Nuisance Bird Prevention

Introduction

Birds are beautiful, wild creatures of nature.  Most species live and flourish in rural environments that provide them natural habitats.  However, some species have successfully adapted to our ever-expanding urbanization of the environment, often conflicting with us.  They have learned to thrive using our buildings and our food to fulfill their harborage needs. Through media coverage of the West Nile Virus and HN51 “Avian” Influenza, we have had our awareness raised to the issue of birds increasingly being identified with disease. Author Steven Covey said, and I paraphrase “begin with end in mind.”  This discussion presupposes that readers are open to learning how to move pest birds on or at their facilities as part of an HAACP plan, AIB compliance, company or governmentally regulated policy, or just plain old good business sense.

Building design professionals, property owners and managers, on-site sanitation professionals , professional wildlife, pest management, environmental and property management companies all need solutions when pest birds encroach or to prevent such encroachment. Our discussion will follow the EDCIF (evaluate, disperse, clean, install, and follow up) model that is biologically based and is the framework followed by professional bird control managers.

EDCIF

The pivotal section of our discussion is the Evaluation of a pest bird situation. We will look at identifying and understanding the environmental and financial consequences of pest birds’ presence to businesses in addition to the prima facie health reasons noted above. Next we will follow a discussion of understanding the attraction of a bird population to a particular place, coined as “bird pressure” by Cameron Riddell, President of Bird Barrier America.

Dispersal or relocation, as well as behavior modification which are occasionally necessary steps in pest bird management, and most often part of an integrated program, will be discussed as well. Many issues in the discussion of dispersal from regulations to behavioral versus structural solutions, to company policy restrictions to experimental measures come into play. Cleaning follows and has two key elements - removal of droppings, nests, carcasses and nesting materials, and sanitization of the cleared surface.

Installation will be a broader discussion of structural methods as appropriate to species and pressure. Some combinations give rise to one of many possible solutions, others to just a few or one.  Bird control measures, especially with newly arrived flocks, must be done right the first time.  Follow-up is simple science and good sense. How are the birds reacting? Has your program worked? What was overlooked? If your plan worked, how do you publicize it and share it with your constituents in your industry or peer groups?

Evaluation

Evaluation of the effect of pest birds on or around a facility is the best accomplished by examining several factors.  The first is image.  What is management telling vendors, customers, upper management, and employees by leaving a pest bird problem untreated?  Simply stated it can be easily inferred that the business or facility just “doesn’t care.”  This is a message that no business wants project to any of its constituencies, yet if unaddressed the look, smell, danger, and mess left occasioned by pest birds speaks volumes. 

The next effect to be evaluated is the cost of clean up.  Pest bird infestations necessitate costly and repetitive clean-up until the birds are moved.  In addition many situations, if out of immediate sight, result in repair or replacement of surfaces affected by long term infestations.  The damage caused by pest birds cannot be underestimated.  At commercial and military airports, the annual costs of pest birds are estimated to be over $1 Billion.  Regarding the repetitive clean-up, property owners or managers who do not recognize pest birds can be humanely moved are in effect “paying to keep” their problem.  Bird droppings are highly acidic, and can eat through paint, roofing material, and soft metals like aluminum.  Droppings leave their mark in an “etched” image on almost any surface they’ve made contact with even after they’ve been cleaned.

Birds are noisy and flocking behavior can be intimidating.  They are scavengers and can steal product.  Their droppings and nesting materials can clog and or contaminate air intake systems, as dried spores can become airborne and introduced in to the building.  They can spoil product, and mar packaging and can cause expensive and business survival threatening recalls.  In 2006 an Illinois mother preparing a meal for her children found a bird’s head in a can of pinto beans.  A voluntary recall of product by the manufacturer resulted.

The health risk posed by pest birds cannot be underestimated.  The invading agents that account for the majority of infectious diseases grouped in five categories: viral, bacterial, mycotic (fungal), protozal and ricketsial, Birds can transmit over sixty types of infectious diseases and forty types of parasites.  Diseases need to be transported from place to place in order to spread and birds are the perfect mechanism because they travel great distances. They are associated with birds in the following ways:  The disease lives in the bird and is passes on when the bird defecates, or lives in the surrounding environment such as nesting materials or already defecated droppings, or inside a parasite that the bird harbors.  Well known illnesses such as histoplasmosis, encephalitis, and salmonella exposure have been associates with pest birds as examples.  In anticipation of Bird Flu scares, or dead birds found inside its locations, a major big box store embarked upon a program last year concerning its 30 distribution centers each of which are more than one million square feet.   It asked pest control vendors to provide proposals for pest bird prevention to the outsides and plans for removal should birds be found inside the facilities.  This was a conscious effort to “get in front of” bird problems before they started, as workers’ health and safety concerns were the motivating factors. 

Evaluation of the attraction of pest birds to a facility can be summarized by three B’s; bird, building, and behavior.  Coined “bird pressure,” a combination of factors draws a bird population to a particular structure or places on that structure.  We have used the term “pest birds” above and this generally refers to the three non-native birds that are not protected by the Migratory Bird Treaty Act of 1918; the pigeon, the starling, and the English sparrow.  Each bird has particular mating, roosting, feeding, and flocking habits.  Even with significant infant mortality, they are all growing in population, despite the ability of professionals to euthanize these non- protected birds some cases in some jurisdictions.

