The incubation duties (lasting 39-51 days) are shared by both parents who may spend several days on the nest at a time.

Pairs defend territories, and both parents share incubation duties.

The female lays 3 or 4 eggs, and incubation duties are shared between both parents, although the male alone incubates during the night.

Incubation period is 25-28 days and only the female performs incubation duties.

Multiple females may lay in the one nest and share the incubation duties.

The exact time taken to incubate the eggs is unknown, but both parents share incubation duties.

Both parents share incubation duties, incubation lasting around 50 days.

They are incubated for around 23 days by both parents, with the female taking over incubation duties towards the end of that time period.

Both parents share the incubation duties and feed the chick once it is hatched.

Since then, we have observed the male and female trading off incubation duties.