The BirdAvert System

The Birdavert System, designed by ornithologists in conjunction with computer and radar technology specialists, is a low-cost, yet highly effective deterrent system with very low maintenance requirements.

Through the use of advanced technology including patented, computer-assisted radar and multiple Hazing scenarios the Birdavert System drastically reduces mortality rates on protected bodies of water.

In contrast to other systems, the Birdavert System design is engineered to protect ponds of' various sizes and shapes without loss of effectiveness. The system can be expanded to protect surface areas in excess of 1,000 acres.

How it works:

The Peregrine Birdavert system consists of several components. They include:

Radar and interface board

Obviously, the purpose of the radar is to detect birds in flight. Because of its low cost, long life, and effectiveness, our current radar of choice for this task is a Furuno marine radar.

The Furuno radar has several adjustments to minimize the effect of rain, remove radar clutter, and operate efficiently at both short and long ranges. After we receive it from Furuno, the off-the-shelf radar is modified internally so the radar image can be downloaded to the computer in real-time via a proprietary radar interface board. The primary purpose of this board is to capture the radar images upon software command and otherwise act as the mediator between the computer software and the radar itself.

Birdavert software

The Birdavert software, designed to run under Windows/NT 4.0 forms the intelligent core of the Birdavert system. It requests images from the radar and scans them for moving objects of sufficient size to be birds. Once birds are detected, the Birdavert software issues firing commands over a radio link to the remote controller units.

These controller units in-turn fire their associated hazing devices. The whole cycle from radar scan to device firing is less than two seconds. It is important to remember that Birdavert detects only moving objects. Background objects that don't move over time are ignored by the radar and effectively masked out, reducing the Birdavert false alarms to a minimum. To further mitigate false alarms during heavy rain or excessively windy periods, the radar-detection becomes dormant and Birdavert instead fires the hazing devices at user-selectable random time intervals. Once the bad weather passes, the system restarts scanning actively.

If desired, any hazing devices (such as the amplified dog barking) can be put to sleep at night to keep the neighborhood happy while the quieter hazing devices can still keep birds away from the site. The sleep times are fully user selectable.

The software also has several tools to modify the Birdavert behavior for individual installations. For example, fifteen alarm zones with sixteen different hazing combinations can be defined using a graphic user interface.

Hazing devices can be tested manually or queried for their health. Nearly every parameter of the Birdavert hazing system can be changed through its Windows interface.

Since competing systems may not possess it, one important aspect of the software requires special mention. When we designed it, we realized that clients seeking to stop bird landings on toxic ponds would purchase Birdavert in order to comply with federal and state environmental regulations. To serve this customer, Birdavert maintains an extensive system history. Every critical action of the radar such as bird detection, alarm zone intrusion, and device triggering is permanently recorded with a date-time stamp. Not only does this provide maintenance information, but provides evidence that the "best available technology" was functioning at the time of bird flyovers. Daylight and low light video cameras and recorders are also available as an option.

Controller units and their peripherals

Each hazing station consists of hazing devices operated by controller units. As you will recall from the discussion above, these controller units receive commands from the host computer via a radio link. Upon receipt of a command, they trigger their attached hazing devices.

In this manner, these controller units provide the local intelligence for the Birdavert system. In fact, should a catastrophic failure take place in the host computer system (such as a lightning-induced power outage), the microprocessors on-board each of the remote controller units would assume local command of their hazing devices and would continue to fire them at periodic intervals. This maintains a measure of protection despite a catastrophic failure of the host computer or radar.

Like the hazing devices themselves, the controller units are solar powered with over 300 amp hours of local battery backup. Because they are solar powered, they are self-contained -- no expensive AC power lines need to be installed to support them. Furthermore, since the units operate at 12 volts DC instead of 120/240 volts AC, they are inherently safe for work-crews to maintain in wet conditions. Nonetheless, extensive ground fault circuitry is employed to further reduce hazard.

Hazing devices

In simple terms, a hazing device is an automated scarecrow. The hazing devices used by Birdavert can be classified as sound, light, or motion. Sounds such as dogs barking, guns firing, and falcons screaming are available at each hazing station. In areas where diving birds are a particular problem, underwater sound can be provided as well.

A high-intensity strobe light attends the sound generation. For motion, two options are available. Oversized plastic falcons with a five-foot wingspan can violently flap their wings. Alternatively, six-foot tall mannequins in bright yellow rain suits with flailing arms can be provided. You will note that air cannons and related noisemakers are not standard hazing devices of Birdavert. While we have made allowances in software and controller units for their installation, we feel that the other devices are adequately effective, less expensive and require less systematic maintenance.


Peregrine Systems listens to its customers and tries to continually improve the Birdavert system. Two future enhancements are particularly interesting. First is the remote access module. This would allow remote access to the Birdavert system via a network, standard modem, or cellular modem. The second is the weather station module. This would allow basic weather data such as temperature, pressure, wind speed, and wind direction to be gathered and stored on the same computer as the Birdavert software. In conjunction with the remote access module, this weather data would be available via telephone or network as well. Further suggestions would be very welcome.