Invasion of the Giant Orange Toads!

The cane toad is an invasive species that has spread through Australia since it was introduced to the continent in 1935 for use as agricultural pest control. They are native to Central and South America.

Scientists wondered why the toads invaded different regions of Australia at different rates, so a research team analyzed 70 years' worth of data on the toads' presence in various areas to see if a pattern emerged. They found that natural selection of toads at the edges of a range may have selected animals that could travel faster, so they could monopolize the best resources in new regions.

"The worrying message from this research is that if control efforts fail and an invasive species spreads across a sufficiently large area, then it may be able to invade a broader region than expected because it has adapted to move across greater distances at the edge of its range," said Mark Urban, a researcher at the National Center for Ecological Analysis and Synthesis in Santa Barbara, Calif.

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Credit: Ben L. Phillips