Biology Students Join Professors on Venezuelan Llanos Research Expedition


Photo: Ana Caudillo Jennie Guilez, left, measures a Llanos side-necked turtle while Adrian Carter records the data. The two Highlands University biology seniors participated in a research expedition to the Venezuelan Llanos led by Highlands biology professors Jesus Rivas and Sarah Corey-Rivas.

Three New Mexico Highlands University biology students joined their professors on a 13-day research expedition deep in the Venezuelan Llanos to study anacondas, caimans and turtles.

In April, biology professors Jesus Rivas and Sarah Corey-Rivas took their students Jennie Guilez, Adrian Carter and Ana Caudillo on a journey of scientific inquiry into the Llanos, a vast tropical grassland plain that floods seasonally, creating the second-largest wetland in the world.

The Venezuelan Llanos make up the heartland of the Ornico River basin that occupies about a third of the country.

Guilez, 26, is conducting her senior research project on the size, weight, and other data she collected from the 30 Llanos side-necked turtles the research team captured and released during the trip. The turtles are one of the main food sources for anacondas.

“My research focus is to determine the relationship between the prey size and the predator size through statistical analysis,” Guilez said. “I’ve always dreamed of being a field wildlife biologist. It was indescribably amazing to do this research in the Llanos. The landscape was a beautiful open field of water and grassland with an incredible diversity of animals coexisting.

“I’m so lucky that I had the chance to travel to Venezuela and conduct research with two knowledgeable, supportive biology professors who are such well-known experts in their field,” Guilez said.

Rivas said there’s no replacement for real field research. “We want to engage students early in novel research, and get them excited about being a biologist,” he said.

Carter’s senior project is about the spectacled caimans he studied in Venezuela. They are crocodilian reptiles that grow up to 8 feet long.

As an 18-year-old freshman, Caudillo exemplifies the professors’ goal of sparking biology fieldwork interest early. Lisa Bentson, a Highlands biology researcher, was also part of the trip.

Rivas and Corey-Rivas, who are married, joined the Highlands University faculty in 2010.

Rivas is a Venezuelan-born wildlife biologist with an international reputation for his anaconda research that spans 19 years. He founded the Anaconda Project in 1992 and published his doctoral dissertation, The Life History of the Green Anaconda, in 2000. He earned his Ph.D. from the University of Tennessee.

Oxford University Press will publish Rivas’ upcoming book about green anacondas in 2012.

Anacondas are the largest snake in the world and are reported to grow to 20 feet in length, and exceed 200 pounds. They are nonvenomous, aquatic snakes from the boa constrictor family. They kill their prey through constriction.

In 2009, Corey-Rivas published her doctoral dissertation, Understanding Amphibian Vulnerability to Extinction. She earned her Ph.D. from The Ohio State University. Her research interests include conservation genetics, landscape ecology of reptiles and amphibians, and New Mexico species of concern.

At Highlands, the two professors established a molecular ecology lab.

Corey-Rivas has also studied anacondas extensively. A focus of her joint research with Rivas is studying the genetic makeup of green anacondas to determine if there are multiple species.

The ultimate goal of Rivas and Corey-Rivas’ green anaconda research is to protect the species through gathering as much scientific data as possible to help make the case for preservation, and sustainable management.

“The anacondas are top predators and require a pristine environment,” Rivas said. “To conserve anacondas, you need to protect all the species in their ecosystem, from butterflies to jaguars.”

Corey-Rivas said: “Understanding the microhabitat needs of the anacondas, what they require to live, is a big piece of our research. We’re trying to determine what degree of habitat disturbance will impact the survival of the species.”

National Geographic and other high-profile documentaries about Rivas and Corey-Rivas’ green anaconda research have educated audiences worldwide. Film crews from the Smithsonian and Venezuela chronicled the Highlands fieldwork in April for documentaries.

Although they are often feared, Rivas described anacondas as gentle giants who are calm and not aggressive, acting defensively only if disturbed or when hunting prey for food.

He said anacondas are possible to capture because they tire quickly after about a minute of being held behind their head. The hardest part is finding them in the water.

The Highlands University research team captured 40 anacondas, 30 spectacled caiman, and 30 Llanos side-necked turtles. Some of the animals were studied onsite, while others were taken to the field station for analysis.

“The well being of the animals is paramount in our research,” Corey said. “Our top concern is that the animal is not hurt and stress is minimized. We’ll hike two hours to return them to their original location the next day.”

Corey-Rivas said an important element of the expedition was to teach students philosophies and techniques for responsible field work practices.

Funding for the Venezuelan research trip came from the Highlands University Foundation, the Western Alliance to Expand Student Opportunities, and anaconda conservation supporters.

Rivas and Corey-Rivas plan to lead another team of student researchers to Venezuela in 2012. They are writing a National Science Foundation grant proposal they hope will fund a return trip.