A horse is a horse, unless it's a turtle!

Oft-times people ask me about 'turtles', I've used inverted commas here, you'll soon understand why. It seems to me there is much confusion surrounding the terms; turtle, tortoise and terrapin. And while I agree the definitions are not clear, understanding these animal's lifestyles however, is actually fairly easy when you look at their bodies. Very few things in nature are a result of happenstance; an animal's physiology is a reflection of where it lives, and this article we highlight the different survival strategies of the turtle.

Irrespective of what you call them, these animals I'm discussing today are easily recognisable by the shells they wear on their backs. Shells are not going out of fashion anytime soon; in fact these animals have been lugging them around for millions of years. They are very successful (shells are) and have been modified in many ways, but I'm not going to spend much time talking about shells because in this article it's much ado about feet and flippers!

Green Sea Turtle at Lady Musgrave Island, QLD

We'll start with this guy (Right), or rather girl. How do I know it's a girl...bear with me it should become clear in just a bit. She is a kind of marine or sea turtle, I've even heard of these animals being described as 'true turtles'. She is completely aquatic, and thus has flippers rather than feet, all the better to swim with my dear! One of the facts I find particularly charming about these creatures is that despite their sea-faring bodies, they are obligated to land because the female lays her eggs ashore. The males however, spend only a few minutes in their entire lives (which may be 100 years or more) ashore. Those few minutes are spent desperately scurrying as newly hatched babies towards the sea, and they never come back to land ever again, they even mate in the ocean. The ocean has molded their bodies so dramatically that the business of laying eggs is extremely difficult (bordering on treacherous) for the female.

Galapagos Tortoise at Australia Zoo, QLD

Next up, is the handsome fella on the left. I'm referring to the tortoise, not the Joel. This is a giant Galapagos tortoise, and it is just that-a giant! It's the largest living tortoise; the very biggest individuals can weigh over 400 kg [1]. Similarly the Galapagos tortoise and it's smaller cousins are all land dwellers, and so it only makes perfect sense that they should have feet rather than flippers, and certainly they do. The Galapagos tortoise not unlike Darwin's finches show amazing divergences in form across different islands. The shape of one's shell is a reflection of the kind of diet a tortoise will have. Simply put, those with 'saddleback' shells can eat a variety of plant material including the foliage from low growing trees, whilst dome-shaped shells restrict a tortoise to eating only grass. The term 'tortoise' is perhaps the most well-accepted name given to these club-footed turtles that don't swim. However, because tortoises do not occur in Australia, some Aussie's have taken to calling some kinds of native turtles 'tortoises' as a way of distinguishing those that swim in the ocean from those that swim in freshwater.

The last kind of turtle, the freshwater turtle has clawed, webbed feet (with one exception), the best arrangement I'm sure you'd agree for an animal that needs to swim mostly and walk occasionally. The freshwater turtle perhaps causes the most confusion when it comes to terminology. Turtle, tortoise and terrapin have all been used at some point to refer to this creature. But whatever you choose to call it, the only important thing to remember is it's lifestyle has shaped it's body. We know the freshwater turtle is more closely related to a tortoise than to a marine turtle. Science explains from an evolutionary point of view that the freshwater turtle is in fact a tortoise that went back to living in the water.

Ultimately, the term 'turtle' describes all of these shelled reptiles discussed above, but sea turtles, tortoises and freshwater turtles live very different lives and now you know what's who, and who's what, I hope...

1. Ebersbach, V.K. (2001) The biology and husbandry of the Aldabra Giant Tortoise (Geochelone gigantea) and the Galapagos Giant Tortoise (Geochelone elephantopus) in captivity with special reference to reproduction. Tierärztliche Hochschule, Hannover

True Blue Reptiles' demonstrations for the classroom are a great way to get kids excited about their natural environment

Brown Tree Snakes in Guam: a place for everything and everything in it's place

Brown Tree Snake at Benaraby, QLD

US military transport carriers may have been the vessel used by Brown Tree Snakes (Boiga irregularis) to invade and successfully conquer Guam. Towards the end of World War II, these Australian native reptiles were busy with an assault of their own; the extirpation of Guams' native birds, bats and lizards.
        Dramatisations aside, this adaptive reptile did in fact wipe out the fauna of the island in just a few short years. Today only 9 native birds have survived the onslaught, every one of which is now considered extremely rare. In fact one endemic rail is now represented only by a small collection bred in captivity to ensure its survival (Fritts and Leasman-Tanner 2001). As a result of the extinction of the island's insectivorous birds, insects and spiders alike have radiated dramatically. For instance, there now exists forty times as many spiders on Guam than on neighbouring Islands (Braun 2012). It is quite clear that these animals are thriving in le of predation from birds. The forests of Guam are an eerie place now, devoid of bird song and blanketed in spider webs.
        As Australians, we're all familiar with the devastation that pests can have on the natural environment, but many of us underestimate the significant predatory power that snakes have in the ecosystem. The Brown Tree Snakes' in Guam have shown us that snakes are an important player in ecosystem dynamics. If we continue to preserve old ideologies that foster negative feelings towards snakes, we risk loosing them altogether and the consequences are likely to be profound.
        Although we are far from understanding the complex roles that the highly diverse and abundant snake fauna plays in ecosystem ecology, hopefully we can appreciate that snakes like all other organisms are apart of something greater, an all encompassing delicately balanced food web, that when tampered with can result in great cascading impacts that ultimately affect us too.

