Thin, with two fingers and a single very thick fingernail: this is how the legs of the ostrich (Struthio camelus) appear. They are fragile only in appearance because they have to carry a considerable weight, given that this bird can reach 160 kilograms.

A load too heavy to be able to fly, though; despite having wings, in fact, the ostrich does not use them. And when he is pursued by a predator, he skillfully uses his legs: with just one step he can do almost four meters!

In the herbivorous sprinters like the ostrich the number of fingers is reduced to the maximum in order not to waste energy. Horses have only one finger … less could not be done!

The Hoffman's Colepo (Choloepus hoffmanni) is a species of sloth that abandons the trees of the forest of central-southern America, where it lives, only to fulfill some … physiological needs. But all the other activities, including childbirth, play them hanging upside down. So much so that the little ones are already born with hooves - long curved claws - with which they anchor themselves to the mother's down so as not to fall to the ground. On the front legs they have two fingers, while on the rear legs three (in the photo). This feature distinguishes them from the "cousins" sloths that are three-toed (three fingers for each paw). Despite being relatives and often neighbors, there is no good blood between the two animals: their encounters frequently result in real aggressions.

More complicated and dangerous, on the other hand, is to closely observe the legs of this scorpion of the family Buthidae, widespread in the hottest climates: the poison of many species of this group is in fact lethal for humans.

For locomotion it is well supplied: eight legs with which it moves quickly and a "navigator". The two large frontal tongs, the pedipalps, in fact, serve to locate the preys. Thanks to some particularly sensitive hairs present on the pincers, it can pick up the vibrations caused by the passage of small animals.

But it is not the only function of the claws, which are also a sensual weapon of conquest: the males use them during courtship to grab the females, involving them in unbridled dances.

It is not a strange planet, but one that would see a mouse a moment before being trampled by an African elephant (Loxodonta africanus). The last animal from which one would like to be trampled. With its approximately five tons of bulk, it is the heaviest terrestrial specimen in nature. And his feet, with a circumference of 120 centimeters, are the widest in the world. Despite the size, however, the elephant moves almost without making any noise, with extreme delicacy, with a swaying gait. This is thanks to a thick cushion of elastic tissue, located at the base of the legs, which allows the pachyderms to cushion and support weight. Even when he runs.

Four Papua penguins (Pygoscelis papua) seem to dance, with almost perfect coordination, in front of the goal of an American researcher in Antarctica. Unlike most birds, penguins migrate on foot. They are so-called gregarious animals: they tend to live in groups and the most numerous colonies can reach 50 thousand units. Sometimes they can give the impression of moving in synchrony, especially when they walk in single file. They do it to shelter from the wind.

Why do their legs, exposed to very cold temperatures (below -80 ° C) and resting for a long time on ice, do not freeze? Find out among the questions and answers.

Photo: © Tom Schonhoff.

From the scorching heat of the savannah to the frost of the mountainous areas in northern Japan. Japanese macaques (Macaca fuscata) - recognizable by the bright red color of their face - can be found in very different habitats. These are the footprints left on the snow. But is there a human hand? It is only an impression, because just like us these animals have the opposable thumb that allows the taking (and manipulation) of objects. Macaques sometimes use it with surprising results. In 1952, some scientists noticed that a Japanese macaque female had started to clean a sweet potato not with her hands, as an ordinary monkey would have done, but washing it in sea water. And some are even able to make snowballs by passing them from one hand to another, just like we do.

The long fingers of chimpanzees (Pan troglodytes) are also useful for an important social "ritual": that of mutual cleansing (the so-called "grooming"). Helping with their hands and often also with their mouth, the chimpanzees look for parasites in the hairs of the other specimens of the pack. And, when they find them, they start smacking their lips and grinding their teeth more and more intensely. Scholars still cannot explain the reason for these strange verses. Grooming is almost a social "duty", since it bonds bonds, releases tension and can become a weapon of seduction.

