Why Is It That The Male Emu Parents??

[Tame Emu Guy]

‘ . . . the effort of producing . . . huge eggs is . . . exhausting.’

Jared Diamond​

Suppose the female emu followed the general avian pattern of laying-then-immediately-incubating her eggs. Because emu eggs take such a long time to hatch, if the female incubated them, she would suffer considerable depletions of her body’s resources: egg-creating then the long incubation.

Now recall Supreme Emu’s thoughts to the effect that the parenting males have to work quite hard in spring to ‘bulk up’ while they are parenting the chicks. Well, if the female normally parented the chicks, by, say, summer, she would have been under strain for quite some time.

Finally, consider the worst-case scenario of the breeding-season that follows a ‘starvation migration.' In that case, any given female would be embarking on her laying-incubating-parenting activities in already-sub-prime condition.

It’s too hard . . . so the males took over the parenting.

Supreme Emu

 

[casuarius]

All good points to consider. And I would like to add, that by a female leaving a clutch for the male to incubate, she can go off and mate with another male to leave a clutch with him. This increases the chance that future generations will survive, because there will be more numbers of chicks hatching. If one male hatches 7 or 8 chicks, probably only 2 or 3 will survive. Also, if the female is doing the incubating, she is tied down to a nest for nearly 2 months, and cannot lay more eggs.

 

[yinepu]

All good points to consider. And I would like to add, that by a female leaving a clutch for the male to incubate, she can go off and mate with another male to leave a clutch with him. This increases the chance that future generations will survive, because there will be more numbers of chicks hatching. If one male hatches 7 or 8 chicks, probably only 2 or 3 will survive. Also, if the female is doing the incubating, she is tied down to a nest for nearly 2 months, and cannot lay more eggs.

my thoughts exactly