The first of new Kakapo chicks are expected to hatch in the coming week

The flightless parrot species with a population of 236 only breeds once every four years - when the Rimu trees is its most plentiful.

Conservationists so far know of 42 fertile eggs this season - and the first ones should start hatching next week.

DOC's Kakapo Science Advisor Andrew Digby says some females with an unsuccessful clutch will be given eggs from another nest.

He says the birds are very good at cross-fostering and don't tend to mind whose chicks they have in their nest.