Forget about snakes on a plane, we have snakes on a page - a blog page! These fascinating legless carnivorous reptiles have featured as terrible man killers in works of fiction for centuries. More often than not this reputation is unfounded and most snakes will actively avoid human contact. Different species of snake vary dramatically in shape, size and colour and are found in a range of different habitats on 6 out of the 7 continents in the world – from dry deserts to lush jungles and even under the sea.

Unsurprisingly, it is the species of snake that are potentially deadly to human that get the most attention (even if there are no reported cases) and we have no shortage of them on ARKive. Here is ARKive’s Top 10 Deadliest Snakes.

Black mamba

A double dose of deadly – two black male mambas fight it out for dominance

The black mamba is a long and extremely venomous snake found in Southern Africa. It gets its name from its distinctive black mouth.  If its neurotoxic venom was not enough for you, the black mamba is also highly aggressive and very fast – not a good mix if you were to stumble into its territory.

Olive-brown sea snake

Danger in the deep -the olive-brown sea snake

The olive-brown sea snake is specially adapted to a life at sea with special glands located in the mouth that allow it to get rid of excess salt. This snake is also somewhat docile making its enzyme-loaded venom (that digests prey from the inside)  slightly less terrifying.

King cobra

The king cobra rests…for now

The forest dwelling king cobra lives the longest out of all venomous snakes – the same can’t be said about its prey: other snakes! At least it will give you a warning if it feels threatened by your presence - it growls!

Namaqua dwarf adder

A hidden danger waiting to strike – the Namaqua dwarf adder

The Namaqua dwarf adder is found in southern Africa and is the smallest venomous snake in the world, but don’t think that means its not afraid to use it long hinged fangs…

Adder

The adders in the UK have British venom in the land!

As Britain’s only venomous snake, the adder automatically wins the title of Britain’s deadliest snake. Though as it is a somewhat shy and timid species you would have to be quite lucky to see one and very unlucky to get bitten by one.

Horned sea snake

That look says it all really

Being on the receiving end of a stare from the horned sea snake would be a scary experience indeed. I doubt knowing that it was also one of the most toxic sea snakes would ease your mind but there have actually no recorded cases of bites to humans.

Green anaconda

The green anaconda showing that you don’t need to be venomous to be deadly

You don’t need to be venomous to be deadly and the green anaconda, the world largest snake, relies solely on constricting its prey to suffocate it so it may be swallowed whole. Despite what you may have seen in various films, attacks on humans are very rare – though there are reported cases.

Arabian horned viper

The desert dwelling Arabian horned viper

King of the desert, the Arabian horned viper is an ambush predator that lies and waits to strike, loading its prey with large quantities of powerful venom.

Indian cobra

An Indian cobra locked in mortal combat with a mongoose

Though often seen with snake charmers in India, the Indian cobra is probably not as easy to win over as you may think. Its neurotoxic venom can paralyse prey and in some cases even cause the heart to stop.

Caucasian viper

Famously venomous – the caucasian viper

The caucasian viper has some of the most potent of all vipers though it is also widely used medicinally to stop heavy bleeding. This snake will often release its prey after it has injected it and track it down later after it has conceded to the venom.

Year of the Snake 2013

In Chinese culture, the 10th February 2013 marks the start of the Year of the Snake. To celebrate, check out our fortune cookies on Facebook and join in with our daily snake hunt on Twitter.

George Bradford, ARKive Media Researcher

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The world’s second largest continent, Africa is home to a spectacular array of wildlife and landscapes. Its outstanding diversity is spread across deserts and savannas, forests and swamps, and some of the most iconic species on earth are found there. With the launch of BBC One’s new Africa series, we thought we would explore some the most popular African species on ARKive.

1. Meerkat

Meerkats are one of the most popular African animals, due to their highly sociable and charismatic nature. Meerkat groups are usually made up of around 50 individuals, including a dominant pair and ‘helpers’ of both sexes. Meerkats demonstrate an extraordinary division of labour: when out hunting, one or more individuals keep lookout to protect the rest of the group from predators, and when young are born, non-breeding adults take turns to ‘babysit’ while the rest are out foraging.

2. Blue wildebeest

Thousands flock to Africa’s National Parks every year to see the famous blue wildebeest migration. Forming some of the largest migratory herds of all antelope species, wildebeest rely on short grass and water to survive, so must migrate between seasonal grazing sites throughout the year. Wildebeest are well known in Africa as the ‘spare-parts animal’, as they are said to look as though they are made up of several different animal parts.

3. Shoebill

The shoebill is a baffling species with a distinctively prehistoric appearance. While it shares many similarities with storks, pelicans and herons, it remains a unique species with many characteristics setting it apart from any other African bird. The shoebill resides in some of the most inaccessible wetland habitats in Africa. Usually feeding at night, it hunts by ambush, standing stock-still until its prey is near, and then snatching it from the water with its sharp, hooked beak.

