despair; on the contrary, it is more like a council of practicality. In terms of the upfront costs to decarbonise the global economy, it is a great investment for the return you get, which is lowering the risk of otherwise catastrophic outcomes. It would help if the IPCC [the United Nations Intergovernmental Panel on Climate Change] took a more in-depth look at tipping points. A large number of countries wanted to see an IPCC special report on tipping points in this assessment cycle, but the IPCC said no. Instead there's due to be a chapter in the next assessment report. Is there an alternative?Yes. I and more than 200 other researchers have published a global tipping points report, and we're writing another one for Cop30, [the UN climate change summit which takes place in Brazil, in November]. We felt the risk was important to communicate and this is a timely moment. So we are trying to fill in the assessment gap in an accessible way. People are crying out for that. I understand the global tipping points conference will also look at positive tipping points in technology, economics and politics?Yes. [There are some] more optimistic scenarios; the impacts of wind power and photovoltaic innovation, or the knock-on effects of campaigning by Greta Thunberg and others. There are also policy feedbacks that could create a change in the landscape in a good way, where you start a policy path towards the renewable energy revolution that's very hard to reverse. That is arguably what the architects of the German feed-in tariffs for renewables managed to do. They made it hard for the doubters to change course even after a change of government. Has renewable energy reached a positive tipping point?Yes, our analysis suggests that solar photovoltaic power is now in a phase of self-propelling global uptake with exponential growth of installed generating capacity, doubling every two years or less. Factoring in the cost of battery storage, solar is already the cheapest source of new power in most of the world, and for every doubling of installed capacity its price drops by nearly a quarter. This is rapidly making solar power the cheapest source of electricity ever, which brings many benefits, including access to electricity for the roughly 700 million people who don't currently have it. And electric vehicles?Yes, the price of batteries plummeted nearly tenfold in a decade as the range you can get from a given mass of battery increased by nearly a factor of three. This has brought China and several European markets to the tipping point where adoption of EVs is self-propelling: the more EVs that get bought, the better and the cheaper they get, encouraging further adoption. The US is lagging behind, but the global south is starting to reap the benefits of electrifying mobility, as it is much cheaper to run an electric rickshaw in India or an electric motorbike taxi in east Africa than their fossil-fuelled equivalents. Any other examples of potential positive tipping points?I'm working on regenerative nature. We already see cases where degraded ecosystems have been tipped back into a better state – for example, when wolves were reintroduced to Yellowstone National Park and started preying on elk, it triggered abrupt vegetation recovery, or when sea otters returned to north Pacific coastal ecosystems and started feasting on sea urchins it tipped the recovery of kelp forests. We also see social tipping points that are nature-positive, where community conservation initiatives, like locally managed marine protected areas, spread rapidly and widely among and across societies. Can you explain cascading feedbacks?In all complex systems – such as the climate and the economy – if you can tip one thing, it can have consequences for other bits of the system. If you tip one part of the system it can make tipping another part of the system more likely. For example, if you've suffered a medical shock it can have knock-on effects on other parts of the body. In the climate, these causal connections can be quite significant and strong. In Earth's history, when there were tipping points in the overturning circulation of the Atlantic Ocean, that tipped major shifts in the tropical monsoons of west Africa and India. In the economy, a cascade can be more positive. For example, an investment in renewable energy can bring forward a tipping point in other sectors. It basically means renewables are making electricity cheaper than it has ever been, and that incentivises electrifying mobility, like cars and trucks and buses, or electrifying heating in homes. At the same time, batteries get cheaper because of economies of scale, which then helps to balance renewable electricity supply and demand. So feedbacks between sectors of the economy can create tipping points that reinforce each other. We've recently mapped out a bunch of positive tipping cascades that could help accelerate change to zero greenhouse gas emissions. What should the world do at Cop30 in Belém to address tipping points?We need policymakers to implement policies that bring forward the positive tipping points we need to stop greenhouse gas emissions and prevent the bad climate tipping points. If the EU and China were to coordinate, it could be enough to shift the balance towards clean green alternatives. Even with Trump in the United States, the beauty of tipping points is you don't need everybody, you typically only need a fifth to tip to the new alternative and then you get to a situation where everybody else is compelled to follow. Tipping points – in the Amazon, Antarctic, coral reefs and more – could cause fundamental parts of the Earth system to change dramatically, irreversibly and with devastating effects. Here, we ask the experts about the latest science – and how it makes them feel. Read more
