Bd—Batrachochytrium dendrobatidis in full—kills frogs and other amphibians by eating away at their skin and triggering fatal heart attacks. It’s often said that the fungus has caused the decline or extinction of 200 amphibian species, but that figure is almost two decades out-of-date. New figures, compiled by a team led by Ben Scheele from the Australian National University, are much worse.

The scale of these losses can be hard to appreciate, especially if you think that a frog is a frog is a frog. But amphibians are ancient survivors that have been diversifying for 370 million years, and in just five decades, one disease has nearly decimated their ranks. Imagine if a new disease started wiping out 6.5 percent of all mammal species—that would be roughly everything with hooves and everything with flippers. The world would freak out.

In the 1970s and ’80s, amphibian experts began sharing ominous anecdotes about once-plentiful populations that had mysteriously disappeared. Streams once full of eggs were clear. Nights once resonant with ribbits were silent. Nothing about the habitats had changed, save for their sudden, inexplicable froglessness. No one knew what the problem was, let alone the culprit. “It was more than a search for a needle in a haystack—we were still debating the existence of the haystack,” Lips wrote recently. Steele’s analysis shows that by the point the fungus was finally identified, in 1998, it had already done the brunt of its lethal work. At least 60 species were already extinct, and hundreds more were going south.

Bd is perhaps the perfect frog killer. It kills with gusto and without fuss. While some diseases affect only specific hosts, Bd covets nutrients found across amphibian skins, and so targets the entire group indiscriminately. It spreads easily through the water, and it persists outside its hosts.

The fungus hasn’t acted alone; humans have been its unwitting accomplice. A genetic study led by Matthew Fisher from Imperial College London suggested that Bd had originated somewhere in Asia. From there, one especially virulent and transmissible strain spread around the world in the early 20th century—a time when international trade was booming. Infected animals could have stowed away aboard ships, or been deliberately transported as food, pets, or pregnancy tests. Either way, the killer strain eventually spread to five other continents.

In the new study, Scheele’s team compares the modern world to Pangaea—the single, epic supercontinent that existed at the dawn of the dinosaurs. It has long split up, but humans have effectively re-created it. For wildlife diseases, all the world is once again a single connected mass, easily traversed. For that reason, new fungal diseases seem to be emerging at an ever-increasing pace, affecting bats, snakes, salamanders, and more. “These fungi would normally have fried on a sailing craft across the Atlantic, but now they’re viable,” Scheele says. “We’re just able to move things around at higher speed and volume than we used to.”

Alpha-Phonics now on Mini Flash Drive, complete with sound!

Limiting its movements remains the best strategy, and that means curbing the wildlife trade. “Moving wildlife around the globe can and does have devastating consequences,”Rowley says. “There’s more awareness of the impact of invasive species like cane toads and rabbits, but this paper highlights that it may be the inadvertent hitchhikers—the parasites and pathogens we don’t see—that cause the most biodiversity loss.”

Encouragingly, the pace of decline has eased. Better still, 60 species have begun to show glimmers of recovery. But no one knows whether this means that frogs have managed to eke out an evolutionary truce with Bd, or whether further outbreaks are to come. That’s possible if the fungus makes it to Papua New Guinea—a thus far Bd-free stronghold that is heaving with amphibians. The virulent, globe-hopping strain has also hybridized with indigenous varieties, raising concerns that hybrids could behave unpredictably.

“There’s no obvious way to deal with this,” Lips says. Some researchers have set up captive-breeding programs to buy time for species in contaminated habitats. Others are

Alpha-Phonics the Book on CDRom

looking at ways of manipulating the fungus, or breeding more tolerant frogs, or pairing the frogs with defensive bacteria, or relocating frogs to sites that are inhospitable to the fungus. None of these solutions is a silver bullet, and none is close to readiness. “It says a lot about the scary nature of the disease that even after intense, long-term collaborations we haven’t come up with a viable solution,” Lips adds.

Alpha-Phonics, the great phonics reading instruction program, is not in danger of extinction because it is so popular….it works!

Find out all about it below:

WEBSITE       TESTIMONIALS       REVIEWS       HOW TO ORDER