PROGRESS AND PROSPECTS IN RINGING

416 MIGRATION AND ORIENTATION : R. SPENCER IBIS 101

PRATT, J. G. & WALLRAFF, H. G. 1958. Zwei-Richtungs-Versuche mit Brieftauben: Langstrecken- fliige auf der Nord-Sud-Achse in Westdeutschland.

SAUER, F. 1957. Die Sternenorientierung nachtlich ziehender Grasmiicken (Sylvia atricapilla, horin und C U T ~ U C ~ ) .

SCHMIDT-KOENIG, K. 1958. Experimentelle Einflussnahme auf die 24-Stunden-Periodik bei Brieftauben und deren Auswirkungen unter besonderer Berucksichtigung des Heimfindever- mogens.

WALLRAFF, H. G. 1959 a. Ortlich und zeitlich bedingte Variabilitlt des Heimkehrverhaltens von Brieftauben.

WALLRAFF, H. G. 1959 b. 8ber Zusammenhange des Heimkehrverhaltens von Brieftauben mit meteorologischen und geophysikalischen Faktoren.

2. Tierpsychol. 15 : 332-339.

2. Tierpsychol. 14 : 29-70.

Z. Tierpsychol. 15 : 301-331.

2. Tier sychol. (in press).

Z. Tierpsychol. (in press).

PROGRESS AND PROSPECTS IN RINGING

ROBERT SPENCER

By a happy coincidence the year 1959, which marks the centenary of the Union, is also the golden jubilee year of the British bird-ringing scheme. It is, therefore, an appropriate time to take stock of the achievements of ringing, not merely to discover what positive contributions it has made to our knowledge of bird migration in its first half-century, but also to seek pointers to those species and those techniques which are most likely to repay further attention in the future.

The development of ringing. Approximately 2,000,000 birds have now been ringed in the British Isles, half this

total having been added since 1950. The annual total ringed reached a pre-war peak of nearly 56,000 in 1939, and after falling below 5000 during the two leanest years of the war, reached 100,000 in 1954, and is now on the threshold of 200,000. The initiative for this remarkable growth of activities has lain almost entirely with the ringers. Although the ringing of a few species has always been prohibited, there have been no serious attempts to promote the ringing of any particular species and much of the work has been of a random, speculative nature.

Ringing practice in Britain has passed through a series of phases, each major inno- vation providing a fillip to increased ringing, and the present scale of activities is due as much to the multiplicity of techniques at the disposal of ringers as to the increase in the number of ornithologists participating in the work of the scheme-now in the region of 600.

Although it was over 20 years before separate figures were kept, it is clear that in the early years of the scheme most ringers confined their activities to nestlings, and ringing was markedly seasonal. At an early stage the advantages offered by colonial species such as the Lesser Black-backed Gull Larus juscus, Common Tern Sterna hirundo and Gannet Sula bassana were recognized and exploited.

Trapping, however, offered the attractions of all-the-year-round ringing and a more " economical " use of rings in that nestling mortality was avoided, and by 1930 the founder and organizer, H. F. Witherby, was exhorting ringers to concentrate more on trapping, and the ringing of nestlings of such species as Willow Warbler Phylloscopus trochilus, Spotted Flycatcher Muscicapa striata and Skylark Alauda aruensis was strongly discouraged (Witherby 1931). But whereas the ringer of nestlings was free to wander the countryside with his rings, the bulk, if not the weight, of trapping equipment tied most trappers to their gardens and to the more limited range of " garden " species, and there many remained until liberated by the advent of the Japanese mist-net in 1956.

