Both parents, sometimes assisted by the young from previous broods, incubate for 13-19 days to hatching.
Helpers, females or possibly juveniles from the previous brood may sometimes assist the parents in feeding the young.
Helpers, possibly young birds from the previous brood may assist the parents, feeding the brooding females and the young birds.
In some species the young from previous broods may also act as helpers for the adults.
Pregnancy usually takes 38-41 days but can be extended significantly if the mother is still breastfeeding the previous brood.
It is suspected that chicks from the previous brood may act as helpers at the nest.
Helpers, offspring from the previous brood, have sometimes been noted to assist in feeding the fledglings at the nest of their parents.
They are cooperative breeders; male offspring of previous broods and sometimes other individuals help breeding pairs (Doerr 2003).
These helpers are young of previous broods which defer breeding 'altruistically' to assist in the rearing of close relatives under ecological conditions which make this difficult.
Both species employ helpers, usually the young of previous broods, to aid the breeding pair in raising the young.