Kids & Reptiles

Kids and reptiles! Can they mix and should they mix?

by Kerrie Alexander

In my opinion yes and sometimes no. In this article I will express some ideas and tips on how to keep the harmony with our kids and reptiles, and also perhaps when we should draw the line.

In my experience with demonstrating reptiles to children I have found 80% are keen to touch and are waiting with lots of questions. This is, of course a fantastic learning experience, but like most things children need some guidance. They need to be shown how to treat and hold the animals in order to understand how these little creatures work.

Usually the children are set some basic rules. These rules are easy for them to understand and are always said in a positive way.

Kids and Reptiles: Examples of rules for children when handling reptiles are as follows:

* Only touch the back, tail or tummy, as they do not like to be touched on the face. (If asked why? we simply ask if they liked being touched all over the face by a stranger, no is usually the answer.) Facing the animal with its tail towards people is the best way to solve this.

* Make sure you support the animals’ legs when holding and do not squeeze, just let them sit or slide through your hands.

* Never poke the animal or do anything that you yourself wouldn’t like.

* Make sure you wash your hands after touching the reptiles.

There is always the other 20% of children who don’t feel comfortable holding or touching the animals - they prefer to just look and this is fine.These children can still learn a lot and sometimes they just need a bit more time to watch you hold the animal and understand them before they feel comfortable. I actually prefer this as I know that they will respect the animal and have some understanding of it. This is better than the children diving in and maybe hurting the animal because they have not listened.

There are times when lines are drawn and strict rules need to be in place. Examples of this include instances when venomous snakes or larger, more dangerous animals such as goannas are being shown. Of course when demonstrating venomous snakes and some larger goannas, the animals should only be touched by or come close to the demonstrator.

When keeping venomous snakes privately they should always be housed in a locked enclosure, off the ground and out of the child’s reach. One effective system used by many keepers to clearly identify potentially dangerous animals is the colour system. A sticker or coloured piece of paper is placed on every enclosure that contains an animal. Dangerous animals are identified by a red sticker, while harmless animals have blue or green. Red, even to the smallest child is associated with hot, stop, dangerous etc and therefore clearly identifies the animals children should never try to touch. Blue or green are associated with calming, go, cold etc. and children can therefore recognize harmless animals.

My daughter, Chloe, 5yrs, has shown a fantastic interest and respect for reptiles. We have been lucky that she keeps a safe distance and obeys our rules when dealing with venomous snakes and their removal. Such a thing cannot be expected by every child and each needs to be assessed individually if they are to come close to these animals. I do not promote or encourage venomous snakes and children to mix.

Reptiles can be a fun and exciting experience for children and encourage responsibility along with a greater understanding of our native animals and how they live.

Kids and Reptiles: The best first reptiles or invertebrates for children are:

• Blue tongue lizards
• Shingle back Skinks
• Bearded dragons
• Long neck Turtles
• Children’s Python or equivalent
• Green Tree Frogs
• Stick insects

These animals can be obtained through your local breeder or pet store. No animal should be taken from the wild.

When there's knowledge and patience, kids and reptiles can get along just fine.

First Genetic Link Between Reptile and Human Heart Evolution

Scientists at the Gladstone Institute of Cardiovascular Disease have traced the evolution of the four-chambered human heart to a common genetic factor linked to the development of hearts in turtles and other reptile species.

The research, published in the September 3 issue of the journal Nature, shows how a specific protein that turns on genes is involved in heart formation in turtles, lizards and humans.

“This is the first genetic link to the evolution of two, rather than one, pumping chamber in the heart, which is a key event in the evolution of becoming warm-blooded,” said Gladstone investigator Benoit Bruneau, PhD, who led the study. “The gene involved, Tbx5, is also implicated in human congenital heart disease, so our results also bring insight into human disease.”

From an evolutionary standpoint, reptile occupies a critical point in heart evolution.

While bird and mammalian hearts have four chambers, frogs and other amphibians have three. “How did hearts evolve from three to four chambers?” Bruneau said. “The different reptile species offer a sort of continuum from three to four chambers. By examining them, we learned a lot about how the human heart chambers normally form.”

He explained that with four chambers—two atria and two ventricles—humans and all other mammals have completely separate blood flows to the lungs and to the rest of the body, which is essential for us to be warm-blooded.

When it comes to reptile species, such as turtles and lizards, there is debate about whether they have one or two ventricles, which are the pumping chambers. “The main question for us to understand the evolution of the heart was to identify the true nature of these early reptile ventricles and to figure out what controls the separation of the heart into left and right sides,” said Dr. Bruneau.

