Bird Strike Committee Proceedings


Date of this Version

August 2001


Fogging of Rejex-it® TP-40 (Fog Force) offers a very efficient method for the management of nuisance birds in many diverse areas without any adverse effects to non-target animals. Despite its effectiveness, there are many factors that influence the effectiveness and desired results. The product alone does not guarantee the desired success. It is not always the quantity that determines fast reaction, but more the form for the specific application. Smaller droplets in the 10-micron range are theoretically 27 times more effective than 30 micron droplets and five micron droplets even 216 times more effective for the same quantity of product applied. It has been shown that droplets below 10 microns are inhaled by birds much more and therefore show an increase in effectiveness. Also, birds in flight with a breathing rate of 50-100 times higher than the resting rate show increased effectiveness. Large droplets not only are relatively ineffective, they also tend to drop to the ground prematurely and are lost. Smaller droplets stay in the air much longer and disappear by evaporation and do not drop to the ground. In large warehouses or hangars it is therefore advisable to bring the fogger to the height where the birds are, so that the fog stays in the upper regions without disturbing any operation on the ground floor. Depending on the situation, it sometimes is still advantageous to use foggers, which do not produce the ideal droplet size, but have other advantages that are needed for success. In strong wind or with thermal currents sometimes larger droplets are needed to reach the nuisance birds. Also, many times automated ULV foggers (e.g., Hurricane, BICO 2000), that work without much noise are more effective than hand held thermal foggers.