Birds are a challenge across the farm but can be particularly damaging for sweet corn growers. (Though they’re not all bad! Some species may actually help with controlling other farm pests.) To successfully control birds, it is best to take action in advance of the problem, because once birds get in the habit of feeding on your corn, it will be harder to stop them. Redwing blackbirds and other flocking birds can cause serious crop losses in some fields. Unfortunately, there is no easy answer and no guarantee that a particular tactic will work.
Redwing blackbirds were found to be the most abundant birds in corn fields in at least one study. They nest in hayfields, marshes, and ditches and congregate at large nighttime roosts near their nesting sites. Large flocks feed in fields and bottomlands, and the worst damage to sweet corn is reported by growers near rivers and marshes. Insects are their dominant food in the nesting season (May through July), then the diet shifts to grain and weed seeds in late summer. This, along with the expanding acreage of ripening sweet corn in mid-July, may explain the ‘sudden’ appearance of flocks in sweet corn at this time. Grains that are affected by redwing blackbirds include sweet corn, ripening grain corn, sunflower, sorghum, and oats. Other birds that might be pests of corn are starlings, crows, or turkeys.
General Tips on Repelling Birds
Time any control techniques so they are in place BEFORE harvest and remain in place until harvest is complete. Birds invade sweet corn fields about three days before picking.
Use multiple tactics that reach more than one sensory mode. For example, combine scare-eye balloons with auditory repellents like shellcrackers or distress calls. This is likely to be more effective than using one tactic alone.
Move devices frequently. Birds can learn and become habituated to any device that is used for a long time in one place.
Leave old corn for birds to eat. After harvest, scare devices can be removed from one block and concentrated in the next block. Try to keep the birds foraging in the old block while delaying their move to the one that’s ready for harvest. Some growers allow birds to scavenge in the old block before disking it in. A method that some growers say works is to rotary mow or disc the interior blocks of the previously harvested fields. Birds like to feed on the ground because it is easier than clinging to an ear, but they prefer perches nearby for protection and rest. It also helps if you plant succession blocks at opposite sides of the field, not right next door.
Good insect control will reduce the corn’s attractiveness to birds. Birds that are attracted to ears by the presence of caterpillars will cause damage to non-infested ears in the block as well. Birds cause a lot more damage than most insects do.
Visual Devices
Scare Balloons. Eye-spot balloons and reflective mylar ribbons can be effective and fairly economical for small to medium sized fields, especially if combined with other tactics like auditory deterrents. Growers report that the following methods make balloons more effective: use at least 8 balloons per acre, place them in the field several days before harvest, and leave the previous block standing, without balloons, to allow birds to feed in the older corn.
Moving Devices, e.g., “air dancers” or the “wavy guys at used car lots”—large nylon tubes that repeatedly inflate and deflate with the help of a fan—can be very effective because they move frequently and unpredictably. Their use range is limited in that they need a power source and can draw a lot of power. Other devices such as bird kites, (e.g., Falcon Kites or Scarem) don’t require power.
Laser scarecrows emit one or more focused beams of light through motor-driven modules that move the beams randomly across a corn field. Birds have keen eyesight and color vision and can perceive light from lasers even under high ambient light conditions, and they are very sensitive to motion. They see the laser beam as a solid object and will try to avoid it. Studies have shown them to be effective, particularly if combined with other tactics, but there are some safety concerns since the beams can cause eye injury in humans (and their effects on birds’ eyes is still being studied). Their use may also be subject to regulations. See the Cornell Extension fact sheet on using Laser Scarecrows for more information.
Sonic Devices
Exploders are gas-fired cannons placed in the field that fire automated, timed discharges. Cannons are available from some agriculture supply sources. Notify your farm neighbors and the local police to let them know what you are going to do. These can be quite effective but are very loud and neighbors may complain.
Shellcrackers are 12-gauge shotgun shells in which the lead shot has been replaced with a bulldog firecracker. When fired from a shotgun, this firecracker travels 75 to 150 yards and explodes in the air with a loud report. Use a single shot, inexpensive 12-gauge shotgun as the loads are very corrosive. Firing a few rounds early and late in the day will unsettle birds. Federal permits are not required. Again, notify local police and neighbors to let them know what you are doing and be sure to check local ordinances. This method can be satisfying on a short-term basis. The disadvantage is that it requires a person to take time in the field to discharge the shellcrackers. For a more details on shellcrackers and other prevention devices, see the USDA Wildlife Services paper on The Use of Explosive materials in Wildlife Damage Management or Problem Animal Control Agents at mass.gov, or call the office in Amherst at (413) 253-2403.
Distress calls and raptor calls. Recordings of distress calls or the calls of predatory birds, which repeat at regular or random intervals and operate on battery or solar power, can be quite effective. Because flocking birds are very responsive to the signals from others in their flock, a distress call from one bird is a sign to all the others that an area is unsafe. These tools have become quite sophisticated, with programmable or random call intervals that help to overcome birds’ ability to acclimate to regular sound intervals. Make sure you are using a distress call that matches the bird species you need to scare away. See, e.g., Bird-X, Bird-B-Gone, and Bird Gard.
