Shirley Cameron wrote:
> 1. On the cliffs nearer to Bell's Beach we watched a pair of rosellas
> going in and out of a wide crack in the cliff face. Is it possible they
> were nesting there? On the cliff face nearer to Anglesea another Rosella
> was sitting on a ledge about 2 metres below the top, seemingly enjoying
the
> sun in a sheltered spot, have others observed this behaviour?
Nesting is one possibility; another is that the crack contains minerals
that the rosellas were eating. Each morning on the way to work, I see
Rock Doves and sometimes Sulphur-crested Cockatoos on the side of the
road cutting along State Circle between the New and Old Parliament Houses.
A booklet that I have, "Rocks and Fossils Around Canberra" mentions the
"State Circle Shale" formation and on top of that, the "Black Mountain
Sandstone" which is a thick marine deposit. These date from the Early
Silurian (around 430 million years ago.) The birds concentrate on
particular layers of rock; my guess is they are selecting those that
contain calcium and that is soft enough to dig out with their beaks.
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Paul Taylor Veni, vidi, tici -
I came, I saw, I ticked.
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