Friday, 25 January 2013

Legal Alien

Today I have visited a Kiwi wildlife centre. In the sense of the bird, not the nickname for the New Zealanders. Apart from seeing the funny and surprisingly large nocturnal and flightless icons of New Zealand, it was educational.

You can understand why the NZ customs guys are so vigilant about introduction of new species when you look at the issues the department of conservation is up against with the legal aliens who reside in the country. Many of these were deliberate introductions. For example, the deer were introduced for game hunting. Unfortunately much as happens in the UK, without natural predators and with abundance of food, the populations increase rapidly and so of course does their rate of consumption of the available vegetation resulting in depletion of habitat. So now the deer here are culled, or more bizarrely to my UK eyes, they are farmed, in that they are held in fields by the road side just as you would expect to see cows, fields of animals peacefully grazing, domesticated. Except when they are big enough, the stags in particular are sent off into the wild so that men with guns can come and shoot them for “sport”. I gag a little as I use the word sport in this context. I'm not sure whether it's really any different to sending cows to abattoirs for meat. Except of course we don't tend to have cows heads stuffed and mounted over our fireplaces. Which is as big or small a thing as you make it.

Stoats were introduced deliberately too, in an attempt to control the rabbit population which was probably doing for young sprouting vegetation what the deer were doing for anything out of the rabbit's reach. Unfortunately the poor old kiwi is a ground dwelling bird not accustomed to such predators, and the rarer ones were becoming rarer still. The kiwi wildlife people now tag the male kiwis, and by transponder can tell what the birdies are up to. Heart rate etc. demonstrates when the birds are sitting eggs. And it's the bloke bird who gets to do the egg sitting. Division of labour, eh? But now the wildlife folk go in and remove eggs, taking them back to the centre to hatch. It seems a bit harsh until you hear the stats which are 95% of eggs left in the wild do not result in viable adults, and in incubation 95% do result in viable adults, all of whom are released back to their original area. The kiwis lay minimal numbers of eggs, and they are huge, so it's a massive investment for the birds to create their one or two young per year. Interesting stuff, eh? Efforts are also under way to reduce the stoat population so it is a two pronged approach.

I kind of like that the kiwis near Franz Josef were only defined as a separate species as recently as 1994. Goes to show we don't know everything about the planet doesn't it. I'm mildly curious as to how this was established. After all, definition of separate species, unless something has changed since these things were inserted into my brain, was about production of viable offspring. Presumably this means it has been established that the local kiwi bird cannot reproduce with those found elsewhere. Did someone take time to try to bring them together, I wonder or is this work done today by geneticists in a lab? Or is it done with syringes, female ova and male whatevers brought together. I rather hope it's a clinical genetic exercise these days. Don't know why. I love the example of horses and donkeys producing the sterile mule for some reason. Sticks in my memory as a clear definition.

Singing I'm an alien, I'm a legal alien ...

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