Cane Toad
Rhinella marina

Cane Toad (Rhinella marina)
Taveuni, Fiji
The infamous Cane Toad (aka Giant Toad, or Marine Toad) (Rhinella marina) naturally occurs from Southern Texas down through Central America and into tropical South America.  However, it is most famous for the fact that it now occurs all over the world due to its introduction to try and control pest insect species. It is now found on islands in the tropical Pacific (including Hawaii, Fiji, the Cook Islands, Marianas Islands, and many others), New Guinea, Australia, the Phillippines, many Caribbean and Antillean Islands, Florida, Bermuda, Japan, Taiwan and there are likely other areas still waiting to be documented.  Once they get established, their generalist habits make them easily adapt to the new environment.  These Cane Toad tadpoles were photographed in a stream right next to the ocean away from the tourist areas on the relatively isolated island of Taveuni, Fiji.

Cane Toad tadpoles
Taveuni, Fiji

The problem is that although the species was introduced as a pest control method, they have become pests themselves in many of these areas.  It is a large toad with a large appetite and will eat anything it can swallow.  It has significantly impacted the local amphibian populations in some areas simply by eating and outcompeting the native frogs and toads. 

large Cane Toad
Costa Rica
Furthermore, for larger animals it presents a problem because it is highly toxic.  It's skin, particularly its massive parotoid glands behind the eye and on the shoulder produce a toxic sticky secretion.  In some areas where it is introduced (e.g. Australia), native animals have no experience with or resistance to its poisonous skin secretions and eat the toads then die.  They have also killed many domestic pets through poisoning.

But, it does have a place in the world.  In its native range there are controls to its population that have evolved along with it.  It isn't the Cane Toad's fault it is a problem, it is the fault of the men who transported it from its native range.

It is a native toad in Texas but is restricted to the southernmost counties along the Rio Grande.

Adult Cane Toad
Chiapas, Mexico

These are massive toads. Adults have exceeded 5 pounds in mass and been over 15 inches long.

The call of the Cane Toad is actually what you would expect for a huge toad.  Toads generally have trilled calls.  Smaller toads have faster, high-pitched trills and big toads have slower, low-pitched trills.  The bigger the toad the lower pitched the trill.  The trill of the Cane Toad is so slow and low pitched that it is drum-like.  This individual was from north of Aguas Zarcas, Costa Rica.

Here's a slightly longer section of call from an individual near Caño Negro, Costa Rica.

Cane Toad call from Caño Negro, Costa Rica

Here's a call from an individual the Daintree National Park in northern Queensland, Australia.

Cane Toad call from Daintree National Park, Australia

© Chris Harrison 2014

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