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Combatting Blackbirds

Tuesday, August 28, 2018
filed under: Birds

Year after year, North Dakota is a top producer of sunflower. The state is also the number-one state for cattail sloughs, which means it contains a large number of roost location acres for migrating blackbirds.
       “North Dakota is the heart of prairie pothole country,” says John Paulson, state director and certified wildlife biologist with the U.S. Department of Agriculture’s Wildlife Services program in Bismarck. “We have more cattail sloughs throughout the central part of North Dakota than any other state in the nation. That’s where blackbirds roost, which means we have more blackbirds, and more blackbird damage to agricultural crops, than other states.”
       Blackbirds are migratory birds — they spend their summers in the north and winters in south.  Paulson explains as they prepare to migrate in early fall, they need to store lots of energy.
       “It’s a long flight for small birds,” he continues.  “The high oil, high protein they get from sunflower seeds is ideal preflight nourishment for them.  The birds migrate in big flocks, and those big flocks cause the most problems for sunflower producers.  Some producers get hit hard every year, and the frustrating thing is that blackbirds are persistent and difficult to move.”

Temporary Personnel Increases
       This year, thanks to some additional funding from Congress, farmers in North Dakota will have some extra help battling blackbirds and preventing damage to their sunflower fields.  The assistance will come in the form of personnel to assist producers, as well as additional equipment.
       “We currently have five full-time wildlife specialists who work blackbirds every fall, and we’re going to add four additional seasonal personnel,” Paulson says. “In addition to that, we have nine full-time wildlife damage specialists who primarily deal with predator damage and beaver damage, but assist with many aspects of wildlife damage management, and they will also assist with blackbird work as needed.”
       The specialists will be spread throughout the state, but additional staff will be sent to southwestern North Dakota.  Paulson says there are more sunflower acres in that region than there were 15 years ago, so that’s where it’s anticipated the blackbirds will be as well.  He explains that some seasonal workers will be what he calls “floaters” — meaning they’ll float to where they’re needed, providing additional boots-on-the-ground to get to the complaints more quickly.
       “Nine people sounds like a lot to work on the blackbird issue, but it really isn’t,” Paulson observes.  “When you look at how big the state is and when producers call us, they need help immediately.  These additional staff will help us get to the producers in a timely manner so we can alleviate or stop the damage from progressing any further.”

John Paulson, North Dakota state director with USDA-Wildlife Serices, is shown mounting a propane cannon atop a cannon plate.

New & Improved Equipment
       In addition to personnel, the extra funding also helped purchase new equipment to fight blackbirds — equipment such as propane cannons and cannon plates.  At $500 each, Paulson says propane cannons are an expensive but effective tool to fight blackbirds.
       “Like any other piece of equipment, they don’t last forever, and some of our cannons are 20 to 30 years old.  We have been buying parts to keep them going on a limited budget, but it is time to purchase some new and repair our existing inventory.  Farmers need these propane cannons working in the fields when people can’t be. “The propane cannons can take the place of a shooter or someone out there with pyrotechnics. We know farmers can’t be guarding their sunflower fields from sunup to sundown.”
       Paulson says they’ve also been researching how to make the propane cannons even more effective and to keep rodents from damaging them. He says the answer may lie in a newly designed cannon plate.
       “One of our WS employees designed it.  It’s a piece of pipe welded to a plate that holds the cannon secure.  A T-post is pounded into the ground which the device slides over the top.  We hope that elevating the cannons will solve several problems,” says Paulson. “Elevating the cannon limits access and damage by field rodents and allows for improved sound resonance above the sunflower canopy.  And, the spinning action of the plate allows for the direction of the noise to change. We have done some field testing and have seen positive results thus far. We will do more testing in sunflower fields this fall.”
       Paulson says they’ve built 300 of the cannon plates and will build more.  He wants each producer who calls his office to receive one for each propane cannon loaned.
       “We don’t have the budget to build thousands of these, but if we give each producer one they can use it as a pattern to build their own; or, there is a welding shop in Bismarck that will make them for producers for about $30 each. We think it will make the propane cannons more effective than they’ve been in the past,” according to Paulson.
       Paulson adds that his department will also purchase more pyrotechnics — specifically “screamers,” as he says they have proven to be the most effective when it comes to harassing blackbirds. Wildlife Services also will purchase some drones, and with four staff members trained on how to use them to harass blackbirds, Paulson is cautiously optimistic that drones could provide even more relief to producers.
       “We don’t want to spend a lot of money on drones until we test they’re effectiveness operationally,” he says. “We are all about using an integrated approach. We don’t have one single answer for producers, but we have several different tools to combat the issue together.  The solution is not just pyrotechnics, not just cannons, and not just drones.  We need to use all the tools in our tool bag.”

