Do bird scare devices work? What the research says

Why do birds stop reacting to scare devices?

The USDA Wildlife Services guide to bird dispersal sets two conditions for any frightening device. The bird has to be able to perceive it, and the bird has to read it as a threat to its safety. A device that meets both on day one can still fail later, because birds habituate: the guide defines that as a response that fades with repeated exposure until the animal no longer reacts at all.

The same guide explains the early success people report. Birds show a neophobic response, a wariness of anything new, to flashing pie pans, foil, ribbon and other objects that blow in the breeze. Once nothing bad follows, the object becomes part of the scenery. Its summary is blunt: no single technique will deter birds in every situation, and there is no silver bullet.

Do plastic owls and hawk decoys keep birds away?

Rarely for long. The USDA guide says simulated predators such as plastic owls and hawks are often used unsuccessfully to keep birds from roosting or nesting, and that birds quickly learn an effigy left in one place is not a threat. The ICWDM says owl models, rubber snakes, balloons, revolving lights and flags have little or no effect on pigeons. Montana FWP's pigeon page agrees that decoy owls, rubber snakes and balloons work only for a short period.

There are narrow exceptions. FWP notes that a plastic owl or a falcon silhouette has had some success scaring woodpeckers, though the ICWDM rates stationary hawk, owl, snake and cat silhouettes as usually ineffective for the same birds. The USDA guide adds that effigies do better when they move and when they are relocated regularly as part of a wider program. An owl bolted to a ridge cap all summer is neither.

Does reflective tape scare birds?

It depends heavily on the species and on what the birds are doing there. The USDA guide reports that Mylar ribbon or tape has deterred blackbirds, gulls, house sparrows and Canada geese from crops and loafing areas, while American robins, house finches, goldfinches and mourning doves ignored it. That matters in a Bitterroot orchard or berry patch, where robins and finches are often the birds on the fruit. Gulls avoided tape on loafing areas and ignored it inside established nesting colonies.

On buildings, the best evidence is for woodpeckers. The ICWDM reports that one brand of reflective tape eliminated woodpecker damage at 50 percent of homes tested in the northeastern United States, and it considers devices that combine a visual signal with motion more effective than stationary ones. Half is a real result and also a coin flip, which is why FWP pairs tape with other measures for flickers on cedar siding. Our guide to northern flicker and woodpecker damage covers that case.

Do predator-eye balloons and hawk kites work?

The record is mixed and short lived. The ICWDM says large balloons painted with owl-like eyes have not been effective against woodpeckers in trials. FWP lists big-eye balloons and hawk kites among the frightening devices that can be tried for magpies and starlings in gardens and fruit trees, alongside its advice to use a variety of techniques.

The USDA guide says kites and balloon and kite combinations shaped like predators have been reported to deter birds from some areas, and that they are an option where noise is restricted. It lists the costs in the same sentence: they are labor intensive, limited by weather, and their area of influence shrinks as birds habituate unless other techniques are used with them.

Do ultrasonic and sonic devices work on birds?

Ultrasonic devices do not. The USDA guide states that birds generally hear a narrower range of frequencies than people do, that the range does not include ultrasound, and that ultrasonic devices therefore will not scare birds. The ICWDM says the same of pigeons, and notes for woodpeckers that high-frequency devices rarely are effective as advertised.

Audible sound is a different question. Recorded alarm and distress calls can disperse birds when used at the right time and place, but the USDA guide says they tend to be species specific, that many birds first fly toward the call to see what the danger is, and that birds habituate to repeated calls when no threat follows. Generic noises lose their effect quickly too. Propane cannons work in some situations, with habituation common when they fire on a timer. In town, the neighbors usually give up before the birds do.

Do lasers work on birds?

For some species, mainly in low light. The USDA guide reports that red and green lasers have been effective at scaring some birds, with red working best in the dark and green in dark and low-light conditions. It notes that the reaction of Canada geese and American crows can drop off under brighter ambient light or where the birds have no other roost to move to.

That makes a laser a tool for dispersing a night roost, operated by a person, and not a fix for pigeons loafing on a parapet at noon. The guide also warns that lasers must be used with caution because of their range and their potential to affect human vision, and that beams must be kept away from aircraft.

Do bird gels and chemical repellents work?

Sticky polybutene gels do repel birds from a treated ledge for a while. The ICWDM says an application may stay effective for six months to two years and is lost faster in dusty areas, and that heat can make the material run while cold can stiffen it. The USDA guide advises caution with gels for the same reasons. The ICWDM's woodpecker page adds the point that matters most for a humane job: small birds may become entrapped by the gel even when it is applied as the label directs.

Other repellents fare worse. The USDA guide reports that when naphthalene, the active ingredient in mothballs, was tested, birds and starlings in particular were not discouraged from treated sites. FWP says chemical or odor repellents have generally proven ineffective for woodpeckers and that no effective chemical repellent is available for magpies, and the U.S. Fish and Wildlife Service says repellents are not effective for swallows. We do not recommend sticky gels, for the entrapment reason above.

When is a scare device worth trying?

When the problem is new, seasonal, or about food. FWP's advice for woodpeckers is the best short version: act promptly, because a bird that has used a site briefly is easier to move than one that has used it for days; use a variety of tactics; and persist every day until it works. FWP says scare tactics are generally effective for only a few days before birds realize they are not a threat. A few days can be enough to protect ripening cherries or interrupt a flicker that has just started on a wall.

There is a legal limit as well. The Fish and Wildlife Service says no federal permit is needed simply to harass or scare birds, with the exception of eagles and federally listed threatened or endangered species. FWP adds that once woodpeckers have eggs or young, it is illegal to scare the adults away from the nest. Scaring is for before nesting, not during it. Our nesting season calendar shows when that window closes.

What works when scaring does not?

Taking the place away. The USDA guide concludes that reducing a site's attractiveness by removing food, water or shelter both reduces conflicts and makes dispersal tools work better. For birds roosting or nesting on a structure, FWP calls blocking access the most cost-effective method in the long run. A bird cannot habituate to a net, a screened vent or a ledge too steep to stand on.

That is the logic behind our bird mitigation work, and our list of the best humane ways to deter birds ranks the physical methods. If you are deciding how much to attempt yourself, see DIY bird control versus hiring a professional. The rest of the series is in the Montana Bird Control Guide.

Call HJ Property Care & Tree Service at (406) 215-7319 or request a bird assessment and we will identify the species, the access points, and what will actually stop them.

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