Different buildings provide harborage opportunities for pest birds, chiefly covered areas providing shelter, features offering protection from wind, ledges and elevations providing exposure to sunlight, height for scouting predators and prey, and the presence of food sources. In addition macro-environmental factors such as presence or lack of other buildings where birds can congregate, proximity to ponds, fields, electrical wires, contribute to a building’s attractiveness to pest birds.  Last, a flock born in a spot will be strongly attracted to that spot, and want to have its young raised in the same place.  The first behavior we’ll consider is overnight roosting and results in what we call heavy pressure.  This is typically an area where a bird feels the security of an overhead cover and back “wall.”  Birds will fight to get to nesting sites when attempts are made to dissuade them.  This strong attraction is understandable from the standpoint that birds make their homes on or in our buildings and fight to get back to their homes. 

Medium to light pressure situations are the second behavior we’ll discuss.  These are situations where birds can take or leave their ability to get back to one of these locations, and can with some little effort find alternate locations.  Typically they involve open ledges and while birds use these sites, they are not as attached as they are to their roost sites and use them just for vantage or rest. 

Thus the combinations of bird, building, and behavior as expressed by the concept of pressure helps us evaluate the attraction of pest birds to a building.  For example English sparrows nesting and living inside of a building may never have seen the light of day and may be one of several generations living this way. Attempts to find and move birds so acclimated are problematical at best and an excellent demonstration of the bird pressure concept.

Dispersal

Dispersal or relocation and behavior modification devices are the set of non-structurally applied methods that dissuade pest birds from structures. These techniques are very often part of an integrated (in combination with exclusion) plan.  Dispersal techniques include psychoactive restricted use pesticides, shooting with air rifles, and trapping. Behavior modification includes audio, visual, and taste, methods.  They interfere with birds’ senses making target buildings less attractive.  The methods above are regulated by a wide and often overlapping range of federal, state, city and local regulations.  It is worthy of note that dispersal methods are very species specific and in the cases where exclusion techniques cannot be performed may be the only attempt at bird control possible.
An example of dispersal being part of an integrated program is trapping before a bird netting exclusion procedure.  A resident flock will fly in and out of an area that is being excluded by a bird netting installation, making the installation difficult and often being trapped inside, behind the net.  If that existing flock is in fact trapped and relocated, the exclusion work can be performed without the complications described above.  An example of dispersal being a stand alone method is inside a building where mist nets are used. Mist nets are suspended in flight paths, and birds are safely ensnared inside them so that they can be released outside of the building.  

Cleaning

Cleaning is a vital component of bird control.  In particular when ectoparasites are involved, exclusion of birds makes it necessary for these parasites to find new hosts inside the building.  Bird droppings dry hard and are most difficult to remove.  Bio-enzyme products are live enzymes which break down and digest bird droppings for easier removal.  For cleaning large amounts of droppings in dusty, enclosed areas, self-contained breathing apparatus must be used and certified bio-hazardous waste removal companies should be considered. After live enzyme treatments are used, germicides/virusides or a combination must be used to ensure that pathogens are not left behind on an otherwise clean appearing surface; in a word: disinfected.  Prepare when cleaning to consider restoration or repair of surfaces that are “etched” or significantly degraded after prolonged contact to droppings or nesting materials.

Installation

Installation of exclusion products is our last major topic.  An understanding of the topics above, most importantly an integrated plan and bird pressure provide for success of exclusion efforts.  The goal of exclusion is simple: deny the pest bird of access to its roosting or perching place by application of devices to building surfaces.  Exclusion products are engineered for species and behavior combinations.  For example, roosting sites can be blocked with polyethylene netting attached to the building with a cable frame.  Yet the birds nesting materials must be removed, the site must be cleaned and optimally the birds must be dissuaded from the area before the netting installation occurs.  Trapping and relocation is the perfect dispersal complement to exclusion with netting. The correct mesh size of net must be chosen so to assure that the currently infesting birds, or others that are smaller, close by, can’t squeeze through the mesh squares.

In general, ledge deterrents are for medium and light pressure situations.  These solutions make the surface the birds are accustomed to lighting and perching upon unstable and thus uncomfortable.  Unable to gain comfortable access to the surfaces they are accustomed to landing on, the pest birds seek other places to perch.  Common exclusion solutions for medium pressure ledge situations are stainless steel or polycarbonate spikes, coil, or tensioned wire.  These, like other solutions are species specific based upon the trade-off of material density or cost against size of bird excluded. 

Exclusion with ledge or “anti-perching” products are time tested, yet new ideas are occasionally being offered and evaluated in the marketplace.  An example of this is Bird Shock.  The flat equivalent of a cattle fence, this technique allows pest birds to receive a mild but memorable shock when landing on a protected ledge.  They remember this unpleasant feeling and not only seek a site that is not protected but remember the sensation and avoid the protected ledge in the future.  This method has been approved by the Humane Society and the Fund for Animals.

For heavy pressure situations, exclusion with bird netting is optimal.  Total exclusion is offered by creating a cable frame and affixing a polyethylene net to it.  The pest birds thus cannot gain access to the area where they were roosting and are forced to find other places to take up residence. 

Installation of exclusion systems as well as many dispersal methods is regulated by state pest control boards and in many cases limited to licensed and professionals.  They have the training, experience, and resources to execute a well thought out bird exclusion plan.  Note that installation of exclusion systems will move birds to places as “close” to the exclusion system as possible if similar harborage opportunities are available in unprotected locations with the possible exception of Bird Shock methods. 

Follow-Up

Follow-up is vital to gauge how the remaining or new bird populations react to the solution chosen.  Failures in product or workmanship often manifest themselves early and movement of the existing flock, if it has not been relocated is most easily traced in early follow-up. 

With the above mentioned news about Avian flu and corresponding information- awareness gap, a pest bird control strategy is vital.4 In summary, bird control systems that are conceived with the EDCIF methodology have the best chance of humanely meeting property owners and business managers needs.

References

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