Physically, Homo sapiens isn’t that special in the animal world. But our species has discovered ways of beating the odds of survival in every habitat, from jungle to Arctic wasteland. In our latest interview with biological anthropologist and broadcaster Alice Roberts, we discuss the wonderful benefits bestowed on us by animals from our evolutionary past. The biochemistry in our cells goes back to the earliest single-celled creatures living in the ancient oceans, and our arms and legs date back to when the first amphibians crawled onto land around 360 million years ago.

Read more: These are the extinct humans that live on in your DNA

Resplendent with its blue stripes and golden legs, this newly described poison dart frog may look imposing, but it is only about the size of a thumbnail, measuring just 14 to 17 millimetres from the tip of its snout to its 诲别谤谤颈猫谤别, or cloaca.

at the National Institute of Amazonian Research in Manaus, Brazil, and his colleagues found the frog in the forests of the Juru谩 river basin in Brazil in 2023 and went back to look for further specimens in 2024. The team has now officially described it and named the species Ranitomeya aetherea.

Little is known about the frog, but there are clues about its parental care system. Koch鈥檚 team hasn鈥檛 found any large groups of tadpoles, hatched from a big clutch of eggs. Instead, they have spotted only individuals, mainly in water-filled cavities where leaves join the stem on palm-like plants called Phenakospermum guyannense.

The team saw one female deposit a single egg, which suggests that eggs are laid singly, as happens in some other poison dart frogs. 鈥淚t鈥檚 possible that the female goes back when the tadpole is developing and lays another unfertilised egg, so that the tadpole can eat this to get energy,鈥� says Koch.

The researchers don鈥檛 know how big the population of the frogs is, so can鈥檛 tell if it is endangered, but in the year between the two surveys, they saw there had been deforestation in the area they searched, which they accessed via a small plane and then an 8-hour boat trip on the river. 鈥淎s the frog is really specific to this plant in this area, any small disturbance could be dangerous to the species,鈥� says Koch.

One of Australia鈥檚 most endangered amphibians can fight off a deadly fungal infection with the help of a naturally heated shelter, which researchers are calling a 鈥渇rog sauna鈥�.

The disease, chytridiomycosis, has wiped out nearly 100 species of frogs, toads and salamanders around the world.

The green and golden bell frog (Litoria aurea) was once widespread in coastal, south-eastern Australia, but has seen its range shrink by 90 per cent. While other factors, like habitat loss, are contributing, chytridiomycosis is thought to be the biggest threat to the endangered creatures.

It has long been known that high temperatures limit fungal infections. Many frog species, including the bell frogs, are particularly susceptible to the disease in winter when it is difficult to raise their body temperatures 鈥� especially when warm spots are hard to find.

To find out more, at Macquarie University in Sydney and his colleagues studied two groups of captive frogs that were deliberately infected with chytridiomycosis during winter.

The first group was provided with bricks with holes in them inside an unshaded greenhouse shelter where temperatures reached highs of nearly 40掳C (104掳F). The second group was provided with the bricks in a shaded greenhouse shelter where temperatures reached 35掳C (95掳F).

In the frogs offered the warmer shelters, the amount of spores of chytrid fungus present on their skin was 100-fold lower than in the other group.

Chytrid fungus struggles to grow above 28掳C (82掳F), but the warmer temperature also seems to activate the frogs鈥� immune system, says Waddle.

鈥淯sing the shelters and surviving is like a vaccination for the frogs,鈥� says Waddle. 鈥淲e have shown that the bell frogs can gain resistance after an infection is cured with heat and this can lead to a 22 times greater chance of surviving a future infection, even under cold conditions.鈥�

While they have only tested the shelters on one species at this stage, the researchers think the technique could work for others facing the threat of chytridiomycosis, providing they naturally seek out warmth when it is cold. Waddle says he can think of at least six Australian species that could benefit.

Importantly, these heat shelters can be readily and inexpensively deployed. 鈥淚t鈥檚 just a small veggie greenhouse from a hardware store and a few bricks and costs only 60 to 70 [Australian] dollars to build,鈥� says Waddle. 鈥淚 envision people putting them in their backyards to help frogs during winter.鈥�

A worm-like creature secretes a nutritious milk from its rear end to feed its hatchlings, in the first known example of an amphibian feeding its young in this way.

The ringed caecilian (Siphonops annulatus) is a legless, egg-laying amphibian that can be found in dark, moist forest floors across South America. It reaches up to 45 centimetres in length, with white grooves encircling its deep blue, cylindrical body.

Ringed caecilians are born with spoon-shaped teeth. They use these to feed on their mother鈥檚 skin, which is rich in lipids and proteins.

鈥淏ut this skin feeding only happens once a week,鈥� says at the Butantan Institute in S茫o Paulo, Brazil. That isn鈥檛 enough food to sustain the rate at which the young develop, he says, with some growing 150 per cent larger within their first week of life.

To find out where their extra nutrition comes from, Jared and his colleagues recorded videos of 16 female ringed caecilians and their hatchlings.

The team observed the hatchlings wriggling around the end of their mother鈥檚 body several times a day, often nibbling and sticking their heads into a posterior orifice, known as a vent.

Closer inspection of the footage showed small drops of a milk-like substance often spilling onto the vent鈥檚 opening, which suggests that the young were actively feeding on it.

Analysis of the milk revealed that it contained lipids and carbohydrates. 鈥淭hese carbohydrates are very important,鈥� says team member , also at the Butantan Institute, as they give the hatchlings the energy they need to grow.

The team also found that touch and sound signals from the hatchlings stimulated milk production in glands within the mother鈥檚 oviduct, or fallopian tube.

Some caecilians that give birth to live young secrete nutritious fluids for the fetuses inside the mother鈥檚 body, says Mailho-Fontana, but this is the first time amphibians have been found to produce fluid to feed their young outside the body.

鈥淐aecilians are a real surprise box,鈥� says Jared. 鈥淭hey鈥檙e very secretive, living inside the subterranean world, which is different to the surface of the earth. They adapted in a world completely different to what we know and needed to invent several new behaviours to live.鈥