1959 MIGRATION AND ORIENTATION : R. SPENCER 417

Three techniques of the old-time bird-catchers were employed in the search for mobility: the clap net, the bat-fowling net and the trammel net, the first two retaining many devotees until today; but the clap-net is principally of use with ground-feeding species and bat-fowling nets are, if anything, even more limited in application, and it was the Heligoland trap, first built in this country by R. M. Lockley about 1933, which enabled ringers to catch the hitherto elusive summer-visitors on a worth-while scale. The cost of these traps, however, and the difficulty of constructing them, generally put them beyond the reach of individuals, led to their being sited only at focal points, island or coastal, most likely to experience concentrations of passage birds, and led also to corporate manning to ensure that full use was made of them. Bird observatories, based thus, on Heligoland traps, were established on Skokholm Island and on the Isle of May by 1934 and provided a great stimulus to ringers. A measure of their early success may be seen in the statement by Thomson (1940) “ No rare or unusual migrants were marked during 1939 as trapping on the Isle of May was necessarily in abeyance ”.

In the thirteen years since the war three developments have been of outstanding importance : the rapid multiplication of the number of observatories, the establishment of the Wildfowl Trust and the advent of the mist-net. At the observatories, Heligoland traps have continued to dominate the scene, as many as ten being in use at a single observatory, and with their aid over 600 warblers have been caught in a day at one station. The Wildfowl Trust has demonstrated the advantages of specialization and of planned programmes of marking. Its ringing campaigns on the northern breeding grounds of the Pink-footed Goose Anser arvensis brachyrhynchus and its development of the rocket-netting technique, though not yet followed by others in this country, have been notable contributions to the scheme. The mist-net, by its mobility and versatility, has done much to make each ringer a mobile bird-observatory, but this very success has tended to attract man-power from the main observatories, thereby endanger- ing the continuity of effort. This is to be regretted insofar as it is often impossible to see in its proper context a bird caught in a local bramble-patch in the way that a migrant caught at a regularly manned site can frequently be related to a particular movement. On the other hand there is much to be said for the more extensive cover made possible by mist-nets.

Ringing results. By the end of 1957 47,465 recoveries have been reported, omitting birds retrapped by

the ringer where ringed. Although 190 species are represented in this total, fewer than a hundred of them achieve individual totals of 25 or more recoveries, and many are represented by fewer than ten. Only 24 species have produced recoveries in excess of 500 (see Table 1) but, together, these represent more than three-quarters of the total recoveries. The types of species qualifying for inclusion in this table reflect closely the history of ringing effort outlined above.

If recoveries are expressed as a percentage of numbers ringed, marked differences in the liability to recovery are revealed. Table 2 lists in descending order the recovery rates of the 98 species for which 25 or more recoveries have been reported.

Small differences in the sequence occur from year to year, and the rate can undoubtedly be influenced but, in general, each species’ tendency to recovery seems to be relatively constant. Many factors must influence this tendency. Conspicuousness, due to both size and colouring, habitat preferences and distribution in relation to human distribution are undoubtedly of great importance, but the sequence in Table 2 suggests that man’s economic interest in a species is the most important factor. With the exceptions of the Kingfisher Alcedo atthis and the Great Spotted Woodpecker Dendro- copos major, the first fifty species listed are all subject to predation by man, although

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TABLE 1.

Grey Lag Goose Cormorant Tufted Duck Shoveler White-fronted Goose Pintail Wigeon Teal Pochard Sparrowhawk Pink-footed Goose Heron Merlin Hen Harrier Montagu’s Harrier Barn Owl Kestrel Mallard Shag Raven coot Little Owl Woodcock Jay Tawny Owl Woodpigeon Stock Dove Red Grouse Rook Carrion/Hooded Crow Long-eared Owl Canada Goose Eider

MIGRATION AND ORIENTATION : R. SPENCER IBIS 101

Species for which there are more than 500 recoveries.

Starling Blackbird Teal Song Thrush Mallard Black-headed Gull Blue Tit Robin Lapwing Pink-footed Goose Cormorant Greenfinch Herring Gull

7,541 4,414 3,692 2,396 2,271 1,907 1,396 1,365 1,320 1,317 1,001

882 845

Manx shearwater 822 Lesser Black-backed Gull 817 House Sparrow 742 Chaffinch 726 Gannet 720 Shag 625 Great Tit Heron Common Tern Swallow Dunnock

606 565 539 524 51 3

Total 37,546

TABLE 2. Recovery rates.

