Stone the Crows

Recently a client approached us with a bird problem that puts a whole new spin on the phrase ‘Stone the crows’…

Our client approached us complaining crows were picking up loose stones from their roof and dropping them at height. Their roof had sections of loose pebbles, which helped with the drainage of rainwater. The stones were dropped onto skylights and glass ceilings causing damage. There was also the concern that the stones would be dropped on people below.

Why do crows drop stones?

Crows drop stones because they mistakenly believe they are food with a hard shell, and dropping them from a great height will break the shell allowing them to eat the food inside. Wild crows have been observed dropping walnuts, crabs and even shellfish onto rocks!

In the fascinating video from the BBC crows in Japan are shown to be very adaptable creatures. They are filmed dropping nuts into oncoming traffic to let the cars break open the shells. They even figured out that it is safer to drop the nuts onto pedestrian crossings and wait for the cars to stop before collecting their prize!

Information About Crows:

  • In the UK we have 8 species of crows. The most common one seen in the UK is the ‘Carrion Crow’, the scientific name in Latin is ‘Corvus Corone’.
  • The crow is predominantly black, although Chough have red beaks and red feet, and rooks have white beaks.
  • They are found across the entire UK, from city centres to the countryside, forests, moors and the seaside.
  • Crows mainly eat insects, worms, nuts, seeds and fruit.
  • The crow is a clever bird. Some researchers claim they are as smart as a seven-year-old child.
  • The saying ‘Stone the crows’ is an exclamation of surprise or annoyance. Its origins are unknown but probably relate to scaring crows away from farm animals by throwing stones at them.
  • Crows tend to be solitary animals found by themselves or in pairs, although they can congregate in flocks on occasion.
  • Their breeding season is during March / April.

How did we prevent Crows from causing damage to the property?

Netting was not an option, as the building had a cradle on the roof as well as abseilers, both required regular access for window cleaning.

Therefore we decided to build custom timber frames around the area where the stones were located on the roof, and then covered these with mesh that was fixed onto the timber frames. This meant the birds could no longer pick up the stones.

Areas we cover to control bird pests:

The MICROBEE bird control team covers London and Southwest England, but we can go further afield on request.

If you have crows, ravens or other birds that are causing you a problem please contact the MICROBEE bird team on 0208 8540 9968 during office hours, or alternatively use the contact form