Technology that automatically recognises protected birds and shuts down wind turbines if they’re in danger of collision cut eagle deaths by 82% during tests in the US, according to research cited by the system’s developer.

The bird protection system – which combines optical recognition and machine learning technologies – delivered the fatality reduction during trials at Duke Energy’s Top of the World wind farm in Wyoming, said IdentiFlight, referencing an article in Journal of Applied Ecology.

IdentiFlight deploys camera towers at projects with proprietary software that can spot and track pre-defined protected species and enact “informed curtailment” of one or more turbines via the wind farm’s control systems if it decides their flight path means they are in danger of collision.

The system developer reckons it can spot a bird up to 1km away and now has 47 million images of protected species in its database, allowing it to make smarter decisions and keep energy loss through curtailment to a minimum.

Chris McClure, director of global conservation science at the Peregrine Fund, and lead author on this study, said the Top of the World research showed the system “can lessen numbers of fatalities of eagles at wind energy facilities, reducing the conflict between wind energy and raptor conservation”.

But McClure added: “Although automated curtailment reduced fatalities, they were not fully eliminated. Therefore, automated curtailment, as implemented here, is not a panacea and its efficacy could be improved if considered in conjunction with other mitigation actions.”

Bird deaths – sometimes known as ‘green on green’ incidents because of the conflict they cause between renewable energy and nature protection – are an issue for the wind industry globally, with conservation groups objecting to some major projects over claims they pose a danger to rare species.

The issue was also regularly seized on by ex-US President Donald Trump, who used it as ammunition in his diatribes against the wind sector.

Other strategies researched to protect populations include painting a single turbine black, or re-nesting birds away from the area of wind farms.