Gators favor fidelity – at least according to findings by University researchers.

After examining hundreds of alligator mothers and their nests, University researchers published a 10-year study in the journal of Molecular Ecology, which concludes 70 percent of female alligators exhibited long-term fidelity in their mating rituals with their male companions.

The journal article is based on studies at Louisiana’s Rockefeller Wildlife Refuge, a densely populated area of alligators and a 2,000-acre study site along the Gulf Coast.

Alligator mating rituals have been studied since the 1960s, but it wasn’t until the 1990s that associate professor Travis Glenn began studying the animals.

“[Other researchers would take] up a part of the marsh and put up these big pens so that you have an enclosure of more than an acre,” Glenn said. “Then they’d put a couple of big adults in there so they couldn’t get out, but they were able to interact however they wanted.”

But semi-natural situations cannot indicate with 100 percent accuracy what the alligators would do in the wild.

The Louisiana marshland where Glenn’s research took place is open, making it easy for researchers to spot alligator nests from helicopters. Once researchers identify a clutch – a nest typically comprised of 30 eggs – it is taken back to the lab and incubated.

When the eggs hatch, blood samples are taken, and the baby alligators are returned to their nest site, where most often, the mother alligators come back for her babies, Glenn said.

“[We] try to catch the females when they guard,” Glenn said. “If we do, we take the blood sample from her and that’s what we do to DNA genotype her.”

Then, researchers try to determine how many males fathered the offspring in a particular nest. Since it is difficult to differentiate between male and female alligators, Glenn said his research team did not try to capture fathers of the offspring. In order to study the alligators’ mating ritual, researchers use extensive markers, or chunks of DNA, to determine the genotype of the father alligator.

“What you do is you have the females and you know what her genotype is, you have the babies and you know what their genotypes are and you do subtractions and figure out the father’s genotype,” Glenn said.

Glenn said researchers wanted to re-trap the same females to understand whether they were mating with the same males year after year.

He said the interests in alligator mating rituals derive from a much deeper purpose than to figure out if alligators exhibit monogamous behaviors.

The study coalesced with a separate study on radiation at another alligator site, the University’s Savannah River Ecology in South Carolina, where there was a population of alligators exposed to low levels of radiation.

Glenn said it is important to understand the mating rituals of animals in the area to gain a better understanding of radiation and its effects on the population.

“Since alligators are at the top of the food chain, if we can determine if they are contaminated, then we’ll know that everything below them is also contaminated,” Glenn said. “We want to know if those low levels of radiation are dangerous to wildlife in the area, and something needs to be done about the contaminated soil.”