Tag Archives: warning

Rattlesnakes modulate their tail wagging to make you think they’re closer than they are

The rattling of rattlesnakes isn’t as simple a warning as we assumed. New research explains that this sound is subtly modulated to change the listener’s perception of its source, making it seem the snake is closer than it actually is.

Image via Pixabay.

Rattlesnakes are quite famous for the warning sounds they produce with their tails, the iconic ‘rattling’ that gives them their name. Far from being a simple wagging of the tail, however, new research suggests that this rattling is a fine-tuned intimidation tool. As the snake rattles its tail, it makes an abrupt shift to a high-frequency mode, the team explains. This makes listeners perceive the source of sound as being closer than it actually is.

In effect, while definitely being deadly, rattlesnakes also engage in some strategic deception.

Rattle my bones

“Our data show that the acoustic display of rattlesnakes, which has been interpreted for decades as a simple acoustic warning signal about the presence of the snake, is in fact a far more intricate interspecies communication signal,” says senior author Boris Chagnaud at Karl-Franzens-University Graz. “The sudden switch to the high-frequency mode acts as a smart signal fooling the listener about its actual distance to the sound source. The misinterpretation of distance by the listener thereby creates a distance safety margin.”

Past studies have shown that rattlesnakes’ rattles vary in frequency, but they didn’t give us any insight into why they do, or what this behavior actually achieves in the real world.

The hypothesis behind this paper was born while Chagnaud was visiting an animal facility and noticed that rattlesnakes increased the frequency of their rattling as someone approached the snakes — but decreased when they walked away. From this observation, Chagnaud and his team developed an experiment in which objects appeared to move towards rattlesnakes. One of these objects was a human-like torso, and another was a looming black disk. The illusion of forward-back movement was created by making the objects increase or decrease in size.

The team reports that over the course of this experiment, as potential threats approached the snakes, they would increase the frequency they rattled at to approximately 40 Hz. But, abruptly, they would switch to an even higher frequency range, between 60 and 100 Hz.

Further experimentation revealed that rattlesnakes adapt their rattling frequency to the (perceived) approach velocity of an object, rather than its size.

“In real life, rattlesnakes make use of additional vibrational and infrared signals to detect approaching mammals, so we would expect the rattling responses to be even more robust,” Chagnaud says.

Inside a virtual reality environment, the team then tested how this shift in rattling frequency is perceived by a person or animal close to the snake. A group of 11 participants were asked to engage in a simulated walk inside the virtual environment — a grassland — and told they’ll be walking towards a snake. Its rattling rate increased as the participants closed in, as per the previous findings, and suddenly raised it to 70 Hz at a virtual distance of 4 meters.

The participants were asked to tell the team when the rattling sounded like it came from only 1 meter away. All the participants underestimated the distance that the virtual snake was at after it increased its rattling frequency.

“Snakes do not just rattle to advertise their presence, but they evolved an innovative solution: a sonic distance warning device similar to the one included in cars while driving backwards,” Chagnaud says. “Evolution is a random process, and what we might interpret from today’s perspective as elegant design is in fact the outcome of thousands of trials of snakes encountering large mammals. The snake rattling co-evolved with mammalian auditory perception by trial and error, leaving those snakes that were best able to avoid being stepped on.”

The paper “Frequency modulation of rattlesnake acoustic display affects acoustic distance perception in humans” has been published in the journal Current Biology.

The FDA warns public not to use potentially toxic hand sanitizers from Eskbiochem

The Food and Drug Administration (FDA) has issued a warning for the public not to buy or use hand sanitizer produced by a particular company as it contains methanol.

Image credits Harvey Boyd.

Methanol, the simplest molecule in the alcohol family, can be toxic when absorbed through the skin or ingested. According to the FDA, certain hygiene products manufactured by Eskbiochem SA de CV in Mexico can potentially contain methanol. As such, the institution warns people not to use them.

“Substantial exposure” to methanol can cause nausea, vomiting, headache, blurred vision, permanent blindness, seizures, coma, permanent damage to the nervous system or even death, according to the FDA.

