Tampa and surrounding Hillsborough County, Fla., are the "migratory Mecca" forstarlings, grackles, and blackbirds. Each year, for some unknownreason, the birds are particularly fond of a half-mile stretch of dedicatedtransit lanes that run through the city's shopping district.
The beauty of the tree-lined, brick-paved street was perennially obscured duringthe birds' return. "It was a huge mess, and the filth was a healthhazard," says Terry Yeager, director of maintenance for the HillsboroughArea Regional Transit Authority.
Several years ago Yeager installed 10 electric BirdXPeller Pro units, sonicdevices that use distress calls to repel birds in trees near bus shelters. Distresscalls are effective with species that feed and migrate in flocks becauseit's the same sound the birds use to communicate alarms to each other.
"Instantly, there were no more birds," he says. "The paversare no longer chalk-white with bird waste."
Like Yeager, public works managers across North America are using everythingfrom nets to dogs to keep birds from staking out territory in the public domain.
REPEL INVADERS FROM THE NORTH
Populations of the once nearly extinct Canada goose have exploded. These giantgeese may be merely a nuisance for their droppings, aggressive behavior, andnoise, or they may represent a serious environmental threat and risk tohuman health and safety.
Heavy concentrations of goose droppings contain nitrogen that leads to excessivealgal growth and reduced water quality. If high goose numbers persistin shallow waters, their droppings may elevate bacteria levels, posing a healthrisk to humans.
Successful and cost-effective goose management combines short- and long-termapproaches to relieve immediate problems and maintain populations at or belowtarget levels. Changing tactics prevents geese from becoming conditionedto any one method.
Scare devices repel geese, but only when applied consistently as soon as thebirds arrive. Once geese become accustomed to an area, they're more difficultto haze.
Philip Whitford, a biology professor at Capital University in Columbus, Ohio, andco-developer of Bird-X's GooseBuster sonic device, has studied the behaviorand vocal communications of the Canada goose for decades. Recently, hewas asked to see how effective the unit is in solving a goose problem ata water treatment facility in Hustisford, Wis. The 8-acre facility is hometo more than 160 geese.
The device, based on digitized forms of the birds' natural calls recorded byWhitford, fires screamers or whistle bombs from a 15-mm launcher. The propellantflies erratically and emits a shrill whistle or scream.
"When the birds showed up, we set the unit for a one-minute alarm call, causingthem to become nervous," Whitford says. "Then we followedup with one or two screamer shells. Following the alarm call with thescreamer shell is, by far, the most effective combination of techniques thatI've ever seen."
According to Whitford, the facility experienced a nearly 100-percent reduction in "goosehours" per week: from more than 14,400 to less than 58. Goosehours are calculated as labor hours; for example, if an area has 10 geesestaying 10 hours/day, total goose hours are 100.
Managers can choose from a wide range of other tactics:
Feeding: Discouraging public feeding just requires signage. But while it eliminatesconcentrations looking for handouts, it has little effect on overall populationsize.
Early water freeze-up: Turning off fountains or aerators eliminates winter habitat.
Dogs: Golf courses and airports have reported success using dogs trained to chasegeese off the property, but the method is expensive because dogs require handlers.
Spray repellents: Repellents can be applied on lawns to deter geese from feeding on the grass. Repellentsmade from grape extract may repel birds from turf area, but becauseof rain and mowing, they're only effective for a short time.
Barriers: Build fencing from plastic snow fence, chain link, woven wire, string, mylartape, or chicken wire. Boulders 2 feet wide or larger placed along a shorelineblock access to grazing sites. A combination of a rock barrier and densevegetation placed above the boulders enhances overall effectiveness.
"When geese leave and enter a water body, they generally use routes thatallow them easy access, as well as a clear view of potential danger," saysKeith Gray, director and president of Integrated Lake Management. "Turfgrass that leads directly to the water's edge provides an easyin and out."
