The Gila Monster

Covered in pink and black bead-like scales, the Gila monster (Heloderma suspectum) is the largest lizard native to the United States. It is one of only two venomous lizards found in North America, along with Mexican beaded lizard. However, they are slow-moving and sluggish by nature so pose little threat to humans.

Gila Monster

These reptiles live in the deserts of southwestern North America, where they hunt insects and ground-dwelling vertebrates, including small mammals. Their name comes from Arizona’s Gila River basin – the area where they were first discovered. Gila monsters spend 90% of their time underground in burrows or rocky shelters, allowing them to stay cool in the desert heat.

Their oversized tails can be used to store large amounts of fat, letting Gilas to go for months without a meal. Unbelievably, these lizards may only consume as few as three big meals a year, and still maintain good health.

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You can clearly see the coloured beads that make up the Gila monster’s skin.

The Gila monster’s venom is a neurotoxin which would be extremely painful to humans, but there have been no reported deaths from being bitten by a Gila monster. Unusually for reptiles, the Gila monster does not inject its venom, instead it latches onto its victim and chews to allow neurotoxins to move through the grooves in their teeth and into the newly created wound. The most fascinating aspect of their venom is the proteins that it contains. A synthetic version of the protein exendin-4, derived from the Gila monster’s saliva, is used for the management of type 2 diabetes. Surprisingly, this protein has proved to be a highly effective treatment for diabetes, emphasising the ever-amazing wonders of wildlife.



Hennessy, K., Wiggins, V. (2014) Animal Encyclopedia: The Definitive Visual Guide. 2nd edn. London. Dorling Kindersley.

The Nile Crocodile

The largest freshwater predator in Africa, the Nile crocodile (Crocodylus niloticus) is a formidable hunter with a great historical significance. They are widespread throughout sub-Saharan Africa, where they feed mainly on fish – like their Indian relative, the Gharial. However, these reptiles are opportunists so will attack almost anything unfortunate enough to cross its path, including zebras, wildebeest, small hippos, warthogs, bushpigs, porcupines, birds, and even other crocodiles. Once they have made a kill, they will rip off and swallow chunks of flesh, using the classic “death roll” to tear off particularly stubborn bits of meat.

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The Nile crocodile is possibly the second largest extant reptile in the world, after the huge saltwater crocodile. They can reach up to 6 metres in length, and weigh over 1000 kilograms in extremely rare cases. Though normally, adults don’t exceed 5 metres, and weigh around 500 kilograms. These crocs are quite sociable animals; sharing their basking spots and food with others. Their hierarchy is strict and determined solely by size and strength.

In the Maasai Mara National Reserve in Kenya, Nile crocodiles enjoy an annual feast. This reserve is famous for the annual migration of zebra, Thomson’s gazelle, and wildebeest to and from the Serengeti every year, known as the Great Migration. During this migration, these mammals must cross the Mara river – a river that is home to hundreds of hungry crocodiles. As huge herds of desperate wildebeest and zebra charge through the river, the crocodiles relish in the free buffet. These crocodiles have adapted, ingeniously, to exploit the delicious meals on offer.

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A Nile crocodile hunting a wildebeest in the Mara river.

Not only are Nile crocodiles superb predators, they also have an incredible past. Modern crocodiles have been around for about 80 million years, and the fact that they are still here today is a testament to their wonderful ability to adapt. In Ancient Egypt, the Nile crocodile was seen as the biggest and most dangerous predator; feared by many. However, the Egyptian people also had some admiration for these creatures – the Egyptian deity Sobek was based upon the crocodile. Mummified crocodiles and crocodile eggs have even been found in Egyptian tombs!

These reptiles were hunted close to extinction in the mid-1900s, but local and international conservation measures have helped populations to recover in most areas. Thankfully, their status is looking secure. The Nile crocodile has an undeserved reputation of being a vicious and ruthless man-eater, however incidents between people and crocodiles are rare. It is estimated that 200 people are killed each year by the Nile crocodile, a minuscule number when compared to the 1.25 million people who die in road crashes every year.

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Nile crocodiles are opportunists – they don’t actively hunt humans but will take an easy meal if presented with one. Crocodiles have been around far longer than we have. We should show them the respect they deserve.



The Pig-Nosed Turtle

As you can probably imagine from their name, the pig-nosed turtle (Carettochelys insculpta) is quite an unusual looking reptile. To some, they may appear a little disturbing, but I actually find them rather adorable. Their odd features are surprisingly phenomenal adaptations to their aquatic habitat, and should be admired rather than mocked.

