The charity said there were only 20 pairs of goshawks in the county.

BBC: Goshawks found poisoned near Exeter

Once close to extinction, goshawks are known as "the phantoms of the forest" because of their elusiveness despite their size.

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The goshawks, found dead in woods to the west of Exeter, were deliberately poisoned with a banned pesticide, the society said.

BBC: Goshawks found poisoned near Exeter

But it said persistent bad weather and low temperatures meant only half survived, while other rare birds including goshawks have also struggled.

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All birds of prey are protected under the Wildlife and Countryside Act, but, because of of their low numbers, goshawks are provided greater protection, according to the RSPB.

BBC: Goshawks found poisoned near Exeter