Musk Ducks

No, that's not a leach stuck to its throat! The piece of skin hanging from under this bird's bill is actually perfectly natural.

The Musk Duck (Biziura lobata) or 'Kodara' (pronounced 'Caw-dar-ah') in the Nyoongar language is a very unusual waterbird, and today I was privileged get a few photographs of the species at a local hills wetland. Kodara are diving ducks, lying very low in the water as they swim (almost like a cormorant) and frequently dipping below the surface to catch freshwater crayfish and other water-dwelling invertebrates. They have very stiff tail feathers which act like a motor to propel them along underwater, and when frightened they will always dive rather than fly away.

Pictured above is a male, which is easy to identify from the conspicuous lobe of skin under its chin. This bizarre feature is an important part of the male's courtship display, which is one of the most unique spectacles in the Australian bird world. In an effort to attract a female, the male bends his neck right back, inflates his chin lobe with air, sticks his tail feathers upward, and while floating in open water, gives a series of loud 'plonk' calls and splashes water over himself with his feet. The call travels great distances and can be heard from several kilometres away across the surface of the water. Males display usually on freshwater wetlands from about June right through to about February, with some unsuccessful individuals persistently carrying on with courtship well into the summer nights.

The female Musk Duck is attracted by this bizarre display, and after mating she retreats to find some cover to build her nest. It is one of the most well-concealed bird nests I have experienced finding, and is usually hidden deep in the reed beds (although I have found one very obvious one in a sparse paperbark sapling in deep water). The female duck builds her nest by first finding a suitable spot, then reaching up and bending the stalks of reeds and other water plants underneath her, while flattening a platform with her body. In this way the nest achieves a domed structure with a sparse 'roof' covering it. She lays the 2-3 eggs in the nest, then like all other ducks, pulls soft down feathers from her body and covers the eggs to keep them warm. Musk Ducks lay HUGE eggs in proportion to their body size (they are about twice the size of a chook's!) so this probably explains why they lay so few compared to most other ducks.

After photographing this male I decided to go exploring in the reeds nearby, and as luck would have it I managed to find a Musk Duck nest! It was well concealed in the reeds and contained 2 eggs - here's what it looks like:

When the eggs hatch the ducklings stay with their mother for many months, learning how to feed by watching her closely. Most often only one duckling will survive - there are many foes in the wetland environment from Australian Ravens and birds of prey above to Long-necked Turtles waiting to pull them under from below. It is common to see a female swimming around with her half-grown offspring (see below) toward the end of Birak, the Nyoongar word for early summer (December and January).

Next time you visit a freshwater wetland, see if you can spot a duck swimming very low in the water. This is our very own and unique Kodara!