To better understand reptile heart evolution, Dr. Bruneau’s team used modern molecular genetics to examine Tbx5. Mutations in the human gene that encodes Tbx5 result in congenital heart disease and, in particular, defects in the ventricular septum, the muscular wall that separates the ventricle into two sections. Tbx5 is a transcription factor, a protein that turns other genes on or off. In humans and other mammals, Tbx5 levels are high in the left ventricle and low in the right. The boundary of high and low levels is right where the septum forms to divide the ventricle into two parts. “Based on these observations,” said Dr. Bruneau, “we thought Tbx5 was a good candidate as a key player in the evolution of septation.”

The team looked at Tbx5 distribution in the turtle and the green anole lizard. During the early stages of heart formation in both reptiles, Tbx5 activity is found throughout the embryonic ventricular chamber. In the lizard, which forms only one ventricle, this pattern stays the same as the heart develops. However, in the turtle, which has a primitive septum that partially separates the ventricles into left and right sides, distribution of Tbx5 is later gradually restricted to the area of the left ventricle, resulting in a leftright gradient of Tbx5 activity. This meant that the gradient of Tbx5 forms later and less sharply in the turtle than in species with a clear septum, such as mammals, providing a tantalizing clue about how septation evolved.

They then wanted to determine whether Tbx5 was really a main regulator of septation or merely a bystander. Mice were genetically engineered to express Tbx5 at a moderate level throughout the developing heart, just like in turtle hearts. By mimicking the turtle pattern, mouse hearts now resembled turtle hearts. The offspring from these mice died young and had only a single ventricle. This striking result conclusively showed that a sharp line delineating an area of high level of Tbx5 is critical to induce formation of a septum between the two ventricles.

“This really nailed the importance of Tbx5 in patterning the heart to allow septation to occur,” said Dr. Bruneau.

During evolution, new genetic regulatory elements evolved to tell the Tbx5 gene to form a sharp boundary of Tbx5 expression. This resulted in two ventricles. Researchers will now work to identify those genetic regulatory mechanisms during the evolution of reptiles. The work also has important implications for the understanding of congenital heart defects, which are the most common human birth defect, occurring in one out of every one hundred births worldwide. Humans born with only one pumping chamber, resembling frog hearts, suffer the highest mortality and require extensive surgery as newborns.

“Our study provides exciting new insights into the evolution of the heart, which had not been examined in over 100 years,” Dr. Bruneau explained. “In a larger context, it provides good support for the concept that changes in the expression levels of various regulatory molecules are important in evolution. From these studies we also hope to understand further how defects in septation occur in humans with congenital heart disease.”

Reptile

Saltwater Crocodile

Crocodylus porosus or the Saltwater Crocodile

The saltwater crocodile is the largest reptile in the world. Males can grow up to 7 metres long, while females can reach a still-impressive 3 metres. In Australia, crocodiles were hunted to near extinction, but their numbers have increased since receiving protection in about 1970. As their name suggests, saltwater crocodiles can live quite happily in salt water. They have numerous salt glands on their tongues which get rid of excess salt from the crocodiles' bodies.

A female saltwater crocodile will make a nest by using her feet to scrape together vegetation, such as leaves, grass, and sticks. She'll then lay about 50 eggs in this nest. As the vegetation rots it generates heat, which keeps the eggs nice and warm, while the mother guards her nest. When the babies hatch, they call out to their mum, who will dig them out and carry them to the water in her mouth. The sex of the babies is determined by the temperature the eggs were incubated at. Mostly males will be produced when the eggs are kept at about 31.6 degrees Celcius, with mostly females resulting from temperatures higher or lower than this.

Did you know...

• The saltwater crocodile is the largest reptile in the world. Males can grow up to 7 metres long, while females can reach a still-impressive 3 metres.
• In Australia, crocodiles were hunted to near extinction, but their numbers have increased since receiving protection around 1970.
• As their name suggests, saltwater crocodiles can live quite happily in salt water. They have dozens of glands on their tongues which get rid of excess salt from the crocodile's body.
• The sex of baby crocs is determined by the temperature the eggs were incubated at. Mostly males will be produced when the eggs are kept at about 31.6 degrees Celcius, with mostly females resulting from temperatures higher or lower than this.

Where to find Saltwater Crocodiles in Australia:

Saltwater Crocodile

Freshwater Crocodile

Crocodylus johnsoni or the Freshwater Crocodile

The freshwater crocodile is the smaller of the two crocodile species found in Australia. Males reach a maximum length of about 3 metres, while the females grow to about 1.5 metres. In the wild the freshwater crocodile is a relatively shy animal that feeds primarily on fish. The snout of this crocodile is long and smooth, compared to the wide, rugged snout of the saltwater crocodile. Crocodiles can easily be called living dinosaurs. With a perfectly evolved body for long life with little need of exertion or food, crocodiles, now that they are protected, should be around for another million years or so.

