The Hen Harrier

  May 23 was a day of broiling sun, blue, hazy distances and the lightest puffs of east wind. I had enticed Arthur Duncan away from Dumfriesshire, always eager at the prospect of a new ornithological experience in Galloway. At 10.45 the nest site was under observation from the same point as before. Almost seven hours later no harrier had shown itself. Arthur had, by then, had to leave for home, generously casting no hint of scepticism on my story that a certain patch of heather concealed a bird on its nest. I am not sure if I still believed it myself, as I continued to gaze at the quiet hillside and watched the shadows lengthen. Then at 17.45 the cock came out of the sky and I heard the hen’s food call as she went up to him for the pass. A Short-eared Owl barked and suddenly the two owls and both the harriers were over the nest, the female sparring with an owl.

  Arthur has exceptionally sharp eyesight and there is no doubt that if the cock had been anywhere in view during this long period we should have spotted him. So a day which was so nearly a non-event taught me that, when a female Hen Harrier is incubating eggs, the cock may not approach the nest for many hours at a stretch. In later years I found that some cocks may behave differently, making fairly frequent visits to the vicinity of nests during incubation, but I am convinced that there is a tendency for the male to avoid such apparently unnecessary appearances at this time. For the hen to remain for seven hours without stirring from the nest proved to be not at all exceptional.

  Over the 17 years of this study, I have noted the times of food passes at many nests. During the incubation period, food is brought at least once in the early part of the day, and at least once in the afternoon or evening, but it may be usual for the hen to be fed three times a day in all. We came to regard the hour between 17.00 and 18.00 as the magic time when the cock’s arrival could be most confidently expected.

  After the first two or three watches, we began to develop an almost proprietry familiarity with the environment of the nest and all that lived there. No doubt some will say that sitting still, watching birds and the ever changing face of a moorland landscape, is lazy and boring. Lazy it may have been but we were never bored. When, for long periods, there was no harrier activity, other moorland birds claimed our attention. Between us and the nesting hill the ground was flat and partly boggy, dammed at one time to form a loch. Some 400 metres away, just in front of the hill, ran a very small burn and a fence, this forming the march between two sheep farms. Everywhere, the landscape in view was sheep country, a patchwork of grassland, heather and bracken, rising to a skyline of 325 metres, with here and there the higher, bluer hill tops showing beyond.

  In 1959, the advancing tide of conifer forest was hardly, if at all, visible from our viewpoint, though a mile and a half behind us, the first block of young trees in the near neighbourhood was being planted that spring. Apart from this, the nearest young plantations were over three miles distant. A long history of sheep grazing, with sporadic burning, had left only a few tracts of old, deep heather, much the strongest growth being on the rather rugged hill which the harriers had selected for their nest site. Yet several other patches of heather, bog myrtle and moor grass provided sufficient cover in later years for harrier nests. Until 1967, moorland habitat extended unbroken on a broad front from here to the west, but that year a belt of new forest reduced the special area of moor to about 500 hectares, and it became an enclave among the plantations. This proved an important change for the harriers and other birds of the neighbourhood.

  In May 1959, the most obvious and vocal of the harriers’ avian neighbours were the Curlews, while Meadow Pipits, followed by Skylarks, were the most numerous passerines. There were three pairs of Curlews nesting between us and the base of the hill. With young recently hatched, the adult Curlews often flew to attack possible predators which passed near them. Crows invariably received this treatment but the harriers worried the Curlews less. If the cock harrier was perched, usually on a fence post, the Curlews ignored him, though one pair had chicks 50 metres or so from one of his favourite resting places. There was some sparring between the Curlews and the cock harrier when he was in flight but, at this and later nests, Curlews paid less and less attention to harriers as the season progressed, and it was not unusual for them to breed successfully within 100 metres or so of a harrier’s nest. Once, at the 1959 site, an attacking Curlew flew at the female, in characteristic, straight, fast flight when she was just above her nest. She feinted to avoid the attack and then made a savage dive at the Curlew when it had landed again, and probably struck it momentarily. Sheep, advancing close to Curlew chicks, caused the greatest outbursts of parental alarm—once, I saw a ewe turned aside in its path by a pair of Curlews barring its way with upraised wings, using both wings and bill to dunt its nose.

  Young Curlews are commonly taken by Hen Harriers in Orkney, yet in Galloway I have not found a trace of them in prey remains or pellets gathered over the years, but Bert Dickson has two records of young Curlews as prey on the moorland Area B. The two next commonest waders on the moor were Golden Plover and Snipe; of these only Snipe have been detected as prey of local harriers. Allowing that my prey sample is by no means conclusive, the absence of young Curlew or Golden Plover invites speculation on the reasons why. It is possible that, on this very open type of moorland, the warning cries of parents are particularly successful at foiling the harrier’s method of capture by surprise approach.

