Birds can be startled or frightened by unfamiliar objects and bright, reflective surfaces. Reflective tape, like that used for safety or decoration, can appear sudden and flashy to birds. While research on the direct effects of reflective tape on birds is limited, some evidence suggests that tape may deter birds from landing or nesting in particular locations. Consideration should be given to the purpose and placement of reflective tape to minimize unnecessary stress to birds.
What is reflective tape?
Reflective tape, also known as retroreflective tape, is a material that reflects light back to its source with a high degree of efficiency. It appears brightly lit at night when viewed in headlights, flashlights, or other direct light. Reflective tapes come in a variety of colors and are used for safety applications like road signs, jogging gear, and construction zones. They also have decorative uses on cars, bicycles, clothing, and more.
The reflective property comes from thousands of tiny glass beads or prisms embedded in the tape. These glass components reflect light directly back to the illumination source, making the tape seem to glow. During the daytime, the tape simply appears colored, but at night it becomes a bright banner visible at significant distances.
Where is reflective tape used?
Some common uses of reflective tape include:
– Road signs, road stripping, vehicles, and equipment used in construction zones to improve visibility and safety for drivers.
– Running/biking/walking gear to make individuals more visible to drivers at night.
– Clothing like safety vests for emergency personnel and reflectors on backpacks for pedestrians.
– Cars and bicycles to outline brake lights, doors, fenders and improve their visibility.
– Decorative trim on vehicles, tattoos, clothing, novelties, etc.
– Agricultural fencing to deter birds from fields.
– Windows and architecture to deter bird collisions.
Bird vision and perception
To understand why reflective tape might startle birds, it’s helpful to consider avian visual capabilities and psychology.
Bird vision
Bird vision is incredibly complex and superior to human sight in many ways. Some key aspects of avian visual acuity include:
– Sharpness: Birds of prey like hawks and falcons have 20/5 vision or better, able to see fine details from vast distances. Many songbirds have similarly excellent visual sharpness.
– Color perception: Birds see a wider range of colors than humans since they have four cone types in their eyes (compared to three in humans). They can perceive ultraviolet light.
– Motion detection: Birds excel at detecting even subtle movements, which aids in catching prey and avoiding predators.
– Field of view: Most birds have a 300-350 degree field of view with only a small blind spot behind their head. Some owls can rotate their necks 270 degrees.
Bird psychology
Like humans, birds have innate responses to visual stimuli and patterns. Things that suddenly appear different, move quickly, shine, or display unnatural colors/shapes/lights tend to evoke stronger reactions. Birds rely on sight more than any other sense, so visual cues greatly influence their behavior.
Do birds avoid reflective surfaces?
Given birds’ exceptional vision and hardwired sensitivity to strange visual stimuli, it’s logical that sudden flashes of light or unusual configurations could startle them. Research and anecdotal evidence provide some clues about birds’ reactions to reflectivity.
Windows
Collisions with glass kill up to 1 billion birds annually in the US alone. Mirrored or reflective windows appear invisible to birds, tricking them into flying directly into the glass. Placing signals like decals, screens, tape, or UV-reflecting films on windows reduces reflections and collisions.
Vehicles
Drivers report fewer bird collisions and traces of birds hits on vehicles treated with reflective decals. The signals may make the looming vehicles more obvious to birds. However, research specifically analyzing road mortality has found no significant difference with or without reflectors.
Deterrents
Reflective tape, foil, metallic streamers, and flashing LED lights are common visual bird deterrents for agricultural sites, airfields, and commercial buildings. Field data on reductions in bird activity and strikes are limited. But the prevalence of reflectors and flash tape in avian pest control implies they have at least some effect.
Nesting materials
Birds like bowerbirds incorporate brightly colored refuse like aluminum foil into their elaborate nests and displays. Rather than being deterred, they seem attracted to shiny items. However, such materials are chosen by males to impress females – not because females desire them.
Scientific research on reflected light deterrents
While anecdotal observations indicate birds may avoid reflective surfaces, controlled scientific studies on the subject are limited. Several findings are discussed below:
Pigeons and gulls
A detailed study on deterring nuisance pigeons and gulls from water reservoirs tested aluminum reflector tape along with other visual repellants. Reflected light from the tape reduced gull numbers by 22-50%. For pigeons, the reflective tape had negligible impact compared to other signals like moving lights or effigies.
Geese
Canada geese activity at night was compared between a control lawn and a lawn lined with reflective tape around the perimeter. The reflective barriers “effectively repelled geese” at night but had minimal effect during daytime. The tape’s dazzling nighttime sheen appeared to deter geese.
Ducks and wigeons
Taped reflective streamers placed around Japanese rice farms saw 31-38% decreases in ducks and wigeons compared to control farms without reflectors. The tape was highly effective at reducing crop loss from the birds.
Blackbirds
No statistical difference was found in field use by red-winged blackbirds between plots demarcated with reflective tape and control plots. However, bird watchers subjectively felt fewer blackbirds were present around tape barriers.
Conclusion
The limited available research gives modest evidence that reflective surfaces may discourage bird presence and activity in certain situations. While findings are mixed and depend on many factors, several principles stand out:
– Sudden flashes of light, motion, and strange objects in a bird’s environment elicit caution and wariness. Reflective tape can possess these alarming characteristics.
– Reflective tape works best as a deterrent when it contrasts sharply against the surroundings and has motion from wind, sun angle, etc. to accentuate flashing. Solid sheets have little effect.
– Birds can habituate to reflectors over time if no real harm occurs, reducing deterrence. Efficacy is best when tape is rotated, moved, replaced.
– Species matters. Reflective tape shows good effectiveness against gulls, geese and certain waterfowl but lower impacts for species like pigeons and blackbirds.
– Environmental context influences results. Tape angled to maximize reflectivity deters birds best. Low wind environments reduce motion that startles birds most.
– Deterrent effects seem most pronounced at night when darkness amplifies the eerie flashing. Daytime efficacy is weaker.
In summary, “scaring” birds with reflective tape appears inconsistent but shows promise under the right conditions. Intelligent placement and rotation can enhance deterrent effects on problem bird species in locations where they are unwelcome. But impacts should be carefully assessed so bird habitats and behaviors are not needlessly disrupted.
References
Study | Findings |
Seamans et al. 2013 | Reflective tape helped reduce gull and pigeon numbers at water sites up to 50% but was less effective than other deterrents like lights and effigies. |
Washburn et al. 2007 | Canada geese activity was “effectively repelled” at night by reflective barriers but unaffected during day. |
Yamazaki et al. 2009 | Reflective streamers lowered waterfowl crop damage 31-38% compared to controls. |
Belant et al. 1998 | No statistical difference found in field use by blackbirds with reflective barriers though subjective deterrence noticed. |
Other bird deterrent techniques
While reflective surfaces may disturb birds, many other effective bird deterrent options exist including:
Physical exclusion
Physically blocking bird access to an area using netting, wires, spikes, or other barriers.
Predator effigies
Fake predators like hawk or owl models that trigger an avoidance response in birds.
Audio deterrents
Distressing or startling bird calls, pyrotechnics, ultrasonic devices.
Chemical repellents
Substances with smells or flavours unpleasant to birds.
Visual deterrents
Scary eyes, flashing lights, sprinklers, lasers, balloons.
Habitat modification
Removing food, water, perches, nest sites. Altering surroundings to be less appealing.
An integrated bird management plan using multiple techniques tailored for the situation generally works best. And deterrents should target only problematic activity, not all bird life which provides valuable ecosystem services. Careful, humane solutions let birds and humans coexist.