RSPB Geltsdale, near Carlisle, has been given ?175,000 to help prevent the hen harrier's local extinction.
The award will be spent on habitat management and direct protection.
It is part of the enriching nature programme run by SITA Trust, which distributes funding through the Landfill Tax Credit Scheme.
Sky dance
Dave O'Hara, warden at the reserve said: "This is a great boost for our work to safeguard hen harriers in northern England and we are very grateful to SITA Trust's Enriching Nature programme for their generous support.
"Hen harriers are spectacular birds, and to watch a male hen harrier performing his stunning "sky dance" over the moors in spring is an unforgettable experience."
The Geltsdale reserve is the only English site outside the Forest of Bowland where hen harriers regularly nest. Last year a pair successfully raised three chicks.
It is also home to black grouse, skylark and other moorland breeding birds.
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