Abstract

The Kakapo, a large NZ native parrot, is under severe threat of extinction. Kakapo breed only in years when the local podocarps, including rimu (Dacrydium cupressinum), are fruiting heavily, and the fruit are the preferred food both in the diet of breeding females and for provisioning chicks. Attempts to provide a supplementary food during years of poor fruit supply have failed to encourage breeding. Nutrient analysis of rimu berries reveals high calcium content (8.4 mg/g dry matter) which would be essential for both egg shell production and the growing skeleton of the chick. Vitamin D is also critical for these processes and for the maintenance of calcium homeostasis, but the source of vitamin D for these nocturnal, ground-dwelling vegetarians is unknown.

Objective To examine the vitamin D status of adult Kakapo, and to investigate the possibility that rimu berries provide vitamin D as well as calcium, thus differentiating them from the supplementary foods provided to date.

Method Previously collected and frozen serum from 10 adult birds (6 females, 4 males) was assayed for 25(OH)D 3 and D 2 . Two batches of previously frozen rimu berries were analysed for vitamin D 3 and D 2 .

Results Vitamin D status of the 10 adult birds was very low; mean 4.9 nmol/l, range 1–14 nmol/l 25(OH)D 3 . No 25(OH)D 2 was detected in any of the birds. High levels of D 2 and moderate levels of D 3 were found in the rimu berries.