Bird Control
By Bill Kern

Bird control is often one of the most challenging types of pest control. People like birds, even pest species. This requires careful public relations management in order to avoid public backlash.  The laws regulating bird control are also broad and stringent. Almost all native migratory birds are protected under the International Migratory Bird Treaty Act. This means that virtually all native birds, their nests, and eggs are protected from take (kill or capture) or from possession.

BIRDS THAT NEST IN STRUCTURES

There are several species of birds that commonly nest within spaces or openings into structures (soffit vents, attic vents, chimneys, utility penetrations, etc.). Feral pigeons, English sparrows, starlings, mynahs, and our native Carolina wrens and chimney swifts all like to nest in homes, businesses and signs. Barn and cliff swallows can also be added to this list in North Florida and other parts of the country. 

These bird nests are generally a messy nuisance, a potential fire hazard, and can be a source of troublesome pests like bird mites, which can bite people. Exclusion is often the cheapest, most permanent, and humane method for dealing with birds nesting in buildings. Hardware cloth, commercially available attic/soffit vents, and chimney caps will prevent a lot of problems before they start.
Feral pigeons roost and nest on protected surfaces. This makes them somewhat more difficult to exclude. Pigeons are a year_round problem and the bread and butter of commercial bird management. Their acidic droppings stain and corrode structures and are potential growth media for medically important fungi and bacteria. Nesting sites and roosting ledges can be made unavailable by installing slanted surfaces, porcupine wire physical deterrents, electrified tracks, landing or roosting disrupters, and adhesive roost deterrents (usually polybutene based).

The avicide, Avitrol, is registered in Florida for feral pigeon control, but requires an Avitrol Permit from the executive director of the Florida Fish and Wildlife Conservation Commission. The permit application is available at http://myfwc.com/permits/protected-wildlife/apps/avitrol.pdf  . 

Industrial bird netting is an excellent tool to close off large spaces to prevent both nesting and loafing.

BIRD MITES

Bird mites are a serious nuisance to people once the normal host birds leave the nest. The month of April seems to be particularly bad in Florida, because that is when the first clutch of starling fledglings leave the nest. Human bites normally occur in the room or rooms just below the nest location, but can spread throughout the structure. The tropical fowl mite is the species most commonly associated with starling nests.

Bird mites are not known to transmit any diseases to humans, but the bites are painful, itchy, and similar to chigger bites. Many people think that bird mites are tiny and too small to be seen. The adults are almost the size of the head of a pin and are visible with the naked eye, especially on smooth surfaces.

Sealing all openings before the birds nest is the best prevention for bird mite infestations. If nests of starlings, English Sparrows, or mynahs are discovered prior to fledging, the nest can be removed (along with most of the mites) and the area treated with a pyrethroid like permethrin.  This method can also be used after the babies fledge, but a much larger area will need to be treated with the insecticide once the mites have dispersed.

WOODPECKERS

Woodpeckers are the most notorious birds for damaging structures. They peck or drum on structures for many reasons. Many times severe damage is caused when they are looking for food, such as carpenter ants, carpenter bees, leafcutter bees, or other wood or crevice infesting insects. Figure 3 shows the damage caused by our second largest woodpecker (since the ivory-billed was rediscovered) opening up a large carpenter bee nest in siding. This behavior is generally controlled by eliminating the insect prey by painting, chalking, and insecticide application if appropriate.

Woodpeckers will also try to excavate nesting cavities in structures because of their hollow sound. These wall voids are almost never suitable for nesting, but the damage is done. This activity may be reduced by providing appropriate nest boxes for the woodpeckers in your area.

The last behavior is the most difficult to control. Drumming is one of the ways that woodpeckers declare their territory. Any hollow object that acts as a reverberation chamber can be drummed on to announce territory ownership. Walls, signs, sewer stacks, and roof vents all have been used and usually at dawn when homeowners are trying to sleep. The only way to defeat this behavior is to deaden the sound with some insulating material or scare the birds away with streamers, balloons, effigies, recorded distress calls, and startle devices. 

VULTURES

Winter flocks of vultures produce a lot of droppings, with staining and odor. Vultures are only a problem when they flock up for the winter and migrate south into Florida. In the spring and summer, vultures pair up and scatter over the countryside to raise families. The arrival of large numbers of northern migrants causes the urban and suburban problems we see. 

These birds are generally dispersed by harassment techniques such as roost deterrents and pyrotechnics. The USDA-Wildlife Services has also found that effigies of dead vultures hanging is very effective when used in conjunction with harassment  pyrotechnics.

Bird control can be a lucrative and rewarding field, but come with an imagination and be prepared to solve complex problems. The arsenal of tools is large and varied and ranges from traps, roost deterrents, motorized sweeps for roosting birds, and electronic alarm calls, to robotic falcons. No single tool works every time, even when dealing with the same species and similar situation. That is what makes bird control so challenging.

Kern is assistant professor in the Entomology and Nematology Department, University of Florida, Ft. Lauderdale Research and Education Center.

Cutlines:

Figure 1.  A common myna has nested in this storefront sign. The irony is that this was a pet store’s sign.

Figure 2.  Bird mites (Tropical Fowl mites) abandon the nest once the fledglings leave and go looking for an alternate host.  Photos by Lyle Buss, UF / IFAS

Figure 3.  A large carpenter bee nest that was opened up and pillaged by a pileated wood pecker.

Figure 4.  When using agricultural pyrotechnics (such as shellcrackers or 15 mm projectiles) for bird harassment, always wear proper personal protection equipment _ eye protection, hearing protection, and gloves to protect the hands.  Also be sure to communicate with law enforcement prior to all harassment activities.