% 24.3 23.2 20.0 19.8 19.0 17.2 16.7 16.1 15.8 15.0 14.7 14.7 14.6 14.0 13.6 12.6 11.5 10.6 10.5 9.8 9.5 8.0 7.6 6-8 6.7 6.4 6.3 6.3 5.6 5.6 5.6 5.3 5.2

Shelduck 5.1 Jackdaw 5.1 Great Black-backed Gull 5.1 Buzzard 4.7 Black-headed Gull 4.7 Oystercatcher 4 7 Snipe 4.5 Lesser Black-backed Gull 4.1 Great Spotted

Woodpecker 4.1 Magpie 4.0 Common Gull 4.0 Kingfisher 4.0 Curlew 3 9 Gannet 3.8 Herring Gull 3.7 Starling 3.6 Guillemot 3.5 Turtle Dove 3.3 Blackbird 3.2 Redshank 2.8 Moorhen 2.8 Razorbill 2.7 Great Skua 2-6 Mistle Thrush 2.5 Cuckoo 2.4 Song Thrush 2.3 Robin 2.3 Nuthatch 2.2 Lapwing 2.0 Common Tern 2.0 Blue Tit 1.7 Kittiwake 1 -7

Bullfinch Greenfinch Dunnock Arctic Tern House Sparrow Ringed Plover Coal Tit Dipper Manx Shearwater Chaffinch Fulmar Redwing Yellowhammer Meadow Pipit House Martin Yellow Wagtail spp. Rock/Water Pipit Swallow Spotted Flycatcher Linnet Skylark Tree Sparrow Puffin Wren Wheatear Reed Bunting Whitethroat Sand Martin Willow Warbler

% 1-6 1-6 1.6 1 *5 1.5 1 *4 1 a3 1.3 1 a3 1 a 3 1.3 1.2 1.2 1.1 1.1 1 .o 0.8 0.8 0.7 0.7 0.7 0.7 0.7 0.7 0.6 0.6 0.5 0.5 0.4 0.4 0.4 0.2 0.2

1959 MIGRATION AND ORIENTATION : R. SPENCER 41 9

in a few cases, as with Gannets drowned in fishing nets, the predation may be accidental. Game birds, in the broadest sense of the term, birds traditionally classified by keepers and farmers as vermin, and sea birds account for all the recovery rates in excess of 4%. It will be seen that with the exception of the Corvidae, the Starling Sturnus ouZgarir, at 3.6y0, has the highest recovery rate of any passerine.

In assessing the value of ringing as an aid to the study of migration it is, of course, necessary to consider not merely the total of recoveries available, but their quality. In particular, 1 locality and date must be considered in the light of data obtained by collection and observation. This is of especial importance in the case of the many summer visitors whose winter quarters lie in Africa. Table 3 summarizes all recoveries reported from Africaor African waters up to 12 March 1959. I t will be noted that, of a total of 470 recoveries, the Procellariiformes, Pelecaniformes and Charadriiformes

TABLE 3 . Recoveries in Africa.

4

Y

G - 1

79 2

Storm Petrel Gannet Teal

1

Garganey Marsh Harrier Oystercatcher

1 1 1

Lapwing Little Rineed Plover

2 1 1

1 1 2

- Turnstone-

Snipe Dunlin Arctic Skua

Lr. Black-backed Gull Black-headed Gull Common Tern

9 1 7 - 2

37 -

45 4

15

3 11

245

4 1 2

-

-

Arctic Tern Roseate Tern Sandwich Tern

Razorbill Puffin Cuckoo

-

1

28 2 1

3 2 1

__

Swallow Wheatear Redstart

Willow Warbler Chiffchaff Wood Warbler

Spotted Flycatcher Meadow Pipit Pied/White Wagtail Yellow Wagtail

Total 3 15 -

73 470

2 D 2


account for no fewer than 417. So far as the 47 Passeriformes are concerned, only the 28 recoveries of Swallows Hirundo rustica provide a reasonably clear picture of winter distribution. The remainder add very little to our knowledge derived from other techniques, and it seems probable that this will continue to be the case if the present pattern of ringing remains in force. Against this may be set the considerable success with such species as the Sandwich Tern Sterna sandvicensis and Gannet, where the broad pattern is now well established (Thomson 1939, 1943).