Pig-Nosed Turtle
Adorable? Yes….no?

The pig-nosed turtle is a freshwater species of turtle native to the lakes, streams, lagoons and rivers of Northern Australia and New Guinea. They are the only extant species in the family Carettochelyidae, which makes them incredibly unique. These reptiles are omnivorous, consuming a varied diet of crustaceans, molluscs, insects, and plant and animal matter. These nocturnal reptiles can reach up to 60cm in length, quickly outgrowing aquariums and fish tanks.

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A new born grasping the art of swimming.

For me, the most fascinating aspect of the pig-nosed turtle is their countless number of specialised adaptations. Unusually for freshwater turtles, the pig-nosed turtle has forelimbs modified as flippers, resembling those of marine turtles. This adaptation helps them ‘fly’ through the water, earning them the less common name of ‘Fly River Turtle’. In addition, their protruding pig-like snout is adapted for breathing air while submerged.  Its grey or olive coloured carapace (shell) lacks the hard scutes (plates) of other turtles and tortoises, and is instead more leathery in texture. This gives the pig-nosed turtle a more streamlined shape. These are just a few of the pig-nosed turtle’s superb adaptations.

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Most people have not heard of the pig-nosed turtle and some may never know about them. The pig-nosed turtle was recently added to the IUCN Red List of endangered species and their population is on the decline. One of their biggest threats is the international pet trade – thousands, sometimes even tens of thousands, of pig-nosed turtles are taken from their natural habitat and shipped off around the world to end up in aquariums and fish tanks, resulting in a rapid decline of their native populations.. Furthermore, they are threatened by demand for their eggs. With an undeniably unique appearance and array of wonderful evolutionary adaptations, the pig-nosed turtle deserves to be protected.

The Green Basilisk Lizard

Also known as the Plumed basilisk (Basiliscus plumifrons) or Jesus Christ lizard (I’ll get to that later), this omnivorous reptile is native to Central America and is part of the Iguana family. In their tropical rainforest habitat, the green basilisk lizard feeds on insects, small mammals, fruits, flowers and even other lizards. They have quite a few natural predators including: snakes, birds of prey and opossums so they need to be speedy.

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A male green basilisk unwinding in the sun.

One of their most distinctive features is their bright green skin covered with small whitish-blue spots. Males can be uniquely identified by their three large crests: one on their head, one on their back and one on their tail whereas females only have the head-crest.

This cold-blooded creature is quite well known since they are able to sprint short distances across water – hence the alias ‘Jesus Christ lizard’ – which can help them swiftly evade predators. This impressive skill has only been made possible through centuries of delicate evolution. The green basilisk lizard has long toes on its hind legs with flaps of skin, giving them a larger surface area on the water thus reducing the pressure exerted. Therefore, they can travel for a reasonable distance before the force of gravity takes over, but not to worry, these lizards are superb swimmers and can stay under water for up to 30 minutes.

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Our lord and saviour: the green basilisk.

Their name is obviously derived from the basilisk – a legendary reptile also referred to as the serpent king. This fictitious creature was made up in Europe and was thought to cause death with a single glance. Although if you’ve seen the basilisk in Harry Potter, you’d probably agree that he was a little more intimidating than the green basilisk lizard. Nevertheless, this reptile is an undoubtedly fascinating creature.

The Panther Chameleon

A large chameleon endemic to Madagascar, the panther chameleon (Furcifer pardalis) is an arboreal reptilian which has also been introduced to Mauritius and Réunion. This vividly bright species is perfectly adapted to live in the tropical forests of northern Madagascar…

The panther chameleon has a long tongue which they use to capture their insect prey; the tongue fires out at great speed, stunning and enveloping prey. Then, they are drawn back into their mouth, crushed and consumed. In addition, their long, prehensile tail acts as a third limb whilst up in the trees, wrapping around branches and helping them climb. Their feet are clawed and spilt, with their toes arranged into groups of two and three on opposite sides of their foot which helps them to easily traverse through the dense foliage with a sturdy grip (animals with this toe arrangement are referred to as  zygodactylous).

Panther Chameleon

It would be a dire disservice to the panther chameleon to not mention their colour changing ability. Males are more vibrantly coloured than females and their colouring significantly varies based on their location. In this particular species, their vibrant colours (ranging from reds to blues to greens to yellows) are not used for camouflage but as an indicator of mood and social status. When males come up against a rival, they inflate their body and change colour in order to assert dominance over their competitor. From a biological perspective, their striking colours are caused by cells called chromatophores which contain pigments – they change size and colour based on their mood.

