Colubrids

The family Colubridae was constructed to represent non-venomous (excluding pythons) and mildly-venomous species, and was originally referred to as ‘the harmless snakes’.  In reality, it is a vast and unwieldy group, lumping together many unrelated evolutionary lineages yet to be properly studied.  Moreover, biologists are discovering that many, if not most, of these species are in fact venomous (some strongly so), hence a rethink of their classification may occur as research continues.
Australia has only 58 species of so-called colubrid – unusual, considering the family represents over half the snake species in the world.  Australia’s strong bias, in terms of percentages, towards the Elapidae (venomous snakes) continues to fascinate biogeographers attempting to understand the species distributions as it relates to their evolution.
None of these species occurs in southern Australia – and all but three are restricted to the tropics and the top end.  The exceptions are…

Brown Tree Snake

The first colubrid we ever caught, this drop-dead gorgeous species is our SnakeSense mascot.  With its naturally curving mouth and big eyes, it always gives the appearance of a smile!

Brown Tree Snake Boiga irregularis

Only mildly venomous, the Brown Tree Snake (Boiga irregularis) has short, grooved fangs at the rear of mouth – and one would have to allow it to chew for a while to envenomate, resulting in few symptoms.
Distributed around the north and east coast to just south as Sydney, it inhabits woodlands, rainforests and rock outcrops.  It is nocturnal and arboreal or cave dwelling.
It catches birds, small mammals and lizards, creeping up upon them whilst they sleep.

Green Tree Snake

Following the same distribution as the Brown Tree Snake (to which, incidentally, it is not related) this extremely attractive species is entirely harmless, possessing no fangs or venom apparatus.  Despite its name, it ranges in colour from golden to dark green, with some specimens in the east of its range being a brilliant sky blue.

Arboreal, the Green Tree Snake (Dendrelaphis punctulata) is found in woodlands and rainforest, eating frogs and lizards.  Incredibly fast, it is always a challenge for us to catch when we head north.

Keelback

Completely harmless, this wonderful species with its nervous, cryptic habits and peculiarly keeled scales is one of the few predators in Australia capable of consuming the introduced Cane Toad, without any ill-effects.  The genus Tropidonophis boasts an evolutionary history of eating toads, hence the Keelback (Tropidonophis mairii) is genetically immune to Cane Toad toxins.
Distributed across northern Australia from Broome around the east coast as far as Sydney, let’s hope this shy, diminutive little snake eats as many toads as it possibly can.