Elephants appear to harmonise their vocal rumbles when they join together to form choruses, tuning their voices to sound more alike as the chorus unfolds.

The findings come from a machine learning study, which also reveals that this convergence is particularly likely to occur during specific kinds of choruses – such as when elephants reconnect with one another or organise group activities – and that the calls themselves may contain information about what the animals are doing. 

The findings could offer new insights into how elephants communicate and navigate life within their complex societies, says  at Earth Species Project, a US non-profit organisation that uses artificial intelligence and machine learning to attempt to decode non-human animal communication.

“It’s sort of like what humans do in conversation, where you almost start to adopt the speaking patterns or accents of whoever you’re interacting with,” says Keen. 

Elephants communicate using a , but also a wide range of sounds. These include their iconic trumpet call, and also throatier roars. The most common call is the rumble – so low-pitched it is often undetectable by humans – which can travel up to 10 kilometres, transmitting long-distance information that can potentially include the identity of the caller and what’s happening at the time.

 at Elephant Voices, a non-profit organisation based in Washington DC, that promotes the study and protection of elephants, says scientists have long been intrigued by the way elephants will rumble together in choruses. Studying those complex sounds, however, has proved extremely difficult because it is hard to pick out any given rumbling elephant in the chorus – what researchers call “the cocktail party problem”.

With significant developments in machine learning, however, Poole, Keen and their colleagues have found that computers are up to the task. They used a collection of 902 recordings of rumbles collected across four decades, emitted by wild female African savannah elephants (Loxodonta africana) from dozens of family groups in Kenya’s Amboseli National Park. The calls were grouped according to six distinct social situations: staying in contact while separated; preparing to move; coordinating what to do next; comforting or reassuring calves; greeting close family members; and participating in large family reunions. 

Machine analyses revealed that elephant choruses carry multiple layers of information at once, and vary in a way that suggests they encode information about what a family is doing together and what happens next, says Keen. Tracking rumbles of individual elephants in the same chorus, the data showed that in some cases, the calls became more acoustically alike as the chorus progressed. Specifically, this convergence occurred when elephants were staying in contact while separated, coordinating what to do next, and greeting after a separation. This suggests that vocal convergence may play a role in helping elephant families build a plan of action, says Keen.

Earlier research that Poole and her colleagues published in 2005 showed that elephants can  when they are calling more generally: the new work shows that this imitation involves the rumbles, too. 

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Combined with other communication tools, including body language, the rumbling calls seem to help facilitate complex social interactions. “They appear able to negotiate, agree and disagree – and make a plan of action,” says Poole.

The findings not only shed light on elephant communication and cognition, but they could also eventually aid conservation by helping researchers track their behaviour and movements remotely, the team says.

Because rumbles allow for long-distance communication, elephants’ ability to unite through their voices is an exciting reflection of their advanced cognition and evolution in their environment, says Andrew McLean, a member of the International Union for the Conservation of Nature’s . “Evolving and elaborating this for social cohesion, group survival and foraging efficiency is very adaptive,” he says. “This is a fascinating finding – although it’s not really surprising, given how intensely social elephants are.”

When dogs hear their owners speak, they are listening for consonants in words rather than vowels, a new study suggests, apparently mimicking a similar human bias that is found across many languages.

Although dogs don’t have language, they live in a speech-rich environment, says at Eötvös Loránd University in Hungary.

“We knew from our previous studies that dogs care about what we speak and how we speak, but until now there was no evidence that dogs’ experience with speech can actually shape how their brains function,” says Andics.

To investigate how a life with humans and listening to constant talk has impacted dogs’ brains, Andics and his colleagues recruited 20 adult human Hungarian speakers and 20 companion dogs with Hungarian owners.

Andics says while many Eastern European languages are consonant heavy, Hungarian isn’t.

“There are some studies suggesting that consonant bias during speech segmentation is weaker, or not there, in people who mostly listen to Mandarin or Danish, in which languages consonants are not, or not that much, more informative about word boundaries than vowels,” he says.

During the experiment, the human and dog participants separately listened to continuous, unsegmented speech streams of nonsense words while connected to EEG monitors, measuring the electrical activity of the participants’ brains.

Consonants and vowels alternated throughout these streams, with no pauses or other acoustic cues separating them, says Andics.

There were three types of nonsense streams. In the first, recurring consonant patterns formed consecutive three-syllable words – such as “mozite”. In the second, stronger vowel patterns formed the skeleton of the words – such as “zobefu”. And in the third, there were no recurring patterns at all, with syllables in a random order – such as “fumoza”.

