For cane toads the scourge of Australia’s vast north, spreading farther and faster is literally backbreaking work. The toads that jump—and thus populate new territory—the fastest are more likely to be larger and have longer legs. But this advantage also has a drawback: up to 10 percent of the biggest invasive toads suffer from arthritis, a new study says.

[source:natgeo]
The large, yellow toads, native to South and Central America, were introduced into the northeastern state of Queensland in northern Australia in 1935 in an attempt to stop cane beetles from devastating sugarcane crops.

Now up to 200 million of the poisonous toads exist in the country, and they are rapidly spreading west through the state of Northern Territory at a rate of up to 37 miles (60 kilometers) a year.

The toads haves severely impacted ecosystems in Australia. Predators—and sometimes pets—that eat toads die immediately from their poison, and the toads themselves feast on any animal they can fit in their mouths. Cane toads also compete with native frogs for habitat.