Ospreys feel the heat
Up until now it has been a fine summer, great for those who enjoy languishing on beaches, good for the makers of ice cream but not so good for fruit farmers.
They they have been unable to recruit enough pickers and so some of their fruits have been left to wither.
Nor has it been a good summer for crop growers. Then lack of rain has parched their crops, which may not harvest at all well.
It can’t have been a particularly good year either for those birds that rely upon worms and other invertebrates for food. The dry conditions will have forced the worms deeper into the soil, beyond the reach of lapwings, curlew and oyster-catchers. Furthermore, the dry conditions have made the ground very hard, which makes the very act of delving deep into the soil difficult if not impossible. I’m sure that in places it will have been almost as bad as winter, when frost can lock up the land.
All three of these birds, once so familiar on farmland, are in serious decline. The curlew and the lapwing are both seriously endangered and on the red list. The future of the oyster-catcher is not as threatened but they are nothing like as common as they used to be.
Farmland birds appear to be in the deepest trouble. Changing patterns of farming practice, most notably the making of silage rather than hay, is one of the main reasons for the increasing absence of these birds from so much of our farmland. The excessive use of chemicals may well be crucial too.
On spring days years ago the fields in this airt fairly rang to the piping of oyster-catchers, the wonderful peewiting of lapwings and the evocative whistling of curlews. I well remember watching newlyhatched peewits running about neighbouring fields with half the eggshell still attached to them.
There was also the breathless song of skylarks to enjoy, a song which I used to hear as early as January or February. Now the skies here are no longer filled by those towering anthems.
I’m sure too that herons will have found fishing some of our burns and rivers less productive than usual, with some watercourses almost running dry.
The heat is also effecting our ospreys. Ospreys rely entirely upon fish for food, quartering high above lochs, looking for fish idling close to the surface.
A hunting osprey, having spotted suitable prey, enters a quite shallow dive which, should the target fish swim into deeper water, will be aborted. If the fish remains close to the surface the dive is accelerated and ends spectacularly as the bird lowers its legs and feet-first hits the water with a mighty splash.
There are moments when the bird seems engulfed as it seeks to establish a firm grip on its prey. Then those mighty wings begin to thrash and the bird rises from the water, pausing when it reaches a height of perhaps 10 feet to shake excess moisture from its plumage and to firm up its grip on the captive fish.
Initially it holds the fish in one taloned foot then it brings the other foot into play, ensuring that its catch is firmly secured before flying off to either a favourite feeding perch or to the eyrie where its young wait in eager anticipation.
The problem ospreys have faced this year is that fish have generally sought out deeper, colder water so there is less activity near the surface.
Fish have been harder to come by and some pairs have abandoned breeding altogether, while several pairs have delayed the process by a good two weeks or more.
I fear a serious knockon effect from the difficult fishing and the later start to the breeding programme which may have serious consequences for the young ospreys.
Ospreys are normally on a pretty tight schedule anyway, usually arriving in late March or early April, but many this year were held up by the poor conditions that prevailed.
Their first job is to restore territorial integrity at the eyrie, which is used year after year by the same pair. Any necessary refurbishments must be completed whilst pair bonding and courtship take place.
By early May eggs are usually laid and the female begins the long process of incubation, a vigil of some 35 days or so. In June the first eggs should hatch. Thereafter it will be some seven or eight weeks before the youngsters first take to the wing.
In late August the parent birds will suddenly up sticks and begin their marathon journeys back to West Africa. The youngsters will be left to their own devices as they struggle to hone the fishing skills by which they will survive or not. Then in early September they too must begin their journeys to Africa, travelling solo and relying on inherent navigational skills to plot their course.
The delay in this year’s breeding programme and the difficulties encountered in catching sufficient fish could therefore narrow survival margins. This shortage of food has automatically reduced the number of chicks reared. Some pairs have reared none.
It may have been a summer to enjoy for us but not, it seems, for ospreys.