North of the Sahara and in southern Europe, despite the poor recovery rates, ringing has been reasonably successful in providing information as to routes, and timing, and speed of migration of a number of summer visitors, and, as is well brought out in a valuable summary by Moreau (1956), has revealed the remarkable convergence of Africa-bound autumn-migrants on the Iberian peninsula from as far to the east as the U.S.S.R. Similarly, to the north of the British Isles, although there are few recoveries of the smaller winter visitors on their northern breeding grounds, a number of recoveries have helped to throw light on the nature of northward migration.

Other valuable contributions made by British ringing have concerned tracing the movements of sea birds such as the Manx Shearwater Procellaria puginus, Kittiwake Rissa tridactyla and Guillemot Uria aalge; the study of the phenomenon of partial migration in species such as the Song Thrush Turdus philomelos (no other technique being available), and above all, the discovery of the origin of the commoner winter visitors to the British Isles from eastern and north-eastern Europe, of which the Teal Anas ctecca and the Starling may be given as examples.

Reference has already been made to the importance of the bird observatories to British ringing. For some years now they have been responsible for about a quarter of all the birds ringed annually in the British Isles, and they have undertaken a far greater proportion of the trapping of chats, warblers and pipits. The results of this effort may be seen in Table 4.

With the exception of nestlings, observatories cannot be said to choose the species which they ring. They ring those species which turn up and it so happens that these are chiefly species with a modest or poor recovery rate. Table 5 sets against a list of the twenty species ringed in largest numbers at observatories in the five years 19561958 the appropriate national recovery rate. Under present conditions, the ringing of certain of these species, at observatories or elsewhere, must be regarded as a long-term speculative investment rather than a current research project.

From this brief survey of British ringing one may draw the general conclusion that singing is most likely to prove effective with species of economic importance (whether positive or negative), with large birds rather than with small, and with those species whose emigrations are undertaken largely or wholly within countries well settled by literate populations.

Yet these results are dearly bought.

TABLE 4. Birds recovered abroad 1954-1958.

Species

Wheatear Whinchat Redstart Black Redstart Whitethroat Willow Warbler Meadow Pipit

National totals

13 6

12 5

38 12 44

Observatory totals

12 6 6 4

24 9

32


TABLE 5. Bird Observatory ringing totals, 1954-1958, for twenty most commonly handled species.

National Numbers recovery

ringed rate yo

Manx Shearwater 24.987 1.17 Willow Warbler Blackbird Whitethroat Starling Wheatear House Sparrow Meadow Pipit Linnet Greenfinch Chiffchaff Herring Gull Rock Pipit Puffin Chaffinch Song Thrush Sedge Warbler Redstart Robin Lesser Black-backed Gull

i3:sos 0.23 13,351 3.24 12.600 0.36 10,296 3.63 5,674 0.39 5,488 1.32 4.393 0-77 4:286 6-66 3,918 1-39 3,817 0.20 3.264 3.66 31248 0.69 3;041 0.50 2,846 1.12 2,787 2.33 2.709 0.18 21444 0.24 2,325 2.32 1,589 4.06

Future prospects. The scope for speculation as to the future course of ringing endeavour is enormous.

If the need were sufficiently vital (and one is occasionally tempted to wish that wild birds were responsible for spreading fowl-pest !) there is little double that ringing could, at a cost, be effective in the study of the migration of most species. But the resources at our disposal are extremely limited-a single win in the football pools could finance present-scale activities for at least twenty-five years. Furthermore, our ringers are not merely volunteers, but actually the source of two-fifths* of our income, and any projects must have their wholehearted support. I t seems clear, however, that to make the most of these limited resources our policy should be to devote special attention to those species which experience has shown to be more rewarding, at the same time making every effort to improve the recovery rate of all species. In the following section some specific suggestions are put forward.

