It had never crossed my mind that olive oil could be environmentally unfriendly, until I read this article which outlines how many producers of the oil use suction to remove the olives from the trees, in the process suctioning out and killing millions of birds a year. I knew that lots of birds were killed in the Mediterranean countries but I had previously thought it was mostly due to hunters shooting them or catching them on lime sticks. The fact that olive oil was implicated in this was a total shock.
So I started researching for a bird friendly olive oil. I guessed that 'hand picked' would be a good indicator of bird friendly. But many producers don't say how they harvest the olives (though most do say how they process the oil - virgin or extra virgin olive oil is pressed rather than treated with chemicals and this is shown on the label by 'produced by mechanical process only' or similar wording.)
I recently saw the film Virgin and Extra at the Edinburgh International Film Festival (you can read my review here) and it seems that the olive farms of Jaen in Spain mostly use manual means to harvest the olives. It would be necessary to research this to find out more, but The Green Gold Olive Oil Company certainly harvests its grapes manually and so is bird friendly.
Locally available in Edinburgh (from Real Foods) Lesbian Donkey is produced by organic methods on the hillsides of the Greek Island of Lesbos, with olives picked without machinery - the trees are shaken to bring the olves down. I've bought my first bottle of Lesbian Donkey and will review it once I've started using it. (My current organic extra virgin olive oil is possibly bird friendly itself, but the makers haven't got back to me to confirm this and I'd rather know for certain).
There's a useful article in Ethical Consumer here, which outlines the issue and looks into which major suppliers of olive oil may be bird friendly.
So if you care about the effect of agriculture on nature, it's well worth checking out whether your olive oil is bird friendly. The trick is to look for hand picked and to be aware that produced by mechanical means only refers to the processing of olives into oil (and indicates Virgin or Extra Virgin) and not to harvesting methods.