Hey, Ellamumu! I have some thoughts from my place:
the season we observed Boy Emu's entire incubation was the season in which two females (Greedy and Felicity) fought for command. I was privileged to hear months of night-time vocalisations that winter.
So, the pairing-up begins in late summer. Pairs are staking out territory by mid autumn. Mating can begin with winter.
Here's the interesting thing, though:
right into late winter, the females here would talk to males before dawn. They were definite 'conversations.' Then, an hour after dawn, a male would arrive in the house-clearing.
My theory is: there are first-, second-, and third-string males. Strong males are sitting on eggs early on. The second stringers are those who mate with the females right after the first consort sits. The third stringers are males not strong enough to make the grade, but they continue trying until almost spring to mate and sit.
We have one observation of a clutch that hatched six or eight weeks after the normal time (cold micro-climate)
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