animal behavior

Meet Veronika, the tool-using cow

animal behavior, animal cognition, animal tool use, animals, Biology, Science / Rejus Almole / January 19, 2026

Each time, Veronika used her tongue to lift and position the broom in her mouth, clamping down with her teeth for a stable grip. This enabled her to use the broom to scratch otherwise hard-to-reach areas on the rear half of her body. Veronika seemed to prefer the brush end to the stick end (i.e., the exploitation of distinct properties of a single object for different functions) although which end she used depended on body area. For example, she used the brush end to scratch her upper body using a scrubbing motion, while using the stick end to scratch more sensitive lower areas like her udders and belly skin flaps using precisely targeted gentle forward pushes. She also anticipated the need to adjust her grip.

The authors conclude that this behavior demonstrates “goal-directed, context-sensitive tooling,” as well as versatility in her tool-use anticipation, and fine-motor targeting. Veronika’s scratching behavior is likely motivated by the desire to relieve itching from insect bites, but her open, complex environment, compared to most livestock, and regular interactions with humans enabled her unusual cognitive abilities to emerge.

The implication is that this kind of technical problem-solving is not confined to species with large brains and hands or beaks. “[Veronika] did not fashion tools like the cow in Gary Larson’s cartoon, but she selected, adjusted, and used one with notable dexterity and flexibility,” the authors wrote. “Perhaps the real absurdity lies not in imagining a tool-using cow, but in assuming such a thing could never exist.”

DOI: Current Biology, 2025. 10.1016/j.cub.2025.11.059 (About DOIs).

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These dogs eavesdrop on their owners to learn new words

animal behavior, animal cognition, animals, dog language, Dogs, Science / Kris Guyer / January 8, 2026

Next, the entire experiment was repeated with one key variation: This time, during the training protocol, rather than addressing the dogs directly when naming new toys, the dogs merely watched while their owners talked to another person while naming the toys, never directly addressing the dogs at all.

The result: 80 percent of the dogs correctly chose the toys in the direct address condition, and 100 percent did so in the overhearing condition. Taken together, the results demonstrate that GWL dogs can learn new object labels just by overhearing interactions, regardless of whether the dogs are active participants in the interactions or passive listeners—much like what has been observed in young children around a year-and-a-half old.

To learn whether temporal continuity (a nonsocial factor) or the lack thereof affects label learning in GWL dogs, the authors also devised a third experimental variation. The owner would show the dog a new toy, place it in a bucket, let the dog take the toy out of the bucket, and then place the toy back in. Then the owner would lift the bucket to prevent the dog from seeing what was inside and repeatedly use the toy name in a sentence while looking back and forth from the dog to the bucket. This was followed by the usual testing phase. The authors concluded that the dogs didn’t need temporal continuity to form object-label mappings. And when the same dogs were re-tested two weeks later, those mappings had not decayed; the dogs remembered.

But GWL dogs are extremely rare, and the findings don’t extend to typical dogs, as the group discovered when they ran both versions of the experiment using 10 non-GWL border collies. There was no evidence of actual learning in these typical dogs; the authors suggest their behavior reflects a doggy preference for novelty when it comes to toy selection, not the ability to learn object-label mappings.

“Our findings show that the socio-cognitive processes enabling word learning from overheard speech are not uniquely human,” said co-author Shany Dror of ELTE and VetMedUni universities. “Under the right conditions, some dogs present behaviors strikingly similar to those of young children. These dogs provide an exceptional model for exploring some of the cognitive abilities that enabled humans to develop language. But we do not suggest that all dogs learn in this way—far from it.”

Science, 2025. DOI: 10.1126/science.adq5474 (About DOIs).

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Scientists catch a shark threesome on camera

animal behavior, aquatic animals, Biology, marine biology, mating, Science, sharks / Rejus Almole / September 23, 2025

Three sharks, two cameras

Three leopard sharks mating - near surface — Moving the action closer to the surface. Credit: Hugo Lassauce/UniSC-Aquarium des Lagons

Lassauce had two GoPro Hero 5 cameras ready at hand, albeit with questionable battery life. That’s why the video footage has two interruptions to the action: once when he had to switch cameras after getting a “low battery” signal, and a second time when he voluntarily stopped filming to conserve the second camera’s battery. Not much happened for 55 minutes, after all, and he wanted to be sure to capture the pivotal moments in the sequence. Lassauce succeeded and was rewarded with triumphant cheers from his fellow marine biologists on the boat, who knew full well the rarity of what had just been documented for posterity.

