Texas Parks & Wildlife Magazine   


Seeds of a Solution

Help prevent the spread of dangerous avian flu by taking a little care with bird feeders.

By Stephen Saito

While there is no cure for aflatoxin, a disease that attacks the immune systems of birds, restocking bird feeders on a more frequent basis may help slow down this deadly problem. Commonly referred to as the bird flu, aflatoxin is caused by a mold that is found primarily in corn and peanuts, ingredients common in most bird feed. The disease can cause cancer, birth defects and immune- system damage in birds.

Scott Henke and other researchers at the Caesar Kleberg Wildlife Research Institute at Texas A&M University-Kingsville have been studying how aflatoxin is produced. They are also finding ways to prevent the disease from spreading.

“There are so many things that can affect the aflatoxin production,” says Henke. “There’s only about three or four big seed companies in the U.S., and they’re basically buying all their grain from the same areas. There’s no real way to tell how old the grain is when they purchase it or bag it.”

Grain with high moisture content can produce the mold that causes aflatoxin. Henke has also found that aflatoxin can develop in storage just as easily as it can in the fields.

State regulations require a limit of 50 parts per billion of aflatoxin in wildlife feed, but the biologists at Texas A & M-Kingsville believe the number should be closer to 20 parts per billion, the limit currently acceptable for human consumption. Henke and his team of researchers came to this conclusion in 1999, when they embarked on a trip across Texas, purchasing bird seed off the shelf at feed stores and supermarkets.

“We had nearly 20 percent of the bags release 100 parts per billion or greater,” says Henke. Henke studied the effects of contaminated feed on bobwhite quail and cardinals. “We gave doses to the quail of 100, 500, 1,000 and 2,000 parts per billion,” Henke says, “and they didn’t necessarily die from the aflatoxin outright, but their immune systems were compromised. For the cardinals, 500 parts per billion killed them outright within about a day or two.”

To prevent the spread of the disease, Henke advises people to clean out their bird feeders frequently, dry them out completely and fill their feeders with only three days worth of food at most. Another solution may be to freeze seed until it’s ready to use, taking care to avoid condensation, which could breed mold.

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    Texas Parks & Wildlife Magazine 
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