November 20, 2007
Lips wins NSF grant to continue frog researchCARBONDALE, Ill. — Frogs eat bugs and snakes eat frogs. Everyone knows that.
But what happens to the bugs and snakes if there are no frogs?
That's the story — and the mystery — in area after area of Central America, as a malevolent fungus continues ravaging the frog populations. In the high mountain jungle "cloud forests" of Costa Rica, Panama and elsewhere, frog populations are crashing. Some varieties face extinction.
A zoologist at Southern Illinois University Carbondale, who has been on the leading edge of research into this phenomenon, will once again lead students into the jungle streams after receiving another round of funding for her work.
Karen R. Lips, associate professor of zoology in the College of Science at SIUC, recently received a grant of almost $265,000 from the National Science Foundation to continue collaborative research on how the "catastrophic" decline in various frog populations is affecting the food web in those areas. Matt R. Whiles, associate professor of zoology at SIUC, also will work on the project, along with some students.
Lips has investigated the issue since 1993 when she happened upon it while working on her doctorate.
"I was working in Costa Rica doing research and I happened upon an area where there were a lot of dead frogs," Lips said. "It was random chance."
She returned later to find the population virtually wiped out. Then, during another expedition in 1996, this time in nearby Panama, she found the same situation. After collecting more specimens, she and some researchers from Australia in 1997 identified the skin problems and fungus.
Since then, Lips has been at the forefront in research in this area. She, along with graduate and doctoral students, have visited the high jungles on numerous occasions, roughing it in the wild as they collected loads of data on the ecological systems before, during and after the fungus arrives.
"We're trying to get an idea of how the frog declines are affecting the whole ecosystem," said Lips, whose work has been featured in numerous articles and popular magazines such as National Geographic and others. "To do that, we have get picture of how things worked before the fungus. Then we can see how things change."
To do that, Lips and her students spend long hours in and along the jungle streams observing and measuring frog populations and various indicators such as fertility rates, tadpole numbers, survival rates and feeding habits. They also examine the health of populations of species that are connected to the frogs in the food web, such as invertebrates, insects, snakes and fish, as well as food sources such as algae.
The fungus, known as Batrachochytrium dendrobatidis, appears to kill adult frogs by causing what is essentially a bad case of athlete's foot on their skin. While such irritation to human skin is an annoyance, to a frog it is deadly as they receive a large amount of oxygen and moisture directly through their skin. Electrolyte imbalance follows infection, which leads to cardiac arrest.
"Anytime you mess with a frog's skin it's very serious," Lips explained. "This fungus attacks the skin."
Piecing together the evidence, the fungus appears to have first emerged in the late 1970s, with reports coming from the western United States and Mexico. From there, it appeared to travel south, arriving at the north end of Costa Rica in 1987 and steadily working south until crossing into Panama about 1993. The fungus continues to rampage through that country and has hit the Andes Mountains of South America.
Lips' next expedition will take her near the southern tip of Panama, near the ecological outpost called Cana, in Serranía de Pirre area, where they will look for an environment yet untouched by the fungus.
But she knows it is coming.
"If you look at the maps on this, you can see this fungus is moving at a very regular pace every few years," she said.
One of the researchers' goals is "time travel." That is, they want to re-examine some ecosystems where the fungus first appeared some 20 years ago to see how it is functioning. In theory, they can apply that scenario to the widening swath of infected areas to predict the cumulative effect of the population declines on the food web and ecosystems in the future.
It isn't just about the dizzying variety of colorful, musical frogs in these areas. The upshot of their decline could have serious implications for humans, as well.
For instance, disease-bearing mosquitoes, biting flies and other insects are natural prey for frogs and their offspring. Fewer frogs could mean more such insects. Also, tadpoles eat algae, meaning a decline in their numbers could affect water quality and fish populations.
Lips and her fellow scientists don't know such effects for sure, but they hope to learn more by compiling more and more data, creating a virtual model of how an ecosystem reacts under such stresses.
Science leaps ahead – Zoologist Karen R. Lips, left, holds a frog specimen known informally as "the smoky jungle" frog as some of her students look on. Lips, associate professor of zoology in the College of Science at Southern Illinois University Carbondale, and a leading researcher on severe frog population declines in the high jungles of Central America, recently received almost $265,000 from the National Science Foundation to continue her work. With Lips are, left to right, Sarah Becker, a graduate student from Deerfield and the daughter of Jeanne and Joe Becker; Brooke Talley, a doctoral student from Evansville, Ind., and the daughter of Terry and Debi Talley; and Tony Frazier, a senior undergraduate majoring in zoology from Cincinnati, and the son of John and Debbi Frazier.
Photo by Russell Bailey, University Communications
It's not easy – Brooke Talley, a doctoral student from Evansville, Ind., displays a common tree frog that lives in a laboratory at Southern Illinois University Carbondale. Talley, the daughter of Terry and Debi Talley, is a student working with Karen R. Lips, associate professor of zoology in the College of Science at SIUC. Lips, a leading researcher on severe frog population declines in the high jungles of Central America, recently received almost $265,000 from the National Science Foundation to continue her work.