The lengthy pre-copulation stage involved all three sharks motionless on the seafloor for nearly an hour, after which the female started swimming with one male shark biting onto each of her pectoral fins. A few minutes later, the first male made his move, “penetrating the female’s cloaca with his left clasper.” Claspers are modified pelvic fins capable of transferring sperm. After the first male shark finished, he lay motionless while the second male held onto the female’s other fin. Then the other shark moved in, did his business, went motionless, and the female shark swam away. The males also swam away soon afterward.

Apart from the scientific first, documenting the sequence is a good indicator that this particular area is a critical mating habitat for leopard sharks, and could lead to better conservation strategies, as well as artificial insemination efforts to “rewild” leopard sharks in Australia and several other countries. “It’s surprising and fascinating that two males were involved sequentially on this occasion,” said co-author Christine Dudgeon, also of UniSC, adding, “From a genetic diversity perspective, we want to find out how many fathers contribute to the batches of eggs laid each year by females.”

Journal of Ethology, 2025. DOI: 10.1007/s10164-025-00866-4 (About DOIs).

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Chimps consume alcohol equivalent of nearly 2 drinks a day

animal behavior, Biology, Science / Tim Belzer / September 20, 2025

Nearly two drinks a day

This latest study involved chimp populations at the Ngogo Chimpanzee Project (Uganda) and a second site at Tai (Ivory Coast), where scientists have estimated the animals consume between 5 to 10 percent of their body weight (about 40 kilos) in fruit each day—around 45 kilograms. The authors collected fallen fruit pulp samples from both sites, packed them in airtight containers, and froze them back at base camp to keep the fruit from ripening further.

Then they quantified the ethanol concentrations using a breathalyzer, a portable gas chromatograph, and chemical testing. The Uganda fruit contained 0.32 percent ethanol, while the Ivory Coast fruit contained 0.31 percent ethanol, which might not sound like much until you consider just how much fruit they eat. And the most frequently consumed fruit at both sites had the highest ethanol content.

If anything, this is a conservative estimate, per Dudley. “If the chimps are randomly sampling ripe fruit, then that’s going to be their average consumption rate, independent of any preference for ethanol,” he said. “But if they are preferring riper and/or more sugar-rich fruits, then this is a conservative lower limit for the likely rate of ethanol ingestion.” That’s in keeping with a 2016 report that captive aye-ayes and slow lorises prefer nectar with the highest alcohol content.

“Our findings imply that our ancestors were similarly chronically exposed to dietary alcohol,” co-author Aleksey Maro, a graduate student at UC Berkeley, told New Scientist. “The drunken monkey hypothesis suggests that this exposure caused our species to evolve an association between alcohol consumption and the reward of finding fruit sugars, and explains human attraction to alcohol today.” One caveat is that apes ingest ethanol accidentally, while humans drink it deliberately.

“What we’re realizing from this work is that our relationship with alcohol goes deep back into evolutionary time, probably about 30 million years,” University of St. Andrews primatologist Catherine Hobaiter, who was not involved with the study, told BBC News. “Maybe for chimpanzees, this is a great way to create social bonds, to hang out together on the forest floor, eating those fallen fruits.”

The next step is to sample the chimps’ urine to see if it contains any alcohol metabolites, as was found in a 2022 study on spider monkeys. This will further refine estimates for how much ethanol-laden fruit the chimps eat every day. Maro spent this summer in Ngogo, sleeping in trees—protected from the constant streams by an umbrella—to collect urine samples.

Science Advances, 2025. DOI: 10.1126/sciadv.adw1665 (About DOIs).

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Some dogs can classify their toys by function

animal behavior, animal cognition, Biology, Dogs, Science / Kris Guyer / September 18, 2025

Certain dogs can not only memorize the names of objects like their favorite toys, but they can also extend those labels to entirely new objects with a similar function, regardless of whether or not they are similar in appearance, according to a new paper published in the journal Current Biology. It’s a cognitively advanced ability known as “label extension,” and for animals to acquire it usually involves years of intensive training in captivity. But the dogs in this new study developed the ability to classify their toys by function with no formal training, merely by playing naturally with their owners.

Co-author Claudia Fugazza of Eötvös Loránd University in Budapest, Hungary, likens this ability to a person calling a hammer and a rock by the same name, or a child understanding that “cup” can describe a mug, a glass, or a tumbler, because they serve the same function. “The rock and the hammer look physically different, but they can be used for the same function,” she said. “So now it turns out that these dogs can do the same.”

