Jan. 23, 2006

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AMARILLO – Thousands of starlings perched on a high wire may be an impressive sight for some, but for livestock operation owners, they are a picture of money flying off the property.

Birds and rodents both cost feed yards, dairies and grain elevators thousands of dollars every day, said Joe Zotter, biologist for the Texas Wildlife Services.

Controlling these pests can minimize not only the amount of grain lost, but also the health risk to humans and animals from bacterial and fungal diseases spread by rodent and bird droppings, Zotter said during the Texas High Plains Grain Elevator Workshop here.

Texas Wildlife Services professionals resolve conflicts resulting from wildlife, Zotter said. The agency is funded by the U.S. Department of Agriculture and the Texas A&M University System.

"The European starling is nothing more than a rat with wings," Zotter said. "Thousands can accumulate on a single feedlot or dairy. We helped one feed yard that had an estimated 1 million birds every day from November to February."

If each bird consumes 2 to 3 ounces of grain per day, that means two semi-truckloads of grain are flying off daily, he said. And, because the birds only select certain grains from the rations being fed to the animals, it throws the whole nutritional balance off, Zotter said.

"It has been reported by some confined animal facilities to have endured economic losses as high as $5,000 per day due to feed loss and disease in livestock caused by starlings and blackbirds," he said.

Droppings from multitudes of birds, whether they are starlings, pigeons or sparrows, can cause disease, he said.

Avicides, pesticides for birds, are one method of control, Zotter said. DRC 1339 has been the most effective product he has used. The government-restricted powder can be used on corn to bait areas where birds habitually feed. The avicide may take one to three days to effect the birds, he said.

"It is an attractive avicide because there is no secondary poisoning to other animals that come in contact with the poisoned birds," he said.

Pigeon numbers may not be as concentrated as starlings, but they can carry serious pathogens that can cause bacterial and fungal diseases. These can be transmitted to workers who walk through or come in contact with the droppings.

Histoplasmosis, which has pneumonia-type symptoms, can lead to serious problems in humans if not properly diagnosed, Zotter said. Other zoonotic diseases transmitted by pigeons include encephalitis, cryptococcosis and salmonella, he said.

Feral pigeons, European starlings and house sparrows rely on human's habits to live, he said. Grain storage facilities or anything in ill repair can serve as a nesting or resting area.

Eliminating and modifying their preferred perches can be done by adding cat-claw wire on the surface or using a slick material such as metal flashing or plastic at a 45 degree angle, Zotter said.

Pigeons, which often avoid laced bait, might need to be controlled with direct shooting, he said. The wildlife services can utilize red lights, night vision equipment, hollow point ammunition and pellets to help provide control, Zotter said.

"We're not out to destroy anything other than pigeons when we do the indoor shoots," he said. "It's a selective method of shooting birds and can be a good alternative to using toxicants where there is a concern for non-target exposure. It's easy, effective and quick.

"Sometimes shooting is the only solution," Zotter said.

Rodents also cause destruction. Rats and mice can chew holes in grain sacks and gnaw on everything from pipe insulation to electric wires. They also spread disease, he said.

Mouse and rat droppings carry a number of pathogens and parasites, as well as viruses. Anyone who walks through a contaminated area may be exposed, Zotter said.

Traps and toxicants are available to help control this kind of pest. Exclusionary methods, such as keeping plastic pipe on wires, screening off vents and placing a slick surface where rodents climb can be effective in controlling their movement, he said. Traps must be set strategically up against a wall or in confined areas to be most effective.

Whether the pest is the rat on the ground or what Zotter calls "flying rats," he advised to use a mixed bag of methods for control and not rely on just one.