The bad alcohol

“Consumers who have been exposed to hand sanitizer containing methanol should seek immediate treatment, which is critical for a potential reversal of toxic effects of methanol poisoning,” the FDA says in a statement.

“Although all persons using these products on their hands are at risk, young children who accidentally ingest these products and adolescents and adults who drink these products as an alcohol (ethanol) substitute, are most at risk for methanol poisoning.

The warning extends to nine products of the company, which the FDA found methanol in samples of. These are All-Clean Hand Sanitizer, Esk Biochem Hand Sanitizer, CleanCare NoGerm Advanced Hand Sanitizer, Lavar 70 Gel Hand Sanitizer, The Good Gel Antibacterial Gel Hand Sanitizer, Saniderm Advanced Hand Sanitizer and three varieties of CleanCare NoGerm Advanced Hand Sanitizer.

Sampling revealed between 28% to 80% methanol and no ethyl alcohol (the last one is the one in beer or other drinks) in some of these products. “methanol and no ethyl alcohol” the agency adds. Products should contain ethyl alcohol (ethanol), isopropyl alcohol (isopropanol), or benzalkonium chloride to be marketed as hand sanitizers.

People who apply the products to their hands are at some risk for methanol poisoning, but the greatest risk comes from ingesting methanol. The FDA notes that children tend to accidentally ingest such products, while others (teens and adults) will sometimes drink them as an alcohol substitute.

If you’ve used these products, seek medical treatment immediately, the FDA advises. Any remaining products should be disposed of as well.

The agency has contacted Eskbiochem to ask them to remove the products from the market but the company has yet to take action, prompting the current public warning.

Methanol is dangerous because our bodies break it down into formic acid, which is toxic to our cells. Around 56 grams of methanol are, on average, the lethal dose for an adult human. Methanol poisoning is most usually associated with unlicensed alcohol production, where methanol isn’t properly removed during the distillation process.


Orangutans can ‘talk’ about the past and the future, study suggests

Orangutans seem to be able to transmit information about a past or future event, a new study concludes.


Image via Pixabay.

They say goldfish can only remember three seconds — but orangutans definitely don’t share this limitation. A new study reports that these primates can transmit information about events in the past, an ability that was thought to be virtually exclusive to humans.

Watch out… seven minutes ago!

When danger lurks about, orangutans issue a specific alarm call. It probably wouldn’t sound particularly distressing for us hairless apes: it’s quite similar to what you’d recognize as a kissing noise. From what we know so far, orangutans will produce this sound to warn the group. However, there’s also debate regarding exactly how they use it — such a signal would also inform any predators that they’ve been spotted, which may determine it to make a hail-mary assault on any exposed group members.

So the team set out to investigate whether such alarm calls involved ‘displaced reference’ — i.e. if they can be issued for threats in the past or future, not the present. They did so by scaring a group of orangutans in the  Ketambe forest, Sumatra, with colorful sheets.

These coverings were either white, spotted, patterned (for example with a tiger-stripe pattern). The researchers (quite hilariously, I imagine) donned the sheets and then bumped around the forest floor for two minutes, making sure orangutan mothers perched in the trees above could see them.

Tiger coat researchers.

One of the researchers playing a tiger. Terrifying!
Image credits Adriano R. Lameira.

Half of these staged stalkings elicited a kiss vocalization, the team reports — the tiger-stripe cover being the most successful.

Only one of the vocalizations occurred when the faux predator was still visible. All others were delayed (for an average of 7 minutes) until the simulated predator left. One particularly old female orangutan delayed this warning by roughly 20 minutes, the researchers add. Once she started, however, “she called for more than an hour,” Adriano Reis e Lameira, one of the researchers, explained to Science Magazine.

“She stopped what she was doing, grabbed her infant, defecated [a sign of distress], and started slowly climbing higher in the tree,” he says. “She was completely quiet.”

“Twenty minutes passed. And then she finally did it.”

The team thinks this isn’t a case of the orangutans being overcome with fear and thus failing to sound the alarm while the predator was prowling. Instead, they believe the mothers might have been waiting to protect their child.

