Polly Want A Cracker

It's well known that crows prefer to congregate in groups, and that in the winter months, crows from many different groups will come together. But imagine a place inside a city of 120,000 where 12,000 crows come together in one area to roost. Unbelievable? Not if you lived in the area around Lake Massasoit in Springfield, Mass. By counting the crows that passed overhead in one minute's time (crows follow a regular flight line to their roosting spots), biologists have concluded that this roost is the largest such roost in southern New England.

Officials approached the U.S. Department of Agriculture to express their concerns about the birds. Westover Air Force Base in nearby Chicopee, Mass., noted that many of the crows that roost in Springfield were staging at the base before flying down to Lake Massasoit. Since the flight line of crows crossed the route used by aircraft, base officials worried that unless the colony was reduced in size, they might interfere with aircraft. Many PCOs probably already know how gulls have been known to damage airplanes when they get sucked into the jet engines. The same problem can be caused by crows.

Officials of Springfield College, which rests on the banks of Lake Massasoit, also wanted the roost dispersed due to the potential health threat from the large amount of crow droppings. One staff member stated that "benches and footpaths near the lake tended to be all white even though it hadn't snowed." With some of the droppings falling within 100 feet of residence halls, officials wondered if students were at risk of becoming sick from the fecal material.

In light of these concerns, the USDA decided to disperse the crows. Laura Henze, director of USDA's Animal & Plant Health Inspection Service (APHIS) Animal Damage Control (ADC) division covering Massachusetts, Connecticut and Rhode Island, reported that shell crackers were chosen to disperse the crows in this situation. I asked Ms. Henze why shell crackers were chosen for this situation as opposed to other options. She said that owl statues and electronic scaring devices have limited effectiveness in roost dispersal. In fact, the college was already using scaring devices with little continued success. Obviously something more drastic had to be used.

Ms. Henze explained that since people didn't want the crows killed, shell crackers were decided upon as the best dispersal option. She was careful to point out that these other methods could be used in conjunction with shell crackers if needed. I asked her why shell crackers worked to disperse birds, since they didn't kill anything. She pointed out that birds will avoid places that have scared them. Since crows are rather intelligent birds they will often disperse the first day, as opposed to starlings, which may need as long as three days to effectively move the roost.

DISPERSAL TIPS. Before you begin the dispersal process, you need to make sure you have enough shooters to properly cover the roost area. Under regular conditions, one shooter should be able to cover one to two acres. In the Springfield situation, seven shooters were positioned along the lake shoreline, one for every 500 feet. Since one part of the roost area was very remote, a propane cannon was used in place of a person. The cannon was set to explode about every 30 to 45 seconds.

The next step is to contact authorities such as police and fire departments and obtain permits. Shell crackers, being pyrotechnics, are noisy and a potential fire hazard when they explode. You don't want police thinking a gang war has just begun. Likewise, neighbors near the site should be notified to prevent anxiety over the shooting. Let them know you will be shooting before the birds land on the trees between late afternoon and nightfall. Of course, announcing your intentions may give animal rights activists time to fight and stop your activities. But despite this possibility you must do the right thing.

The first day is important. You want to make a strong impression on the birds. Each shooter should be in place before the birds arrive to roost. Take time to scout the travel patterns and times that the crows arrive at the location to roost. Ask your clients for their input. The information should be easy to obtain.

Crows follow a regular flight line to their roosting area. Timing and positioning is of the utmost importance. It is critical that shooting begin before the birds land in the trees. Shooting after the birds have already roosted has only a limited effect, and may even result in the birds becoming accustomed to the shell crackers.

Shooters should aim the shots at a 45-degree angle from the horizon, placing the shot between the birds and their roost. Each shooter should have at least 50 rounds.

Once you begin shooting, continue until it becomes dark. Even though crows will disperse rather readily, repeat the process for the next few days until the desired results have been accomplished.

If the crows simply move into a neighboring area to roost, continue to disperse them from there as well. Having been already moved once, they should move even more readily now.

In the Springfield situation, a few hundred crows returned in a couple of weeks. College personnel dispersed them by firing a few more shell crackers. As of the writing of this article, the dispersal success rate was 100%.

SAFETY PRECAUTIONS. As with any device shot from a gun, safety should be a high priority. Safety goggles and ear protection are a must for all shooters. If possible, choose a single-shot break-open shotgun. The gun must be 12-gauge because shell crackers come only in this size. The break-open design is preferred because shell crackers tend to foul up the bore. In fact, the bore should be checked after each shooting to make sure that the wadding has not become lodged inside. After every three shots, the barrel should be wiped clean with a bore brush pushed into the barrel with a cleaning rod.

Always be cognizant of wind direction. Don't fire shell crackers into the wind because they may come back at you. Always be keenly aware of your surroundings. Shell crackers can fly out about 300 feet into the air before exploding.

WHAT TO CHARGE. Billing this type of job is relatively straightforward. You should figure at least 10 hours of field time. At two hours per day, you have enough time to scout and shoot for three days. Obviously, if you need to bring other workers to shoot, be sure to add their two hours per day as well. Don't forget to charge for warning neighbors, especially if you are dispersing in a large wooded area surrounded by a residential community.

Consider your travel time carefully. I suggest you add into your estimate your time for all trips of more than 15 minutes in one direction.

The next cost center lies with supplies and equipment. Remember that you will need at least 50 shell crackers per person for the first day. Perhaps only 50 more per person will last the next two days. Factor in the gun cleaning time and supplies as well. With these items in mind, you should be able to estimate how many hours you need to charge for crow roost dispersal. PCT

Stephen Vantassel is a columnist for the Animal Damage Control Association newsletter The Probe and the author of The Wildlife Removal Handbook. He may be contacted at 340 Cooley St., Box 102, Springfield MA 01128.