4. Hippopotamus

The hippopotamus is a surprisingly speedy animal, both underwater and on land, despite the fact that a male hippopotamus can weigh as much as 3,200 kg. This, coupled with its aggressive nature, makes it one of the most dangerous African animals. Its semi-aquatic lifestyle earned the hippopotamus its name, which means ‘river horse’. Once widespread across sub-Saharan Africa, the hippopotamus is now mainly found in the East African countries, particularly Tanzania, Zambia and Mozambique.

5. Giraffe

There are nine types of giraffe living in Africa, six of which may be genetically distinct subspecies, and the different types can be distinguished by their spot patterns. The Latin camelopardalis means ‘camel marked like leopard’, and the giraffe’s brown blotches help to camouflage it in the shade patterns created by the trees it feeds on. Giraffes are surprisingly hard to see among the trees for this reason; however, out on the plains they can be seen in their full glory. Despite its extremely long neck, the giraffe actually has the same number of neck vertebrae as most mammals, including humans.

6. Ostrich

This flightless bird is the fastest running bird in the world, reaching speeds of up to 70 km per hour. To add to this, it is also the heaviest of all living birds and has the biggest eyes of all land animals. The ostrich is an instantly recognisable bird with a long bare neck, soft smooth plumage, and prehistoric-looking feet with just two toes. The male ostrich produces a booming call which is said to sound like the roar of a lion. Ostriches are found across the majority of the African continent, and have also been introduced to southern Australia.

7. Plains zebra

Clearly related to horses, the plains zebra is another of Africa’s most iconic animals. Its most characteristic feature is the pattern of black and white stripes all across its body. There are many theories as to the purpose of the conspicuous black and white stripes, but one likely explanation may be a social one, with the stripes being thought to encourage group structure and grooming behaviour. Zebras are the most abundant of all Africa’s grazers, and are preyed upon by several of Africa’s large predators, such as lions and hyenas.

8. Eastern gorilla

Gorillas are the largest of the living apes, and have now been recognised as two separate species – the eastern and western gorillas. Eastern gorillas are found in Rwanda,Uganda and the Democratic Republic of Congo (DRC), although one subspecies is solely restricted to eastern DRC. There are two subspecies: the mountain gorilla, occurring at altitudes between 1,160 and 4,100 metres, and the eastern lowland gorilla, which is found between 600 and 2,900 metres above sea level. Each family group of eastern gorillas is led by a dominant silverback male, and groups can sometimes be made up of more than 50 individuals.

9. Nile crocodile

The Nile crocodile is a formidable African predator, and one of the largest of all crocodilians. To enable it to lie low in the water and ambush prey, its eyes, ears and nostrils are located on the top of the head. A valve at the back of the throat stops water from entering when the crocodile grabs prey in its jaws and holds it underwater. The Nile crocodile is capable of taking prey as large as buffalo, zebras, wildebeest and other antelopes, which it drags into the water, but the female can also be surprisingly gentle, carrying her newly hatched young to water in her mouth.

10. African rock python

As Africa’s largest snake, the ill-tempered African rock python is not to be reckoned with. It is a non-venomous snake, killing its prey by coiling around it and squeezing tighter with each breath the victim takes, until its prey dies by cardiac arrest. The African rock python can feed on animals as large as crocodiles, and is found across most of sub-Saharan Africa.

These are but a few of the most well-known and fascinating animals that Africa has to offer. Over the next few weeks we’ll introduce you to some lesser-known species, as well as ‘the big five’, ‘the little five’ and more…watch this space!

Kaz Armour, ARKive Text Author

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Green turtle (Chelonia mydas)

Species: Green turtle (Chelonia mydas)

Status: Endangered (EN)

Interesting Fact: Despite its common name, the green of the green turtle is not initially obvious – it actually derives this name from the green colour of its fat and connective tissues.

The green turtle (Chelonia mydas) is one of the largest and most widespread of all the marine turtles. Found throughout the Pacific, Atlantic and Indian Oceans, these marine reptiles undertake tremendous feats of navigation and may travel thousands of kilometres across the open ocean to return to a particular beach to breed. Unlike other marine turtles, the adult green turtle is almost completely herbivorous, grazing on sea grasses and algae. Juveniles will typically feed on jellyfish, molluscs and sponges.

The green turtle is overharvested in many areas for both its meat and eggs. By catch, habitat degradation, and disease also threaten this species. International legislation, including its listing on Appendix I of CITES, has reduced the direct impact we are having on green turtle populations. However, a lack of monitoring of fisheries and continued habitat degredation still pose problems to protecting this, and the six other species of marine turtle.

For more information about green turtles and their conservation see the WWF website.

See videos and images of the green turtle on ARKive.

Lauren Pascoe, ARKive Researcher

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Despite their thick skins, crocodilians are actually more sensitive to touch than humans, according to new research.

Black caiman with jaws open

Crocodilians – a group comprising crocodiles, alligators and gharials – possess large numbers of dome-shaped dots around their jaws, but until now the function of these structures has been unclear.