“Vocal delay was also a function of perceived danger for another – an infant – suggesting high-order cognition,” the study reads. “Our findings suggest that displaced reference in language is likely to have originally piggybacked on akin behaviours in an ancestral hominid.”

The findings are quite exciting as they suggest that humanity’s ability to understand and communicate information regarding past (or future) events may be directly rooted in our ancestors — most likely in a common ancestor between humans and orangutans.

This is far from a definitive conclusion, however, and further research will be needed to fully confirm the findings. But orangutans have proven themselves to be quite intelligent animals, so personally, I wouldn’t put displaced reference beyond them.

The paper “Time-space–displaced responses in the orangutan vocal system” has been published in the journal Science Advances.

Soft drink.

Show people the dangers of sugary beverages and they’ll pick healthier options

Images showcasing the dangers of excessive sugar consumption help reduce sugary beverage consumption, while text labels have no effect on consumer behavior.

Soft drink.

Image credits Markus Spiske.

Don’t we just love some sugar? Of course we do. But too much of it is bad for you — and, according to the World Health Organization (WHO), we’re having too much of it. This gives rise to all hosts of problems, from tooth decay and type 2 diabetes to obesity (which itself invites further health complications). According to a new study from the Harvard T.H. Chan School of Public Health and Harvard Business School, however, plastering soft drinks with images showcasing the dangers of sugar can help curb excess sugar consumption.

Sweet images, bro

“Warning labels have been around a long time for tobacco products, but they’re a new concept for sugary drinks,” said study co-lead author Grant Donnelly. “Text warning labels have been passed in San Francisco and are being considered in many jurisdictions in the U.S. and around the world. Ours is the first study to evaluate the effectiveness of sugary drink warning labels in the field.”

The study wanted to compare the effectiveness of graphic labels against those of text labels in helping people curb sugar intake. The research, conducted in a hospital cafeteria, found that the former reduced sugary beverage purchases by 14.8%, while text labels had no noticeable effect.

Donnelly and his team tested three types of labels: text warnings and graphic warnings regarding the health risk of sugary drinks, and lists of each beverage’s caloric value. These labels were displayed near bottled and fountain beverages in a Massachusetts hospital cafeteria. Each label was displayed alone, with a two-week period between each test when no label was displayed to “washout” any lingering effects. Over 20,000 beverage sales were recorded during the research.

During the weeks when graphic warnings were displayed, sales of sugar-sweetened beverages in the cafeteria declined by 14.8%, the team writes. Consumers generally opted for bottled water in favor of these beverages. This shift in purchasing behavior led to a decrease in average calories per sold drink from 88 to 75 while graphic ads were on display, they add. Finally, the team found that text labels had no noticeable effect on purchasing patterns.

The team followed-up their research with online studies. The first asked consumers how a warning label would influence their sugary beverage purchases. According to participants’ answers, these warnings increased their negative feelings towards sugary drinks and helped them consider health risks over taste or enjoyment.

During the second, nationally-representative online study, over 400 participants were asked whether they would support the addition of the three labels on sugar-sweetened beverages. When informed that the graphic warnings were found to be effective in reducing consumption of sugary drinks, participants were equally supportive of these, text warnings, and calorie labels.

The team believes their work illustrates both the effectiveness of and the need to include such graphic warnings on sugar-heavy beverages. Such drinks are the “largest source of added sugars in the American diet,” notes co-lead author Laura Zatz. Reducing our intake of such products would have very beneficial effects on our health, and on overall public health.

“As policymakers search for ways to reduce excess consumption of sugary drinks, graphic warning labels merit consideration as a tool that can empower consumers with salient information to encourage healthier choices,” she adds.

This isn’t the first effort to help people drop the sugary habit. Back in September 2017, a tax on sugary beverages came into effect in the UK. Drinks with a sugar content higher than 5g per 100ml will be taxed 18p ($0.25) per liter, and drinks with 8g or more will be taxed 24p ($0.34) — authorities hope this measure will help curb the rise of obesity in the island nation. It’s not a non-issue by any means. Excessive sugar can and will kill, and those of us in developed countries are most at-risk of this sweetened finale.

The graphic-label approach was used (quite successfully) with tobacco, but many people criticize them for being too gruesome and off-putting; on the other end of the stick, plain packaging also seems to have some merits in reducing tobacco sales — maybe the same approach would work for sugary beverages, too?

So, what do you think? Should we use the stick of graphic warnings or the carrot of plain packaging to steer people away from excessively-sugary drinks? Let us know in the comments below.

The paper “The Effect of Graphic Warnings on Sugary Drink Purchasing,” has been published in the journal Psychological Science.


Australian magpies can understand what other birds are ‘saying’ with surprising clarity

Australian magpies can understand the warning calls of other birds, a new study suggests.


Image credits Toby Hudson.

Despite their name, Australian magpies (Gymnorhina tibicen) aren’t actually very magpie-y. They’re actually part of a separate family of birds that are indigenous to Australia, Southern Asia, and the Indo-Pacific, while true magpies (family Corvidae) belong to the evolutionary family of crows.

However, the magpies down under seem to have an ace up their wings that should allow them to fit right in with their European counterparts. New research showed the birds can understand signals of at least one other species, the noisy miner, suggesting they could learn to interpret other species as well.

Orange balls and noisy miners

Noisy miners (Manorina melanocephala, not the profession) are a native species of birds that share their ecosystem with the Australian magpie. This small bird of the honeyeater family uses different calls to warn its peers of incoming predators. One characteristic that’s been especially useful for the team is that the noisy miners employ different warning calls for airborne and ground-based predators.

By playing recordings of both calls to wild magpies, the team observed that these could understand the meaning behind the noisy miners’ warnings.

The study took part in four locations in Canberra, including the Australian National University campus and parks in Turner. The researchers lured unsuspecting wild magpies with, funnily enough, grated cheese — then played the recorded calls back to them and filmed the results. As a control, the researchers used a large orange ball. They’d either roll this towards magpies, to gauge their response to ground threats, or throw it around, to see how the birds reacted to airborne predators. Which must have been hilarious to witness.

Over 30 adult, wild magpies had their reactions video-taped twice, while 9 individuals simply flew away.

magpie beak angle

B marks the base of the beak and T the tip. Tracker software was used to obtain coordinates for both B and T for every video frame, and researchers used this to calculate the change in beak angle.
Image credits Branislav Igic/Australian National University.

The team reports that the Australian magpie’s typical response to perceived threats is a tilting of the beak: the birds showed an average maximum beak angle of 29 degrees for the thrown ball, and an average maximum of 9 degrees when it was rolled. The miners’ aerial warning calls prompted an average maximum beak angle of 31 degrees, while the ground warning prompted an average of 24.

It may seem like useless trivia, but the reason why the team measured these angles is quite central to the research. They wanted to determine not just whether the magpies use the miners’ calls as danger warnings — the authors wanted to see if the magpies can understand what kind of danger each call signaled. The control test proved that magpies will aim their beaks towards the expected elevation of a threat. The second round of tests suggests that they can indeed discern the meaning of the miners’ calls, as the magpies consistently aimed their beaks higher for aerial warning calls than they did for terrestrial warning signals.

“A lot of birds around the world have been shown to respond to a degree of threat, but this is a little bit more nuanced,” says co-author Dominique Potvin. “We’re not looking at ‘if you scream louder does that mean more danger and you hide’. This is a very particular sound that indicates the spatial location of something. For the magpies to actually hone in on that is pretty new.”

Speaking in beaks

The team writes that Australian magpies and noisy miners face the same type of predators: brown goshawks, peregrine falcons and boobook owls from the skies, and foxes, cats, dogs, and snakes on the ground. The two species also frequently share the same ecosystems. But the magpies spend most of their time on the ground looking for food, while noisy miners, completely out of character with their name, like to perch out in trees.

The team believes that listening in to the latter’s warnings gave the magpies an edge against predators. So far, they’re the only species that we know of with this ability.

