Filstone Success Story: Eliminating the Presence of Crows

Multinational Filstone Comercio de Rochas explains how they managed to eliminate the presence of crows at their Casal Farto quarry in Fátima, Portugal.

Filstone, a benchmark in the stone industry

Filstone Comercio de Rochas is one of the largest benchmarks in the stone industry in Portugal. The company is engaged in limestone quarrying, processing the product into stone furniture, and its subsequent marketing. The company exports to the international market, primarily to the Chinese market in Asia.

In 2008, Filstone acquired the quarry in Casal Farto, in the province of Fátima, north of Lisbon. This quarry, surrounded by mountains, has an area of approximately 40 hectares. In the area, there is a high presence of crows.


Crows, birds of ill omen


Since time immemorial, the crow has been associated as a bird of ill omen, a bearer of bad luck, and other dark and shadowy elements. A messenger of bad news, the crow is identified with death.

The crows present in the Casal Farto area are of the Corvus Corax species. These are the largest corvids, very similar in size to a vulture and with entirely black plumage.

There were flocks of hundreds of crows surrounding the quarry, and they were present throughout the year. That is why the company’s management decided to look for a solution to keep the crows away from the quarry.

Searching for solutions to eliminate the presence of crows in the quarry


Filstone conducted a study of the different solutions available in the market to repel crows. They found that Bird Gard bioacoustic repellers had the best references. After contacting BirdGard Iberia, they purchased three Bird Gard Super Pro Amp #49 repellent devices to keep crows away from their Casal Farto quarry.

In May 2021, the three bioacoustic repeller devices were installed throughout the quarry, configured to emit sounds only during the day. Each of these crow repellers provides coverage for approximately 12 hectares.

Success of Bird Gard crow repellers

João Calado, the company’s public relations manager, comments on the results achieved to keep crows away from the area:

We needed to eliminate the presence of crows in our quarry, and the Bird Gard Super Pro Amp crow repellers have been the solution. They have worked perfectly since the moment we installed them.

The results were immediate, and since they are operational, the crows no longer appear in the quarry.

The sounds emitted by the crow repellents are not annoying to the people who work here.

We certainly recommend this solution to other companies that need to repel crows in large outdoor areas.

João Calado, Public Relations, Filstone

Eliminating the presence of crows – Other success stories

The Bird Gard bioacoustic repellers are very effective at scaring away crows, as demonstrated by the following customer references:

If you need to protect your crop, industrial facility, landfill… from a corvid infestation, whether they are crows, jackdaws, rooks, or choughs, do not hesitate to contact BirdGard Iberia. One of their experts will advise you, free of charge and without obligation, on the most suitable solution for your case.