THE Atkins diet might work for Hollywood starlets, but it鈥檚 hopeless at coaxing the world鈥檚 biggest and most endangered parrot to breed. Conservationists have been filling kakapos with high-protein supplements in the hope of boosting their numbers above just 91, but it now seems they have been focusing on the wrong nutrient.
The flightless New Zealand birds only breed when they can feast on the rimu, a conifer that only fruits every three to four years. In non-fruiting years, the scientists fed the birds protein as it is known to be important for breeding in general.
To find out why these breeding programmes failed, nutritional ecologist David Raubenheimer at Massey University, Auckland, compared the nutrient content of the supplements and the rimu. He found the supplements were high in protein and low in calcium, while the fruit was the opposite.
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This might be why efforts to get the birds breeding have failed. Calcium is vital for bone growth, says Raubenheimer, and the kakapo have an 鈥渦nusually large skeleton鈥�. The supplements may have been too protein-rich, he suggests: animals can鈥檛 process too much protein, so the kakapo would have stopped eating before they got enough calcium.