Likewise, unmown shoreline buffers of tall grasses discourage geese from visiting. Allowingvegetation to grow costs virtually nothing.
Translocation: Trap and move birds out of the area. But because of strong homing instinctsand a tendency to return to their former nesting area, this method can becostly and ineffective.
Egg depredation: Addling or oiling the eggs, as permitted and directed by state law, preventsgeese from having a successful nesting season. These techniques destroy theembryo, resulting in long-term population control, but require a large laborinvestment to search ground around the pond or lake for nests.
Hunting: Canadian geese are federally protected by the Migratory Bird Treaty Act, butcan be legally hunted with the proper licenses.
Pigeons eat anything and everything, including garbage. They carry fleas, lice, mites, andticks and play a role in transmitting more than 40 diseases. Theycreate the potential for slip-and-fall lawsuits, occupational diseases (seesidebar), and poor indoor air quality.
Inspect, control, and reinspect, advises Greg Baumann, vice president of technicalservices and senior scientist for the National Pest Management Associationin Fairfax, Va.
"The best strategy is to prevent pigeon problems in the first place," hesays. "But if workers see pigeons at equipment facilities orother buildings -- inside or out -- they should contact supervisorsimmediately."
Launch control measures at the first hint of a problem.
"All bird-control products can be effective in the right setting withproper installation," Baumann says. "But pigeons get used to anypattern, and unless you put a lot of effort into mixing up methods, they'llrealize there's no danger."
By analyzing their flight pattern, noting how they enter, and observing wherethey roost, you can determine the optimum spots to position control mechanisms.
Habitat manipulation: Barring openings to lofts, towers, vents, steeples, under eaves, and behindsigns is very effective. "For building interiors, physical exclusionis the best bet," Baumann says. "Netting is widely used and veryeffective."
Visuals: Replicas of hawks and owls, whirling devices, colored flags, balloons, revolvinglights, and scarecrows are low-cost and harmless ways to frighten birds.
Anti-roosting devices or repellents: Porcupine wire, consisting of strips of flexible, rustproof base bars withspikes or needles, can be installed along building ledges and window sills.
Electrical repellents involve two permanently installed grounded wires thatadminister a nonlethal shock. The systems require maintenance, though, becausesticks and straw dropped by birds cause shorts.
Chemical repellents are referred to as "glue" or "jellies." Thesesticky, non- or slow-drying compounds are applied to window sills, ridgelines of roofs, gutter edges, ornamental coping, and ledges. There'sa potential downfall: Because the material is sensitive to heat, cold, andairborne dust, it has a limited life span.
Sonic devices: Check local ordinances before deploying sound devices, including electric alarms, recordeddistress calls, automatic exploders or gas cannons, and pyrotechnics.
"Electronic alarms aren't suitable for city use, but can be effectivefor large warehouses in isolated areas," says Heath Waldorf, vice presidentof Bell Bird Control. "The alarm produces loud screeching, intermittent, amplifiedsounds."
Population control: The best time to reduce bird production is before the young start to hatchin the spring. Some methods can stop birds from building nests or force themto abandon their eggs.
English sparrows and feral pigeons can be reduced by destroying eggs at two-weekintervals in the spring and summer, but this is labor intensive.
Eliminate standing water: Finally, although eliminating water sources isn't always simple, or even possible, takecare of standing water such as puddles on roof tops.
- Katherine Frisch is a freelance writer based in Lakewood, Ohio, andformer editor of Government Procurement magazine.
Web extra: To find a bird control professional in your area, visit the "articlelinks" page under "resources" at www.pwmag.com.
Four ways to keep crews safe:
- Saturate droppings with water before removing to prevent debris and pathogens from becoming airborne.
- Schedule removal for weekends or other periods of minimum building or area use.
- Protect indoor air quality by closing all heating and cooling system air intakes.
- Double-bag droppings and associated soil in thick plastic bags, secure, and transport to the landfill to be buried.