Solar-powered: Scarecrow boat chases birds from ponds

When Randy Price first came to LSU a couple of years ago, he and colleagues started looking at all the agriculture-related problems in the state and seeing what was feasible to tackle. Many aquaculture professors encouraged the group of agriculture engineers to look at bird deterrents on ponds. Why was this an important area of study? Because on a regular-sized aquaculture facility, over $20,000 is often spent annually to protect fish from birds.

“We were certainly interested in working in the area, but didn't have a real focus on what to do,” says Price, assistant professor in LSU's Biological and Agricultural Engineering Department.

Then last December, a group of 30 to 40 pelicans settled on a 10-acre aquaculture pond at an LSU research station. After staying three or four weeks, the birds had emptied the pond of about $16,000 worth of fish.

One of the problems with the pelican situation was the pond was very big and the usual deterrents didn't work. Pyrotechnic rifles and noisemakers didn't work because by the time the rifle reached one end of the pond, the birds had moved to the other. And if the devices were employed, the pelicans were back a half hour later. The birds just couldn't be managed, says Price.

Enter the scarecrow boat.

“The boat was our idea. All we were asked was to develop something to help. When we came up with the boat we wanted something relatively easy that we could get out within a year. We also wanted something a farmer could throw out onto his pond that would stay there, functioning, until it he came to collect it three months later,” says Price.

The team was first going to develop an airplane that could fly over an entire farm to scare off birds. Price says the team is still working on that and believes it has “come up with a way to get that built.”

But the airplane is an in-depth, long-term project. Something less complex that could be out on the pond quickly was needed.

“So we decided to build a boat. We wanted a solar-powered boat that could be left on a pond all day scaring birds. At first we were going to put GPS on it and make it stay within certain boundaries. We may still do that. But as we got into the project, we knew we had to have collision-avoidance sensors. It turned out that shore feelers (employed much like curb feelers on older cars) work very well. We put them at the four corners of the boat. The sensors make the boat react like some remote controlled cars — it'll bump into the shore, turn around and go another direction.”

The boat also contains a cheap machine vision system often used in children's toys. The system actually detects and sees the color of a bird. When it sees a bird, the boat will turn and head towards it. This chasing system harasses the bird into leaving.

“Right now, we're just concerned with harassing pelicans, so the sensor is only set to white. But we're looking at future versions being able to notice multiple colors.”

How does the vision system work? When you look at a pond's surface through a camera, it's rather uniform and flat. The sensor sees the same thing. What the vision system is looking for is a blob of something different.

The vision system is also hooked up to a small squirt cannon. The cannon will shoot water at birds up to 20 or 30 feet away. The water is sucked from the pond and is an environmentally friendly way to push the bird away, says Price.

“The boat we built is moved by a paddlewheel and is about 3 feet by 3 feet and about 40 or 50 pounds. It's made out of Styrofoam. Right now, the research model is sheathed in aluminum. But for a production model, we'll probably just go with Styrofoam. The boat is pretty small, but this was research and we just picked a reasonable size for holding all the equipment we put on.”

Early on, Price found that the boat needed to sit pretty deep into the water. “You're dealing not only with the wind hitting what's exposed, but you're also dealing with the waves and whatever is happening beneath the water. So part of the engineering of this was in trying to cover the pond in a certain amount of time regardless of wind and waves. If wind kicks up and the boat is unable to leave one side of the pond all day, it's useless.”

Price's team came up with ways for the boat to carry on despite wind. Part of that solution was to make sure a minimal amount of the boat is protruding above the water surface.

How have the birds reacted to the boat?

“We don't know how the pelicans will react yet. We got the boat done this summer but the pelicans — which are migratory — aren't likely to arrive on the research ponds until December. We have tested the boat on geese and herons. It's worked very well on those. Those birds were so scared of the boat that they tended to simply abandon the pond. One future test will be in checking if many of these boats across an operation can totally push the birds away.”

Price says one problem over time is the birds, as they grow hungrier, will grow braver. For that reason, he needs to continue developing new features so the birds don't get too comfortable around the boats. “We're coming up with ideas with everything from flashing lights to noisemakers.”

One suggestion Price has gotten involves alligators. He's gearing up to give it a shot.

“The birds, we're told, are very frightened of alligators. We're going to dress one of the boats up to resemble a gator — or at least give a gator outline from the air. That should spook them.”

Already, Price has had several people interested in buying a manufactured version of the boat. Some people also want a larger version for municipal water reservoirs.

“We're still ironing out the kinks, so I don't know where that's going exactly. But hopefully this boat will be cost-effective and easy to operate, and if farmers want one they'll be able to get one.”

e-mail: [email protected]

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