From a viper with a bloodthirsty hitchhiker to a bullfrog narrowly missing its lunch, these photographs, all of which are in the running for this year’s Wildlife Photographer of the Year competition, offer a glimpse into the drama unfolding across the animal kingdom.

Biting Back,��an intimidating shot captured by Andrea and Maceo Grammatico,��was highly commended in the contest’s Animal Portraits category.��The twins say it wasn’t until reviewing their photographs that they spotted a mosquito drinking from the head of the fer-de-lance – the most dangerous snake in Central America.

There was a near miss in Jens Cullmann’s Split-Second Escape, highly commended in the Behaviour: Amphibians and Reptiles category and shown in the main image.��The moment was almost as fleeting as the frog’s prey – an African babul blue butterfly – and all the more remarkable given that Cullmann had spotted tadpoles a month earlier, returning to find them transformed into young bullfrogs. African bullfrogs spend much of the year underground in an inactive state known as aestivation,��emerging only for a short period after the rainy season to breed,��hunt and gorge.��

Hiding not hunting is the speciality of the lichen dragon katydid captured by Gil Wizen,��below. Named Hidden Dragon, Wizen’s shot, highly commended in the Behaviour: Invertebrates category, captures the almost perfectly camouflaged, 15-millimetre-long, spiky insect – a rare species found only in the Ecuadorian Andes mountains.

Moving away from rural environments,���ʴǴDZ��پ��������ʲ����پ�������by Loren Elliott,��below, was highly commended in the Urban Wildlife category. Elliott captures the unusual sight of a black bear taking time to chill in a swimming pool in southern California. While the bear may look somewhat out of place,��these run-ins are becoming surprisingly common as housing developments continue to encroach on bear territory.�� 

Finally,��a black vulture grasps the carcass of a yacare caiman in Andrew Parkinson’s Wings of Darkness,��below, captured in Brazil’s Pantanal wetlands and also highly commended in the Animal Portraits category.��Despite a seemingly firm grip, the scavenger’s meal wasn’t to be,��with a jaguar waiting just out of shot for the perfect opportunity to claim the caiman.

The competition’s overall winner will be announced on 13 October. The Wildlife Photographer of the Year contest is organised by London’s Natural History Museum,��which will run an of the images from 16 October to 11 July 2027.

Male mouse embryos have been turned into females by a procedure that involves eliminating the Y chromosome. The technique relies on CRISPR gene editing and has been used to create healthy and fertile female and male mice, both of which are clones of the father.

“We thought if we could remove the Y chromosomes immediately after fertilisation, we can change the sex,” says at the University of Yamanashi, Japan. “It is essentially sex reversal.”

The method may become useful for conserving animals that are so close to extinction they are down to just one male or only a few.

In animals that reproduce sexually, running out of males or females can mean the end of the line for a population or species. However, some species can turn to asexual reproduction, through budding off new organisms, such as jellyfish-like, or by parthenogenesis, in which unfertilised eggs of animals including lizards, stick insects and sharks can develop into a new animal. This produces offspring that are identical clones of the parent and the same sex. Clones created in labs, such as Dolly the sheep, are made through a similar process.

A few animals, like Okinawa rubble gobies (Trimma okinawae), can change sex to ensure sexual reproduction can continue. Inspired by these colourful marine fish, Ishiuchi and his colleagues came up with a method to change the sex of a male clone embryo, so sexual reproduction between individuals could take place – albeit exceedingly closely related ones.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

when the male-determining Y sex chromosome was deleted, leaving the specimen with just one X chromosome (known as XO), rather than an XY pair.

Ishiuchi and his colleagues developed a CRISPR-based tool called Y-CUT to reliably eliminate the Y chromosome from male mouse embryos.

