An electronic bird repeller can be very effective, if you buy the correct type. Beware of buying products on ebay and other websites that sell bird control products. There is an electronic bird repeller that uses ultrasonic sound waves to scare away birds. This does not work. Ultrasonic means nearly silent to humans.
Birds Do Not Hear an Electronic Bird Repeller using Ultrasonic Sound
Birds and human hearing are very similar. They do not have hears as humans do, but they have openings on the sides of their heads that are covered by special feathers. Birds communicate using sound. They tweet and call to one another alerting others of food sources and alerting others of impending doom such as a predator close by.
There is an electronic bird repeller that uses the actual bird calls and warnings to scare birds away. If you have a large backyard, or a large plot of land that you need to keep the birds out of, a sound deterrent that uses the bird calls and not the ultrasonic sounds is the ideal bird control product to use. This product speaks the birds own language. The sound deterrents have over 22 different bird species programmed into the unit. The built-in speaker will provide protection for an entire acre. With additional speakers added, the coverage goes up to five acres. If you own a vineyard, this is a great bird control method to consider.
There are three effective bird control products that are considered an electronic bird repeller. One works on solar power and one works with a standard 110v power cord. The third works by sounds of a dog barking and flashing LED lights, it is called the Sonic Shield. It not only deters pest birds, but works in scaring away critters such as raccoons and squirrels. It also works in a more localized area such as the balcony, patio, or near trash cans or a shed. It is also motion triggered. There are two modes of operation, daytime and nighttime. Flashing lights will be triggered during the nighttime mode, leaving out the barking dog sound.
The solar powered and plug-in electronic bird repeller options cover a much larger area. Which bird control repellent you choose depends are your particular pest bird and critter problem.