"Mullin's problem was far from unique," says Mona Zemsky, a technical consultant with Bird-X, Inc., a Chicago company that has specialized in humane bird and pest control products since 1964. And it's a problem that can potentially cost stadium operators big bucks to combat. Mullin figures it cost the Great American Ball Park $3,500 every week throughout a nine-month season to clean up after the birds.
"Bird infestations and droppings have caused problems for all sorts of buildings and structures, worldwide," Zemsky notes. "Bridges, municipal buildings, courthouses, airports, golf courses, warehouses, loading docks and more are subject to the property devaluation, cleaning costs and health risks associated with these messy intruders. It's unlikely that any stadium or sports complex anywhere will never have a bird problem, unless they have taken preventative steps to keep birds from taking up residence in the first place."
All Bases Covered
"Ignoring the problem was simply not an option," Mullin advises. "The cost of cleaning and repainting bird-fouled areas was considerable, and the birds themselves created an unpleasant atmosphere for the more than 2 million annual visitors to the stadium. Not to mention that bird droppings and dead birds were a significant health concern. The stadium's location on the Ohio River meant dried excrement easily became airborne," Mullin notes. "And if droppings ever met concession areas, health officials could conceivably shut down concession operations."
The problem evolved after city and county officials successfully blocked pigeons from roosting under overpasses near the stadium. "The city placed netting on walkways and overpasses outside the stadium, and the birds moved to the stadium," Mullin says.
Mullin's quest for a solution was limited by local ordinances on how businesses can deal with bird infestations. Poisoning and shooting were prohibited, as were bird spikes, even though the spikes are not a lethal option, just an uncomfortable roost inhibitor. Mullin's team tried noise deterrents and plastic owls. "They laughed at us," he recalls.
For the Great American Ball Park, netting was the answer. "The netting was easy to work with and install," Mullin says. He chose polypropylene netting over the knotted polyethylene, though both netting materials effectively block birds from roosting in a favorite location. The lightweight netting is heavy-duty and UV stabilized for longevity of up to 20 years, yet it's nearly invisible from a distance so as not to detract from the stadium's architectural appeal. Mullin's crews began placing the netting around the park in February in preparation for opening day April 2. "We saw a dramatic change by mid-May," he says.
A few states away, in Nebraska, the operations staff of the University of Nebraska in Kearney fought a similar battle. Nestled in a pastoral setting just 130 miles west of Lincoln, the university is home to 6,500 students during the school year. Because of the campus proximity to corn and wheat fields, the university grounds were a favorite haunt for thousands of crows seeking the plentiful food supply. "They seemed especially fond of the university's athletic facilities, where they roosted under the stadium bleachers and nested on the athletic fields," says Lee McQueen, UNK's Facilities Director.
"The problem was so bad that people used umbrellas to protect themselves from bird droppings while walking across campus, because the birds roosted in every tree," McQueen recalls. Toys at a nearby daycare center were regularly rendered useless because they were covered in droppings. University grounds keepers patrolled the campus after dark, beating metal tubs with spatulas to try to scare the crows away. After a few years of crow occupation, the campus was buried beneath the build up.
A Winning Game Plan
Desperate, university officials began seeking solutions. Their quest led them to specialized repellent products, along with advice on how to use the products, and how to keep the birds from returning once they left. "The solution for the university was a combination of high-tech and low-tech devices," McQueen says.
The cost of cleaning and repainting bird-fouled areas of any sports stadium can be considerable.
Ultrasonic and sonic repellent devices that produce both high and low frequency sound waves were placed around campus. The sounds generated by the devices can range from noise that simply annoys the birds to sounds that mimic the cries of predators or the distress calls of injured birds. "Ultrasonics create sounds that are inaudible to humans but are highly distressing to birds," Zemsky says. Most of the devices offer multiple volume settings and can be set to generate a varying range of noises that are offensive to birds.
The university realized the appeal of the area, and wanted to attack the problem on multiple fronts. In addition to installing the sound repellers, staff sprayed trees with a non-toxic but tacky liquid bird repellent. Next, they positioned large commercial-grade visual devices specifically designed for scaring pest birds -- huge spheres festooned with holographic owl faces -- around the campus. "Within three months of starting the treatment, the crows had left," McQueen says. Not long after the crows disappeared from the campus, university grounds keepers got a call from their counterparts at the nearby high school. It seems the crows had relocated, and the high school officials wanted the university's advice on how to get rid of the birds.
No Harm, No Fowl
"Mullin and McQueen solved their respective bird problems the right away with non-lethal methods," says Bird-X's Zemsky. "Not only are lethal methods prohibited in many areas, they are also doomed to failure," she explains. "Killing the birds may appear to eliminate the immediate problem, but really all you are doing is creating an opportunity for more birds to move in. And most organizations, high profile or not, prefer to avoid the potential public relations nightmare this almost always creates from local residents, businesses and animal advocacy groups."
"Non-lethal methods work long-term," she adds, "because they teach birds that a location is undesirable. Birds are very smart, and they are creatures of habit. If you can convince them that a location is no longer safe for them, they will leave and not return," Zemsky says. Mullin agrees that making the stadium inhospitable to the birds was the key. "Our contacts at the Cincinnati Zoo kept telling us we had to completely disrupt the birds roosting patterns. Otherwise, they would just keep coming back."
Effective repellent measures include taste aversion, which convinces the birds a food supply in a given area is no longer viable; sight and sound aversion, which make birds believe an area is unsafe; and physical barriers such as netting or spikes that prevent birds from occupying favorite roosts. "Sometimes, it takes more than one type of deterrent to eliminate the problem," Zemsky says. "Costs can range from a few hundred dollars for visual deterrents like plastic owls to several thousand for sonic devices and physical barriers like netting."
When measured against the damage potential of a bird infestation, however, the cost of deterrent devices can seem well worth the investment. Just ask Mullin; some quick math calculations reveal why he's now a believer. At $3,500 per week to clean up after the birds, the stadium was spending $14,000 a month over a nine-month season. That's $126,000 per year. By contrast, it cost Mullin just $4,000 to place netting throughout the stadium.
That means his one-time investment of just a few thousand dollars will save the Great American Ball Park nearly $2 million over the 15-year estimated usable life of the netting. It's an investment he expects will be paying off for the stadium long after Mullin himself has retired.