The effect of nutritional supplements on egg production of kakapo Strigops habroptilus on Codfish and Pearl Islands, New Zealand

  • Published source details Houston D., Mcinnes K., Elliott G., Eason D., Moorhouse R. & Cockrem J. (2007) The use of a nutritional supplement to improve egg production in the endangered kakapo. Biological Conservation, 138, 248-255


This study is summarised as evidence for the following.

Action Category

Provide supplementary food for parrots to increase reproductive success

Action Link
Bird Conservation
  1. Provide supplementary food for parrots to increase reproductive success

    A small study on Codfish and Pearl Islands, South Island, New Zealand, during 1997–2005 (Houston et al. 2007), found that kakapos Strigopus habroptilus fed with food pellets (specially formulated to provide nutrients missing from kakapos’ diets) laid larger clutches than those provided with either nuts (almonds, walnuts, Brazil nuts and honey-water) or no supplementary food (76% of 29 pellet fed birds having 3-4 eggs/clutch and an average of 2.76 eggs/clutch; 33% and 2.22 for nine nut-fed birds; 33% and 2.00 eggs/clutch for three unfed birds). However, fed birds did not nest more frequently than unfed birds, with nesting apparently related to the fruiting of rimu Dacrydium cupressinum trees. Food was either fed ad libitum or was 20 g of nuts every three days or 50-150 g of pellets every three days year-round.


Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 17

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust