The Hen Harrier Page 18
The recoveries of ringed birds, discussed below, do not at present provide enough data to confirm the impression, from field observation, that a high proportion of adult males, wintering in Britain, are to be found in the west of the country. Although counts at winter roosts (see Chapter 18) may give a good indication of the proportion of adult males and ringtails in a particular region, this cannot be completely relied upon in this respect owing to the difficulty of ensuring that all roosting sites, communal or solitary, are known. Nevertheless, it can be noted that very few adult males are seen at winter roosts in Orkney (Balfour and Green, pers. comm.) or on Deeside (Picozzi, pers. comm.), but Frank King found a roost occupied entirely by adult males in Kerry, south-west Ireland during October.
In Belgian Lorraine, Mois noted that males exceeded females by two or three to one between October and the beginning of March, and females usually predominated in March and April. The winter climate of this region is not particularly severe and so generally provides suitable hunting conditions for males. It appears that, with the onset of the most severe weather in Denmark, especially in late January and early February, a number of harriers, including a majority of adult males, travel south to Lorraine and the Grand Duchy of Luxembourg (Mois, 1975; Wassenich, 1968). It is also likely that there is a westerly movement into Britain in mid winter; this may explain why Hen Harriers are most often seen at Gibraltar Point observatory, on the Lincolnshire coast, in January and February (Durman, 1975). The record of an adult male ringed in Belgium on 11 November and found in Norfolk on the following 9 February could be consistent with such a late westerly migration. The decline in the proportion of adult males at winter roosts from February onwards, which has been noted in Galloway and Lorraine, may be due to a tendency on the part of males to seek breeding grounds in advance of females.
Before 1974, a total of 1544 Hen Harriers had been ringed in Britain and Ireland, and 143 (9%) had been recovered (Spencer and Hudson, 1973). All but twelve of those recovered were ringed as chicks or juveniles. In Fig. 8 and Fig. 9 I have plotted all recoveries of birds ringed in Britain and Ireland, and British recoveries of birds ringed abroad, up to November 1975, at distances greater than 80 kilometres from the ringing localities. Mead (1973) has published an earlier analysis and I am indebted to the guidelines set by his maps.
The great majority of the records are of birds ringed in Orkney by Balfour. Mead noted that the British evidence showed a southerly movement during the winter with exceptional birds travelling 500 or even 1,000 kilometres. Even so, the remarkably scattered pattern of recoveries is illustrated by the two most distant, one (January) from Argyll south to the Basses Pyrenees and the other (February) from Orkney north-eastward to Buroya islet off the Norwegian coast. The wide dispersal of some Orkney birds is further illustrated by recoveries in south Norway, Denmark, the Netherlands, West Germany, south-west Ireland and East Anglia. The eight breeding season recoveries of Orkney birds at distant localities are of particular interest, suggesting, as Mead pointed out, that there has been colonisation of fresh areas by the ‘vigorous Orkney population’. Although five of these records are in eastern Scotland, including at least one shot at a nest, three are much more distant, two in the Netherlands and one in West Germany.
Fig. 8 Recoveries of Hen Harriers in Scotland (one recovery of a male, Kincardineshire–Banff in August, age c. 2 months, is not shown
Four winter recoveries give evidence of immigration into England: from Finland, the Netherlands, Belgium, and one from Noord Holland having travelled as far north as Lancashire. Goethe and Kuhk (1951), quoted by Mead, listed German recoveries and showed that a few Hen Harriers remain in Germany and the Netherlands, but most winter in France and Italy. Bernis (1966) records two north German birds, one in north-east Spain and one on the north Portuguese coast. Most of the Hen Harriers wintering on the south-east shores of the North Sea originate in Norway and Sweden (Mead).
Fig. 9 Recoveries of Hen Harriers outside Scotland
more than 80 km distant
I have examined the ringing recoveries for evidence of any differences in the migratory pattern of first year and older birds, or of males and females. Considering all the cannot be regarded as conclusiveacceptable reports* there is a close similarity between the proportions of first year and older birds found distantly from the ringing locality (see Table 5). If first year birds are not significantly more migratory than older birds, as the table suggests, then the Hen Harrier differs in this respect from some predators in Britain, such as Kestrel and Merlin (Mead, 1973).
