England's only resident golden eagle is feared to have died after he failed to appear this Spring.
Wildlife experts said they are "losing hope" that the bird is still alive, as he has not been seen by RSPB staff since November.
The eagle, which has been a resident at Riggindale near Haweswater, Cumbria, since 2001, would usually be seen at this time of year building a nest and displaying to try to attract a mate.
Lee Schofield, site manager at RSPB Haweswater, said: “When the eagle didn’t appear last month we thought there was a chance he might be hunting in a nearby valley but over the past few weeks we’ve been gradually losing hope.”
There are an estimated 440 annual breeding pairs of golden eagles in the UK, which mostly inhabit the wide-open moorlands and mountains of Scotland.
The eagle, who did not have a name, was thought to be the last in England, and had lived alone since the death of his mate in 2004.
It is thought the bird, who is believed to have been around 20 years old, may have died from natural causes.
Mr Schofield added: "By this time of year you would have expected to have seen him on display to attract a mate.
"As the last golden eagle in England, it's an element of wildness that has gone.
"There's no real way of knowing for sure. It's a single bird in a huge landscape and he was of an age we couldn't rule out death by natural causes."
