'Do we know what makes a good incubation place, then?'
We do.
The second incubation we observed – Felicity Emu and Noddy Big Ears – was ‘textbook’ for us, and it went like this:
the pair first spends weeks thrashing the feathers off any other emus that encroach on the section of pasture that the pair has chosen. Then, in the month short of mid-winter, they gradually move in a smaller and smaller area of this turf, which will abutt the trees.
Now, about the first of July – two weeks short of mid-winter – we assume that the mating begins. Recall that a female can store viable semen in her body for days as she lays eggs.
And about this time, Mr. and Mrs. Emu have twee little meetings, in the trees, just off the clearing, as they think about a nest.
The ‘nest’, we note, is not very nest-ey at all! I once found an empty bird’s nest in the plum tree. It was a ball with an opening at the bottom. When I put my hand in, it was like a feather glove, a very nice place to hatch.
But an emu ‘nest’ is just a spot where the twigs and branches are pushed a bit to one side. It is nothing like the birds’ nests you see in documentaries.
Now, at this point – in the fortnight after egg-laying has presumably begun – you are gettin’ down to the wire. The pair still comes for their bit of wheat each day, until one day only the female comes.
Then you assume that the male has begun incubating, and you start quietly scouting the gums just off where the ‘world getting smaller’ behaviour has been going on.
Final Note: it’s of interest that, once you get the hang of it, you can find roosts off any pasture on which emus are grazing. If there are fresh poops on a pasture, you can walk about 30 yards into the trees, and patiently walk along, parallel to the pasture, and you’ll find night-time poops. And if you get down on your hands and knees, and put your nose down near the ground, you’ll find a chest feather, where the emus breast was pressed into the earth as it slept.
In other words, a roost and a nesting-spot are, as best we understand, both going to be just off a section of nice pasture.