If a fox should see a golden eagle soaring over the wild countryside of the Scottish highlands and islands, it will raise its tail as a warning flag.
The fox will continue to walk with its tail in the air to indicate the eagle's presence. I have never observed this but have it on the authority of a trio of Scandinavian ornithologists, Bruun, Delin and Svensson. I mention Scotland, as the eagles' establishment and, indeed, survival in the hills of Donegal has been under a cloud of apprehension. I had missed the recent news story of the eagles' plight as I had been away - not, unfortunately, once again in the amazing Spanish countryside of Extramadura where I had watched eagles on an official birding trip.
There, with the historic city of Caceres as a base, I saw Bonelli's, booted, and short-toed eagles and, twice, the rare imperial eagle, soaring over rocky gorges with winding river vistas on the edges of vast expanses of steppe-like country of scattered cork oaks and a sparse human population.
But the Donegal eagles are of greater concern. There have been news stories and statements, letters to the papers. The re-introduction of the goldens, when it started a few years back, was an exciting, hope-filled venture. After an absence of about 100 years the newcomers would, it was hoped, breed and raise young. Ireland would have its eagles back.
A Golden Eagle Trust was formed, Glenveagh National Park chosen as an excellent location for nest sites and there was an abundance of goodwill from the general public if not some nervousness from local sheep farmers who, reservedly, saw the birds as further possible predators to add to their vigilance duties of foxes and unchecked dogs at lambing time.
But it has, apparently, turned out to be more serious, although, interestingly, and ironically, sheep play a singular role.
The fact is that the eagles are starving. The national park and general mountain environment cannot support them. They are surviving on corvids, magpies, fox and badger cubs. There are few rabbits, hares or game-birds such as grouse which are plentiful in Scotland.
The Irish Wildlife Trust (IWT) has asked the relevant State agencies to immediately implement a 'Burren-style' agricultural/environment plan to rescue the eagle project. This involves the sheep men and the intensively grazed mountain slopes being more tightly managed. This will not come about overnight.
Padraig Fogarty of the IWT has said the loss of the eagles would be a tragedy and a huge blow to Donegal, and the country. There appears to be a management vacuum in relation to the birds at Glenveagh - two or three young have fledged and died because of food scarcity.
The eagle trust feels the conditions on the Donegal mountainside can be changed with improved management to become more eagle-friendly. Human activity has shaped the limited capacity of the hill country for wildlife. Intensive grazing, turf extraction and burning - the current historic pattern of hillside activity - are impeding the natural development of the landscape.
This is not a revelation. George Monbiot, the renowned environmentalist and author, sees an increased sheep population as the cause of the barrenness of his beloved Welsh countryside.
His remarkable book, Feral, now a Penguin paperback, is recommended reading for all interested in a re-wilding of the natural landscape and sustaining it for future generations.