From August to September females dig nests in the open sandy areas approximately 10 metres from the water, in which they will lay about 12 eggs. After some 90 days the babies begin to hatch. The cries of the baby crocodiles will prompt the mother, or another female close by, to excavate the nest, setting the babies free. Just like the saltwater crocodile, the freshwater crocodile will carry its young to the water. Groups of juvenile freshwater crocodiles form creches that are attended by adult female crocodiles.

Did you know...

• The freshwater crocodile is the smaller of the two crocodile species found in Australia. Males reach a maximum length of about 3 metres, while the females grow to about 1.5 metres.
• In the wild the freshwater crocodile is a relatively shy animal that feeds primarily on fish.
• Crocodiles can easily be called 'living dinosaurs', with fossil crocodiles dating back hundreds of millions of years.
• There's a belief that crocodiles haven't changed much over this time, but nothing could be further from the truth. Millions of years ago, there were many more species of crocodiles, ranging from sea-dwellers through to tree-climbing crocs!

Where Freswater Crocodiles can be found in Australia:

Did you know... The freshwater crocodile is the smaller of the two crocodile species found in Australia. Males reach a maximum length of about 3 metres, while the females grow to about 1.5 metres.

In the wild the freshwater crocodile is a relatively shy animal that feeds primarily on fish. Crocodiles can easily be called 'living dinosaurs', with fossil crocodiles dating back hundreds of millions of years.

There's a belief that crocodiles haven't changed much over this time, but nothing could be further from the truth. Millions of years ago, there were many more species of crocodiles, ranging from sea-dwellers through to treeclimbing crocs!

Freshwater Crocodile

The Tale Of The Mighty Crocodile

Crocodile

They are the world's largest living reptiles and can grow up to 23 feet. They are also one of the most ancient, having existed unchanged for nearly two hundred million years. Crocodiles are adept at learning and memorising routines, such as the location of nearby campers or the routes of travellers. In water, they tend to drag their prey under and drown them.

Crocodiles can be found basking along river banks, Fresh Water Crocodiles in Australia can grow to about 3 metres. Main habitats include wetlands, rivers, creeks, freshwater billabongs and swamps. They display fairly wide habitat preferences (clear water, muddy, still, fast flowing, shallow or deep). Salt Water Crocodiles can also frequent ocean habitats as well as rivers and freshwater marshes near where people live. Their maximum size is enormous, more than 20 feet.

When a crocodile warms-up, their heart rate increases and more blood flows to the surface. This speeds up heat intake and distribution through the body. Crocodiles are protected in many parts of the world, but they also are farmed commercially.

Crocodiles are hunted for their meat, their skin (which is made into leather), and their musk (which is used in perfumes). Because of hunting and destruction of their habitat most crocodile species are endangered.

The adult crocodiles are conditioned to respond to distress calls of the young. Despite parental care, mortality in hatchling crocodiles is generally over 90% due to predators like fishes, crabs, snakes, monitor lizards, raptors, large wading birds, mongooses, foxes, and jackals.

Crocodiles are fast over very short distances out of water. They have extremely powerful jaws capable of biting down with 3,000 pounds of pressure per square inch, and sharp teeth for tearing flesh, but cannot open their mouth if it is held closed.

Freshwater Crocodiles

These crocodiles make their home in inland freshwater rivers, billabongs and swamps of northern Australia. they are generally very timid and primarily eat insects and small fish. As with all native wildlife these amazing creatures should be treated with respect and not interfered with. Despite passage of wildlife protection laws at the national level, communities are often unaware that crocodiles are officially protected.

Freshwater crocodiles are common in the Kimberley , where they bask in and around rivers, lakes and pools in gorges. While they may look ferocious, they are relatively harmless.

Saltwater Crocodiles

Saltwater crocodiles can be dangerous, they are also quite capable of living in the open ocean for periods of time and will cross large expanses of water to reach new areas. Young crocodiles are about 30 centimeters (1 foot) long at birth. After that, they will grow about 25 centimeters per year (10 inches) until they reach six years of age. Saltwater crocodiles are big and awe-inspiring. Males reaching 5 m long regularly and some odd individuals reaching 6-7 meters.

Females will lay up to 50 eggs in a large pile of vegetation, sand and soil, usually on the banks of a river, swamp or estuary. They also point out that because saltwater crocodiles are migratory,  rivers cannot be assumed to be croc free, as a croc could have moved in recently.

These reptiles are very intelligent and instinctive, and have great memory capabilities. If something causes a crocodile stress it will avoid that cause of stress for the rest of its life. The adult crocodiles are said to feed on anything it can outswim or ambush and overpower. Odd objects like chunks of wood, pebbles and even rocks are found in crocodiles stomach.

Crocodile