Experience has shown the ringing of winter visitors from the east and northeasi to be rewarding, yet of the common passerine species in this category only the Blackbird Turdus merula and the Starling have been ringed on a scale necessary to produce the recoveries required for a detailed analysis. The Chaffinch Fringilla coelebs appears high up on the list of species ringed, but it seems probable that a relatively small proportion of the birds handled have been of immigrant stock, for the small number of foreign recoveries (75) does not seem in keeping with the immense scale of immigration observed in most years. Even more so may this be said of the Skylark, which observations show to be an abundant winter visitor. To date there seem to have been few systematic attempts to trap these birds on a large scale, and there are only six foreign recoveries, but one in Norway and one off the S.W. coast of Finland suggest that the species would repay special attention. The Redwing Turdus musicus (3624 ringed), Brambling Fringilla montifringilla (2952) and even more strikingly, the Fieldfare Turdus pilaris (779) have not so far been caught on a large scale in Britain, but the recoveries here of birds ringed on the breeding grounds indicate the possibilities. Similarly, winter recoveries in Britain of foreign-ringed Lapwing Vanellus vanellus indicate that the winter trapping of this species would be well worth perfecting.

* The remaining funds are provided by the Nature Conservancy on a contractual basis.


It has been suggested that the recovery rate reflects, primarily, man’s interest in a species, and interest abroad is not necessarily limited to the conventional sporting species of Great Britain. In Spain and Portugal, for example, the Whitethroat Sylvia communis and Meadow Pipit Anthus pyatensis are commonly hunted and the effect of this may be judged from the fact that fewer than a quarter of the pipits recovered in Iberia are claimed to have been found dead. Over 70% are stated to have been netted or shot. The need for food is a powerful motive for trapping. If the conservation laws in Iberia were to come into line with those of the most advanced countries of western Europe it is clear that we should experience a marked decline in the numbers of recoveries of many species unless some fresh and acceptable motive could be devised. Meanwhile it is also clear that many recoveries are not reported. R. E. Moreau has pointed out (personal communication) that to a Portuguese peasant living at subsistence level the postage fee to England represents an appreciable proportion of a day’s earnings. The surprising thing is that so many rings are reported at all, and many European ringing schemes are indebted to Mr. G. M. Tait of Oporto, and to his uncle before him, who over the years have encouraged the reporting of rings in the local press, and in this way have been responsible for a disturbingly large proportion of recoveries notified from Portugal. Such matters should not be left to the initiative of one person. This type of problem effects every scheme and we must be prepared to spend a greater proportion of our income on propaganda, at home, and, if necessary, abroad. It would also be worth going to considerable trouble to devise an arrangement whereby postage on recovery letters could be paid by the addressee. The French experience with rewards in North Africa was not encouraging. On the other hand the system has worked well in Greenland and there are probably other areas, especially in Europe, where it could be employed with safety and to good effect, and it should not be written off too readily.

One of the encouraging signs for the future is the way which ringers are now re- trapping each other’s birds. Already this is a valuable source of recoveries in the British Isles and, aided by the widespread increase in ringing, it is becoming important internationally. This suggests the desirability of paying special attention to selected species as a means of increasing recoveries, initially on a national scale, perhaps, but ultimately over a wide area by international agreement. The Hirundines, for example, would be an admirable group for this type of project, for, being colonial, it is generally possible to ring them on a large scale on the breeding grounds, and their habits of con- centrating to feed over water and of roosting communally, enable them to be taken on a large scale by means of mist-nets. Extensive dyeing of plumage, in conjunction with ringing, would offer a method of detecting the presence of “ foreign ” individuals, and this is, in fact, already being practiced on a modest scale with European Swallows wintering in South Africa. Even within so small an area as the British Isles such a project might be expected to produce results, and the same technique might be applied to the study of the inland passage of waders. The Common Sandpiper Tringa hypoleucos would be an excellent species for study in this manner, for many concentration points are already known and well watched, and its habit of flying low over the water renders it particularly susceptible to mist-nets.

The problems of obtaining more recoveries of passerines from their winter quarters, or even on passage through Africa are considerable, and only a long-term campaign would be likely to show any improvements. Similarly, the thinness of the human population in Greenland, Iceland and northern Scandinavia leaves little room for hope of a dramatic improvement in the rate of recoveries from those areas. If ringing is to be of real value in these regions it must be carried out there. In the case of the Pink-footed Goose, the Wildfowl Trust, with the co-operation of Dr. Finnur Gudmund- sson, ringed intensively on the restricted Icelandic breeding grounds, relying for recoveries on the more densely populated winter-quarters. This technique could be extended in


varying degree to certain other northern species, and, in Africa the reverse process, of ringing Palaearctic migrants in the thinly populated winter-quarters, should be increased as much as possible. Unfortunately, whereas with the geese there were strong economic interests to justify the expense of such an operation, pure research is generally less successful in attracting the necessary backing. Furthermore, few species are so conveniently restricted in their breeding distribution as the Pink-footed Goose, so that a brief campaign would suffice, and in Africa at least, it would be necessary to think more in terms of establishing semi-permanent stations. Unfortunately, too, there are very few ringers or potential ringers resident in the important areas. Africa, in particular, is virtually untouched, yet the pioneer work of the French at Cape Bon and G a b b has shown that the potentialities are immense, and their two new stations in southern Algeria and Senegal should prove of great value.

A useful species to start on in Africa would be the Yellow Wagtail Motucillu flava, of which large concentrations have been reported wintering in Kenya (Meinertzhagen 1956). This is a species which can be trapped readily, and large-scale ringing carried out during several winters, if supported by complementary summer and autumn campaigns in the European breeding areas would have every chance of success.

The study of European migration by means of ringing is hampered by the multiplicity of schemes and the lack of co-ordination of effort. Whereas two schemes, closely linked, administer ringing over the whole North American continent, in Europe there are over thirty general schemes of international importance. There is, it is true, the complication of language differences to overcome, nor can national aspirations be ignored, but it would be an immense step forward if these schemes could be reduced to not more than one in each country, and if recovery data could be made readily available between schemes. Not least in Great Britain, there has been a tendency to interpret recoveries from a somewhat parochial standpoint and the difficulty of assembling all the data encourages this. Nowhere is there so great a need as in Europe for an international committee to co-ordinate efforts, unify equipment, and to facilitate the assembly of data for extensive surveys such as that on the Heron Ardea cinerea by Rydzewski (1956). We cannot really afford to work in such watertight compartments when we are dealing so often with the same species and even the same populations.

Although it lies outside the migrational theme of this paper, it is necessary to mention in conclusion the other important aspect of ringing. The early papers by Lack on age and survival (1943, 1946) demonstrated the value of ringing in this field of study. More recently the statistical approach has been developed by several authors, one of the most detailed studies being that on the Teal by Boyd (1957). This growing interest in population studies has led, in Great Britain, to an increasing awareness of the unsatisfac- tory nature of conventional aluminium rings, which have been shown to gape and fall off, or to deteriorate very rapidly on certain species due to abrasion or corrosion. The development of an improved ring, capable of meeting the exacting requirements of longevity studies, has high priority, and there are grounds for hope that a solution is not far distant. The availability of adequate rings is likely to stimulate a series of long-term population-studies, and this aspect of ringing research seems destined to become as important as the migration studies.

SUMMARY 1. The main features of the first fifty years of British ringing are described. 2. Recovery rates are discussed.