Fugazza and her Hungarian colleagues have been studying canine behavior and cognition for several years. For instance, in 2023, we reported on the group’s experiments on how dogs interpret gestures, such as pointing at a specific object. A dog will interpret the gesture as a directional cue, unlike a human toddler, who will more likely focus on the object itself. It’s called spatial bias, and the team concluded that the phenomenon arises from a combination of how dogs see (visual acuity) and how they think, with “smarter” dog breeds prioritizing an object’s appearance as much as its location. This suggests the smarter dogs’ information processing is more similar to that of humans.

Another aspect of the study involved measuring the length of a dog’s head, which prior research has shown is correlated with visual acuity. The shorter a dog’s head, the more similar their visual acuity is to human vision. That’s because there is a higher concentration of retinal ganglion cells in the center of their field of vision, making vision sharper and giving such dogs binocular depth vision. The testing showed that dogs with better visual acuity, and who also scored higher on the series of cognitive tests, also exhibited less spatial bias. This suggests that canine spatial bias is not simply a sensory matter but is also influenced by how they think. “Smarter” dogs have less spatial bias.

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Incredible shrinking clownfish beats the heat

animal behavior, Biology, clownfish, Science / Kris Guyer / May 22, 2025

Let’s get small

The team observed 67 breeding pairs of wild clownfish—briefly caught and photographed for distinctive markings and measured before being returned to the water—living on single anemones in Kimbe Bay, Papua New Guinea, between February and August 2023. This happened to coincide with the world’s fourth global bleaching event. They measured the body size of the fish once a month and measured the temperature around the individual anemones every four to six days. Then the team analyzed the collected data.

two clownfish swimming around a white anemone against a black background — “Individual fish can shrink in response to heat stress.” Credit: Morgan Bennett-Smith

The results: Over the course of those months, 101 of the 134 clownfish shrank at least once in response to heat stress, and doing so boosted their likelihood of survival up to 78 percent compared to the 33 fish that did not shrink. And between breeding pairs, there were distinctive growth ratios between the dominant and subordinate fish; those pairs that shrank together were also more likely to survive the heat waves.

“We were so surprised to see shrinking in these fish that, to be sure, we measured each fish individual repeatedly over a period of five months,” said Versteeg. “In the end, we discovered it was very common in this population. It was a surprise to see how rapidly clownfish can adapt to a changing environment, and we witnessed how flexibly they regulated their size, as individuals and as breeding pairs, in response to heat stress as a successful technique to help them survive.”

Versteeg et al. have not yet identified a possible mechanism for the shrinkage, but suggest the triggering of neuroendocrine pathways via thyroid hormones might play a role, since those hormones regulate growth. The adaptive strategy could also be a means of adjusting to changing metabolic needs. But there are trade-offs: While shrinking in response to heat waves ensures greater survivability, there can also be a corresponding decrease in birth rates.

“Our findings show that individual fish can shrink in response to heat stress, which is further impacted by social conflict, and that shrinking can lead to improving their chances of survival,” said senior author Theresa Rueger, also of Newcastle University. “If individual shrinking were widespread and happening among different species of fish, it could provide a plausible alternative hypothesis for why the size of many fish species is declining, and further studies are needed in this area.”

Science Advances, 2025. DOI: 10.1126/sciadv.adt7079 (About DOIs).

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Are these chimps having a fruity booze-up in the wild?

animal behavior, Biology, chimpanzees, primates, Science / Rejus Almole / April 22, 2025

Is there anything more human than gathering in groups to share food and partake in a fermented beverage or two (or three, or….)? Researchers have caught wild chimpanzees on camera engaging in what appears to be similar activity: sharing fermented African breadfruit with measurable alcoholic content. According to a new paper published in the journal Current Biology, the observational data is the first evidence of the sharing of alcoholic foods among nonhuman great apes in the wild.

The fruit in question is seasonal and comes from Treculia africana trees common across the home environment of the wild chimps in Cantanhez National Park in Guinea-Bissau. Once mature, the fruits drop from the tree to the ground and slowly ripen from a hard, deep green exterior to a yellow, spongier texture. Because the chimps are unhabituated, the authors deployed camera traps at three separate locations to record their feeding and sharing behavior.

They recorded 10 instances of selective fruit sharing among 17 chimps, with the animals exhibiting a marked preference for riper fruit. Between April and July 2022, the authors measured the alcohol content of the fruit with a handy portable breathalyzer and found almost all of the fallen fruit (90 percent) contained some ethanol, with the ripest containing the highest levels—the equivalent of 0.61 percent ABV (alcohol by volume).