First, they inserted DNA from the blood cells of a male mouse into mouse egg cells that had already had their own DNA removed – a technique called somatic cell nuclear transfer. They treated some of these embryos with Y-CUT and transferred them to surrogate female mice.��

All of the mice born after the use of Y-CUT were female clones – genetically identical to the father apart from lacking the Y chromosome. Other offspring, which hadn’t undergone Y-CUT, were all male clones.

“We call this dual-sex cloning,” says team member at the RIKEN BioResource Research Center in Tsukuba, Japan.

Introducing the father mouse to his clones was a very special moment, says Ishiuchi. “He could see the female version of himself, which is like sci-fi.”

The clones were fertile, and when they mated together, they produced offspring that seemed healthy. “This means sexual reproduction was initiated from a single male genome,” says Matoba. “The kids have survived over a year so far with no clear defects.”

Ishiuchi hopes that the Y-CUT technique could help revive species that are highly endangered or extinct, and for which only frozen tissue remains in cell banks.

“It would be incredibly valuable if this were successful in species other than mice,” says , also at the University of Yamanashi, who wasn’t involved in the study.

at wildlife conservation organisation Revive & Restore, which has been involved in cloning efforts with endangered species including and the , thinks similarly. “They are laying the foundations for a future of manipulating chromosomes that is probably going to be important in many cases for conservation,” he says.

Novak agrees the technique may be useful for frozen tissue samples from endangered or extinct species, where we have samples from only one or two individuals.

A previous study generated both , but it used a method that is unlikely to work in other species, unlike somatic cell nuclear transfer, which has been successfully applied to many mammal species and works with living or stored donor material.

One issue is that, though an XO female mouse is healthy and fertile, that isn’t the case in many other species.

“Y-deleted offspring are not fertile in humans and horses, and therefore this is likely to be the case in multiple wildlife species,” says of SEZARC, a group of zoos and conservation centres based in the US. She also says there could be ethical concerns with producing Y-deleted animals.

Ishiuchi accepts this, but notes that there is research showing that , so it might be possible to do this in combination with Y-CUT to make resulting females fertile in a wider range of species.

Penfold also warns that breeding from clones of a single animal would create genetic issues. “There is a lack of genetic diversity, which is critical for healthy populations,” she says.

Novak is more positive about that aspect. “Sexual reproduction with one individual is certainly better than no sexual reproduction,” he says, but he adds that we should do everything we can now to never have to use such tools. “While they’re awesome, their use indicates that you’ve gotten to a situation that’s so dire that you need sex reversal,” he says.

Habitat protection and reducing hunting will always be much more effective at conserving species, says Penfold.

Two beagles called Alfie and Bailey lack the main protein that causes allergic reactions to dogs, thanks to CRISPR gene editing. The dogs will be 2 years old in September and show no signs of adverse effects, according to , the company behind them.

“I’ve lived with allergies my whole life. They prevented me and my family from ever having a dog,” says Kindred co-founder Matt Walker. “And my wife, Maggie, has always wanted a dog.” Walker previously worked as a researcher studying neuron development in worms by using CRISPR gene editing to disable specific genes. He realised it might be possible to use the technique to prevent dogs causing allergies, and founded Kindred in 2020.

How were Alfie and Bailey created?

Previous studies have found that the main allergen that triggers reactions to dogs is a protein called Can f 1. It is secreted by the tongue and by glands in the skin, so it is present both in the fur of dogs and in their saliva.

The Kindred team took skin cells from a female beagle and used the gene-editing tool CRISPR Cas9 to mutate the Can f 1 gene – the result was an extra DNA letter at the start of the gene that shifts the way the recipe for making the Can f 1 protein is read by cells, turning it into gibberish. Once the team members had confirmed they had made the desired change without introducing unwanted mutations, they cloned the cells. Altogether, the team transferred 25 embryos to a surrogate, of which two implanted and developed to term.

Does removing this protein really prevent allergies?

