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Why New York is to switch off lights for migrating birds

28 April 2015 Last updated at 09:07 BST

New York Governor Andrew Cuomo has announced that the state of New York is to turn off non-essential lights in state-run buildings.

But rather than this being an energy saving measure - instead, it is to help migrating birds navigate routes in spring and autumn.

Ornithologists say that birds become disorientated by electric lights, causing them to crash into buildings - also known as "fatal light attraction".

Lucas De Jong explains.