That’s comparatively low to alcoholic drinks typically consumed by humans, but then again, fruit accounts for as much as 60 to 80 percent of the chimps’ diet, so the amount of ethanol consumed could add up quickly. It’s highly unlikely the chimps would get drunk, however. It wouldn’t confer any evolutionary advantage, and per the authors, there is evidence in the common ancestor of African apes of a molecular mechanism that increases the ability to metabolize alcohol.

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Monkeys are better yodelers than humans, study finds

acoustics, animal behavior, animal vocalizations, animals, Biology, monkeys, Science, yodeling / Tim Belzer / April 4, 2025

Monkey see, monkey yodel?

That’s how it works for humans, but when it comes to the question of yodeling animals, it depends on how you define yodeling, according to bioacoustician Tecumseh Fitch of the University of Vienna in Austria, who co-authored this latest paper. Plenty of animal vocalizations use repeated sudden changes in pitch (including birds), and a 2023 study found that toothed whales can produce vocal registers through their noses for echolocation and communication.

There haven’t been as many studies of vocal registers in non-human primates, but researchers have found, for example, that the “coo” call of the Japanese macaque is similar to a human falsetto; the squeal of a Syke monkey is similar to the human “modal” register; and the Diana monkey produces alarm calls that are similar to “vocal fry” in humans.

It’s known that non-human primates have something humans have lost over the course of evolution: very thin, light vocal membranes just above the vocal folds. Scientists have pondered the purpose of those membranes, and a 2022 study concluded that this membrane was crucial for producing sounds. The co-authors of this latest paper wanted to test their hypothesis that the membranes serve as an additional oscillator to enable such non-human primates to achieve the equivalent of human voice registers. That, in turn, would render them capable in principle of producing a wider range of calls—perhaps even a yodel.

The team studied many species, including black and gold howler monkeys, tufted capuchins, black-capped squirrel monkeys, and Peruvian spider monkeys. They took CT scans of excised monkey larynxes housed at the Japan Monkey Center, as well as two excised larynxes from tufted capuchin monkeys at Kyoto University. They also made live recordings of monkey calls at the La Senda Verde animal refuge in the Bolivian Andes, using non-invasive EGG to monitor vocal fold vibrations.

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Study: Cuttlefish adapt camouflage displays when hunting prey

animal behavior, Biology, cuttlefish, marine animals, Science / Rejus Almole / February 20, 2025

Crafty cuttlefish employ several different camouflaging displays while hunting their prey, according to a new paper published in the journal Ecology, including mimicking benign ocean objects like a leaf or coral, or flashing dark stripes down their bodies. And individual cuttlefish seem to choose different preferred hunting displays for different environments.

It’s well-known that cuttlefish and several other cephalopods can rapidly shift the colors in their skin thanks to that skin’s unique structure. As previously reported, squid skin is translucent and features an outer layer of pigment cells called chromatophores that control light absorption. Each chromatophore is attached to muscle fibers that line the skin’s surface, and those fibers, in turn, are connected to a nerve fiber. It’s a simple matter to stimulate those nerves with electrical pulses, causing the muscles to contract. And because the muscles are pulling in different directions, the cell expands, along with the pigmented areas, changing the color. When the cell shrinks, so do the pigmented areas.

Underneath the chromatophores, there is a separate layer of iridophores. Unlike the chromatophores, the iridophores aren’t pigment-based but are an example of structural color, similar to the crystals in the wings of a butterfly, except a squid’s iridophores are dynamic rather than static. They can be tuned to reflect different wavelengths of light. A 2012 paper suggested that this dynamically tunable structural color of the iridophores is linked to a neurotransmitter called acetylcholine. The two layers work together to generate the unique optical properties of squid skin.

And then there are leucophores, which are similar to the iridophores, except they scatter the full spectrum of light, so they appear white. They contain reflectin proteins that typically clump together into nanoparticles so that light scatters instead of being absorbed or directly transmitted. Leucophores are mostly found in cuttlefish and octopuses, but there are some female squid of the genus Sepioteuthis that have leucophores that they can “tune” to only scatter certain wavelengths of light. If the cells allow light through with little scattering, they’ll seem more transparent, while the cells become opaque and more apparent by scattering a lot more light.

Scientists learned in 2023 that the process by which cuttlefish generate their camouflage patterns is significantly more complex than scientists previously thought. Specifically, cuttlefish readily adapted their skin patterns to match different backgrounds, whether natural or artificial. And the creatures didn’t follow the same transitional pathway every time, often pausing in between. That means that contrary to prior assumptions, feedback seems to be critical to the process, and the cuttlefish were correcting their patterns to match the backgrounds better.