  The harriers’ predatory neighbours were Short-eared Owls and Kestrels, both nesting quite near. There was only occasional buffeting between owls and harriers but the cock Kestrel, carrying prey to its mate in an old Raven’s nest on a rock face, was chased or dived at by either harrier if he passed close to their nest. Carrion Crows and Ravens were assured of an onslaught whenever they appeared with 500 metres if the male was about, or the female off the nest. We soon learned to listen for the protesting calls of harassed crows—though they were sometimes the attackers—to lead our eyes to the male harrier approaching with food. We occasionally saw a Merlin slip across the hill but there was no sign of its nest that year, though a pair have bred there more recently. Many, but by no means all, of the Galloway harrier nests have had Short-eared Owls breeding fairly near them, twice at 200–250 metres distance, but I am not sure if any special association between the two species could be argued. Short-eared Owls’ nests are very difficult to find and the chances of locating one, if it happened to be near a watched harrier’s nest, were obviously much higher than elsewhere in the same area.

  We were aware from the beginning that there was some gamekeeper activity on the moorland and that questions would be asked about the harriers’ feeding habits. No attempt was being made to manage the heather in the interests of Red Grouse and the keepers did little more than wage a sporadic war on crows and foxes. The population of grouse was low compared with the major grouse moors, but considering the sparseness of heather it was not negligible. Red Grouse could probably be bracketed with Curlew as the most numerous of the larger birds nesting on the moorland. To the casual observer, they appear much less numerous than they really are, during their time of incubation in April–May. I recall that, in 1959, neither Sir Arthur Duncan nor I expected that grouse would be an important prey of Hen Harriers. Jimmy (J. W.) Campbell had suggested that young waders formed the major part of their diet, probably from his experience in the Outer Isles; and the most recently published summary of their prey in Britain, in the Handbook of British Birds, mentioned Red Grouse as only occasional prey.

  Over the ensuing years a good deal of evidence has been gathered about prey taken by harriers in Galloway (Chapters 16 and 17). At the first nest only one of eleven identified kills was a Red Grouse (young), found after the harrier brood had flown. The rest were Meadow Pipits (3), Skylark (5) and Whinchats (2), the latter being probably the fourth commonest passerine species on the moor, exceeded only by the first two and the Wheatear. More than once, the shepherds told me, keepers would have shot the harriers if they had not known that the nest was being watched—on
ce we overheard them discussing the fact that ‘bodies in the heather were watching the birds’ and I have no doubt that, if they had found one or two kills of grouse, the harriers would have been destroyed. It is fair to add that, in recent years, I have had some very friendly talks with the principal keeper in the district, who now prefers photographing birds of prey to killing them, though I doubt if he will ever rate harriers among his favourites.

  We were fortunate in having found a nest ideally situated for observation, set in one of the most delectable landscapes in Galloway, and luckier still that the pair were particularly fine examples of their kind. It now seems hard to believe, but it was 27 May before I was fully convinced that we had been watching Hen Harriers and not Montagu’s; or, riduculous thought, Pallid Harriers! We certainly did not know the harrier species well enough to distinguish the females at a distance and it was not easy, in dazzling sunlight, to swear that the cock did have a white rump and did not have a black mid-line on the wing. In fact the cock was one of the palest of his sex that I have ever seen, causing a note to be made that the blue-grey head and breast hardly stood out from the white below; and that the back and tail were so pale that the white rump was scarcely noticeable. So he did look a little like a cock Pallid Harrier! Both birds must have been old, the cock from plumage colour and the hen from her brilliant yellow eyes, and it seems almost certain that they had bred for several years before, most likely locally.

  Kestrel’s nest

  On 27 May I made my first morning watch, reaching the look-out at 06.00 hours. The cool grey early light slowly brightened, bringing the first hint of blue to the far away hump of Cairnsmore. In the still morning air Cuckoos called almost without a break, and the songs of Whinchat, Whitethroat and Reed Bunting carried up from the scatter of willow bushes along the burn. Neither Whitethroat nor Reed Bunting had been evident during previous watches at later hours. In this study of Montagu’s Harriers in Cornwall, Ryves maintained that small birds nesting close to the harriers’ nests were immune from attack. This was probably because his female Montagu’s did not hunt till the young were fledged. At this, and many other, Hen Harriers’ nests, we were to see the female hunting very close at hand, once even jumping about in the crown of a big willow bush, shadowing the movements of a Reed Bunting in the branches below. The cock, like Ryves’ cock Montagu’s, very rarely hunted near the nest. We did not know the extent of his hunting range although, by watching him till out of sight, it was possible to say that he regularly travelled well over a kilometre from the nest and probably much further. The size of hunting areas in Orkney is being studied by observing colour-marked birds, but no colour marking has been done in Galloway, so precise information on this subject remains lacking in the region.

  On the first morning watch I expected to see a food pass fairly soon. Possibly the hen had already been fed, but from 06.00 she received nothing till 10.45. The cock had flown in at 06.50, heralded by a little excited Curlew chatter, but not the prolonged alarm calls signifying danger in the form of man or fox. The cock harrier remained for nearly an hour, perched on different fence posts, but sometimes he made his low-pitched yikkering call, indicating for the first time that he was uneasily aware of my presence. It may have been a flash of light on my telescope which bothered him; through it I was able to see his fierce-looking yellow eye and note the quick owlish swivelling of his big grey head. At later nests we often found that it was well into the morning before a sitting female was fed, but the nagging thought that we might sometimes have missed a pass soon after first light could not be discounted.

