Deadly Cane Toads have Nearly Wiped out Dwarf Crocodile Population in Australia

According to a new study, cane toads in Australia have almost wiped out some population of dwarf crocodiles in the region.

Adam Britton from Charles Darwin University's Research Institute for the Environment and colleagues found that dwarf crocodiles have now begun eating the poisonous toads as their food source is rapidly vanishing.

Cane toads are large amphibians native to South and Central America and were introduced in Australia to control the pest beetles in the sugar cane industry in 1935. Many native species such as quolls, snakes, goannas and freshwater crocodiles have been poisoned after eating these toads.

According to estimates, there might be about 100 million cane toads in Australia. Last year, many volunteers had signed up to cull these toads. This year, a conservation group in Australia called Frog Watch called for strict action against these toads that have become a threat to local lizard population.

Australian tarantulas, wolf spiders and racing stripe spiders, however, have the ability to keep the numbers of these deadly toads in check.

In the present study, researchers found that dwarf crocodiles died after eating these toads.

"The dwarf species found in upstream escarpments are unique because they are so small - less than half the size of your typical freshwater crocodile," Dr Britton said in a news release. "We already know that cane toads kill freshwater crocodiles, but we were concerned that cane toads might have a major impact on dwarf populations because of their small size and lack of alternative food sources."

Researchers said that the cane toads in the region might not be just affecting local dwarf population, but also many other species of local animals. The study shows that the crocodiles may learn to avoid being poisoned by eating only the back legs of the toads.

The study, "Impact of a toxic invasive species on freshwater crocodile (Crocodylus johnstoni) populations in upstream escarpments," is published in the journal Wildlife Research.