Bufo decline a towering mystery

Hawai'i's population of bufos is in big trouble, and that unfortunately is good for termites.

This is purely an anecdotal observation, but there's lots of anecdotal data.

(Image: The death of this particular bufo is no mystery. It was run over by a car.)

For some years, longtime Hawai'i residents have commented there seem to be fewer dead bufos on the road. And that you see fewer bufos sitting out on the road on rainy nights.

My own unscientific addition to this body of evidence derives from the annual termite swarms of early summer. On calm, hot nights of late May and early June, termite alates swarm out of their colonies before sunset, and go looking for new sources of cellulose on which to gorge. They do it, probably, by the tens of tens of millions.

They are attracted to lights. That means you'll see a living halo of flying insects around every street light. And if your lights are on in the house, they'll soon be inside, dropping their wings and slipping behind molding and into furniture, looking for the right environmental conditions to launch new colonies.

Like many Hawai'i residents, I'll reduce house lights to a minimum and fire up a lantern and set it out in the yard. The termites soon swarm to the lantern light.

And this attracts bufos, which proceed to gorge on termites. Sometimes they fill up so completely they can barely hop.

Several years ago, I counted 17 bufos one night, circling the lantern, all of them feasting.

Last week, one night when the termites swarmed, only three bufos appeared. Last night, just one bufo.

What this means in the larger picture, I don't know. But around here, clearly there are fewer bufos this year than just a few years ago. Lots fewer.

Bufo marinus, the giant neotropical toad or cane toad, was brought to Hawai'i to control insects, and it does. It is an invasive critter, and in some parts of the world (Australia, for instance) it is a real problem because it primarily eats native creatures. Here, it's mainly eating aliens.

The bufo will eat rats, mice, cockroaches, termites and ultimately, almost “any terrestrial animal” it can fit down its gullet, according to the Global Invasive Species Database (http://www.issg.org/database/species/ecology.asp?fr=1&si=113.)

It's best not to handle the bufos, or to let your dog or kids play with them, as they exude a powerful toxin through their skin. (My dog Socrates died in convulsions after chewing on a bufo.)

But it appears to be suffering from the mysterious decline that is affecting frogs and toads globally—all of them, except the coqui frog in Hawai'i, it seems.

In Australia, an epidemic disease has been identified as a culprit killing rain forest frogs of multiple species. But in most cases, the causes are not clearly understood. Amphibians are being lost around the world, with more than 100 species extinct in recent decades (http://amphibiaweb.org/declines/declines.html.)

Among the suspects in the decline are habitat loss, an unpronounceable fungal disease called chytridiomycosis, climate change, chemicals, and ultraviolet radiation from the sun.

In many cases, frogs and toads are being found with bizarre deformities. Extra legs. Extra eyes.
The U.S. Fish and Wildlife Service is looking into the possibility that it might be some kind of contaminant (http://www.fws.gov/contaminants/Issues/Amphibians.cfm.)

I'm not aware that anyone has identified a factor in the Hawai'i bufo decline, but it seems clear there are fewer of them.

Which is good, unfortunately, for termites.

© Jan TenBruggencate 2009