The Wisconsin Department of Agriculture, Trade and Consumer Protection (WDATCP) is moving forward with a new, non-lethal pesticide. Avipel will be applied to corn seed in Wisconsin to discourage sandhill cranes (Antigone canadensis) from consuming and destroying crops.
The news raised concerns for crane advocates who are worried about negative impacts the program may have on the once threatened species.
The 21st century has been kinder to the sandhill crane than the early 1900s. Back then, and throughout the 20th century, the bird was nearly driven to extinction due to habitat destruction and hunting. “We say they are a conservation success story,” Anne Lacy, a biologist with the International Crane Foundation, told Wisconsin Examiner. Preservation efforts were so successful, in fact, that Lacey says, “there’s now more than a few people who consider them as pests.”
Sandhill cranes come in conflict with farmers because of their preferred habitats. The long-legged, ground-roosting birds are never found too far from standing water like ponds. Fertile, open fields stuffed with plants and small prey animals are also necessary for the birds to thrive. Walking up from wading in a nearby pond, a sandhill crane will forage in these areas, which often happen to be planted with crops.
“The greatest amount of damage is to planted corn,” explains Lacy. “They will pull out the germinating seed, the little green sprout. They don’t eat the green part, and use that as a marker for where the seed is.” Gently stepping across the field, glancing up and around as it goes, a single crane can damage numerous individual crops.
The crane foundation has been working with farmers and the University of Wisconsin agricultural extension as well as the company that makes the product, called Avipel, to find a way to use seed treatment as a deterrent for cranes. Oftentimes, noise-makers are deployed in the hopes of scaring away problem birds. However, the notably territorial crane species tends to linger long enough to learn that the noises pose no real danger. “We needed to figure out, working with the bird’s ecology, what would be an effective means of deterrence,” says Lacy.
The chemical that Avipel is derived from, 9, 10-antraquinone, is designed to discourage birds from taking fruit. “It’s kind of a bittering agent,” explains Lacy, “it’s a powder or liquid that farmers can apply to seed before it’s put in the ground.” The bad taste convinces the cranes to leave corn seed alone, while not pushing them out of their habitat. “It leaves the crane there, and they’re not doing damage,” says Lacy.
Lacy, who interned with the ICF on seed treatment options for cranes, says the chemical is generally non-toxic. Even if the birds experience an upset stomach, the method means that the crane only consumes treated seed a couple of times before giving up on the crop. Although more study is necessary, researchers say there should be no effects on the avian’s breeding cycles or young.
Avipel has been used in the United Kingdom and other countries, but it has not been registered by the U.S. Environmental Protection Agency. U.S. law states that this can occur when a product won’t be widely used, or is for very specific local needs.
Nevertheless, Avipel contains a warning not to “discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans or other waters unless in accordance with the requirements of a National Pollutant Discharge Elimination System (NPDES).