Bird Gard has been building bioacoustic bird deterrents in Sisters, Oregon for over 35 years. This page explains what the technology actually does, what the published research supports, and — because it matters more than the marketing — where the honest limits are.
The principle: information, not noise
A bioacoustic deterrent broadcasts sounds birds already understand: the distress calls of their own species, the alarm calls of their flock, and the calls of predators that hunt them. It does not injure birds, and it is not ultrasonic.
That last distinction is physiology rather than positioning. USDA-APHIS Wildlife Services places most bird hearing in the 1,000 to 3,000 Hz range and states the conclusion directly: because that range does not include ultrasonic frequencies, ultrasonic devices will not scare birds (Seamans & Gosser, 2016, “Bird Dispersal Techniques,” USDA-APHIS Wildlife Damage Management Technical Series). Bioacoustics operates in the audible range because that is where a bird’s own alarm vocabulary lives.
The objective is not to clear the sky. It is to make a block read, to a bird, as a worse place to feed than the field next door — and so to reduce the damage done to the crop.
What the published research shows
In nine commercial Pinot noir vineyards in California’s Carneros AVA studied over two seasons, blocks using conventional methods alone showed 13.0% damage. Blocks that added broadcast alarm and distress calls showed 5.7%. Netting, the benchmark, showed 2.3%. Units were deployed at roughly one per 0.6 hectares along vineyard perimeters and relocated weekly (Berge et al., 2007, American Journal of Enology and Viticulture 58(1): 135–143).
A 2024 peer-reviewed pear-orchard study reported a 44–54% reduction, but it tested a combined ultrasonic-and-acoustic emitter without separating the two, so that figure cannot be credited to bioacoustics alone. We cite it for the finding it does establish cleanly: intermittent playback outperformed constant playback (Chen et al., 2024, Frontiers in Plant Science 15: 1365275).
The problem those numbers apply to is substantial. A USDA-authored, peer-reviewed survey of 1,590 fruit growers across California, Michigan, New York, Oregon and Washington estimated aggregate bird damage across five crops in those states at $189 million per year, with damage ranging from $104 per hectare in Oregon tart cherries to $7,267 per hectare in Washington Honeycrisp apples. New York sweet cherry growers reported average yield loss of 31.4% (Anderson et al., 2013, “Bird damage to select fruit crops,” Crop Protection 52: 103–109).
The honest limitation: habituation
Any grower who has run a sound system for a full season knows what comes next, so we won’t pretend otherwise. Birds habituate. If the sound is predictable, birds learn that nothing bad follows it and stop reacting.
University of Minnesota Extension rates bird distress calls as moderately to highly effective, but less consistently reliable than netting, and reports that birds typically acclimate within two to six weeks (Klodd, Loegering & Clark, 2021, University of Minnesota Extension).
A California Department of Food and Agriculture field project on crows in almonds saw both outcomes in the same study. In Fresno County, crows and ravens largely abandoned the study orchards from mid-July through August with damage held to $4.40 per acre. In one Yuba County block, habituation caused crow numbers and damage to increase by late August, with losses reaching $70.06 per acre (CDFA Vertebrate Pest Control Research Advisory Committee, 1999 field trials).
If a bird control company tells you habituation isn’t real, they are either not paying attention or not being straight with you.
The innovation: engineering against predictability
Here is the insight the research points at. Habituation is not an inherent property of bioacoustics — it is a failure mode of predictability. A system that plays the same call, from the same place, at the same interval teaches birds a pattern. A system engineered to be unpredictable gives them no pattern to learn.
The evidence is suggestive on this point. The field trials above ran on fixed-playback equipment of their era; the 1999 almond project report contains no discussion of rotating or randomizing calls. The Carneros trial did relocate units weekly — and produced the strongest acoustic result of the group.
A 2024 field study in a Nanjing pear orchard points the same way: damage was 13.07% with no device, 7.29% with a continuously operating acoustic repeller, and 6.03% with one triggered intermittently. The authors concluded that birds adapt more readily to continuous sound. One caveat we’ll state rather than bury — the tested unit paired predator calls with an ultrasonic emitter and the study did not separate the two, so the reduction can’t be credited to either component alone. We cite it for the finding it establishes cleanly: intermittent playback outperformed constant playback.
IntelliGard OS
IntelliGard OS is Bird Gard’s anti-habituation operating system, standard on the Sonic Hawk 500 and Sonic Hawk 100. It automates the anti-predictability protocol rather than leaving it to the operator to remember:
- Randomized playback intervals and sequences, so there is no pattern to learn.
- Strategic time-off periods — silence is part of the signal; constant playback is what birds tune out.
- A library of 250+ species-specific bioacoustic profiles, developed in collaboration with researchers and updated free by USB.
- High-fidelity authentic recordings with matching frequencies, rather than synthetic loops.
- Selective targeting, so profiles address nuisance species while beneficial birds remain present.
We’ll say the obvious thing here: that is a description of how the system is engineered, not a published trial result. The peer-reviewed data above was gathered on earlier equipment. We think the design reasoning is sound and it matches what the research identifies as the cause of failure — but we’re not going to hand you a number we can’t source.
Owners of Super Pro USB and Super Pro AMP USB units can add the platform with the IntelliGard OS USB upgrade kit.
How the systems are built
Bird Gard products are designed and assembled in Sisters, Oregon. The Sonic Hawk 500 uses a 20-speaker omnidirectional tower covering up to 500 feet in all directions (~15 acres typical under normal field conditions) with output up to 125 dB. The Sonic Hawk 100 uses a 4-speaker box covering roughly 3 acres. Both run on 12V deep-cycle battery power with solar or AC options, load sounds by USB, and carry a 5-year parts and labor warranty. Typical service life is 10–12 years, with no annual operating costs after purchase.
Go deeper
- What is bioacoustic bird control? An evidence-based guide
- How Bird Gard systems work, step by step
- Best practices for agricultural applications
- Bird identification guide
Questions about whether this fits your operation? Call 541.549.0205 or ask a bird control advisor.