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<u>TOLEDO BLADE</u> (Ohio) 06 August 06 Questions surround disappearance of salamanders - Dramatic decline observed in U.S., the tropics (Jenni Laidman)
There were so many salamanders in some parts of the United States, together they outweighed every other life-form in the neighborhood. Today, those salamanders and many others around the world are vanishing.
Richard Highton is an expert on salamanders, an amphibian amateurs sometimes mistake for a lizard because of its slender body, short legs, and long tail. Mr. Highton's particular specialty is a group called Plethodons, the woodland salamanders, unusual because they have no lungs.
In the 1990s, Mr. Highton began to revisit places where he had found salamanders since the 1950s. What he discovered was troubling.
He looked at 205 Plethodon populations. He recorded how many members of a particular species remained in each location. Of those, 180 were much reduced. Most populations were halved. In 50 populations, only a remnant remained, about 10 percent of the original population. And 32 populations vanished entirely.
"They used to be incredibly abundant in the Appalachians," Mr. Highton said.
In an earlier study, one of his students found 8,000 salamanders of a single species on a single hectare [about 2.5 acres] of land.
The student also counted 800 representatives of another species. And there were eight more species he didn't count. Other studies have shown salamander densities of up to 100,000 individuals per acre in the Appalachian Mountains.
At first, the dramatic drop in salamanders just didn't seem real. Mr. Highton, an emeritus biology professor at the University of Maryland, doubted his observations.
"It took me a long time to figure this out,'' he said. "Am I losing my touch? Am I getting old? Am I not seeing the salamanders the way I used to? It took me two to three years to be convinced it was real," he said.
While frog disappearances have attracted scientific attention since the late 1980s, it appeared that other branches of the amphibian family, salamanders and caecilians, a legless animal that looks more like a worm or a snake than an amphibian, were not in trouble.
That no longer appears to be the case for salamanders.
From New York to Florida, from the Atlantic to Missouri, Oklahoma, Arkansas, and Texas, everywhere Mr. Highton looked, salamanders were on the decline.
Salamanders appear to be similarly hard-hit in the tropics.
The mountains just outside the Mexican city of Oaxaca "were a paradise for salamanders in the 1970s. I've never seen anything like it," said David Wake, an expert on salamanders from the University of California at Berkeley.
"For example, there's a pine forest with just thousands of logs, and every log you approach ... would have salamanders under its bark. ... We would observe hundreds of salamanders on any given day."
Three years ago, he returned to the mountain with three other amphibian biologists.
"Together we had like 70 years of experience between us. Maybe more. Working all day, the four of us found four salamanders.''
It is not certain what is behind the decline of salamanders. The deadly chytrid fungus known to be lethal to frogs could play a role, and salamanders have been found with chytrid on their skin. But chytrid hasn't been found in the Plethodon populations Mr. Highton studies. Then again, no one monitors these populations for chytrid.
Mr. Highton posits acid rain could be the cause of Plethodon declines. Studies have shown Plethodon species are sensitive to increased acidity, but no study has definitively linked declining Plethodon numbers to any single cause.
Salamander populations are more difficult to track than frogs since many species spend most of their lives underground.
Almost nothing is known about the status of the third amphibian order, the caecilians, which spend their entire lives underground.
"We need to know a lot more about amphibians, although some species are going extinct as fast as we can find them," said Robert Lacy, chairman of the Conservation Breeding Specialist Group, the committee within the World Conservation Union attempting to coordinate amphibian rescue efforts around the world.
"Salamanders may be heading downhill just as fast as frogs. We don't know," the Waterville resident said.
http://toledoblade.com/apps/pbcs.dll/article?AID=/20060806/NEWS06/608060307
There were so many salamanders in some parts of the United States, together they outweighed every other life-form in the neighborhood. Today, those salamanders and many others around the world are vanishing.
Richard Highton is an expert on salamanders, an amphibian amateurs sometimes mistake for a lizard because of its slender body, short legs, and long tail. Mr. Highton's particular specialty is a group called Plethodons, the woodland salamanders, unusual because they have no lungs.
In the 1990s, Mr. Highton began to revisit places where he had found salamanders since the 1950s. What he discovered was troubling.
He looked at 205 Plethodon populations. He recorded how many members of a particular species remained in each location. Of those, 180 were much reduced. Most populations were halved. In 50 populations, only a remnant remained, about 10 percent of the original population. And 32 populations vanished entirely.
"They used to be incredibly abundant in the Appalachians," Mr. Highton said.
In an earlier study, one of his students found 8,000 salamanders of a single species on a single hectare [about 2.5 acres] of land.
The student also counted 800 representatives of another species. And there were eight more species he didn't count. Other studies have shown salamander densities of up to 100,000 individuals per acre in the Appalachian Mountains.
At first, the dramatic drop in salamanders just didn't seem real. Mr. Highton, an emeritus biology professor at the University of Maryland, doubted his observations.
"It took me a long time to figure this out,'' he said. "Am I losing my touch? Am I getting old? Am I not seeing the salamanders the way I used to? It took me two to three years to be convinced it was real," he said.
While frog disappearances have attracted scientific attention since the late 1980s, it appeared that other branches of the amphibian family, salamanders and caecilians, a legless animal that looks more like a worm or a snake than an amphibian, were not in trouble.
That no longer appears to be the case for salamanders.
From New York to Florida, from the Atlantic to Missouri, Oklahoma, Arkansas, and Texas, everywhere Mr. Highton looked, salamanders were on the decline.
Salamanders appear to be similarly hard-hit in the tropics.
The mountains just outside the Mexican city of Oaxaca "were a paradise for salamanders in the 1970s. I've never seen anything like it," said David Wake, an expert on salamanders from the University of California at Berkeley.
"For example, there's a pine forest with just thousands of logs, and every log you approach ... would have salamanders under its bark. ... We would observe hundreds of salamanders on any given day."
Three years ago, he returned to the mountain with three other amphibian biologists.
"Together we had like 70 years of experience between us. Maybe more. Working all day, the four of us found four salamanders.''
It is not certain what is behind the decline of salamanders. The deadly chytrid fungus known to be lethal to frogs could play a role, and salamanders have been found with chytrid on their skin. But chytrid hasn't been found in the Plethodon populations Mr. Highton studies. Then again, no one monitors these populations for chytrid.
Mr. Highton posits acid rain could be the cause of Plethodon declines. Studies have shown Plethodon species are sensitive to increased acidity, but no study has definitively linked declining Plethodon numbers to any single cause.
Salamander populations are more difficult to track than frogs since many species spend most of their lives underground.
Almost nothing is known about the status of the third amphibian order, the caecilians, which spend their entire lives underground.
"We need to know a lot more about amphibians, although some species are going extinct as fast as we can find them," said Robert Lacy, chairman of the Conservation Breeding Specialist Group, the committee within the World Conservation Union attempting to coordinate amphibian rescue efforts around the world.
"Salamanders may be heading downhill just as fast as frogs. We don't know," the Waterville resident said.
http://toledoblade.com/apps/pbcs.dll/article?AID=/20060806/NEWS06/608060307