“It pays for the magpie to pay attention to somebody who has a better view of predators than they do,” Potvin explains. “Magpies are a pretty smart group. We’re not sure if they’re learning this from other magpies or if they’re figuring it out on their own, but the ability is there. We don’t think this would be isolated to Canberra populations.”

Just to make sure the birds weren’t reacting to the sound alone, the team also played a third call: the generic, non-warning call of a crimson rosella (Platycercus elegans), a parrot native to eastern and southeastern Australia. The magpies showed no response to this call.

The paper “Birds orient their heads appropriately in response to functionally referential alarm calls of heterospecifics” has been published in the journal Animal Behavior.


Smartphones used as sensors for earthquake early warnings

There’s so much you can do with a smartphone today – much more than just browsing the web or social media. When you can combine them in a network, however, the possibilities might be endless. For instance, researchers at Caltech and the United States Geological Survey (USGS) are working on an earthquake early warning system based on the collective data fed in by thousands of smartphones. Only a couple of countries in the world give vulnerable cities an early warning – often just enough time to hit cover and save your life – but smartphones are virtually ubiquitous all over the world, even in poor countries which lack basic infrastructure like roads or flushing toilets.


A network of smartphones can be used to provide a cheap, but reliable early warning system for earthquakes. Image: Damn Geeky

Hundreds of millions of people live in earthquake prone areas, like those along fault lines. Yet, there are only a couple of countries and states that use an early warning system for earthquake, since the monitoring equipment and staff can be prohibitively expensive. Some might actually be surprised to hear that California, a notoriously vulnerable region of the United States, is well behind countries like Mexico, Japan and even Turkey in terms of early warning capabilities. These can send up to a minute heads start to schools, fire stations and even individuals who signup for an early warning, where this is available. These exploit a simple principle:  shaking from an earthquake travels slower than the speed of today’s telecommunications system. For example, it would take more than a minute for a 7.8 earthquake near the Salton Sea to shake up Los Angeles, 150 miles away. But within a few seconds since the shaking starts, seismic sensors would pick up the signal and send it through the network in a heartbeat.

Sarah Minson, a USGS geophysicist and lead author of the study which appears in the April 10 issue of the new journal Science Advancesrealized that smartphones could very well be used as seismic sensors, albeit not as sensitive. Harnessing the collective power of many smartphones can thus help build a crowd-sourced alert network. Their findings suggest that GPS receivers in smartphones are sufficient to detect the permanent ground movement, or displacement, caused by fault motion in earthquakes that are approximately magnitude 7 and larger. The signal is passed through the network and an algorithm analyzes it to determine where the earthquake took place and how long it will take until reaches an individual user, which becomes alerted.

“Thirty years ago it took months to assemble a crude picture of the deformations from an earthquake. This new technology promises to provide a near-instantaneous picture with much greater resolution,” says Thomas Heaton, professor of engineering seismology and  a coauthor of the new study.

The crowd-sourced earthquake early warning (EEW) system was tested on data that simulated a magnitude 7 earthquake, and with real data from the 2011 magnitude 9 Tohoku-oki which devastated Japan. The results show that EEW works fairly good with as little as 5,000 smartphones connected in a large metropolitan area – these are enough to send an early warning to a city farther away.

According to the paper, earthquakes with a magnitude smaller than 7 can’t be detected by GPS, which isn’t sensitive enough. However, all smartphones are equipped with accelerometers (the kind that help you tell where north is or let you play really cool video games just by moving your phone around). A new system based on these microelectromechanical systems  might detect earthquakes as low as magnitude 5.  Caltech’s Community Seismic Network Project is currently developing an EEW system based on accelerometers. Seismologists from the National Institute of Geophysics and Volcanology in Italy have already built one – they report promising results for earthquakes larger than magnitude 5.

“The U.S. earthquake early warning system is being built on our high-quality scientific earthquake networks, but crowd-sourced approaches can augment our system and have real potential to make warnings possible in places that don’t have high-quality networks,” says Douglas Given, USGS coordinator of the ShakeAlert Earthquake Early Warning System.