Table 6 gives the proportions of first year and older birds found more than 80 kilometres distant from ringing localities in the period September to April. The suggestion, in Table 6, that a higher proportion of older than first year birds winter distantly from breeding grounds, is supported by a different analysis, using only Orkney ringed birds recovered in the mid-winter months, November to February. According to this, 13 first year birds were found in Orkney and the same number outside Orkney, while only five older birds (33%) were recovered in Orkney compared with ten (66%) elsewhere. Although, as has been shown, many British Hen Harriers travel a long distance from breeding areas in autumn or winter, it seems remarkable that so many appear to make no appreciable migration at all.
If, however, a comparison is made between first summer recoveries (May to August, i.e. including birds recovered in the August of the year after they were hatched) and those in later summers, there is a strong suggestion that older birds are more likely to spend the breeding season in or near their natal area. Nevertheless, the results of this comparison cannot be regarded as conclusive owing to the small sample of first year birds available (Table 7).
Whereas older birds recorded in Table 7 are likely to have been breeding, only a proportion of first year birds may have been doing so. It is interesting to find that some of the oldest birds recovered have been found in the breeding season, close to where they were ringed as chicks; one of the most remarkable was a female, ringed as a chick in Orkney in July 1963, which was alive and breeding only 15 km away almost twelve years later. Similar faithfulness to the home region, after a long period, was shown by an eight year old female in Galloway. Males do not appear to differ obviously in this respect: two breeding season recoveries, in the home area of Orkney, being of birds approaching five and six years old.
There are 51 recoveries, for all seasons, of British ringed Hen Harriers of known sex. Of these, eight out of 23 males (35%), and twelve out of 28 females (43%), were recovered more than 80 kilometres from the place of ringing. There is therefore only a slight suggestion that females may be more migratory than males.
Balfour and Cadbury found that although a large proportion of the young in Orkney had been ringed each year, only 19 out of 83 (23%) breeding adults captured there had been ringed as chicks in the archipelago. They considered that immigration, particularly of males, might be necessary to maintain the population level in Orkney. As I have pointed out in Chapter 6, they also found that the proportion of females over five years old (42%) was higher, and that of first and second year birds lower, in the Orkney breeding population than was expected, and they considered exclusion of younger birds by social behaviour a possible explanation.
In Table 8 I have given the age groups of all ringed Hen Harriers known to have died, or been killed, after they had fledged. This table demonstrates the high mortality in the first year, and shows that in later years life expectancy for the survivors declines very slowly. There is no apparent difference in survival of males and females. According to Brown and Amadon, the average life of a Hen Harrier, ‘once mature’, must be about seven years, and length of life is occasionally as much as 16 years.
Man was responsible, deliberately or by accident, for most deaths of Hen Harriers for which the cause was known. Out of 37 recoveries of ringed birds for which the cause of death was certainly or almost certainly known, ten were reported shot, five trapped and one poisoned (43%), and 13 (35%) appeare
d to have been killed by overhead wires. When Balfour and Cadbury (1975) analysed the recoveries of Orkney ringed birds for which the cause of death was known, they pointed out that 16 out of 26 (62%) found outside Orkney had been shot, trapped or poisoned, compared with none out of ten found in Orkney. They also commented on the high proportion of casualties from striking overhead wires in Britain as a whole; deaths of Hen Harriers from this cause were more than three times as common as of Kestrels, a proportion which was thought to reflect the different hunting methods.
There can be little doubt that awareness of the protection laws has resulted in many cases of deliberate killing being reported as ‘found dead’ and, probably, of more not being reported at all. I have found that nine (18%) of the first 50 ringing recoveries (1939–59) were reported as shot or trapped, compared with only two (4%) of the last 50 (1967–75). It might be argued that this suggests that fewer harriers have been killed by man in recent years, but my own subjective impression is that the reverse is likely to be true. A. A. Bell (see Table 3) has reported two instances, in Perthshire and Norfolk, of deaths ‘undoubtedly due to exceptionally high levels of dieldrin’ and one of death from eating carrion bait containing mevinphos. As these chemicals were found among only nine birds analysed, it seems possible that mortality from toxic chemicals or poisoned bait may not be uncommon among British Hen Harriers. As I have said in Chapter 6, however, evidence that toxic chemicals have impaired the breeding success of British Hen Harriers is lacking; but this has occurred elsewhere.
Three Hen Harriers were killed by road traffic, one was found dead on a railway and another ‘pursued a bird into a building and could not escape’. Wild predators probably killed two adult females: one was found ‘freshly-killed in a fox den’ in Caithness in June, and the other was probably killed by a Golden Eagle in Galloway (see here). At least two birds probably died from starvation. Perhaps the most curious reports were of one ‘freshly dead on a rose-bush’ and another ‘stuck in a tree’—and released!
* In my analysis of ringing recoveries I am greatly indebted to the Ringing and Migration Committee of the British Trust for Ornithology for permission to examine all the recoveries of Hen Harriers ringed in Britain and Ireland, and those ringed abroad and recovered in Britain (none of the latter have been found in Ireland).
† Two chicks, illegally taken from a brood in North Wales, were ringed and ‘hacked back’ in Anglesey, and released on 14 and 19 July 1973. The first was found shot on 29 July near Oswestry, Shropshire (100 km ESE) and the second was ‘shot’ on an unspecified date in August near Basingstoke, Hampshire (290 km ESE).
* Since this was written, R. C. Dickson has seen a ringtail with a white wing-tag at a roost in Galloway on 24 October 1976. Nick Picozzi tells me that this bird must have been tagged as an adult, by him, in Orkney during the summer of 1975.
* Recoveries up to and including August of the year hatched are excluded from the tables as some may have been of birds which never fledged and others are certain to be of birds still dependent on their parents. I have also excluded any in which the circumstances of the recovery made it impossible to judge whether the bird was first year or older. Birds recovered up to August of the year after hatching are counted as first year.
CHAPTER EIGHT
The Hen Harrier as an Artist’s Bird
Since the illustrations play a considerable part in this book it may be appropriate to give some account of their origins. I realised, many years ago, that for a bird artist with a special interest in depicting his subjects in their environment, harriers offered exciting possibilities. Even so, my early attempts at painting Pied Harriers over the Burmese paddy fields and Hen Harriers hunting the Hebridean machair, were frustrating, to say the least. I could capture nothing of that elegant flight and only succeeded in spoiling a promising background with birds whose impossibly angled wings seemed pinned to their bodies.
I only began to make tentative progress when I spent a whole summer watching my first pair of Galloway Hen Harriers with a sketch book always at hand. I did not particularly want to make static close-up portraits of the birds. These, of course, had been done to great effect by artists like Wolf, Thorburn and Lodge but, when the great illustrators painted birds of prey in flight, I thought they sometimes diminished their impact by too much detail of feather markings. In this respect it is interesting to note how Liljefors, the master of European wildlife art, increasingly eliminated detail in his later, most monumental works. It seemed to me that few bird artists had tackled Hen Harriers as I saw them, small in scale yet making a vital focus in a spacious setting, though Charles Tunnicliffe and J. C. Harrison had each done impressive studies of Montagu’s Harriers in flight, capturing the elusive moment of the food pass. I had also seen and greatly admired some small flight studies of Hen and Montagu’s Harriers by Eric Ennion. These convinced me that I had everything to learn.
I am often asked whether I use photographs as aids to bird drawing and when I answer that I only do so sparingly the questioner seems to think, sometimes, that I am being perverse and making unnecessary difficulties for myself. So I had better explain. Of course, I admire and enjoy good photographs of birds and, as Talbot Kelly said, ‘no painter can ignore the photograph’. In his beautifully written book, Bird Life and the Painter, he said almost all there is to say about how and why a bird artist goes to work. ‘If we are to absorb birds as the Chinese artists did,’ wrote Talbot Kelly, ‘we must begin by sharing something with them, whether it is the plum blossom among which the myna sits, or the trough of the sea that embowers the petrel. . . The artist must see bird and environment, and the bird’s actions, as one whole.’ For myself, at any rate, the study of photographs cannot be a substitute for such experiences. As Russow, the biographer of the painter Liljefors, said: ‘our eyes always combine several movements into an impression and therefore have a different conception of truth from the photograph.’
