The Mediterranean olive harvest, that runs from October until January, is killing millions of songbirds each year, researchers have warned.
It is reported that in the autonomous community of Andalusia, Spain, 2.6 million birds are killed by harvesting tractors - who are 'vacuumed' out of olive trees as machinery collects the fruit.
According to The Independent, when the harvest takes place at night - 'the light of the machines dazzle and disorientate the birds' resulting in a 'catastrophic' number of deaths, as many as '100 dead birds in each harvest trailer'.
Vacuumed to death
Lead researcher Vanessa Mata, from the Research Centre in Biodiversity and Genetic Resources, told The Independent: "The machinery is perfectly fine if used during the day, as birds are able to see and escape while they are operating.
"However, during the night they use very strong lights which confuse the birds and lead to their death as they are 'sucked in' by the tractor."
The birds -including robins, greenfinches, and other British breeds - are legally protected, but authorities are yet to ban the annual harvest.
Mata added: "Local governments and local, national and international communities urgently need to assess the impact of the practice and take steps to end it."