Pelican display

Common around these waterways, our Australian Pelicans are always amazing birds to watch. I never tire of watching them take off, or land on their watery runways, wings out as brakes.

On a breezy day, most of this flock were curled in on themselves, hunkered down and looking backwards with their large eyes, in the disconcerting way they do.

 But then I saw the large area of pink on one; what was it doing? Was it airing the inside of its bill? Was it yawning?!

Then it seemed to lay the soft lower bill pouch, inside out, flat across its chest. None of its fellows looked surprised, so it must happen often enough.

This display happened very quickly before it returned its head and bill to a more usual position.

Snapping away almost blindly, it was only when I looked at the photos at home that I saw that one of its erstwhile dozing mates had woken up.

Then it did  this … but what am I looking at? What is it doing?!

Our Pelicans have the largest bill of any living bird. I accept that they are extraordinary birds; after all I saw…and loved  and wept at… the film Storm Boy, decades ago.

But the mystery remains of what else it does with its bill other than use it as a mating display, a scratcher, a trawling net, or to catch and temporarily hold prey.  Why does it turn it inside out?

No information site yielded an answer, so I will be greatly pleased if somebody can tell me!