Sunday, June 20, 2010

A Salamander Vanishing Before Our Eyes

As I stood along the edge of an isolated swamp deep in the heart of the Florida panhandle, I used my ears to listen for any calling frogs but my eyes were distracted as I watched a C-130 gunship lay waste to the ground below it as it flew in tight circles far above. Orange tracer rounds exploded out of the airplane and streaked to the ground like shooting stars. The gunners use these radiant rounds to help narrow in on their targets. Flashes of light from the airplane lit up the sky as the guns unloaded, it would take long seconds before the sounds of the blasts reached me, reminiscent of popcorn popping in the microwave.

Watching the military plane conducting its training exercises, it was surreal to consider the swamp in front of me was one of the few remaining wetlands where you had at least a chance of finding one of the rarest amphibian in the world, the reticulated flatwoods salamander, Ambystoma bishopi. I shivered in the cold April night and withdrew my arms into my short sleeved shirt as I tried to identify any male frog with love on their mind, singing their distinctive calls to attract mates. I was assisting on a research project attempting to determine key characteristics of flatwoods salamander breeding ponds, there are so few breeding wetlands left that it’s important to know them as well as we can. By identifying what other species share these habitats, it may be possible to identify potential flatwoods salamander breeding ponds without actually seeing the rare and secretive salamander’s themselves.

Like many species closely associated with the longleaf pine ecosystem, the flatwoods salamander requires open canopy forests and limited undergrowth to survive and persist. The key to keeping longleaf pine forests in this condition is allowing fires to burn through every two to three years. These fires reduce the amount of woody and brushy vegetation on the ground while allowing wiregrass, an indicator of a healthy longleaf pine forest, to thrive. Fires also discourage hardwood trees, such as turkey oaks, from becoming established. Keeping these oaks out keeps the canopy open, which increases the amount of sunlight reaching the ground (much to the delight of gopher tortoises, among other sun-loving species).

Oak trees have another, devious effect on flatwoods salamander breeding ponds. These wetlands are often so shallow they may even appear as just grassy depressions on the landscape. They’re so shallow they may completely dry up under the pressure from the intense summer sun (several large salamander species in the southeast breed during the winter and spend the rest of the year underground for this reason). When oak trees surround and even penetrate these shallow wetlands, their thirsty roots soak up much of the water. Over time, these unique wetlands may simply cease to exist. Resident salamanders are left to live out the rest of their lives without an opportunity to succesfuly breed, dooming the population to eventual extinction.

From South Carolina down through Georgia, the Florida panhandle and southwestern Alabama, many of the unique and isolated wetlands suitable for flatwoods salamanders have been converted to agricultural land and urban development, and fire was suppressed in many areas where they remained. As a result, the flatwoods salamander declined precipitously across its range, they’re even thought to have disappeared completely from Alabama.

In 2007, the already imperiled flatwoods salamander became even rarer due to an unlikely source. Geneticists, after examining flatwood salamanders from across their range, actually determined that what we previously thought of as one species were actually two separate animals!

Every individual has some unique genes; this is why no two people look exactly alike. Even identical twins have some differences. But, there are some genes that don’t change within a species, they are the same for every individual. Researchers use these genes to differentiate between species; if they are different, it’s evidence they’re not dealing with the same kind of animal. And that’s what they determined for the flatwoods salamander. Long ago, as the Apalachicola and Flint River system was formed, the once united salamander was divided into two groups. These groups were unable to cross the river, keeping them from interbreeding. Over time, this resulted in the salamanders diverging genetically, eventually to the point they could no longer be referred to as one species.

And just like that, this already rare salamander just became two even rarer salamanders! Populations of this salamander east of Apalachicola and Flint Rivers were named the Frosted Flatwoods Salamander, Ambystoma cingulatum, and populations west of these rivers were dubbed the Reticulated Flatwoods Salamander, Ambystoma bishopi.

Shivering, I recorded the cricket frogs and occasional leopard frog daring enough to reveal their presence in the frigid Florida night (yes, there is such a thing). It was about 1:00 o’clock in the morning by the time we finally finished surveying the required wetlands; cold and tired, I was ready to call it a night. But, as we were loading ourselves into the truck, the researcher I was assisting mentioned to me an exciting find he had come across the previous night. Alongside a wetland we had not visited, he had found a small flatwoods salamander residing under a log. This young salamander had just metamorphosed from its aquatic, tadpole-like stage, and was making its way onto land before dispersing across the landscape. During this time of year, it is sometimes possible to find flatwoods salamanders under logs and rocks, before they find deeper burrows and disappear until they are ready to breed.

A larval flatwoods salamander

Intrigued by the possibility of finding one of the rarest amphibians in the world for the first time ever, I agreed to extend the night a bit longer. After navigating through miles of sandy roads, we finally reached the pond, barely distinguishable as a wetland in the darkness of the forest. Rolling all the logs we could (and carefully replacing them after thoroughly examining the ground with our headlamps), it wasn’t long before a small and non-descript salamander was revealed under a large piece of bark. Drab and not particularly exciting to look at, it was hard to believe the little animal before me was one of the world’s rarest. The opportunity to see a flatwoods salamander with my own eyes was one I was sure to exploit, stories like this one may be all that’s left of the species for future generations.

Photos courtesy of Kelly Jones


Ted C. MacRae said...

There is something both satisfying and depressing about successfully finding such rare species. I enjoy the hunt, but it is only because of our actions that such species have become so rare to begin with.

David Steen said...

Hi Ted,

Bittersweet indeed. Although the prospects for this species are grim, there are several breeding ponds within protected land in the FL panhandle and this land is managed with frequent prescribed burns. A number of the ponds produced offspring this year. However, sometimes development can threaten wildlife on even protected lands and we will have to be vigilant to protect this species.

Bill said...

We have to believe that vigilant efforts to preserve the remaining habitat for this special salamander will preserve it for future generations. We need to know more about the specifics of its habitat requirements to adequately protect it. Until then NO development should be allowed anywhere near its stomping grounds.

Let's hope for the best.

Cindy said...

Well, the two species certainly have attractive names and sometimes that is the start of getting support to protecting them.

Amber Coakley said...

Sure sounds like an exciting experience! The work you are doing must be very rewarding - it is the dedicated work performed by people like you that helps give our declining species a chance. Thanks for all you do!