Invasive/Introduced Species...attempts to control populations.

[vetusvates]

I started to put this in Natural History/Field Observation...but that section does specify corn snakes.

This National Geographic article is for the ecologist, population ecologist, and zoologist in all of us.
We have all read about deliberately or accidentally introduced species (Australia and Hawaii, for example) in grade school, and the vicious cycle of events that this can initiate.
Here is another example with the Brown Tree Snake and Guam.
I'm wondering, of course, if the poison hoppers are going to kill the target species.

http://news.nationalgeographic.com/news/2010/09/100924-science-animals-guam-brown-tree-snakes-mouse-tylenol/

 

[dionythicus]

My friend works for the USDA, working with pest species and how to control them. They've worked with these snakes in the past. Don't know if this is something they came up with.

 

[tyflier]

...There are very few snakes that will consume something that they haven't killed themselves," added Dan Vice, assistant state director of USDA Wildlife Services in Hawaii, Guam, and the Pacific Islands....

Really? Is this guy serious? Has this guy done any research on any snakes anywhere in the world before being put in charge of this ridiculous project?:awcrap:

 

[Leew]

I think they are going to find a lot of dead monitor lizards.

 

[Nanci]

In other news:

Cane toad takes over Australia — and then doesn't

The cane toad infestation thought to be devastating Australia turns out not to be that bad.

The cane toad is native to central and South America, but in the 1930s it was brought to Australia to eradicate a beetle decimating sugar cane crops. Instead, the poisonous toad proliferated across the continent, killing every predator that ate it. In turn, marsupials, snakes, and northern quolls began dying off en masse. Experts feared the toad explosion would eclipse competing birds and reptiles. Biologists declared defeat and Down Under braced for the mass elimination of species.

Except it never happened. As New Scientist reports, the toads are being absorbed into the environment without the devastating effects originally predicted. Richard Shine is an invasive species researcher at the University of Sydney who has studied the cane toads. As he told New Scientist, "People saw these ugly creatures moving across tropical Australia and common sense said there was going to be a huge disaster. But it just hasn't happened at the scale that we feared." Other experts agree that “the system seems to be absorbing the toads” and the impact is much less severe than originally thought.

How is this happening? Biologist point out that when a cane toad arrives new to an area, predators will eat them. Both predator and toad will die off, having eaten and been eaten. But who remains is a bit more judicious in the next round of sampling. Also, young cane toads are less toxic than adult cane toads. So while a predator might get a nasty digestive issue from eating a young cane toad, they won’t necessarily die.

 

[vetusvates]

In Australia, I was thinking more about the insidious populations of introduced rabbits (and foxes and pigs and etc.) and their damage to crops and the resulting erosion,...than the dubious dangers and debates of the cane toad.

History of Rabbits in Australia
The European Rabbit (Oryctolagus cuniculus) came out to Australia with the First Fleet in 1788. The rabbit was introduced to Tasmania and the first feral populations were recorded in 1827 in south-eastern Tasmania.

Later, in 1859, Thomas Austin brought out 24 rabbits, 5 hares and 72 partridges and released them on his property, just outside of Geelong in Victoria, called ‘Barwon Park' on Christmas Day.

From ‘Barwon Park’, rabbits spread north and west, and in 1866 there was another release in Kapunda, South Australia. After that it took only 15 years to reach New South Wales, it reached the south-western border of Queensland in 1887, they were first sighted Northern Territory in 1894 at Charlotte Waters, and by the 1900’s there were feral populations in Western Australia. It seemed as if nothing would stop it, and not far behind the rabbit was the Fox. In 1890, the rabbit population in Australia reached plague numbers and something needed to be done.

In 1907 the longest anti-rabbit fence was finished. It was constructed by the Western Australian Government and it was 1 833 kilometres long. It was from Starvation Boat Harbour, in the south, and Cape Keraudren. One problem was that by the time that most rabbit-proof fences are finished, rabbits have already crossed into the area that the fence is trying to keep them out.

In the 1950’s a virus was introduced. It was called the Myxoma Virus and it caused the fatal Myxomatosis. The proposition of introducing the Myxoma Virus to Australia was put forward in 1918 by a Brazilian scientist called H. de Beaureparie Aragao. It was rejected because it “wouldn’t work”, but the rabbit populations kept getting worse. Finally, in the 1920’s, specially trained scientists of the Australian Government and the CSIRO had begun to assess the possibility of introducing the Myxoma Virus.

Trials were run in Britain, Denmark, Sweden, and southern Australia. These were unsuccessful, but the CSIRO was persistent in developing the virus. Finally they had developed a Virus that would be effective and only species-specific (only effected the specific species). The Myxoma Virus was released at 5 different field sites in the Murray River valley, southern New South Wales.

Eventually the virus lost it’s effect and the populations recovered, due to the survival of rabbits that had natural resistance to the virus. The CSIRO introduced the European rabbit flea in 1957 and again in 1966 to try and give the virus a kick-start again. It was once again a short answer. Finally in 1993 the Spanish rabbit flea was introduced in hoping to help the rabbit populations, but the fleas died out in the hot rangelands.

In 1995 a Calicivirus (RHD, RCD) was introduced and it dropped the populations down, but it came back up. At the moment the CSIRO is developing an immunocontraceptive to hopefully reduce the number.

http://library.thinkquest.org/03oct/00128/en/rabbits/history.htm
http://www.animalcontrol.com.au/rabbit.htm
http://www.environment.gov.au/biodiversity/invasive/ferals/index.html