Who’s a pretty Polly?ONE of the problems suffered by a species on the brink of extinction is low genetic diversity. Initially this is caused by lack of numbers, but then it is exacerbated by the inbreeding which inevitably results. Inbreeding brings with it infertility and susceptibility to disease. Hence concern for the kakapo, a nocturnal parrot that lives in New Zealand. Like many other island-dwelling birds, it has become flightless. It is also, at up to 4kg, the world’s heaviest parrot. Both of these things make it an attractive target for predatory mammals, which thankfully were absent for most of the 80m years during which it and its ancestors have inhabited the archipelago.
The kakapo’s downfall began with New Zealand’s first wave of human colonisation, some 700 years ago, by Polynesians. These arrivals hunted it, and also brought rats with them, which ate nestling chicks. The second, European wave of immigrants brought cats and stoats to add to the birds’ woes. Humans also destroyed much of their habitat to make way for crops. Conservation efforts are not assisted by the birds’ reproductive habits. They...Continue reading
Source: Science and technology http://ift.tt/1VaCsW5
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