Eleven participants converged at the Regatta Point car park at 9AM for a walk round the ponds in Commonwealth Gardens. The main purpose of this outing was to look more closely at the behaviour of waterfowl, with Pacific Black Duck being the main likely subject. Unfortunately, few social interactions were to be observed on this cold, dull, and overcast morning with the ever present threat of rain. However, we could cover the subtleties of distinguishing drakes from ducks by differences in calls and a close attention to plumage features. We did see a variety of other species including a lone dull-plumaged drake Hardhead and a large flock of Red-rumped Parrot.
Generally, we found well separated pairs of Pacific Black Duck either loafing or occasionally preening but a small group of unattached drakes did offer us some insight into the ways that males assert social dominance amongst themselves. There was some discussion on the ways that social signals have developed from preening or comfort behaviour and we had a wonderful opportunity to watch, at very close quarters, a pair of Black Swan going about nest construction. The hen (pen) had laid one egg and together with the male (cob) the two of them went about the business of painstakingly moving material towards and into the nest. This was a perfect demonstration of the peculiarity of all waterfowl in their limitations in transporting nest material other than by picking it up in front and passing it to their side.
The behaviour of a lone Maned Duck (Australasian Wood Duck) was interpreted as being most likely a paired drake loafing while his partner was at the nest site; almost certainly somewhere nearby in a tree hollow.
Finally, we were able contrast the social behaviour of waterfowl with that of rails, notably, Dusky Moorhens, Eurasian Coots and Purple Swamphens.
An enjoyable outing. — Peter Fullagar