Canis lupus hominis

A cane toad. Look into those eyes. What do you see? Pure evil.

Those of you who know me are fully aware that I have always loved Mark Lewis’s Cane Toads: An Unnatural History. The film details the introduction of cane toads to northern Australia to control the cane beetle, which was destroying the country’s sugar industry in the 1930’s, and the subsequent ecological catastrophe that resulted from having vast swarms of poisonous giant toads with rapid reproductive rates and ravenous appetites sweep across the countryside.

I have a copy of this documentary. It is not on DVD or any other newfangled technology. It is on a VHS cassette that was used to tape the film from the Discovery Channel.  In those days, my family taped a lot of television shows in VHS, and in those days, you could buy several blank cassettes that had their own adhesive  labels that could be used to identify the film. With this particular VHS cassette, I could not find the labels, so I was forced to resort to using a band-aid– on which I scribbled the words “Cain Toad.”

Even though I spelled the word incorrectly, I think that this name fits this animal a little better.  Cain was Abel’s murderer, and this toad has been a destructive force where ever it has been introduced.  Not only does it possess a particular toxic venom that is released from two large glands on the back of its head, they are big enough to eat animals that are the size of mouse–which includes many different rare animals that are endemic to various tropical islands and Australia. It kills those who attack it, but it also kills to eat.

I first encountered this species for myself in Hawaii. My family was on vacation on Maui, and we were staying at resort that had extensive landscaping on its grounds.  Because this resort was in the rain shadow of Haleakala, it required some irrigation canals to maintain the veneer of natural lushness. It was dark, and we had just come back from a long day of sight-seeing. As anyone would expect from Americans from the Eastern US in Hawaii, we were jet-lagged and a bit tired.  I was looking forward to a good night’s sleep, but as we crossed the foot bridge over the little irrigation canal, something moved.  The beams from the faux tiki torch landscape lights illuminated the dark water, and as I looked over the edge of the foot bridge, I noticed a tannish yellow blob floating in the black water. My eyes made out the profile of a toad. It was not dissimilar from the American and Fowler’s toads with which I was much more intimately familiar, but it was massive.  To my eye, it was a large as a chihuahua, though this may have been an exaggeration that my imagination has added to it over the years. It took me a few seconds for me to register what this creature was, but it soon hit me:  I was looking at the infamous cane toad, destroyer of ecosystems and invasive species extraordinaire.

I was reminded of this experience when I came across Mark Derr’s piece in today’s New York Times.  Mark Derr lives in southern Florida, where cane toads were also introduced to control pests in the fields of sugar cane. The toads have liked Florida almost as well as they have enjoyed Australia, and they have definitely cause their share of ecological problems.

However, the real issue with cane toads in Florida is the danger the pose to the dogs, which is why he killed a cane toad that had decided to set up residence in his pond.

Derr is not an anti-exotic purist, maintaining non-native plants on his own property and establishing a relationship with an introduced African lungfush, but this toad was a clear and present danger to his dog and other dogs in the neighborhood.

Dogs die from cane toad venom when they put toads in their mouths. Most dogs in my part of the country won’t touch a toad.  That’s because they have been trained by the local Fowler’s and American toads that toads will make your mouth burn. It usually takes just one attempt of a local dog putting a toad in its mouth before it learns very quickly to leave them alone. Of course, the bufotoxin released by an American or Fowler’s toad is not as severe as that released by the cane toad, but in some situations, it is possible for a small dog to die if it ingests toad poison. Larger dogs are usually fine once they have their mouths flushed, and they learn a valuable lesson– leave the toads alone!

Of course, if a dog ingests cane toad venom, it may not get a chance to learn.  Dogs have been known to drop dead within minutes of putting the toad in their mouths.

So it makes sense that one would want to protect “toad naive” dogs from cane toads.

Derr managed to spear the toad with a home-made gig, and the neighborhood dogs were finally safe.

However, removing the toad had several ancillary benefits:

I acted to protect our dog without a thought toward other consequences. But within a week of the Bufo’s death, I began to notice changes in and around the pond. Young and old gambusia [mosquito fish] appeared in significant numbers, swimming freely and openly. I am no expert on Bufo behavior, but this one had an ability to knock down plants growing around its chosen resting spots. Once this Bufo was removed, the pond plants grew lush. Anole lizards, whose absence I had silently noted for some time, became everywhere apparent, and I have begun to hear tree frogs again, as well. Even better, the mosquito population collapsed, leading me to conclude that although the Bufo did not appear to eat the mosquito-loving gambusia, its physical presence had somehow intimidated them and forced them into hiding.

Of course, much of Florida– indeed much of the country– is hardly a balanced ecosystem. The unbalancing of the ecosystems began when Columbus showed up, and we simply cannot go back to the forest primeval of legend, which itself was intensely and artfully managed by various indigenous peoples before the European colonizers came. Humans have been altering the ecosystems for our own benefit in this hemisphere for millennia, and the only thing we can do is preserve what we can.

But cane toads are not nice things to have around.

Even if there were no potential ecological benefits to removing them, it would still be just to kill them– even if killing them really didn’t do much to control their numbers.

I just hope another cane toad doesn’t show up at this pond. However, it is very likely that another one will soon be in residence.

It reminds me of what my grandpa said about people shooting rabbits out of their gardens. Yes, it killed the rabbit, but somehow two or three would come to its funeral.

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NB:  Here is a good site on first aid if you dog bites any cane toads or any other toads in North America.