Continued Research

Randy Smith, a Wildlife Services district supervisor in Texas and also a USDA UAS (Unmanned Aricraft System) instruction, advises research wildlife biologist researcher Page Klug on a drone's operation.

       Dr. Page Klug, a research wildlife biologist at the USDA-APHIS/Wildlife Services, National Wildlife Research Center’s North Dakota Field Station, has been researching the effectiveness of drones.  Her team continues to explore the best way to use this technology to scare off blackbirds.
       “We did both a captive study and field study with red-winged blackbirds, using fixed-wing raptor-shaped and quadcopter aircraft,” explains Klug.  “The quadcopter doesn’t look like a native predator, so we wanted to evaluate if one shape might be better.  We discovered that the birds alerted the fastest to the raptor and next to the fixed-wing plane, and that the birds took flight in response to the raptor and fixed-wing — but not the quadcopter.”
       Klug says based on the captive study, it seems the best bet is to use an unmanned aerial system (UAS) that looks something like a predator.  She says initial studies also found that when a drone looked more like a raptor, it cut down on the amount of eating the birds did. “The idea is that the birds become more concerned with watching for the raptor and they don’t eat as much,” she says.
       But how does that translate to the field?
       “As far as the field study, the flocks responded to all three aircraft,” Klug reports. “But getting the birds to leave sunflower fields was difficult with the short duration of hazing we attempted. The smaller the flock and smaller the field, the easier it was to get the birds to leave.”
       Klug says future research will evaluate using drones to apply an avian repellent such as methyl anthranilate directly on a flock or to herd flocks away from sunflower fields rather than trying to scare them.  She says future work will not only evaluate how to encourage birds to leave the sunflower fields, but also harass birds in their roosting habitat to encourage smaller roosting flocks.  After multiple days of extended hazing, she says the larger flocks may disperse across the landscape and become more manageable.
       Klug’s team is also working in collaboration with a student from the College of William and Mary in Virginia in looking at reducing cattail habitat to decrease flock size.  She says there is work being done with “sonic nets,” which are solar-powered speakers that project sound at the same frequency the birds communicate. The idea is if they can’t communicate with each other they would find the habitat risky — which may then reduce large roosting flocks in the cattail sloughs.
       “We think if we mask their communication, they will find the habitat scary and risky and find another place to roost.  This approach focuses on reducing the roost site habitat and may result in smaller, more manageable flocks” Klug observes.
       Klug also has a student working on a blackbird repellent.  It is a project that has been in the works for several years. She says current research is focused on optimizing the formula and creating a foliar application specific to sunflower.
       “The challenge will be getting it on the sunflower and having the birds consume enough to have an effect.  They have to ingest a certain amount before it will have negative response.  And then there is the question of how we apply the repellent to the crop. We have done some work on plots at the NDSU Carrington Research Extension Center and have used drop-nozzle technology, but we need to do more studies with different formulations to optimize the amount of repellent on the sunflower face.
       “The repellent is an attractive idea for producers because it’s something they’re familiar with — they’re used to applying something to their crops.  It’s just now a matter of translating our work in the lab to the field.  There are a lot of challenges.”
       Like Paulson, Klug says the secret to managing blackbirds comes down to an integrated approach. — Jody Kerzman