Here's InTheNews.co.uk with some (not altogether new) news on the dietary supplements being given to the 86 Kakapos in order to help them breed more often.

Hindering the kakapo's return to its previous numbers is its unusual eating habits. The bird breeds every two to six years when fruit is in bloom on pink pine and rimu trees, which they feed their young on.

During the rest of the time the kakapo's diet consists of grasses, leaves and herbs which lack the nutrients it needs to be able to breed.
[...]
A total of 67 eggs were laid in 2002, the first year in which the new diet was trialled.

That's an interesting follow-up to Tuesday's Kakapo post which mentioned the Kakapo's perceived diet in 1862. Here's another snippet from "Handbook to the Birds of Australia".

The cause of the deformity was supposed to be the want of proper food, and too close confinement. They were fed chiefly on soaked bread, oatmeal, and water and boiled potatoes. When let loose in a garden they would eat lettuces, cabbages, and grass, and would taste almost every green leaf that they came across. One, which I brought within six hundred miles of England (when it was accidentally killed), whilst at Sydney, ate eagerly of the leaves of a Banknia and several species of Eucalyptus, as well as grass, appearing to prefer them all to its usual diet of bread and water. It was also very fond of nuts and almonds, and during the latter part of the homeward voyage lived almost entirely on Brazilian ground-nuts.