Braun, D. (2012) Spiders take control as birds fade from Guam. Retrieved from: http://newswatch.nationalgeographic.com/2012/09/16/spiders-take-control-as-birds-fade-from-guam/

Fritts, T.H., and D. Leasman-Tanner. (2001) The Brown Treesnake on Guam: How the arrival of one invasive species damaged the ecology, commerce, electrical systems, and human health on Guam: A comprehensive information source. Retrieved from: http://www.fort.usgs.gov/resources/education/bts/bts_home.asp

Take advantage of True Blue Reptiles' 'Snake Awareness' demonstrations that help you to identify snakes, understand their behaviour, recognise their habitats and teach you snake bite first aid.

Bullying the Black Snake

Red-bellied Black Snake at Christmas Creek, QLD

I was recently subjected to a story about a snake in a suburban backyard that frightened the home owner so much that it required the immediate removal of it's head via a shovel. After all, it's a boring story that ends with, 'and so after I saw the snake I proceeded to go about doing whatever it was I was doing before I saw the snake.'
       When I tell people that I'm passionate about reptiles, it's quite shocking to me how often a person will then proceed to describe the manner in which they most like to butcher snakes. My subject today is the Red-bellied Black Snake Pseudechis porphyriacus. It's as likely a candidate as any, as one of Australia's most familiar snakes and too often, the victim in many of these grizzly stories. It's crime? It likes the climate here, and is distributed throughout the regions where unfortunately for them (the snakes) Australia's population is highly concentrated.
        Red-bellied Black Snakes have a reputation that is unfounded and highly exaggerated, their venom toxicity is nothing to write home about, and they're truly docile snakes; rarely showing aggression, mostly bluffing, and keen to flee when harassed. Despite the fear that some people foster for it, there have been no confirmed deaths resulting from a bite from this snake. That's not to say they aren't dangerous; they're considered to be dangerously venomous, and should be left well alone.
        In those areas where the red-bellied black snakes' distribution overlaps with the introduced cane toad, as is the case in coastal South East Queensland, considerably fewer are seen. Whilst some people may rejoice in this knowledge, it may also be of interest to note that red-bellied black snakes are known cannibals and will eat their own kind and other snakes, namely juvenile Eastern Brown Snakes. The latter pose a significantly greater risk to human life accounting for half of the snake bite fatalities in Australia. It might then be argued that red-bellied black snakes do us a service by eating these far more dangerous snakes.
        Irrespective of your feelings towards snakes, there is no denying they play a very important role in the ecosystem, especially in Australia whereby there exists no large terrestrial predators. So if you're lucky enough to be sharing a backyard with a beautiful red-bellied black snake, instead of reaching for the shovel, perhaps give thanks instead because they take good care of our environment, and we too often repay them with bullying and abuse.

Unsure about a snake in your backyard? Contact the professionals at True Blue Reptiles

 

Snakes: Venomous or Non-Venomous

Water Python by J. SULLIVAN / Ribbit Photography

You'd be forgiven for thinking that the snake pictured here is a venomous one, in fact this snake shares a likeness with the deadly king brown snake, it happens however to be a harmless water python. So how does one tell the difference between a dangerous snake and harmless one?
       The shape of its head and its colouration do have some bearing on identification, but to assume a snakes identity from these traits alone can have disastrous consequences.
       Two species: Tropidechus carinatus (rough scaled snake) and Tropidonophis mairii (keelback) both grow to approximately 900mm, both have strongly keeled scales, both have large eyes and round pupils, both have the same dark irregular bands, both occur along the East coast and Northern tropics and what's more they favour the same habitats. Here's the punch line, one is a harmless colubrid, the other a dangerously venomous land snake. So which is which?
       Well, you could try counting the body scales. For instance, if a snake has no more than 23 rows of scales then it's a venomous snake, if it has between 23-30 rows of scales then it's a colubrid, if a snake has more than 30 rows of scales it's a python, and finally if it doesn't fit into any of these categories you're possibly dealing with an earth worm or a skipping rope.
       To suggest that you count the rows of scales present on a wild snake you've just encountered to determine if it's dangerous or not, is I realise down right absurd.  If you're close enough to count it's scales then you're close enough to be bitten, and really the only time a snake can be truly dangerous is when you're close enough to be bitten by it!
       Even expert collectors have been known to miss-identify snakes, in fact just before publishing this blog, the Coffs Coast Advocate reported an incident whereby snake catcher Bruce Dwyer mistook a rough scaled snake for a colubrid and was bitten twice before crashing his car after loosing consciousness. He was rushed to hospital in a serious condition.
       Unfortunately there exists no definitive tool to aid you in separating the venomous from the non-venomous snakes; not the shape of the head, the colour of it's back, nor it's inclination for tree climbing. By all means learn about the snakes that occur in your region, but remember if you're not an expert, it's probably best to assume all snakes you see as potentially dangerous and leave them well alone.

Get informed with True Blue Reptiles' demonstrations for the classroom, fete, open day or event.