Corroboree frogs

Step by step work in progress during the making of "Scramble" (watercolour and ink).

Rough sketch

Initially I just rough out a sketch of the frogs and their habitat in order to get an idea of composition.

Detailed drawing

The frogs have very particular markings, and these patterns of yellow and black markings are specific to individual frogs, although they may change mildly as the frogs age (ie, gain an extra spot). Photographic mark recognition is one way by which these individual frogs can be identified in mark-recapture studies for monitoring populations in the wild.

Adding ink

Since the dark markings of the frogs are so dark, the easiest way to achieve that effect is through the use of acrylic black ink, which is very smooth, fluid and very black.

Inking the frogs

I add washes of black ink for areas that need to be a flat black colour, and I hatch or stipple areas that are grey through light reflections. I am careful to leave upper body glints the pure white of the paper underneath.

Yellow!

The yellow markings on the frogs are not all a flat hue or tone, they vary from whites through to orange, and from pale to dark particularly in the shadow areas. Since most of the rest of the frogs are black, the yellow areas are where I must convey form through shadows.

Sphagnum moss

The original photos for these corroborees came from frogs in captivity, and not in their natural environment (because the frogs are so endangered, if not now extinct in the wild). This meant that I needed to research some of their habitat in order to place them in a background. The frogs live deep in sphagnum moss bogs in the alpine regions of Kosciuszko National Park. The males usually have a nest deep in layers of moss, and it would be unusual to see four together like this. Despite this, I decided to place them on the sporulating tops of the moss, as though they were young frogs dispersing from a nest.

Final image

I finished the sphagnum, but because of their striking colouring, I decided to retain the cartoonish feel to the piece, and hence did not add shadows to the moss underneath the frog bodies.