The Guardian
a day ago
- The Guardian
‘Positive cascades could help accelerate change': social tipping points expert on fixing climate crisis
Timothy Lenton is a professor of climate change and Earth system science at the University of Exeter. He started working on tipping points in the 1990s, making him one of the first scientists in the world to study this form of planetary risk. In an upcoming book, Positive Tipping Points: How to Fix the Climate Crisis, he argues the Earth has entered an 'unstable period' but humanity can still prevail if we can trigger positive social and economic tipping points to reverse the damage that has already been done. On 30 June, he will host a global conference on tipping points. How do you define a tipping point?A tipping point is where change becomes self-propelling within a system, meaning it will shift from one state to another. That can happen because the balance of feedback in the system switches from damping feedback to amplifying feedback. The result can look very rapid and irreversible. How has our understanding of these risks changed?We first published a map of climate tipping elements in 2008, Since then, we have added much more than we have subtracted from that map. And, unfortunately, in the intervening 17 years, the evidence suggests we're much closer to some of these tipping points than we thought. Which tipping points might we have passed?Things are undoubtedly happening faster than anticipated. The tipping points of greatest concern include the West Antarctic ice sheet, where the loss of a significant chunk of the ice sheet is self-propelling, which could raise the world's sea levels by about 1.2 metres. There is also the Greenland ice sheet, which is losing mass at an accelerating rate. Then we have the permafrost, parts of which are already passing localised tipping points – and that's adding methane and carbon dioxide to the atmosphere. Then there's the unprecedented bleaching and dieback of coral reefs, which hundreds of millions of people depend on for their livelihoods. And which are close?There's a tipping point in the circulation of the north Atlantic Ocean, when deep water stops forming in the middle of the subpolar gyre south-west of Greenland. That system seems quite volatile, and a tipping point there is like a small version of a bigger tipping point of the Atlantic meridional overturning circulation (Amoc), which studies suggest is at much greater risk than we thought even a few years ago. That in turn could trigger monsoon tipping points in west Africa and India. I'd also note the risk of tipping Amazon rainforest dieback from a mixture of climate change and direct human disruption. Unfortunately, I could reel off quite a few more. How accurate are the predictions?If anything, we have underestimated the risks. When we did our first assessment in 2008, we thought Greenland was close to a big tipping point. We haven't changed that judgment, but we thought West Antarctica would need at least 3C of warming [above pre-industrial levels]. Unfortunately, everything that's been observed since suggests we were way too optimistic. As a rule, the more we learn, the closer we think the tipping points are – and meanwhile we've been warming the planet up. It's like running faster into a sea that is rising to drown us. Why has it taken so long for the world to talk about these catastrophic threats?In the climate science community, we have tended to concentrate on assessing what's the most likely thing to happen, but the more important question is: what's the worst thing that could happen? That's the difference between a scientific assessment and a risk assessment. I would argue we've not been treating climate change as a risk assessment. That is also because a lot of well-funded entities have been systematically undermining the knowledge consensus on climate change, which has forced the scientific community to defend what's in effect 19th-century physics. That hasn't put us in a great position to emphasise tipping point risks, which inherently have more uncertainty around them. Why do we need to talk about them now?Because tipping point risks are real and potentially existential. If we have a tipping point in the Atlantic Ocean – the so-called Amoc – we could lose more than half the area for growing staple crops worldwide. It would cause water security crises and severely disrupt the monsoons in west Africa and India, which would affect billions of people. We have to level up to those risks, better understand them and how close they are, and what things we can do in response. Even if we can't stop the events happening, we can do things that reduce the vulnerability of people exposed to the risks. That is why we are drawing attention to tipping points. This is not as a council of despair; on the contrary, it is more like a council of practicality. In terms of the upfront