TWEAN (Austin, Texas) 07 October 07 Biologists exploring how two species coexist
It's midnight in the swamp, and while most folks are fast asleep, wildlife biologists are on the hunt for American alligators.
They want to find out what these feisty gators are feasting on. They may be eating many of the mottled ducks that live in this same habitat.
"In 1996, our department initiated a mottled duck research banding project along the Texas coast. During that time we occasionally saw American alligators consuming mottled ducks that we'd just released. And we wondered if that happens when we're banding mottled ducks, what's going on in the marsh when we are not there," biologist Marc Ealy said.
The mottled duck is the only waterfowl species that spends its whole life here in Texas.
"Since their numbers have been dropping since the 1980s, we've had major concerns and done extensive research to try and improve the critical needs of the duck," biologist David Lobpires said.
It's ironic that alligators could be a threat to an entire species of waterfowl. Data from the early 1970s show most alligators could only be found in a small pocket of southeast Texas. Now their range has expanded dramatically, with an estimated population of more than 300,000.
The current study will determine if they are partly to blame for the drop in mottled duck numbers.
After the alligators are caught, biologists carefully bag them on board and head back to land to find out what they're eating. To do this, they must flush the gators' stomachs.
"He's filling the stomach up with water. You can see the stomach start to expand with water. Once it gets full Matt will push on both sides and forward and it should expel what's in the stomach," Ealy said.
More than 150 alligators were examined from Port Lavaca to Port Arthur, and while biologists found lots of crab shells, spiders and snake skins, they found no mottled duck feathers.
"We found feathers in one stomach but we don't believe these to be mottled duck feathers. So far preliminary it looks like the alligators are not the culprit that we first thought. There's more going on out there in the marsh than we know about," biologist Amos Cooper said.
These marsh neighbors' lives seem to be parallel. Both rely on healthy wetlands.
More work needs to be done before scientists figure out what's happening to the mottled duck. Regardless, biologists say alligators have a role to play.
"The alligator is very important in our marshes. It is the keystone species, top carnivore, and it's very important for our ecosystem out there that we have those alligators out there in the wild," Cooper said.
Biologists exploring how two species coexist