Previous theories suggested that the bumps were used to detect electrical or magnetic fields, to secrete fluid or to detect salinity. However, new research published in the Journal of Experimental Biology has found that the unusual structures are extremely sensitive to touch. In fact, they are even more sensitive than human fingertips.

“When I used a calibrated series of fibres to touch or tickle the [bumps], I found that they were responsive to forces finer than our own fingertips – a sensory system widely studied for its own sensitivity,” said Duncan Leitch, one of the authors of the study.

Close-up of Nile crocodile jaws, showing black bumps on the skin

Network of nerves

When the researchers analysed the bumps, they found that they were made up of many specialised cell receptors. Numerous free nerve endings occurred near the surface of the bumps, while deeper in the skin were structures sensitive to pressure and vibrations.

By tracing the nerves, the researchers also found that the Nile crocodiles and American alligators they studied had a delicate network of nerves running throughout their jaws, threading through the skull before ending in the bumps. The scientists suggest that this layout, with the nerve network largely enclosed within the skull, may help to protect the nerves during aggressive encounters or when the animal is hunting.

American alligator

Sensitive armour

The super-sensitive nature of crocodilians’ jaws may play a role in their rapid reaction times when hunting, allowing them to effortlessly detect movements in the water. It may also allow these armoured reptiles to more easily distinguish between food and inedible debris.

“I was very surprised at these results, especially considering how armoured and scaly the crocodiles and alligators appear,” said Leitch. “However, it seems to make sense that an animal that might need to carefully discriminate between inedible objects and food, especially in dark or nocturnal environments, would be well-served by having an exquisite sense of touch.”

Despite their large size and fearsome reputation, female crocodiles can also be incredibly gentle, using their jaws to help their eggs to hatch, and even carrying their offspring in their mouths. Having highly sensitive jaws is an obvious advantage in performing these delicate, controlled movements.

Female crocodilians, like this American alligator, take great care of their eggs and young

Evolutionary puzzle

According to Leitch, one of the goals of the research is to gain a better understanding of how the nervous systems of different species – in this case, crocodilians and humans – have evolved to solve similar problems, such as the processing of touch sensations.

As ancient reptiles that have been around for millions of years, crocodilians can play a key role in our understanding of evolutionary processes.

Close-up of Nile crocodile eye

“It is interesting to consider what adaptations, including possibly sensory capabilities, have made them such robust creatures,” said Leitch.

Read more on this story at BBC Nature News – Crocs have super-sensitive jaws.

View photos and videos of crocodilians on ARKive.

Liz Shaw, ARKive Text Author

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An unusual species of turtle has been found to excrete waste substances through its mouth, according to a team of scientists in Singapore.

The scientists were puzzled by the behaviour of the Chinese softshell turtle (Pelodiscus sinensis) as, despite needing to breathe air, it often submerged its head in water for up to 100 minutes at a time.

When they studied the turtle in the lab, the team found that it regularly dipped its head into water and rinsed it through its mouth. The rhythmic motion of its throat, not to mention the fact that it did not drown, indicated that it was still ‘breathing’ while submerged.

Excreting urea

After testing the water, the scientists found increased levels of the chemical compound urea, a nitrogen-rich waste substance that is excreted by most vertebrates via the kidneys and passed out as urine. In turtles, urea normally passes out of the cloaca, a single orifice used for excretion and for reproduction.

However, the team’s findings showed that the Chinese softshell turtle excretes significantly more urea through its mouth than through its cloaca. This adds to previous research that indicated that this species has highly specialised mouth tissues, a fact first discussed over a century ago when it was suggested that their velvety mouth functions in a similar way to fish gills. The findings of the research have been published in The Journal of Experimental Biology.

According to Professor Ip Yuen Kwong, one of the researchers, “These results indicate for the first time that [mouth tissue] processes and rhythmic [throat] movements were involved in urea excretion in P. sinensis.”

“We were greatly surprised by our novel results because it is generally accepted that the kidney is responsible for the excretion of urea in vertebrates – except fish,” he said.

Farmed for food

An odd-looking turtle with a leathery shell, the Chinese softshell turtle is native to much of East Asia, occurring in China, Japan, Taiwan and Vietnam. It has also been introduced to Thailand and the United States.

The Chinese softshell turtle is typically found in swampy, brackish water, and the scientists have suggested that the ability to excrete urea via the mouth may have helped this and other soft-shelled turtles to successfully invade brackish and marine environments.

To produce urine in the kidneys, the turtles would have to regularly take in water, which would be harmful when the water is too salty. By simply rinsing its mouth with the brackish water, the turtle can avoid the problems associated with drinking it.

The Chinese softshell turtle may also be able to take in oxygen through its mouth tissues.

Considered a delicacy in many parts of Asia, this species is farmed in vast numbers for food, but its wild populations also continue to be exploited. As a result, the Chinese softshell turtle is in decline, and has been classified as Vulnerable on the IUCN Red List.

Read more on this story at BBC News – Chinese turtle passes waste urea through its mouth.

View more photos and videos of turtles on ARKive.

Liz Shaw, ARKive Text Author

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