Frequency deterrents. Some devices impair birds’ abilities to perceive their environment. “Sonic nets”, for example, are not physical nets; they are systems that broadcast noise at the same frequencies at which birds communicate, potentially interfering with birds’ ability to warn each other about danger. One test showed that the nets deterred birds from an airfield. By reducing birds’ abilities to communicate and perceive predators, these techniques may be less susceptible to habituation than scare techniques. One producer of such devices is Sonic Nets.
Chemical Deterrents
There are several bird deterrent sprays on the market (e.g., Avex, Avian Control, Avian Migrate, Corvus, R-Avex), which contain methyl anthranilate as the active ingredient. Methyl anthranilate is allowed for use on fruits and vegetables and is also a food additive that imparts a fruity odor to products. Methyl anthranilate works by irritating nerves in birds’ bills. There is not strong evidence that methyl anthranilate deters birds in field settings, so if you use this material, follow the label as closely as possible to increase the likelihood of effectiveness. For example, efficacy may be improved if the material is applied with foggers, which produce smaller droplets, than typical sprayers. Sprays also need to be reapplied after rain. Repellents are also likely to be most effective if combined with other tactics.
Other methods
Netting is often used in berry or cherry production and is sometimes used by enterprising sweet corn growers too. This was considered the most effective bird deterrent in a survey of 1500 fruit growers (Anderson et al. 2013). Netting requires considerable effort and materials. Some farmers who have been successful using this method in corn recommend setting the nets after sidedressing and leaving extra netting for the crop to push up as it grows. You will need a sturdier netting than that used in fruit settings. At the UMass/SEMAP twilight meeting last night focused on pest control in corn, Chris Clegg from 4 Town Farm described his success at using a citrus netting machine and custom-designed nets from Smart Net Systems to completely exclude birds from his sweet corn plantings, with the added advantage that it keeps corn earworm moths out too. The system is an investment but has been worth it for this farm.
Raptors. Even better than recorded raptor calls is the real thing! There are falconer clubs in many areas. Hire a falconer to fly their bird over your field. Nothing will clear out a flock of blackbirds faster than a falcon swooping over the field! American kestrels can also be attracted to some fields with nest boxes. Several organizations provide plans online for building nest boxes, including The Raptor Trust, here. Kestrels nest in May, June and sometimes July, and they are most likely to be helpful as a bird deterrent if your crop is ripening during those months—these also work well in sweet cherry orchards. The nest boxes can also be attractive to European starlings. If a starling occupies a box, it will add grass and other materials to the box and lay 5-7 pale blue eggs. A starling nest should be removed from the box, and new wood shavings added to the box if needed. Starlings are not native to North American and are not protected by the Migratory Bird Treaty Act so no permits are needed to remove their nests. An important consideration is that kestrels eat voles and mice, so rodenticides should not be used in fields when kestrels are present.
Sweet corn topping (de-tasseling). A technique that has been studied in NY and CT is to ‘top’ the corn. Topping is the removal of the top of the corn plant from just above the silk or top of the ear, after pollen shed and pollination. The advantages may include 1) harvesting 2 to 3 days earlier than un-topped, 2) improved picking ease 3) reduced bird damage, 4) easier to monitor bird activity in the block 5) improved spray coverage and 6) reduced lodging due to wind. One significant risk is that cut stems are sharp and pointed and can cause eye injury to pickers; it’s a good idea for pickers to wear goggles in topped fields. It is important to use equipment that is designed for this purpose to ensure safety; one source for a topper unit is Hagie. As with other methods, topping should be done early, several days before harvest, so the birds are not already feeding in the block.
Hunting. A federal permit is not required to shoot or otherwise control blackbirds, cowbirds, grackles, crows, or magpies when they are found committing or are about to commit damage to or “depredation upon” agricultural crops. In Massachusetts, state permits are not needed for controlling starlings. State regulations allow hunting of crows any time of year except during the nesting season. For more details contact your MA Division of Fish and Wildlife District Office. From now through the rest of the corn harvest season, no permit should be required to hunt crows (see MA Crow Hunting Regulations). While hunting can reduce numbers over the long term, it may not be effective against flocks of invading birds. It is not illegal to display dead birds in the field, but it is not clear that this is an effective deterrent. For regulations on geese, consult the US Fish and Wildlife service at 413-253-8200.
References & Resources
- 2025-2026 New England Vegetable Management Guide. Vertebrate Pest Management. https://nevegetable.org/pest-management/vertebrate-pest-management.
- Lindell, Catherine. Bird Management in Fruit Crops - Risk Factors and Management Strategies. https://www.canr.msu.edu/fruit_management_guide/uploads/files/Bird_Management.pdf.
- Cornell Cooperative Extension. Bird Damage: Management Options in Sweet Corn Production. https://rvpadmin.cce.cornell.edu/uploads/doc_691.pdf.
- Cornell Cooperative Extension. Laser Scarecrows to Deter Birds in Sweet Corn and Other High-Value Agricultural Crops. https://rvpadmin.cce.cornell.edu/uploads/doc_1193.pdf.
- Anderson, A., C. Lindell, K.M. Moxcey, B. Siemer, P. Curtis, J. Carroll, C. Burrows, J. Boulanger, K. Steensma and S. A. Shwiff. 2013. Bird Damage to Select Fruit Crops: The Costs of damage and the benefits of control in Five States. Crop Protection 52:103-109. https://www.sciencedirect.com/science/article/pii/S0261219413001415
--UMass Vegetable Program; updated for 2025 by L. McKeag