National Wildlife Health Center Investigates Educator Guide

“The National Wildlife Health Center is sort of what it says. We're a national center and we receive carcasses from refuges and state management areas all around the country, usually from state biologists, federal biologists, tribal biologists,” says disease investigation chief Dr. Scott Wright. Those carcasses shipped overnight to the center are most often samples taken from large animal die-offs. It’s the job of the center to determine the cause of death.

“Much like the CDC would do for human health, or the USDA would do for agricultural animals, for livestock and so forth, that's the role we play for wildlife,” says Wright.

At the heart of the center is a level 3 bio-safety lab where the animal samples are processed and examined through necropsy, the animal version of an autopsy. “Every case that comes in is a potential real challenge,” says veterinary pathologist Dr. David Green. “I sit down and look at all of these different lab results; the toxicology, the poison tests, the virus cultures, the bacterial cultures. And I have to put all of these pieces of information together to determine why was that animal sick, why did that animal die or why did 500 birds die at this site.”

It was 5000 red winged blackbirds dying in a small Arkansas town on New Year’s Eve 2010 that briefly thrust the work of the Center into the national spotlight. “Oh there were just all sorts of clever names applied to the event,” remembers Green. “'Aflockolypse' was, I think, the cleverest.”

Harbinger of the end times, covert military testing, magnetic disruption, all manner of strange theories were applied to the event. The intense interest surprised the NWHC staff, says Wright. “There were people calling me at my home at night, on weekends wanting to know what was going on.”

The cause of death, determined after numerous bird necropsies, was much more banal than the theories. “All of the tests and cultures that we did for infectious diseases and parasites and chemicals came back negative,” says Green. “Basically it came down to, we couldn't find anything other than physical injuries, what we call blunt force trauma in the birds.”

Those necropsy findings, combined with field reports of New Year’s fireworks, and the fact that blackbirds are terrible night flyers came together to paint a picture of startled birds flying into each other and stationary objects and succumbing to traumatic injury.

This most plausible explanation didn’t satisfy the most dedicated conspiracy-theorists according to Wright. “It really sort of floored us. We didn't expect that. We didn't expect to be not believed.”

That’s something that Dr. Wright, who is soon to retire from the Center, finds a troubling omen for the future of science and public understanding. “Science is not being believed,” he says. “That's not a good sign, because there's too much important stuff coming that we need to be stepping up and telling everybody, ‘This is what's going on.’ And they hopefully will believe us.”

Rough-skinned newt. Photo: ap.

The newts are on the move again. Each fall, after the rains start, the newts of Berkeley’s Tilden Park start migrating from the woods to waters of Wildcat Creek, where they mate and lay their eggs. South Park Drive, popular with cyclists and Sunday drivers, crosses their migratory path. Each year from November 1 to April 1 the road is closed to cars, to prevent the newts from getting squished. (How did the newt cross the road? Not by being run over, that’s for sure.)

The newts in question are the California newt, Taricha torosa, brown with a yellow/orange belly, and the rough-skinned newt, Taricha granulosa, which also has an orange belly and, as its name suggests, has rough, brown skin. The newts’ orange bellies are warning signs to predators—both species produce tetrodotoxin, a powerful neurotoxin. However, the rough-skinned newt’s toxin is ten times more powerful than the California newt’s toxin.

Newts lay egg masses, like these, in ponds and slow-flowing streams. Photo: Jennifer Skene.While these two species are not technically threatened, their habitat has been impacted in recent years: their forests and fields have become our neighborhoods, roads have chopped their remaining habitat into fragments, and the streams and ponds where they lay their eggs have been degraded. The least we can do at this point is refrain from running them over!

Newts are amphibians, animals that spend the early part of their life in the water, and their adult life on land. Amphibians are going extinct at an alarming rate; their decline has been referred to as the world’s Sixth Mass Extinction. Habitat destruction is playing a role, but the main problem is an infectious fungus, called chitrid. San Francisco State professor Vance Vredenburg studies yellow-legged frogs in the high altitude lakes of the Sierra Nevada Mountains. He has seen hundreds of frog populations die out because of chitrid. Learn more about Vance’s work and amphibian declines in QUEST’s TV story, Disappearing Frogs, and in a recent New York Times article and accompanying audio slide show.

Chitrid hasn’t affected the newts in Tilden, but the closure of South Park Drive reminds us that amphibians worldwide face some serious threats.

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That was one of the things we wanted to document when we began our exploration of Briones Regional Park, just east of Berkeley. This park is a favorite spot for locals, but is also home to some amazing wildlife. With the help of East Bay Regional Parks naturalist Meg Platt, we put together a science hike where you can see some of the amazing things the park has to offer. But you'll also notice on the map that we didn't pinpoint exactly where the newts live.

As Meg described, this is a fragile species and thanks to Parks District's work, the newts are able to thrive in Briones and several other East Bay parks. But it's important for hikers and park users to give this species plenty of space, especially during mating season. Make sure to keep dogs out of the park's ponds. Luckily, the East Bay Regional Parks district puts together programs for the public so everyone can safely discover this amazing species.

Check out the interactive map of the Briones exploration online, and watch our audio slide show about California Newts.

Lauren Sommer is an Associate Media Producer for QUEST.

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Quest Educational Resources

 Print Guide - Briones Regional Park

 Briones Regional Park KML file

 Tips to get the kids in your life out into nature

 Designing an Exploration on Google Maps

Additional Links

• AmphibiaWeb: California Newt
• AmphibiaWeb: Rough Skinned Newt
• More about California Amphibians

A Pacific Chorus Frog

I'm sad to say my daughter probably won't share those same experiences I had. I could say it's because we live in San Francisco and cities aren't as amphibian-friendly as the suburbs. But my parents still live in the same house where I grew up. Unfortunately, it has been years since we've seen toads in the garden there. And the quiet singing of the tree frogs seems much lonelier today.

Amphibian decline is happening all over the world. And as depressing as it is not to have those fun childhood experiences of catching, playing with and hearing frogs in the garden, there is a much more serious problem going on. This can have some serious consequences to local food webs. It is also an alarming sign that there is something really unusual happening with the world's environment.

There are many reasons for the decline in the world's amphibian populations. And it seems that each region of the globe, and maybe even each species, may have its own ticking time bomb. Some places may be experiencing rapid habitat decline. There is pollution in the rainwater and chemical run-off in lakes and streams. Some places are seeing a sharp increase in parasites and diseases. Scientists are even looking at increased UV radiation. Or maybe it's a combination of multiple factors. The result is part of what some scientists are now calling the "sixth wave of extinction."

That’s a lot of doom and gloom. Luckily, scientists are racing to understand this decline and hopefully may come up with a means of curbing it before it is too late. We were fortunate to meet some of the best. We joined herpetologists Karen Swaim and Vance Vredenburg out into the field to learn more about what is happening to our local California red-legged frogs. We also visited the laboratory of Professor Tyrone Hayes at UC Berkeley to learn what his team is discovering about the connection between agricultural pesticides and frog decline. (See our additional web-only interview with Professor Hayes) You can test your amphibian knowledge by taking our QUEST quiz. Do you know why my brother and I always put down those toads?

Watch the "Disappearing Frogs" TV Story online, as well as find additional links and resources.

Chris Bauer is a Segment Producer for television on QUEST.

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