In evolutionary terms, on the other hand, the "prehensile" hand and foot would have allowed the chimpanzees to hang better on the trees to pass from one branch to another.

On the fossil bed of a prehistoric lake someone has left his footprints. These are the dinosaur footprints found in Sucre, Bolivia. But how do we know exactly what dinosaur footprints are? The study of fossil footprints is a branch of paleontology called icnology. Understanding which prehistoric animal has trodden on land is not an easy task, but the analysis of its footprints can provide many interesting clues to its way of walking, for example. From the way the ground was trodden on, it can be inferred if the animal was on the run; finding a group of footprints around the trace of an ancient tree may indicate that that point was chosen by a pack to make a "snack" based on leaves; instead, finding parallel fingerprints can make us think of the passage of a group of dinosaurs in the migratory phase.

Thanks to its paw the plumed basilisk (Basiliscus plumifrons) has earned the nickname "lizard of Jesus Christ": in fact it has the "gift" of walking on the waters of the marshes and lakes of Central America, where it lives. If he succeeds it is all thanks to his very fast paws: he moves them so quickly that they do not have time to sink. Indeed, due to pressure, small air cushions form between the water and its feet which keep it afloat. Perhaps because of his skill - or more likely because of his not so reassuring appearance - he was much feared in antiquity. Even Leonardo da Vinci, in his Bestiario, described it as a cruel animal with other animals and capable of drying plants. Powers, however, that have not been confirmed. In the video below you can see it running on the water.

If at the sight of this photo you have thought about a walk in a mountain forest, enlivened by a pungent pine scent, you are mistaken. Change the scene and imagine rather a hot day in a desert of Mexico or southern United States and an encounter with one of its inhabitants, the Mexican tarantula (Brachypelma smithi). The saplings in the photo are in fact the electronic micrograph hair of his paws. Thanks to them this tarantula, which does not have a good visual capacity, perceives noises and vibrations that put it on alert. They are also an excellent defense weapon since contact with them causes an intense burning sensation. Don't worry, however, this spider is poisonous only for other insects, its favorite prey.

Long claw-like claws and legs are indispensable tools for the mole (Talpa europaea), which feels at home only between soil and underground passages. Despite its small size, a single mole is capable of constructing a network of underground tunnels that can extend even for hundreds of meters. An astute strategy, not only to find shelter and move without going out into the open, but above all to get food. The tunnel is a perfect trap for those animals, such as earthworms, that move vertically in the ground. And the earthworms are at the top of the list of the "menu" of any self-respecting mole: also of the blind mole (Talpa caeca), a mammal very similar to the common mole, but with the eyes completely covered by a membrane that "stops them" " permanently.

They belong to the order of "ungulates", but there is almost no trace of nails. The nails of some animals, such as this roe deer, have in fact been strengthened over time to become hooves. Many large mammals are part of this large family, such as horses, giraffes, hippos and … whales.

According to some research, hippos and whales are in fact "cousins" of the first degree: it seems that they descend from a single ancestor - a lover of water and lived between 50 and 60 million years ago - who gave birth to two groups of animals.

The first, that of which the hippopotamuses are part, preferred life on land; the second, that of cetaceans, pushed itself more and more towards the water until it completely lost its legs.

A snow leopard comes out into the open. His legs, very large - as seen in the photo - are covered with a thick fur (thicker than in the rest of the body) and allow him to approach his prey very quietly.

These large cats are widespread in the mountainous and sparsely populated regions of Central Asia.

