Has been observed in the species before. It is one of the several variants of a range of birds putting odd things on their feathers.
From: Robin Hide [
Sent: Sunday, 17 July, 2016 5:53 PM
To: Canberra Birds
Subject: [canberrabirds] A query about White-winged Choughs and soil
Do Ww Choughs use clay/soil for other purposes than making nests?
This afternoon amongst pines between the RC Golf Course and Warrina Inlet there was a large flock of Choughs, some of which appeared to be pecking at soil at the foot of a pine.
They would then fluff up their feathers and appeared to be applying soil to them.
The soil where they had been pecking.
I saw similar behaviour late one evening (full dusk) beside pine trees in urban Challis Street in Dickson about 6-8 weeks ago- though there they just appeared to be pecking
at the ground.