For those who are familiar with the Cane Toad studies of the invasion on Australia, you know that amphibious creatures can be a particularly pesky threat when it comes to invasive species. Not only do they procreate much faster than mammalian counterparts, with a much higher rate of replication and fecundity, but they are insatiable creatures. Not only will they eat everything from vegetation to insects native to the area, but if they get hungry enough they may just eat one another.

Facing a new threat of American Bullfrogs, a recent study published in the journal Aquatic Invasions shows that Yellowstone River situated in the state of Montana may see permanent damage left in the wake of the invading voracious species.

Found worldwide for their insidious ability to adapt to nearly any ecosystem and easily transported by unsuspecting humans, American Bullfrogs are the pets that can successfully take over their dominion once released or escaped back into nature. And once they find a home, they're likely to propagate entirely out of control. Even conservative models fear the overwhelming abilities of the American Bullfrog to demolish existing ecosystems, as they pose a threat to native species because they will virtually eat anything they can swallow.

"They are going to eat anything they can fit into their mouths" co-author of the study and biologist for the U.S. Geological Survey, Adam Sepulveda says. "It doesn't matter if it's another frog or a bird or a mosquito."

"The impacts of bullfrogs on native amphibians in the Yellowstone River are not yet known, but native Northern Leopard Frogs are likely to be the most vulnerable to bullfrog invasion and spread because their habitats overlap."

And researchers are concerned that consumption is the least of their problems in this new invasion. Over the course of the three year study, the bullfrog population living in Yellowstone River nearly doubled and expanded its range to 66 square-miles, posing a great threat to the overall biodiversity of the area. By eating nearly everything in sight and eliminating competitive native amphibian species through the introduction of disease, the American Bullfrog is one threat that the department of fish and game and researchers alike are not equipped to tackle.

The USGS says that "bullfrogs are extremely difficult to eradicate because they are highly fecund (females can produce up to 40,000 eggs per clutch) and are extremely mobile."

For that reason, and because these amphibious terrors were introduced to the region by man, Sepulveda believes that the greatest efforts that can be made in combating the invasive species are to educate the public about their threat and contain the large amphibians in their current range, as to maintain the biodiversity in surrounding areas.