According to the Ecological Society of America, http://www.esa.org invasive species often succeed in new environments because they can out compete native species within an area for some resource, such as food, mates or habitat. What’s less clear is exactly what gives them this edge over local species that should be experts at living in their home territory.
A study by Joshua King and Walter Tschinkel published online in the Proceedings of the National Academy of Sciences investigates just what gives a common southern pest, the invasive fire ant, the ability to muscle out local ants seemingly everywhere there’s a human disturbance. Notorious for their huge nests (as many as 100,000 ants per colony on average), aggressive swarming behavior and painful stings, these red ants have become a major menace in the U.S., Australia, the Philippines, China and Taiwan.
Because the ants are usually found in highly disturbed areas, such as roadsides, parking lots, strip malls and subdivisions, the authors wondered if the ants’ success depends on their environment. The authors compared the success of native ant populations in areas that were recently disturbed by humans to natural areas where fire ants were introduced.
Somewhat surprisingly, the fire ants by themselves had less of a negative effect on native ant populations than simple plowing. The ecologists suggest that fire ants may not be so much an invasive species but a “disturbance specialist,” with the ability to capitalize on an open niche when they see one – a description that might fit other invasive species as well.
1 comments:
Nice post, just thought I'd add some information to clarify your point about RIFA in Australia. These disturbance specialists were first discovered in one of the fastest-growing urban areas of Australia, South East Queensland, in early 2001, after having been in residence and spreading for at least 5-10 years. In some suburbs the density of infestation was as bad or worse than anywhere in the US. Since 2001 Australia has spent roughly A$190m on eradicating fire ants (from more than 90,000 hectares of urban and country environments) with massive success - way more than 99% of all the RIFA in Australia have been killed. The number of known colonies has been reduced from 65,000 plus in 2001 to just a couple of hundred in 2008, which have all been treated. However, occasional small infestations are still being located - as is usual in all eradication campaigns - and with RIFA just one viable queen is enough to put you back to square one pretty fast.
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