Bailey is Walker’s pet dog, and he says he has no reaction to her at all. She was cavorting in the background when 91av spoke to him. Kindred has also showing that Can f 1 is undetectable in Alfie and Bailey, and that there are no allergic reactions to samples from them in skin-prick tests, whereas samples from normal dogs do provoke a reaction.

However, Can f 1 isn’t the only protein in dogs that can trigger allergic reactions – there are also so-called minor allergens, such as Can f 2. “If we do find that there’s a substantial population that is still responding to the dogs, then that is something we could address,” says Walker.

And could the process be harmful to dogs?

We don’t know for sure what the function of Can f 1 is, but Walker says he was confident from experiments on mice that there would be no serious consequences from deleting it. So far, both dogs appear normal and healthy, he says. “Of course, that’s something that we’re monitoring very closely, and will continue to monitor over the animals’ lives.”

Isn’t it already possible to buy “hypoallergenic” dogs?

Some breeds, such as poodles and goldendoodles, are said to be less likely to trigger allergic reactions, but Walker says he responds just as much to the goldendoodle his parents bought after he left home as he does to any other dog. In the paper, his team shows that Can f 1 is detectable in both breeds, and that samples from them trigger reactions in skin-prick tests.

This is in line with independent evidence. The American Academy of Asthma, Allergy and Immunology says some “hypoallergenic” breeds .��

Free newsletter

Sign up to Health Check

Sign up to newsletter

When will these dogs be commercially available?

Not for some time. Kindred first needs regulatory approval from the US Food and Drug Administration. If it gets that, it then needs to create lots more of these dogs. For each dog breed, the company will have to create a genetically diverse set of “founder” dogs that can then be bred normally. Walker couldn’t say how many founder dogs would be required per breed.

Is it ethical to genetically engineer dogs just to prevent allergies?

“We aren’t using gene editing for novelty or some cosmetic reason,” says Walker. “Allergies are a real health problem. They affect a significant portion of the population, and lead to serious conditions such as asthma triggering asthmatic attacks.”

By contrast,��conventional dog breeding is often done purely for the sake of appearance, and can introduce mutations that cause serious harm, such as those found in breeds like pugs .��Nevertheless, Kindred is altering dogs for the benefit of humans rather than the benefit of the animals themselves. In response to this, Walker says people discovering they are allergic to dogs is a leading reason for animals having to be rehomed.��

Is Kindred planning to gene-edit cats, too, to prevent allergies?

“Right now, we’re focused exclusively on dogs,” Walker says. The main allergen in cats, called fel d 1, is encoded by two genes rather than one, so getting rid of the protein is more complex. Another company called InBio announced plans to create cats free of fel d 1 in 2022.

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.”

Subscriber-only newsletter

Sign up to Editor’s Highlights

Sign up to newsletter

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 .

Don’t treat your pets for parasites such as ticks and fleas unless they actually need treating. We can’t be sure that these treatments are safe for you and your family, and there is growing evidence that they pose a danger to wildlife.

So says a by the Environment and Climate Change Committee of the UK’s House of Lords. It is calling for the sale of these treatments to be restricted, so people can only buy them after consultation with a vet, pharmacist or qualified pet shop staff.

The main issue is that there is no rigorous assessment of pet treatments before they are approved, the report says. It has simply been assumed by national and international regulators that they are safe, but this assumption is turning out to be wrong.

In particular, at least two potent pesticides found in tick and flea treatments are getting into UK rivers at levels high enough to affect wildlife. These pesticides can break down into other substances that are even more harmful.

“There is also worryingly insufficient evidence to assess whether or not [pet parasite medicines] are harmful to human health,” says the report.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

It also says regulators aren’t sufficiently independent. Both UK and international regulators “appear to be too influenced by and beholden to the views of the industry”, it states.

While the report focuses on the UK, the same tick and flea treatments are sold in many countries. “This is a worldwide issue,” says at Imperial College London, one of the experts who gave evidence to the committee.