He says the team made use of a phenomenon called “neural synchronisation”, in which brain activity can take on the rhythm that we detect in the sounds we hear.

“The more reliably we detect that rhythm, the more rhythmic the brain response becomes,” says Andics. “We expected that if a species’ brain has a preference for consonants, it should follow the rhythm of the words more easily when consonants form the structure of those words.”

The difference was substantial, the scientists found. In dogs, the neural response to consonant-based regularities was 42 per cent stronger than the response to vowel-based regularities, and 55 per cent stronger than the response to the random stream.

“So, this is how much more dog brains tracked word rhythm when consonants defined the words,” says Andics.

In humans, the response to consonant-patterned words was nearly 25 per cent higher than to vowel-based regularities and 77 per cent higher than to the random condition.
The team thinks that dogs who weren’t exposed to human speech wouldn’t have this bias, although they haven’t yet tested this idea.

“We argue that the only reason companion dogs have a consonant bias is that human speech, and specifically the characteristics of words, reshaped their brains,” says Andics.

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at the University of Sydney, Australia, says the team convincingly shows that these dogs display more sensitivity to statistical patterns in consonants, rather than in vowels.

But with some important caveats – especially that these are Hungarian dogs, living with Hungarian speakers.

“There’s 7000 different languages in the world and some of them rely a lot more on things like tonal distinctions,” says Enfield. But if you do want your dog to pay attention to you, there may be a practical take home, he says.

“The lesson here may be to give your dog a name with more consonants in it than one with more vowels.”

Young orangutans who spend little time working out for themselves how to build a broad diet can partly compensate by watching how other orangutans choose what to eat.

The findings suggest that orangutans have different strategies for developing broad survival skills, says at the Max Planck Institute of Animal Behavior in Germany.

Young orangutans acquire a substantial body of knowledge before they can survive independently, which they must do by the time they are 8.5 years old. This includes understanding what foods are safe to eat, where to find them and how to process them in a rainforest offering hundreds of food options of varying levels of accessibility – from easy-to-access leaves to the more inaccessible but also more nutritious seeds at the heart of a tough, spiny neesia fruit.

Scientists already know that orangutans can acquire this knowledge both by observing their mothers and other individuals in their social circle – a process known as social learning – and by exploring entirely on their own without any input from others, which is known as individual learning. But how these two forms of learning work together – and how they affect what orangutans learn to eat before becoming independent – hasn’t been clear.

To find out, Thillaikumar and her colleagues analysed nearly 7000 instances of learning recorded during more than 1700 hours of observations of wild Sumatran orangutans at Suaq Balimbing, a research station in Indonesia. The observations, collected over 12 years, tracked 21 youngsters as they closely watched other orangutans who were interacting with foods and other objects.

The young apes varied considerably in how much they relied on different kinds of learning, with some using more social learning, and others exploring independently much more often. This might, in part, reflect personality differences, and might also be influenced by early development – including differences in how mothers care for their young, says Thillaikumar.

Youngsters who learned by watching others also tended to continue manipulating new objects or trying new foods for about 145 minutes after they had closely observed another orangutan. This activity is reminiscent of the way in which children will spend time imitating an activity they have just seen demonstrated by an adult, says Thillaikumar. “Yeah, it’s practice.”

Next, the researchers drew on about 4700 hours of feeding observations for 13 of the youngsters to estimate the range of foods they had learned to eat by the time they reached independence. Unsurprisingly, the team found that the individuals who had engaged in plenty of social learning and plenty of individual learning had acquired the broadest diets.

But they also found that young orangutans who engaged in very little truly individual learning could partially compensate and develop a reasonably broad diet if they were good social learners.

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A male Sumatran orangutan chewed the leaves of a plant used in Indonesian traditional medicine and placed them on a wound on his face

at Duke University in North Carolina says she’s impressed by the sheer scale of the work, following young orangutans through the rainforest across their entire, lengthy period of dependency on adults. She was particularly intrigued by how often social observation was followed by young orangutans practising the techniques they had observed. “In simpler terms, they show clearly what we see in human children and other apes – that they watch others perform a behaviour and then go try it out on their own.”

The variability in learning styles – even at an individual level – is especially interesting, says , also at Duke University. It suggests that no single form of learning can tell the whole story. “Predicting dietary breadth at maturity requires looking at all types of learning.”

Some 150,000 baby common octopuses (Octopus vulgaris) have just been released into the waters off Italy’s Adriatic coast in one of Europe’s first pilot experiments to test whether the species can help control the invasive blue crab (Callinectes sapidus), which eats native shellfish and threatens the fishing industry and marine ecosystems.