Steve Winter, National Geographic Magazine

The night is young for the gracile lori (Loris tardigradus), a widespread primate in India and Sri Lanka that wakes up only with darkness. Thanks to long and very thin limbs and to these prehensile paws it manages to hold on to the branches for long periods of time and to move from one place to another with a slow and undulating gait. It will be the wild eyes or the "nottambule" habits, the fact is that at first glance it could be mistaken for an owl, with which among other things it shares the reputation of "porta iella". A sad reputation for these small animals that weigh no more than three ounces and can be in the palm of a hand: when they approach the inhabited centers, they are chased away and killed by the most superstitious. And even in their natural habitat they are safe: they are hunted for the phantom aphrodisiac properties of bones and to be used as living voodoo dolls. This ruthless hunt has led them to a serious danger of extinction.

Some grains of pollen on the feet of a bee (Apis mellifera) taken with an electronic microscope. After a year of work, the sequencing of the genome of this insect has been almost completed. The news should make researchers, breeders and victims of bites happy. Here because.

The bee genome is one tenth of that of humans and it will be easier to identify genes and understand the genetics of aging and social behavior. In fact, the queen bees live about 5 times longer than the working ones. Breeders will be able to fight a pest of bees, called varna, resistant to pesticides. And finally, the victims of punctures will benefit from a better understanding of the aggressive behavior of some swarms of African bees, also capable of killing. The genome could reveal whether and which genes are associated with aggression.

The flying gecko (Ptychozoon Kuhli) is a reptile widespread especially in Thailand, Indonesia and Malaysia. It is able to remain "glued" to any vertical surface, including glass, but its legs have no glue: they are the millions of small hairs that cover its legs to exert a force of attraction that scientists have been trying to recreate for years. It has been calculated that the gecko, hanging upside down, could hold up to 40 kg. Fortunately it weighs only 200 grams. And even if the "adhesive" legs do not work perfectly, they always have a "parachute": the thin membranes of skin that wrap around the tail, the legs and the side parts of the body can in fact make the small reptile glide to allow it a soft landing .

The interest in the ability of geckos, small reptiles present in Africa, Asia and Europe, to adhere to any surface with any degree of inclination, has always been alive.

Recent research has also studied the ability of their paws to be, at the same time, highly adhesive and free from impurities (which would obviously compromise their adherence).

These animals do not directly take care of their paws or secrete cleaning liquids: the millions of microscopic bristles have a self-cleaning effect. The researchers have in fact calculated that the force of attraction between the dirt and the bristles is less than that which exists between the surface and the dirt itself. As if to say that the greasy particles remain where they are, as the gecko passes.

These mole legs (Talpa europaea) were found in England in the early 1900s. Used as amulets, they were thought to possess healing properties: it was thought to relieve muscle cramps and toothache.

Photo © Science Museum, London

So much the cat goes to the lard that leaves us a hand. This time, however, the cat in question, named Oscar, of paws has left two. For a fatal distraction (he slept soundly in the middle of the fields) he did not hear the reaper arrive and in a moment the car severed his hind legs.

His owners rushed to Dr. Noel Fitzpatrick's veterinary clinic in Eashing (southern England) where Oscar was not only saved but became the first bionic cat in the world. The custom-made prostheses, coated with hydroxyapatite (a material used for bone implants), were grafted into the ankle joints with a particular curvature that allowed the artificial limbs to seal to the skin avoiding possible infections.

Thanks to this particular technique, developed by a team from University College London, Oscar not only returned to run, jump and climb trees with his new gray metallic paws, but he was able to maintain even the elegant and irresistible feline gait .

You might also like: Do monkeys have fingerprints? Why don't penguins' feet freeze? Bestial sleeps With the tail between the legs Thin, with two fingers and a single very thick nail: this is how the legs of the ostrich (Struthio camelus) appear. They are fragile only in appearance because they have to carry a considerable weight, given that this bird can reach 160 kilograms.
A load too heavy to be able to fly, though; despite having wings, in fact, the ostrich does not use them. And when he is pursued by a predator, he skillfully uses his legs: with just one step he can do almost four meters!
In the herbivorous sprinters like the ostrich the number of fingers is reduced to the maximum in order not to waste energy. Horses have only one finger … less could not be done!