Wednesday, April 2, 2008

Kakapo love

The Kakapo is a large, nocturnal and flightless parrot found in New Zealand. Only 86 Kakapo remain and the birds prospects look dim since they only breed every three to five years. On the bright side the birds are long-lived, possibly one of the world's most long lived birds. I don't know how many species are so rare that every individual has a name but Kakapo are part of that select club.

Reproduction seems to be correlated with bumper crops of the Rimu tree but the eggs are incubated for 30 days so the Kakapo must lay them well before the fruit is ripe. How do Kakapo know to start reproducing? Research published this week unravels the mystery:

The unripened fruit of the rimu contains chemicals that mimic the action of the birds' sex hormones. Prior to a bumper crop, kakapo eat more unripened fruit than usual. The chemicals in it prime the liver so that come summer, when the lengthening days trigger the birds' ovaries to produce the sex hormone oestrogen, the liver responds by producing more egg-yolk protein, essential for developing eggs (Wildlife Research, vol 35, p 1).

Although this is just a hypothesis, it is testable and, if shown to be correct, may help conservation workers improve Kakapo breeding success.

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