Blackbirds have been a serious concern for sunflower growers since the dawn of time. Recent estimates of crop damage caused by these birds are hard to come by, but in 2013, annual sunflower loss in North Dakota alone was about $3.5 million. Bird damage is greatest near roosts, and takes place roughly over about eight weeks from seed-set in mid-August to harvest in October.
While various methods have provided some degree of control over the years, recent research shines more light on how to use these methods effectively.
In a thesis submitted at North Dakota State University (NDSU) in late 2021, Master’s student Mallory Gyovai White reports on her research into sunflower farmers’ perceptions of new and current crop damage mitigation methods. Overall, farmers reported few effective control methods available to them. The most-effective tool is cattail marsh management, but it’s being used less frequently than those methods that are perceived as relatively ineffective (e.g. propane cannons).
However, cannons have become a popular method to repel blackbirds in the U.S., most likely due to their scalability and cost-effectiveness. But even though this control method is fairly common, research has been scant into how best to use it. In 2021, Dr. Page Klug at the USDA-APHIS-Wildlife Services, National Wildlife Research Center in North Dakota and undergrad (now grad student) Jessica Duttenhefner at NDSU conducted new research into the startle response of caged blackbirds and brown-headed cowbirds to canons placed at various distances.
“Based on this study, our recommendations are to place your propane cannons 300-500 meters apart and create paths to allow interior cannon placement,” says Klug. “Further research should examine whether greater distances cause a significant startle response, and a look at the impact of other factors such as cannon direction and weather.”
Jessica Duttenhefner loading birds into cage for propane cannon study.
Photo credits – Page Klug, USDA & Alli Schumacher