“There’s been a historical assumption that any veterinary medicine used in non-food animals – cats and dogs, companion animals – is associated with negligible environmental risk,” she says. “Effectively, they have no meaningful environmental risk assessment.”

But recent research shows they do pose a risk, says Perkins. “It’s really opened up a Pandora’s box, because we have dozens of these products that have been approved based on this assumption that we now know is not scientifically valid.”

For instance, two common pesticides found in products such as spot-on flea treatments are fipronil, a broad-spectrum insecticide, and imidacloprid, a neonicotinoid. “They’re incredibly potent at extremely low levels,” says Perkins.

Both pesticides used to be used on farms until they were banned a few years ago. But they have continued to be found in rivers. In fact, with the development of more sensitive tests, they are turning up “pretty much everywhere in waterways”, says Perkins.

Initially, it was thought this was a legacy of their use by farmers, but work by Perkins and others suggests parasite medications are now the main source of these pesticides in waterways. In many cases, levels are high enough to harm invertebrates such as mayflies, dragonflies and caddisflies, with knock-on effects on the fish and birds that feed on them.

We don’t know how big a problem this is, says the report. “The true scale of environmental harm resulting from pet parasite medications is not known.”

How are the pesticides getting into rivers? Once they are applied to pets, they end up all over the home, says Perkins. When people bathe their pets or wash pet bedding, they can end up in wastewater.

Product packaging currently recommends that dogs are not bathed for four days after treatment, but this needs to be extended to 28 days, the report recommends.

Another major source of the pesticides in water is hand-washing, says Perkins. “We detected [pesticides] in the wash-off even before we asked people to stroke their pets, so they’re just constantly on the hands of pet owners.”

Products containing fipronil and imidacloprid are now being replaced by ones containing isoxazolines, typically sold in the form of chewable tablets. Isoxazolines are less water-soluble but can bind to sediments and accumulate in soils and sewage sludge. They might be ending up in fields when sewage sludge is sprayed as fertiliser and harming pollinators.

“There has not been much work done to date to assess this,” says the report.

Shed dog fur is yet another way these chemicals can end up in the environment. The report says contaminated fur has been found in bird nests.

In light of these findings, the use of pet parasite medications should be minimised until there is independent research clarifying their risks, says the report. At present, manufacturers of parasite treatments are promoting the idea that routine treatment for parasites is required, and encouraging pet owners to get them via monthly subscriptions. “However, the benefits of routine, and certainly monthly, pet parasite medicine usage are not supported by scientific evidence.”

It is an excellent report, says Perkins, but she hoped it would go further and recommend making these products prescription-only. Some wildlife groups, meanwhile, want .

Yet another reason for restricting their use is to slow the development of resistance, says Perkins. She sees a lot of animals treated with old spot-on treatments containing fipronil that still have fleas. “We need effective parasite treatments, and we need to make sure we preserve their efficacy,” she says.

A tiny, long-necked marine predator that lived 245 million years ago is the oldest reptile ever found with an intact digestive system.

The exquisitely preserved fossil, including almost the entire skeleton as well as the stomach, liver and intestines, was found in Yunnan province in China in 2023 and is named Austronaga minuta.

Even blood vessels and the scales of a partially digested fish meal are visible in the remains.

“A fossil this age with such clear preservation of its organs is really a world treasure,” says at Flinders University in Adelaide, Australia, who wasn’t involved in the research.

Austronaga dates back to the Triassic Period, when dinosaurs first evolved, but it isn’t a dinosaur. It belongs to a broader group called archosaurs, which includes dinosaurs, birds and crocodiles, but not other famous marine reptiles like mosasaurs or ichthyosaurs.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

The archosaurs were incredibly diverse in the Triassic and included “all kinds of interesting and strange-looking reptiles”, says at the Natural History Museum Stuttgart, Germany, a member of the team that analysed the fossil. Only later, during the Jurassic and beyond, did they become more restricted, mostly being limited to dinosaurs, including birds, and crocodiles.