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Parrots struggle when told to do something other than mimic their peers

animal behavior, Behavioral science, Biology, parrots, Science / Paul Patrick / February 6, 2025

There have been many studies on the capability of non-human animals to mimic transitive actions—actions that have a purpose. Hardly any studies have shown that animals are also capable of intransitive actions. Even though intransitive actions have no particular purpose, imitating these non-conscious movements is still thought to help with socialization and strengthen bonds for both animals and humans.

Zoologist Esha Haldar and colleagues from the Comparative Cognition Research group worked with blue-throated macaws, which are critically endangered, at the Loro Parque Fundación in Tenerife. They trained the macaws to perform two intransitive actions, then set up a conflict: Two neighboring macaws were asked to do different actions.

What Haldar and her team found was that individual birds were more likely to perform the same intransitive action as a bird next to them, no matter what they’d been asked to do. This could mean that macaws possess mirror neurons, the same neurons that, in humans, fire when we are watching intransitive movements and cause us to imitate them (at least if these neurons function the way some think they do).

But it wasn’t on purpose

Parrots are already known for their mimicry of transitive actions, such as grabbing an object. Because they are highly social creatures with brains that are large relative to the size of their bodies, they made excellent subjects for a study that gauged how susceptible they were to copying intransitive actions.

Mirroring of intransitive actions, also called automatic imitation, can be measured with what’s called a stimulus-response-compatibility (SRC) test. These tests measure the response time between seeing an intransitive movement (the visual stimulus) and mimicking it (the action). A faster response time indicates a stronger reaction to the stimulus. They also measure the accuracy with which they reproduce the stimulus.

Until now, there have only been three studies that showed non-human animals are capable of copying intransitive actions, but the intransitive actions in these studies were all by-products of transitive actions. Only one of these focused on a parrot species. Haldar and her team would be the first to test directly for animal mimicry of intransitive actions.

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Let us spray: River dolphins launch pee streams into air

animal behavior, animal communication, animals, Biology, dolphins, Science / Tim Belzer / February 3, 2025

According to Amazonian folklore, the area’s male river dolphins are shapeshifters (encantade), transforming at night into handsome young men who seduce and impregnate human women. The legend’s origins may lie in the fact that dolphins have rather human-like genitalia. A group of Canadian biologists didn’t spot any suspicious shapeshifting behavior over the four years they spent monitoring a dolphin population in central Brazil, but they did document 36 cases of another human-like behavior: what appears to be some sort of cetacean pissing contest.

Specifically, the male dolphins rolled over onto their backs, displayed their male members, and launched a stream of urine as high as 3 feet into the air. This usually occurred when other males were around, who seemed fascinated in turn by the arching streams of pee, even chasing after them with their snouts. It’s possibly a form of chemical sensory communication and not merely a need to relieve themselves, according to the biologists, who described their findings in a paper published in the journal Behavioral Processes. As co-author Claryana Araújo-Wang of CetAsia Research Group in Ontario, Canada, told New Scientist, “We were really shocked, as it was something we had never seen before.”

Spraying urine is a common behavior in many animal species, used to mark territory, defend against predators, communicate with other members of one’s species, or as a means of mate selection since it has been suggested that the chemicals in the urine carry useful information about physical health or social dominance.

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Peeing is contagious among chimps

animal behavior, animals, Biology, chimpanzees, Science, zoology / Rejus Almole / January 20, 2025

Those results supported the initial hypothesis that chimps tended to urinate in sync rather than randomly. Further analysis showed that the closer a chimp was to another peeing chimp, the more likely the probability of that chimp peeing as well—evidence of social contagion. Finally, Onishi et al. wanted to explore whether social relationships (like socially close pairs, evidenced by mutual grooming and similar behaviors) influenced contagious urination. The only social factor that proved relevant was dominance, with less-dominant chimps being more prone to contagious urination.

There may still be other factors influencing the behavior, and more experimental research is needed on potential sensory cues and social triggers in order to identify possible underlying mechanisms for the phenomenon. Furthermore, this study was conducted with a captive chimp population; to better understand potential evolutionary roots, there should be research on wild chimp populations, looking at possible links between contagious urination and factors like ranging patterns, territory use, and so forth.

“This was an unexpected and fascinating result, as it opens up multiple possibilities for interpretation,” said coauthor Shinya Yamamoto, also of Kyoto University. “For instance, it could reflect hidden leadership in synchronizing group activities, the reinforcement of social bonds, or attention bias among lower-ranking individuals. These findings raise intriguing questions about the social functions of this behavior.”

DOI: Current Biology, 2025. 10.1016/j.cub.2024.11.052 (About DOIs).

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