Wood Ducklings

["David McDonald (personal)" <>]

Hi Mariko, this is conspecific brood parasitism, also called 'dump nesting' or 'egg dumping'. Not uncommon in waterfowl. One or more other females have laid their eggs in the nest. A good strategy for a female who has not got a nest for some reason, or that uses the strategy to get two lots of her offspring out into the world!

Re the video I posted from Wamboin a few days ago to which Philip refers - the large number of wood ducklings floating down to the ground from the nesting hollow - apparently there were about 26 eggs in the nest. I don't know how many of them hatched and jumped from the nest. HANZAB gives the average clutch size as 10.5 for the Australian Wood Duck, while noting that the liklihood of egg dumping would impact on that average.

Best wishes - David

On 2020-04-13 17:44, Philip Veerman wrote:

Many people have wondered for years if these extraordinary large number of ducklings (which is a sort of common occurrence for this species) can belong to one pair. Probably not, as normally a bird will only lay about one egg a day, so how can she put out 23 eggs over that long and they still be viable and hatch together. I believe we don't know the answer. Am I wrong? Is odd, as it would seem to be an easy question to look at, compared to say how much is known about Fairy-wrens. Also the bit of film a few days ago that shows several adults gathered around as young jumped from a nest, sort of suggests (to me) that it is likely to be more than one set of parents. As ducklings get imprinted on the first relevant moving thing they see, it probably does not matter if it is their actual parent or some other duck of the same species.

 

Philip

 

From: mariko buszynski [
Sent: Monday, 13 April, 2020 3:59 PM
To: canberrabirds
Subject: [canberrabirds] Wood Ducklings

 

Since the Federal Golf Course is closed for some time, I ventured to see a pond in the Course.  I saw 23 ducklings escorted by an adult pair.  There were many wood ducks lounging about but they showed no interest and I presumed the ducklings did not belong to them.  But is it possible that all 23  belongs to one pair?

 

Mariko