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Another unique adaptation of the panther chameleon are the distinctive ‘gun turret’ eyes. Each eye is able to rotate and focus independently so one eye can be looking out for potential predators whilst the other can be in search of prey.

The panther chameleon is a wonderfully unique species, which has cleverly evolved over millions of years, making them suitably adapted to their habitat. Being native to Madagascar, the panther chameleon has been allowed to evolve independently, along with hundreds of other Madagascan species, many of which are found nowhere else. For this reason, it is vital that the fragile habitats and ecosystems of Madagascar are protected and conserved. The beautiful uniqueness and vivid patterns of the panther chameleon make it one of the most intriguing species to me.

The Leatherback Sea Turtle

The leatherback sea turtle (Dermochelys coriacea) is the world’s largest turtle, weighing between 250 and 700 kilograms. Instead of having a bony shell like other sea turtle, the leatherback has a leathery carapace made up of skin and oily tissue. They are mainly grey/black in colour with frequent white spots in places. Their dark dorsal surface contrasts their lighter underside – demonstrating countershading.

Baby Leatherback Turtle

Countershading is an effective camouflage technique incorporated by many species so when light hits them from above, they are harder to detect by predators. This is especially important within newborn leatherbacks as they are vulnerable to a plethora of predators such as seabirds, crabs, monitor lizards, dogs, coyotes and mongooses (depending on their nesting site) and that’s just while they’re on the shore. Once the survivors reach the ocean, they face even more predation from cephalopods, sharks, other large fish and more seabirds.

The leatherback turtle has a worldwide distribution, which includes subarctic waters, and one of the largest migratory journeys. The leatherback’s diet consists almost entirely of jellyfish; Pacific leatherbacks migrate nearly 10,000 kilometres across the Pacific Ocean from Indonesia to California just to feed on the abundant jellyfish found there. Sadly, Californians use billions of plastic bags every year and many of these end up in the ocean where leatherbacks mistake these floating plastics for jellyfish. This is one of the causes of the leatherback’s ‘vulnerable’ status by the IUCN, but many subpopulations are listed as ‘critically endangered’. By consuming even small quantities of plastic debris, the leatherback’s digestive tract can become clogged, often leading to nutrient deficiencies or death.

Leatherback Turtle

Along with plastic rubbish, the leatherback sea turtle is also threatened by people who harvest their eggs, particularly in Southeast Asia where sea turtle eggs are considered a delicacy. This has led to a complete decline in leatherback sea turtles rendering them locally extinct in countries such as Malaysia. Moreover, leatherbacks play a vital role in marine ecosystems by keeping jellyfish populations low so their decline damages the entire food chain and has had knock-on effects to other species (due to species interdependence).

The leatherback turtle is yet another species which is rapidly declining at the hands of Homo sapiens. As the only extant species in the family Dermochelyidae, this reptilian is a truly prehistoric and unique animal which faces extinction, but we can help. By reducing the demand for turtle eggs, minimising our plastic pollution and establishing conservation schemes, we can hopefully help to protect thousands of marine and aquatic species which are suffering the same torture as the leatherback. Even by just refusing a plastic bag in a supermarket, maybe one animal, somewhere in the world, can live a while longer…

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Thousands of species are having to adjust to a new world of plastic.

The Gharial

With fewer than 240 individuals, the gharial (Gavialis gangeticus) is a critically endangered crocodilian which is endemic to the Indian subcontinent. This species has an olive-green body and a long, slender snout with rows of sharp teeth which it uses to catch fish (the gharial’s main prey).


This reptilian once inhabited a vast area of south Asia but the gharial’s distribution has been drastically reduced because of habitat loss, a depletion of fish supplies and they are often caught and entangled in fishing nets.

The gharial is cold-blooded – like other crocodilians – so spends most of its day basking in the sun around rivers. Adult males can reach up to 6 metres in length whilst females don’t usually grow past 4 metres.

As with many of today’s species, the gharial faces extinction and needs conservation in order to survive. The gharial is a beautiful and unique species; its long snout and razor sharp teeth are a testament to the wonders of natural selection.

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However, their population is rapidly declining and their struggle will only get worse as India’s human population rises and their natural habitats are destroyed to make room for new houses, farms or industries. I hope this post widens our awareness of this spectacular creature and that the gharial’s population can be improved through conservation projects such as the National Chambal Sanctuary in northern India.