Kernels saved may benefit game birds, researcher says

Making sure that seeds are getting planted and not accidentally spilling on the ground can help farmers stretch their dollars and it can also pay dividends for game birds, according to a staff veterinarian and a researcher at the University of Minnesota.

Dana Franzen-Klein, with the University of Minnesota College of Veterinary Medicine’s Raptor Center, and her research team, studied the impact of imidacloprid, one of several widely used chemicals in the class of neonicotinoid pesticides. These insecticides protect spring-planted crops from insects that rob yields. Those insecticides can be used in different forms, from spray to granules in the soil. While they can be used in urban gardens, the most common use of the neonicotinoid class of insecticides is for corn and soybeans. The seed is coated with the pesticide and then as the plant grows the treatment is released. The ingredient is an external coating and that’s where the risk to the health of wild-grain eating birds, including grouse and pheasants, that live in the High Plains region.

To get a feel for what it could mean the researchers used domestic chickens as test birds. The team focused on the results and what might happen in a field if game birds ate treated seeds, Franzen-Klein said.

 The chickens were exposed to a known amount of imidacloprid over a seven-day period that included groups of various aged male and female chickens that range in age from 6 to 9 weeks.

Each group had different levels of exposures, including one set that did not receive any pesticide to serve as a base. The chickens weighed 1 kilogram or 2.2 pounds, were the equivalent of medium-sized grouse or pheasant found in the wild.

The chickens in the set that only received the equivalent of one treated soybean seed a day for one week did not show any problems and appeared normal. But as the amount of pesticide increased for the next four categories the birds struggled in comparison to the control birds. The birds first looked to be sleepy, at lower dosages they could shake it off. As the dosage increased it took longer for the birds to perk up. Also, as the levels increase the birds struggled to walk a sign of uncoordinated muscle movements. And some would have whole body muscle tremors.

“What we found is that they had various different types of neurological problems or impaired nervous system function and as the dose increased the severity of those neurological signs increased or got worse,” Franzen-Klein said.

In all, in the mild cases it could take approximately 30 minutes for the birds to return to normal behavior, but it could take as long as 5 1/2 hours in the severe cases. She believed that correlates to what happens to game birds in their native habitat. The longer it takes for birds to recover the more likely they will be eaten by a predator.

“Because neonicotinoids are the most widely used class of insecticides in the world, there have been some concerns about the unintended consequences of their use and associated environmental contamination,” Franzen-Klein said.

From a practical standpoint, treated seed while it was on the ground and not being used for its intended purpose of growing into a plant, is a loss for the producer and to game birds. Seed that is commonly found on the ground can occur if a planter is not calibrated right, if the planter box that holds the seed is overfilled, she said. Paying attention to correctly filling seed hoppers in planters and cleaning up treated seeds that fall on the ground makes a difference to wild bird populations, she said. Sharp corners are another place planters may accidentally spill seed that a producer may miss on first glance.

What might at first glance look like a temporary spill may result in wasted resources particularly this year when every dollar saved is crucial to the bottom line particularly in this period when the price per bushel for corn and soybeans is exceptionally low.

Being more aware of the effects that practices and choices have on native wildlife can help the producer and the wildlife, she said.

The native birds are important to the ecological balance and play an important part of eating insects and they also provide wildlife for hunters, which is an important revenue source to landowners and helps support rural economies, she said.

She also noted that North America has lost more than one in four native birds over the past 50 years, which means populations of those grain-eating birds are slowly declining and farmers can help improve the health of the birds because they oversee much of the habitat.

Franzen-Klein, who grew up in the heart of corn and soybean production areas in Iowa, says that farmers are proven environmental stewards, and she said the study can serve as a reminder that in the haste to get crops planted that even a small amount of spillage not only hits their bottom line it can have an adverse impact on game birds that share the landscape.

The findings were recently published in the Journal of Toxicology and Environmental Health.

Dave Bergmeier can be reached at 620-227-1822 or [email protected].