No doubt, if field study is impossible, the wonderful modern films of wildlife could provide a vicarious reality from which an artist might work, but it must be remembered that the best films are already creative to a high degree and cannot therefore be regarded by the painter as the raw material of nature. Surely the wildlife artist needs to experience the excitement, the difficulty and, often, the discomfort of observing and selecting his subject matter in direct confrontation with nature. Even the best photographers admit that colours and tones in their pictures can be capricious. This, of course, is not to say that reference to photography and museums is not of great value in increasing an artist’s stock-in-trade of knowledge, especially in regard to details of plumage and structure which may elude him in the field. Tame birds, in zoos or elsewhere, provide marvellous models for sketching and study of detail, but here a caveat must be sounded. I think it was Charles Simpson who spoke of ‘the beauty of detail lost’. How easy it is when faced with the close-up zoo animal or dead specimen in the studio to become obsessed with the charm of detail, and entirely lose the liveliness of the swift impression which belongs to a few particular moments in time. It is particularly risky to rely on even the cleverest taxidermy in a mounted specimen as a guide to the posture of a living bird.
To return to the Hen Harrier, it must be said that it is no better as a subject for the artist than many other birds. Yet it has several features which I find extremely stimulating and I can honestly say that I never tire of trying to master the bewildering variety of its flight postures. I have watched the swift manoeuvre of the food pass countless times but have never yet achieved a satisfying drawing of the actual exchange. Undoubtedly the dimorphism of male and female Hen Harrier is particularly attractive to an artist. Then, too, as some politicians are natural subjects for the caricaturist, I find Hen Harriers with their rakish outline more tempting to draw than the blunter short-tailed Buzzard or eagle; yet I much admire the best flight studies of these, such as Liljefors achieved and Douglas Weir seems able to manage with a deceptively throw-away ease. I need only to
look back at my own sketch books to be reminded that year after year certain species recur unfailingly while others, as often seen, are rather neglected. Not all are favourites for the same reasons but it is certainly true that such diverse examples as Spotted Flycatchers, Great Grey Shrikes and Hen Harriers share a kind of élan which makes my fingers itch for a pencil and paper.
I have already explained, in the Introduction to this book, how a pair of harriers make a compelling focus of life in a spacious landscape. Whether in its pallid mood of spring ochres and browns or, later, when the high green of bracken beds and bronze-purple heather shimmered beneath a summer sky, the pictorial interest of the setting filled as many pages of my sketch books as the birds which related to it so intimately. The sketch book was no less important on winter days when a harrier might appear unexpectedly, brushing the skeletal grass heads, or at the roost with its special opportunities for flight studies. Some of the drawings in this book are the results of the many encounters with other wildlife on days when harriers were the principal objective.
I usually carry a small ‘Bushey’ sketch book, 17.5 × 11 cm, which fits easily into an anorak pocket. In a car I like to have a much larger one. Sketch books must be able to withstand rough usage, in all weathers, and I detest those which fall apart after a couple of outings. One or two pencils (B or softer) still seem to me adequate for my purpose, though I have tried several kinds of pens. For me, the essence of sketch book drawing lies in concentrated observation, watching the bird perform the same action over and over again—but of course it often doesn’t do that.
July is an excellent time to make flight drawings, when a female in charge of fledged young will sometimes fly a long way from the nesting site to mob you. Both she and her fledged brood can then be watched through binoculars, from a comfortable vantage point, without causing them undue disturbance. At this season, however, there is no certainty that a male will be seen. Observe the female overhead: it is close enough to reveal, momentarily, every detail of the splayed flight feathers but the wings are continually changing angle and appearance as it twists and banks. It is approaching you in a half dive but, in a second, is rising again and leaving you. Watch her make another run and perhaps one more. Has some impression of that wonderful, emphatic outline imprinted itself on your memory? You must hope so and concentrate rapidly on the sketch; no, not one sketch, but several, put down like writing, for in seconds the bird has assumed a whole range of flight shapes. The results may be mostly worthless, but the effort should be made. Something true may emerge. If not, the memory will have stored an image which may isolate itself half-an-hour later when you can recollect those breathless moments in a little tranquillity. I have been told that Joseph Crawhall stood for hours leaning on a gate watching farmyard bantams or ducks; so good was his visual memory that he drew nothing at the time but could produce a masterpiece in recollection.