In study, use of barn owls and kestrels has led to 50% to 90% drop in applications for highly toxic chemicals.
By Zafrir Rinat | Jan. 12, 2015

The use of birds of prey to tackle pest control has led to a marked reduction in the use of highly toxic chemical pesticides by farmers, according to Israeli scientists.

In its conclusions for 2014, the national project for the use of raptors for biological pest control, which has been underway for eight years, shows that permit applications for chemical pesticides have declined significantly.

The project, headed by Dr. Yossi Leshem of Tel Aviv University, involves placing nesting boxes in farming areas to encourage the presence of barn owls and kestrels. Until a few years ago, the barn owl was an avian creature whose expressive face was of interest only to bird enthusiasts. But recently, its stock has risen among farmers due to its effectiveness against rodents.

A number of government ministries are involved in the project, along with the Society for the Protection of Nature in Israel and Tel Aviv University’s International Center for the Study of Bird Migration. In recent years, Palestinian and Jordanian farmers have also joined the project.

Some 3,000 nesting boxes have been installed so far, in which kestrels and barn owls nest, preying on large numbers of crop-decimating rodents – among them voles, gerbils and mice.

One of the project’s experts, Dr. Yoav Motro, compared the rate of pesticide permit applications by farmers to the presence of the nesting boxes of the barn owls, whose density in Israel is among the highest in the world.

In comparing permit applications for Rosh-80 – a highly toxic pesticide that is the only type permitted for use in Israel against rodents in fields and orchards – to the presence of nesting boxes, Motro found that the number of applications had fallen by 50 percent to 90 percent over the past four years. During that same period, the number of nesting boxes had risen considerably.

There was a rise in permit applications for Rosh-80 in 2013 because of an unusually high rodent infestation, but the figure was still lower than before the nesting boxes came into use. “If we take into account that the main goal of the national barn owl project was to present an environmentally friendly alternative against rodents, we can say that, so far, this goal has been impressively achieved,” Motro wrote. However, he added that efforts must continue so that toxins are used only when all other choices have been exhausted.

As part of the project, one study surveyed 1,400 nesting boxes and found barn owls in 22 percent of them. Half the boxes were empty and the others were occupied by kestrel and jackdaw nests. Almost 80 percent of the barn owls had managed to raise at least one chick that fledged.