This specimen is a mere 60 centimetres in length, but as it is the only known example and the reptile’s age at death is unknown, it is impossible to say whether the species grew larger, says Spiekman.

However, he is confident that it was unlikely to have reached the size of its very long relative Dinocephalosaurus, the “Chinese sea dragon”, which could easily grow to over 4 metres.

“This was certainly a good and agile swimmer, mainly using its tail for swimming, its long front flippers for steering and its long neck to catch fish,” says Spiekman. “A�ܲ��ٰ��DzԲ����� probably would have looked a little like a lizard or a croc trying to be a seal or an otter and likely would have had scaly skin, for example.”

The fossil shows that the basic plan of the reptilian digestive tract has changed little in 245 million years, he says, and the “straight and simple intestines is what we see in most modern predatory reptiles, including those eating fish”.

Although the fossil is of high quality, the internal organs of Austronaga are only preserved in two dimensions. This is unlike those of a 380-million-year-old fossil of an armoured fish that Long and his colleagues , which is regarded as having the oldest known organs of any vertebrate.

“But this is still an incredibly well-preserved fossil,” he says.

Extraordinary underwater videos have captured orcas making sunfish explode by ramming them at high speed. The behaviour may help juvenile orcas feed by breaking the prey into many small pieces, but it also appears that the orcas may enjoy playing with their food.

“It’s a hunting tactic, but that involves a play game in the process,” says , an independent marine biologist in Mexico. “There’s ‘high-octane’ adrenaline and a lot of other hormones rushing through their bodies, so, of course, there’s got to be some sort of excitement.”

Sharp-tail sunfish (Masturus lanceolatus) are among the largest bony fish, weighing up to 2000 kilograms. Higuera had already seen groups of orcas (Orcinus orca) attacking sunfish in the Gulf of California, ripping off parts of their flesh and tossing them around to each other in a playful manner. In the past few years, he had even witnessed them .

Then, in July 2024, his colleague at US non-profit organisation Beneath the Waves caught an explosive interaction on her GoPro camera while diving in the Gulf of California. An adult female orca held onto a dead sunfish while an adult male orca swam upside down towards it at full speed. The female released the sunfish at the last second, and the male hit it with so much force that the fish burst into a flurry of small fragments.

A year later, tourist Hector Franz shot a similar underwater scene in the same bay. This time, an adult female rammed right-side-up into a sharp-tail sunfish held in place by another adult female, popping it into pieces. Combined, the two events mark the first time scientists have seen such behaviour by orcas, say Higuera, Ayres and their colleagues.

Sunfish have “an incredibly dense, rubbery, collagenous” outer layer that’s harder to bite through, so bursting them open could be an effective way to feed on them, says Higuera.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

“The explosive fragmentation seemed mostly to be of the stiff gelatinous capsule that makes up a high percentage – more than 80 per cent in large fish – of the body mass of the sunfish,” says at University College Cork in Ireland. “I suspect that calves cannot achieve enough force to do this, as their mass is too low. But they can exploit a cloud of objects that contain tasty morsels.”

Earlier sightings without full footage indicated that the entire pod was involved in a strategic attack process leading up to the rammings, says Higuera. The findings point to advanced cooperative hunting skills and even planning – especially adapting their techniques for different kinds of prey, he says.

Higuera suspects that popping the sunfish offered a learning experience for the calves, while providing them with bite-sized snacks. Simultaneously, these events could also reinforce social bonds through “play” and social learning in this highly intelligent species, he adds.

at the University of Tennessee in Knoxville says it is possible the orcas were having some fun in demolishing the fish, but play wouldn’t be the only goal, as there is clearly cooperative foraging going on as well.

“One of the fascinating things about play is that it can be a driver of behavioural innovation,” says at the University of Pisa, Italy. “It’s possible that a behaviour like this may have originated in a playful context and later acquired a feeding function, or vice versa. At this stage, we simply don’t know.”