Friday, December 02, 2011

Coffee and Provocation



  • A Sudden Disappearance of Argentine Fire Ants:
    The Argentine Fire Ant, one of the world's worst invasive species, is disappearing from New Zealand – without any human intervention. The reason is not entirely know, but one theory is that low genetic diversity within the New Zealand population has resulted in less disease resistance..

5 comments:

Éadaoin said...

Ohhh I'm excited about that camera stabiliser! I have a terrible shake in my hand that causes a good 80% of all photos I take to be irredeemably blurred. Have you tried the bolt-and-washer thing yourself? If so, does it work?

Seahorse said...

Wow, so much in these links, but the cheery on top was the "Outside" article on Jim Harrison. A lot to ponder in that one. Thanks, as I'd never have seen it otherwise.

Seahorse

PBurns said...

Yes Éadaoin, it does work. Your get braced for up and down and in and out... a kind of tripod effect with your two legs and the string. Simple stuff that works pretty darn well!

P

an American in Copenhagen said...

Given that population size dipped below 30, do we not think that the Nēnē will eventually head the same direction as those fire ants?

PBurns said...

.

No. For starts, I do not believe the Argentine Fire Ant in NZ **actually** has a problem with genetic diversity. More likely, we will find this non-native species was wiped out by a type of ground fungus. Perfect fungus conditions may not exist in the soil for years on end, and then a perfect litanty of hot and cold weather, with the right levels of rain and humidity, and they can erupt like a tidal wave.

Why do I think genetic diversity is an unlikely cause of the demise of NZ fire ants? For the simple reason that high-production species, like ants, rarely suffer from genetic bottlenecks as they contain, within their own production numbers, the capacity for pretty rapid genetic drift.

Remember that all the insects, rats, mice, and birds on almost all islands are the product of just one or two individual colonists. The Nene itself is an example; it is a descendant from a large Canada Goose that was blow. on to the islands about 800,000 years ago.

For more on how breeding numbers and habits impact genetic drift, see "Islands of Wolves, Rats, Lions and Dogs" at >> http://terriermandotcom.blogspot.com/2011/05/islands-of-wolves-rats-lions-and-dogs.html

P