  We maintained our cautious policy of not visiting the nest until we were sure that hatching had taken place. On 2 June, after a food pass, the hen stayed off the nest for only eight minutes, instead of her usual 15–20, and obviously carried in most of the prey. It seemed certain that one or two chicks had hatched and, next day, Alan and I went to look at the nest for the first time. The hen was off, having just taken a food pass. She was much less aggressive at this first visit than later on, coming no lower than six metres above our heads. Her yikkering alarm call, on first hearing, reminded me of a Song Thrush’s alarm notes. I wrote in my diary of this first exciting look at a nest: ‘As we approached the now well-known spot through deep heather, I feared treading on the nest but the first view of it was startlingly clear—a clear space in the heather with neat, spotless nest, black heather stalks, grass lined, somewhat flattened—by no means large—with two very small young and three eggs, piled in the centre. Young much of a size, a day or two old, pinkish with scarcely any down yet, some blueish skin especially above eyes, flat, broad skulls, pitch-dark eyes, jet-black bills, pinkish ceres and flesh-pink, weak looking feet and legs. Made no sound, only just able to raise heads to look blearily at us. Eggs surprisingly small, dull whitish, slightly brown stained.’

  We stayed only a few moments, lest the diving, yikkering female attracted notice from passers-by on the road. She followed us down the hill, in some frenzy, alighting and glaring from rocks, but did not come out over the moor. The male did not appear. As soon as we were back at the look-out below the road she returned to the nest.

  If the first chick had hatched on 31 May, incubation had begun about 1 May. It may have begun after the first egg was laid or later.

  During the ten days of the pre-hatching period since the nest had been found, it had been under observation for 31 hours, the longest period I have watched a nest with eggs. We had seen only five food passes in this time, so that, on average, the female sat for over six hours at a stretch. During the early days of June, with young to be fed, the cock’s visits with prey greatly increased, but we had some puzzling and slightly disturbing watches. Was it time to retire to a more distant or less open look-out? On 6 June, the cock came five times with prey between 10.30 and 18.00 hours, but there were no food passes and only his last catch reached the nest. This was dropped by the cock when almost stalled over the nest. Later, I learned that this was common behaviour, especially around the hatch.

  It was a coldish day with some heavy rain at mid-day and the chicks evidently required much brooding. We had noticed that the cock sometimes flew with prey to a gully beyond the nest, where an old hawthorn was a favourite perch. Beneath the tree we found the plucked, headless, but uneaten carcases of a Meadow Pipit and a fledgling Skylark. I made more, but similar, finds at a cock’s ‘look-out’ post at a 1961 nest. In both cases it seemed possible that the cock had become nervous of us, although in 1961 I had a more concealed observation point. Eddie Balfour always considered that male harriers had, in general, more nervous temperaments than females. On the other hand, a more plausible explanation may be that, when the young are very small, some cocks bring more prey than the hen will accept.

  Back in 1959 I was only beginning to learn. It is easy to say that it was imprudent to go to the nest in the rather poor weather of that 6 June, but we had watched for a long time and were puzzled to have seen nothing of the hen, and eager to make certain that some disaster had not struck the nest. We were relieved to find four chicks had hatched and we received some spectacular head-high onslaughts from the hen; but, again, the cock did not come into view. The hen returned to brood her chicks as soon as we were back at our look-out.

  In early June we were still having difficulty in deciding whether it was always the female which made the far carrying ‘squealing wail’, or food call, ‘twiss-yew’, just before the food pass. Although this is typically the begging call of the female to her mate, later experience showed that males make a very similar call, notably when a female refuses to rise for a pass. The low call which the male may always make, as he approaches with prey, is audible to human ears for less than 100 metres.

  On 12 June, Willie Austin joined me on an evening watch. At 19.30 the sun was already dropping behind the rather commanding skyline of hill which we had christened the ‘Lion’s Head’. It was a radiant evening, with long banners of sun-topped cloud over the far hills and a flawless sky above.
The harriers’ nesting slope was in deepest shadow and the cock was engaged in a magnificent exhibition of leisured, soaring flight over the other, still sunlit, side of the hill. At 19.55 he had a small kill but apparently consumed it himself, re-appearing as a black silhouette floating in the sunset sky. He was still up there, in the glow of sundown, at almost 22.00 hours. One previous night he had been perched high up on the hill above the nest, where he would probably remain to roost. How to explain the apparently effortless, so evidently enjoyable, high flying? It seems to me that there is really no need for the scientist and the layman to fall out on this. If such behaviour must have ‘survival value’ for it to persist, there is no need to deny enjoyment, too. There can surely be two sides to the same coin, as an athlete or a primitive hunting man for that matter, may be exhilarated by keeping himself to the peak of fitness.