3. A brief assessment is made of the contribution of British ringing to migration studies. 4. Some ringing projects are suggested. 5. Closer international co-operation is required to promote the reporting of recoveries. To

6. The number of separate ringing schemes in Europe causes difficulty in assembling data

It is suggested that man’s interest in a species is the most important determining factor.

this end propaganda campaigns and joint studies are advocated.

for extensive studies.

424 MIGRATION AND ORIENTATION : R. K. CORNWALLIS IBIS 101

REFERENCES

BOYD, H. 1957. LACK, D. 1943. LACK, D. 1946. MEINERTZHAGEN, R. 1956. MOREAU, R. E. 1956. RYDZEWSKI, W. R. 1956. The nomadic movements and migrations of the European Common

THOMSON, A. L. 1939. The migration of the Gannet : results of markings in the British Isles.

THOMSON, A. L. 1940. Report of the Bird-ringing Committee for 1939. THOMSON, A. L. 1943. The migration of the Sandwich Tern : results of British ringing. Brit.

Birds 37 : 62-69. WITHERBY, H. F. 1931. Report on British Birds Marking Scheme for 1930. Brit. Birds 24:

Mortality and kill amongst British-ringed Teal Anus crecca. The age of the Blackbird. Do juvenile birds survive less wcll than adults?

Ibis 99 : 157-177. Brit. Birds 36 : 166-175.

Brit. Birds 39 : 258-264. Yellow Wagtails in Kenya. Brit. Birds 49 : 240.

T h e Iberian Peninsula and migration. Bird Study 3 : 1-25.

Heron Ardea cinerea L. Ardea 44 : 71-188.

Brit. Birds 32 : 282-289. Brit. Birds 33 : 319.

236-237.

BIRD OBSERVATORIES

R. K. CORNWALLIS

Although observatories were established on Skokholm and the Isle of May in the thirties, it was not till after the war that the idea spread and the chain of coastal stations that has been such a feature of post-war field ornithology in Britain was gradually formed.

There are now 14 fully-established observatories-Fair Isle, Isle of May, Monks’ House, Spurn, Gibraltar Point and Cley covering the North Sea coast; Dungeness, Portland and Jersey in the English Channel ; Lundy, Skokholm, Bardsey, Copeland and Great Saltee covering the Irish Sea area. In addition more ephemeral or less fully- equipped stations are operating at Walberswick, Bradwell, Sandwich, St. Catherine’s I.O.W., Scilly, Hilbre Island, Tory Island and St. Kilda.

Observatory work has three main aspects-visual observation and counting of birds reaching the various stations; ringing; critical examination of birds in the hand.

The most distinctive contribution to migration studies that the observatories have made during the twelve years or so they have been operating has probably been the provision of regular and simultaneous observations throughout the migration seasons and over a wide area. Collation of these simultaneous observations has made possible a new assessment of the way migration takes place in and through Britain and, coupled with the study of meteorology and the application of the synoptic weather-charts, has led to a new realisation of the important role weather and particularly winds play in the fortunes of migrating birds. Earlier workers, notably Eagle Clarke, tended to discount the importance of weather but, although this view was challenged by Baxter and Rintoul, Coward and others, it was not until the work of the observatories showed clearly that certain types of movement are quite characteristic of certain patterns of weather that its importance received general recognition.

The aspect of these studies that has received most (some people maintain too much) attention is the theory of “ drift ” developed particularly by Kenneth Williamson. It is true that every study-method carries within itself its own inherent limitations and its own inherent biases. It was thus inevitable that simultaneous observations, especially along the east coast of Britain, should highlight the fact that in certain conditions winds blowing off the Continent bring heavy falls of night-migrants simultaneously to wide stretches of this coast, and likewise westerly winds inhibit them. These falls of off- course, displaced birds often contain rarities of eastern or southeastern origin, which again has focused attention on them. It is fashionable today to despise rarity-hunting; nevertheless these misplaced vagrants do sometimes give valuable clues about the origins of these movements.

PROGRESS AND PROSPECTS IN RINGING

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