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Jul 2, 2013 2:45 PM by Posted by Alyse Rzemek

Gator eggs used in research studies

DELEON SPRINGS, Fla. (AP) - A pair of biologists nervously kept an eye on an 8-foot alligator just a few feet away as they pilfered eggs from her nest along the edge of Spring Garden Lake near DeLeon Springs. "Welcome to fieldwork," joked an internationally known researcher as a group of about 15 biologists fanned out across Spring Garden Lake and nearby waterways in the Lake Woodruff system searching for alligator eggs. The eggs - contributed by sometimes less-than-willing alligators - will be studied worldwide for information on genetics, environmental contaminants and human health.


Louis Guillette, a professor of obstetrics and gynecology and director of marine biomedicine and environmental sciences at the Medical University of South Carolina, has researched alligators in the Lake Woodruff National Wildlife Refuge and Lake Apopka for 25 years.

When he started, they were doing mostly "simple biology." Today, tissue and genetic samples from the eggs are analyzed and compared using the latest techniques in genetic research and molecular biology. Guillette said samples from the eggs collected last week are headed to laboratories in Japan and France and will be studied by at least eight Ph.D. students and several post-doctoral fellows.

"If we are going to do this work we have to learn everything we can," said Guillette. They look at basic biology, but also eco-technology, trying to understand environmental contaminants and how those contaminants might lead to birth defects in alligators, and humans.

But first the biologists and researchers have to get the eggs. And that's no easy feat.

The work is at once hot and messy, thrilling and beautiful.

Nests aren't always easy to find amidst a sea of rose mallow and spartina growing along the water. When a nest is spotted, either from an airboat or a helicopter overhead, the biologists push through reeds and bushes higher than their heads and slog through slick mud under a blistering sun.

Female alligators sometimes crawl long distances to build the mounds that will insulate their eggs for 60 to 65 days. They use their mouths, tails and legs to thrash down the surrounding plants and pile up the nests.

One of the collection teams working on Spring Garden Lake last week included Arnold Brunell, an alligator biologist with the Florida Fish and Wildlife Conservation Commission, and Ben Parrott, a post-doctoral research associate working with Guillette.

By noon, Parrott's forearms were criss-crossed with cuts from razor sharp saw grass. In addition to their encounter with the alligator, the team also had close encounters with a ruby-throated hummingbird feeding on the pink mallow blooms and a horde of large grasshoppers, commonly known as lubbers.

When researchers find a nest, they measure it and record the air temperature. Then they collect some of the decaying plant material piled in the nest and place it in bins to cushion the eggs. The eggs they collected took a long trip back to Guillette's South Carolina laboratory later that day.

The eggs - usually around 35 - are counted and added to an observation form completed for each nest. Each egg is marked with a graphite pencil to record its upright position.

The commission also supervises an alligator egg collection in other waterways in July for commercial alligator farmers, who pay a $5-per-egg fee. Adult alligators do not reproduce well in captivity, said commission biologist Jason Waller. In order to have a viable industry for meat and hides, Waller said they need to be able to collect eggs.

Finding an egg-filled nest can be a matter of luck. For several years, the egg collection at Lake Woodruff, permitted by the wildlife commission and U.S. Fish and Wildlife Service, has taken place during roughly the same week. But Guillette and the others never know what to expect because they see variation in when the alligators lay eggs. They suspect it might be influenced by a certain consecutive number of warm spring days.

Last year, they found eggs that had already been in the nest 10 days, nearly too late for some of their research. This year, on the other hand, they found a lot of nests that were ready for eggs, but the alligators hadn't yet laid them. Guillette hoped to return in a few days to try to collect a few more eggs. His research permit allows harvest of up to 20 nests.

Allan Woodward, the commission's alligator and reptile research program leader, said the annual permits are granted to Guillette based on the importance of the research collected from the eggs.

"The research that Dr. Guillette is doing is important for us to understand more about the effects of contaminants on alligator endocrine systems," Woodward said. "It helps us understand populations, why they grow and what sorts of things cause problems."

Eggs collected at Lake Woodruff are used as the control in experiments with eggs from Lake Apopka and from NASA-owned land at Cape Canaveral.

"This is a fairly stable environment," said Guillette, gesturing to the area around him. "We have really good quality eggs and reproduction. This is a special place."

They know for example that there are "pretty dramatic differences" in the reproductive tissues of young alligators in the contaminated waters of Lake Apopka compared with the alligators in Lake Woodruff.

Arnold Brunell, a wildlife biologist with the Florida Fish and Wildlife Conservation Commission, said Guillette's work has provided "lots and lots of good information" that explains what the commission's field biologists have seen in their work with alligators.

"His research spans a broad spectrum of wildlife health issues, and potentially human health issues," said Brunell.

The studies are important for two reasons, the researchers said.

The first is to help the state monitor and manage the alligator population, so people can "bring their kids and grandkids out to see this amazing set of animals," Guillette said.

And the other?

"If these animals can tell us something is going on in our environment, that's also powerful," Guillette said. "If this environment is not healthy for alligators, it's not healthy for us."

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