costs to decarbonise the global economy, it is a great investment for the return you get, which is lowering the risk of otherwise catastrophic outcomes. It would help if the IPCC [the United Nations Intergovernmental Panel on Climate Change] took a more in-depth look at tipping points. A large number of countries wanted to see an IPCC special report on tipping points in this assessment cycle, but the IPCC said no. Instead there's due to be a chapter in the next assessment report. Is there an alternative?Yes. I and more than 200 other researchers have published a global tipping points report, and we're writing another one for Cop30, [the UN climate change summit which takes place in Brazil, in November]. We felt the risk was important to communicate and this is a timely moment. So we are trying to fill in the assessment gap in an accessible way. People are crying out for that. I understand the global tipping points conference will also look at positive tipping points in technology, economics and politics?Yes. [There are some] more optimistic scenarios; the impacts of wind power and photovoltaic innovation, or the knock-on effects of campaigning by Greta Thunberg and others. There are also policy feedbacks that could create a change in the landscape in a good way, where you start a policy path towards the renewable energy revolution that's very hard to reverse. That is arguably what the architects of the German feed-in tariffs for renewables managed to do. They made it hard for the doubters to change course even after a change of government. Has renewable energy reached a positive tipping point?Yes, our analysis suggests that solar photovoltaic power is now in a phase of self-propelling global uptake with exponential growth of installed generating capacity, doubling every two years or less. Factoring in the cost of battery storage, solar is already the cheapest source of new power in most of the world, and for every doubling of installed capacity its price drops by nearly a quarter. This is rapidly making solar power the cheapest source of electricity ever, which brings many benefits, including access to electricity for the roughly 700 million people who don't currently have it. And electric vehicles?Yes, the price of batteries plummeted nearly tenfold in a decade as the range you can get from a given mass of battery increased by nearly a factor of three. This has brought China and several European markets to the tipping point where adoption of EVs is self-propelling: the more EVs that get bought, the better and the cheaper they get, encouraging further adoption. The US is lagging behind, but the global south is starting to reap the benefits of electrifying mobility, as it is much cheaper to run an electric rickshaw in India or an electric motorbike taxi in east Africa than their fossil-fuelled equivalents. Any other examples of potential positive tipping points?I'm working on regenerative nature. We already see cases where degraded ecosystems have been tipped back into a better state – for example, when wolves were reintroduced to Yellowstone National Park and started preying on elk, it triggered abrupt vegetation recovery, or when sea otters returned to north Pacific coastal ecosystems and started feasting on sea urchins it tipped the recovery of kelp forests. We also see social tipping points that are nature-positive, where community conservation initiatives, like locally managed marine protected areas, spread rapidly and widely among and across societies. Can you explain cascading feedbacks?In all complex systems – such as the climate and the economy – if you can tip one thing, it can have consequences for other bits of the system. If you tip one part of the system it can make tipping another part of the system more likely. For example, if you've suffered a medical shock it can have knock-on effects on other parts of the body. In the climate, these causal connections can be quite significant and strong. In Earth's history, when there were tipping points in the overturning circulation of the Atlantic Ocean, that tipped major shifts in the tropical monsoons of west Africa and India. In the economy, a cascade can be more positive. For example, an investment in renewable energy can bring forward a tipping point in other sectors. It basically means renewables are making electricity cheaper than it has ever been, and that incentivises electrifying mobility, like cars and trucks and buses, or electrifying heating in homes. At the same time, batteries get cheaper because of economies of scale, which then helps to balance renewable electricity supply and demand. So feedbacks between sectors of the economy can create tipping points that reinforce each other. We've recently mapped out a bunch of positive tipping cascades that could help accelerate change to zero greenhouse gas emissions. What should the world do at Cop30 in Belém to address tipping points?We need policymakers to implement policies that bring forward the positive tipping points we need to stop greenhouse gas emissions and prevent the bad climate tipping points. If the EU and China were to coordinate, it could be enough to shift the balance towards clean green alternatives. Even with Trump in the United States, the beauty of tipping points is you don't need everybody, you typically only need a fifth to tip to the new alternative and then you get to a situation where everybody else is compelled to follow. Tipping points – in the Amazon, Antarctic, coral reefs and more – could cause fundamental parts of the Earth system to change dramatically, irreversibly and with devastating effects. Here, we ask the experts about the latest science – and how it makes them feel. Read more