“Crowd-sourced data are less precise, but for larger earthquakes that cause large shifts in the ground surface, they contain enough information to detect that an earthquake has occurred, information necessary for early warning,” says study coauthor Susan Owen of JPL.

Cigarettes get slapped with bigger and harsher warnings

Remember the days when cigarettes didn’t have to feature labels of all the bad things that can happen if you smoke ? Well, I don’t; but then again, maybe in a few decades people won’t remember the days when cigarettes used to have such ‘light warnings’.

Practically, in just a generation or so, things have switched from ‘cigarettes may cause illnesses in some persons’ to ‘you will get cancer and die, or be impotent, or both’ – and this is a really good thing, at least if you ask me. Thing is, in June, Food and Drug Administration (FDA) plans to implement even tougher warnings, on an even larger part of the pack. According to a few studies conducted this month, this will have a significant impact on at least some of the 20 percent still smoking in the US.

To say that smoking is bad is like saying that going out in the rain will get you wet; everybody knows this, but even so, some choose to do it. How do they deal with the problem of knowing this ? Well, smokers typically fall into three categories: the ‘so what if it kills me’; the ones who know it’s bad, but just don’t want to know how bad it is, and the ones who are trying to quit, but for one reason or another, they don’t do it. The FDA is targeting the latter two groups, trying to make the 2nd group more aware of what they are doing to themselves, and give the last ones the extra budge they need to make the big step and quit smoking.

In June 2009, president Barack Obama, who used to be a smoker himself (and he smoked quite more than cigarettes) signed into law the Family Smoking Prevention and Tobacco Control Act, basically giving the FDA the possibility to control all tobacco sales and marketing campaigns. Now, two years after that, they are close to making the first major move, after a planification stage that took about one and a half years. Here are just a few of the proposed labeling types.

Another thing the cigarettes pack will have to do is display some direct information about the cigarettes inside them, rather than the chemical information that is displayed now; for example, ‘cigarettes contain carbon monoxide’ will be replaced with ‘cigarettes cause heart attacks and strokes’.

Among the developed countries, Canada has one of the lowest smoking rates (18 percent and dropping), and they have been using graphic images instead of messages for years, with very powerful messages, such as ‘smoking makes you impotent’ – best argument if you ask me. The thing is, tobacco companies are extremely good at going around the corners and finding new solutions to the problems they have to face. For example, when the FDA limited the use of terms such as “light,” “mild,” and “low” on packaging, the tobacco companies struck back with “silver”, “gold” and “white”.

The FDA tobacco act however is not without its contestants – out of which, of course, tobacco companies have to be mentioned. The 2009 act banned all the flavoured cigarettes except for menthol (which accounts for some 30% of the market and is especially popular among African Americans and young people.

Of course, you might just feel sorry about the tobacco industry – but then you have to remember that they lied for 50 years, indirectly killed tens of millions of people, and gave your dad that nasty cough.

Via Livescience


Further heartbreaking information about the Japan earthquake + info on threatened areas

The earthquake that struck Japan is much worse than original estimates ! The original 7.9 magnitude actually just got upgraded to 8.9, which makes it 10 times more powerful, and the 4th most powerful earthquake in the past 100 years.

Sadly, reports of injured and killed people keep coming in, and will likely not stop for a long time, especially as the earthquake hit some refineries, causing several deadly fires, and to make matters even worse, there are reports of actual tsunamis actually catching fire !

Here is a time map of the threatened areas, if you are in one of them, PLEASE BE PREPARED !  Sirens in Hawaii are already ringing, but there is also a warning for Russia, Guam, Taiwan, Marshall Islands and Wake Islands, so if you are in one of those areas, or know anyone who is there, be prepared for it

Also, Al Jazeera is doing a way better job at live coverage than American television, so you can watch live streaming here – but it’s not for the faint of heart. I just watched several people trying to run from the tsunami… but didn’t make it.

It breakes my heart to see something like this happen, and it’s a testament of what nature can do, even to one of the most developed countries in the world, which is used to earthquakes by now, and always prepared for them. We’ll keep you posted as things continue to develop.

Picture sources: 1 2