Night on Black Mountain

South of Cooktown is a tiny national park called Black Mountain National Park. There are actually two peaks to the 'mountain' of black boulders, with the highway passing between them. The boulders are granite - the remains of a big batholith that has been fractured, weathered and eroded over time - and encrusted with a lichen layer that gives them their black surfaces.

Black Mountain - Volley Country!

Incredibly, in this tiny area, scurrying over the boulders and sheltering within their cracks, are three vertebrates that occur nowhere else - a gecko, a skink and most interesting of the three, a frog.

The Black Mountain Frog, Cophixalus saxatillis is surely one of the most extraordinary animals in the wet tropics. It's a giant amongst the microhylids, with females reaching almost 5 cm long. And as you can see, the colour of these females is just beyond belief. The males are smaller, and less strikingly coloured (the ones I saw all were quite yellow, though I've seen other photos where they are simply mottled brown). [Edit - I suspect that these were just young females rather than males - they're just too yellow]

These frogs live on the edges of the boulder-fields, where there's a bit of vegetation, and I was startled by just how many of the delightful females I saw, festooning the rocks in certain areas. The males were less common for some reason. They are evidently quite good at climbing despite their rather pudgy appearance - I saw a few females climbing on tree branches alongside rocks.