Daily Mail
2 days ago
- Daily Mail
Scientists pinpoint diet tweak that can help people lose 1lb a week without counting calories
Ditching meat for a just a few months could help you lose almost a pound a week, shock new research has suggested. US scientists found that overweight adults who went vegan for roughly four months were just over 13lbs (6kg) lighter by the end of the study. They credited the slimming effect to plant-based diets—those devoid of meat, dairy and eggs—producing less acid during digestion. Researchers said the higher levels 'dietary acid' produced by animal products increased inflammation in the body. This in turn disrupts the delicate internal processes in the body— like the metabolism and hormone production—contributing to weight gain, they explained. Dr Hana Kahleova, an expert in nutrition from the Physicians Committee for Responsible Medicine in Washington and lead author of the new study, claimed the findings show the benefits of embracing veganism. 'Replacing animal products with plant-based foods like leafy greens, berries, and legumes can help promote weight loss and create a healthy gut microbiome,' she said. In the study, 62 overweight adults were put on either a vegan-diet or the health-focused Mediterranean diet for 16 weeks. The latter emphasises eating fresh vegetables, healthy fats such as those from olive oil and nuts and lean meats like fish and chicken. Participants' body weight was measured before and after the diet. Then—after a four week break—the group did another 16 weeks on the other diet. This allowed researchers to compare weight loss across the two diets using the same participants. Scientists also compared the 'dietary acid' scores of the foods the participants consumed across the two diets. At the study's conclusion, the vegan diet saw participants lose an average of 13.2 lbs (6kg) in 16 weeks, roughly 13oz (375g) per week. By contrast, those on the Mediterranean diet didn't experience any significant weight loss, the authors said. Writing in the journal the Frontiers in Nutrition, they recommended dieters looking to slim down to incorporate more fruit, vegetables and grains that counteract dietary acid— a process called alkalising—into their diet. The team specifically highlighted vegetables like leafy greens, broccoli, beets, asparagus, garlic, carrots, and cabbage. For fruits, they recommended berries, apples, cherries, apricots, or melons. Researchers also said legumes like lentils, chickpeas, peas, beans, soy products such as tofu and alternative grains like quinoa or millet could also have this effect. While Britons have been told for years to up their intake of fresh fruit and vegetables and cut down of fatty cuts and processed meats for their health, there are some health hazards to going completely vegan. Nutritionists have previously warned that vegans can miss out on a range of key vitamins and minerals by shunning animal products. These include a lack of vitamin B12, which is in found milk and eggs, which can lead to fatigue or tiredness and negatively impact mental health. Vitamin D is another nutrient found mainly in animal products, like oily fish, that those on vegan diets can be deficient in. A vitamin D deficiency can lead to issues with bone development and cause pain. A lack of iron, found in red meat and liver, can also lead to anaemia, causing people to feel tired and have heart palpitations. Iodine, mainly found in seafood, is another nutrient known to be lacking in vegan diets and is important in maintaining a health metabolism. While plant-based diets can include all of these mentioned nutrients, vegans need to carefully manage what they eat, or take supplements, to ensure they get enough. There have also been concerns about the potential health impacts of fake 'meats' in vegan diets. Last year, British experts found those who ate plant-based versions of sausages, burgers and mince seemingly had worse blood pressure than their meat-consuming counterparts Another recent UK study revealed that opting for ultra-processed plant foods, like vegan sausages and burgers, as well as cakes and crisps, was linked to a 15 per cent higher risk of suffering heart attacks and strokes. Interest in a plant-based diet has soared in recent years, with vegans citing ethical, environmental or health reasons. The exact numbers of vegans now in the UK is almost impossible to establish. But one recent survey suggested around 600,000 people are believed to be on a plant-based diet. In England, one in four adults are now obese, while just over three in five are overweight. However, four out of five adults are either overweight or obese in some areas of the country. The NHS recommends that those overweight wanting to lose weight focus on consuming fewer calories overall and eating more healthily while upping the amount of weekly exercise. The health service cautions that using what it dubs 'fad diets' may lead to short term weight loss this is rarely sustainable.
