Brown Treecreeper - Breeding

Breeding

The breeding female usually lays a clutch-size usually of three smooth (sometimes two or four), slightly glossy, fine-grained, slightly pink or rose, reddish-brown or red and purplish-red speckled eggs measuring 22.6 by 17.9 mm. Intervals between egg-laying is most likely 24 hours, with re-laying occurring in the event of failure. Females are able to raise two broods in a season but more often raise one brood. Hatchlings emerge with grey down on their head and back fourteen to sixteen days after incubation.

For a few days after hatching, the female is fed by the primary male. The young are fed by the breeding female who is passed food by the primary male. Faecal sacs are removed from the nest by all members of the group though most often it is the males who do so. Helpers, usually young males related to the breeding male, service their territorial nest and often will service other nests in 2–3 other territories. A variety of insects are fed to the young, with lepidopteran larvae forming the bulk of their diet. Adults avoid feeding the young ants, likely due to the ant's formic acid content. The contribution of helpers to feeding the young is generally equal to the efforts of the breeding pair. Records exist of a single helper servicing the nests of five different territories. Records indicate that in nests attended by helpers, breeding success is four times more likely and significantly more offspring are produced.