“The project is appropriate as a carefully controlled pilot experiment, but it is not yet a proven effective control strategy,” says , a marine ecologist at the Virginia Institute of Marine Science, who isn’t involved in the initiative.

Two years ago, �����Ի���, two aquaculture researchers at the University of Bologna, Italy, began to wonder whether octopuses offered a way to control blue crabs off the coast of Emilia-Romagna, a region of north-east Italy where damage caused by the blue crabs has cost the fishing industry £14.7 million since 2022. 

Previous studies had , backing up what local fishers had been seeing for a decade as populations of the Atlantic-native invasive species began to surge along Italian coasts.

However, octopuses tend to do better on rocky seabeds, while the Adriatic coast is rather sandy, which may help explain why octopus numbers there have been falling in recent decades. The regional government of Emilia-Romagna has installed artificial shelters for octopuses in an effort to reverse the decline. 

Under a research project co-financed by the regional government, Mordenti and Casalini caught eight common octopuses – four females and four males – from the Emilia-Romagna coast, transferred them to the laboratory and gave them about three months to acclimatise to their new surroundings. Their tanks were carefully monitored and maintained under conditions designed to simulate those at sea. “Not only did we find that the fishermen were right, but we also found that octopuses could consume up to four blue crabs a day,” says Mordenti.

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The researchers then arranged the octopuses into four breeding pairs and allowed them to mate and produce eggs. 

Earlier this week, the scientists released 150,000 millimetre-long, lab-raised larvae into the waters off the coastal towns of Cesenatico and Riccione. 

They estimate that only 1 per cent will survive to adulthood. After hatching, octopuses start their lives as tiny, free-floating larvae known as paralarvae. They drift through the water and may be eaten by fish. The hope is that a few will escape this fate and grow large enough to begin preying on blue crabs — a feat even small common octopuses weighing less than 800 grams are capable of, the researchers say.

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“Our aim was to bolster the population of a native species already found naturally in the Adriatic,” says Casalini. 

“We’ll work with fishermen to assess whether the releases will have had an effect by the end of the year,” says Mordenti. 

But some scientists argue that this strategy needs more study. “Blue crabs are extremely prolific and fast‑growing, and their preferred habitats often differ from those of octopuses,” says marine biologist  at the Institute of Marine Research, Spain. 

“Starting by releasing paralarvae as if they were wheat seeds scattered in the water seems like a rather simplistic approach,” says , a zoologist at the University of Naples Federico II, Italy. “A controlled environment is one thing; the open sea is a whole different ball game.”

Large predators can make people safer by reducing the number of road accidents involving collisions with deer. A study in Washington state has shown that the presence of cougars led to a 76 per cent reduction in the number of such accidents.

“I think that this road-safety benefit could be playing out in many other places,” says of the non-profit Conservation Science Partners. “That’s just one of several ecosystem services that these large carnivores provide.”

A 2021 study in Wisconsin found that the return of wolves to a county , providing economic benefits 63 times greater than the costs of wolves killing livestock. These reductions were due to changes in deer behaviour, as well as deer numbers falling due to predation by wolves, the study concluded.

Now Suraci and his colleagues have looked at what’s happening on the Olympic Peninsula in Washington state, where there’s a stable population of cougars – also known as pumas – and deer. “We worked with Native American communities, who are running their own wildlife monitoring programs,” he says.

More than 500 camera traps have been set up as part of these programs, and nearly 60 cougars were collared. This allowed the researchers to see where and when deer and cougars were present. Their analysis shows that deer avoid road edges and the margins of towns and cities when cougars are present, making them less likely to be hit by cars or trucks.

“Those habitat edges are the best hunting habitat for pumas. They can hide in the forest and attack a deer foraging along the roadside,” says Suraci. “So what we think is happening is that deer are moving away from these more fragmented, edgy areas with higher road density where the pumas are present.”

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When cougars were present, deer were also less active at night and more active during the day. This is likely a response to the fact that cougars hunt mainly at night, and may also have contributed to the reduction in accidents.

This is an example of a “landscape of fear” in action, says at Western University in Canada. “This is an excellent paper. It provides many compelling lines of evidence that paint a clear picture – that large carnivores benefit society. The authors beautifully demonstrate that the mere presence of large carnivores can reduce vehicle collisions with deer.”

“That is good news all around,” she says. “As though that weren’t enough, cougars also provide this service completely free of charge.”

Suraci also thinks this will be generally true for large predators. Discussions about the reintroduction of large predators tend to focus on the negative aspects, such as the killing of livestock, he says. But many benefits often aren’t obvious.

For instance, large predators may also reduce the damage deer do to crops and gardens, and the spread of diseases .