Territorial and other Behaviour of the Woodpigeon

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1 Bird Study ISSN: (Print) (Online) Journal homepage: Territorial and other Behaviour of the Woodpigeon S. Cramp To cite this article: S. Cramp (1958) Territorial and other Behaviour of the Woodpigeon, Bird Study, 5:2, 55-66, DOI: / To link to this article: Published online: 17 Jun Submit your article to this journal Article views: 2120 View related articles Citing articles: 10 View citing articles Full Terms & Conditions of access and use can be found at

2 1958 SWAN CENSUS 55 REFERENCES BAXTER, E. V. & RINTOUL, L. J The Birds of Scotland. Vol. 2. Edinburgh & London. RAWCLIFFE, C. P Breeding of Mute Swans in the Lothians and Edinb. Bird Bull., 4 :70--I. RAWCLIFFE, C. P Breeding of Mute Swans in the Lothians 1953 and 19J4. Edinb. Bird Bull., 5:25. TERRITORIAL AND OTHER BEHAVIOUR OF THE WOODPIGEON by S. CRAMP Received 28 November 1957 SUMMARY T. The behaviour of the Woodpigeon (Columba palumbus) was studied, mainly in central London, for over eight years. Territories are established in early winter and maintained until the end of the breeding season. Ownership of territory is proclaimed by song and display flight to some extent, but mainly by the male's continued presence for long periods and by his driving off all trespassers. 2. Where the population density is high, only the trees in a territory are defended regularly, but in other cases areas of ground may also be included in the territory. 3. The process of pair formation is described and the displays which contribute to the strengthening of the pair bond. These displays, and mating, have been observed only in trees within the territory. 4. The function of territory in this species is discussed. Its main purpose appears to be to provide a safe place where the pair-strengthening displays and coition can take place without interference. It also helps to ensure sufficient nesting sites for a species which often makes many repeat attempts in one season. INTRODUCTION The extreme wariness of the Woodpigeon (Columba palumbus) in most areas makes any detailed study of its behaviour difficult. In central London, however, the task is much easier as it is both surprisingly tame and numerous. These observations are based on a continuous study of the species for many years, mainly in Holborn, Westminster and the Royal Parks. ESTABLISHMENT OF TERRITORY Colquhoun (1951) has stated that Woodpigeons appear to have little or no territorial behaviour. In fact, the Woodpigeon is a species with strong and well-developed territorial habits, and many birds in central London maintain a territory over the greater part of the year. It is convenient to start the account of the Woodpigeon's year in November, as nesting activity comes to an end in late August and early September and during the whole of October they are almost absent from the central area (see Figure 1). They then seek a change of food, feeding on acorns, seed and grain, and

3 56 WOODPIGEON BEHAVIOUR 5(2) large flocks may be seen at this season wherever oaks are found, such as the larger parks and at Ken Wood, Hampstead, as well as on sewage farms and fields in the outer districts Z 20 ^ i0 195q-tgS3` Figure 1. Counts of Woodpigeons in Central London Squares (monthly averages, Jan.-Dec.). In November they begin to return to the centre and odd males may be seen sitting quietly in trees in their territory, often for long periods each day. The date of the first bird to return to its territory has become progressively earlier (from 1 i December in 1949 to 2 November in 1956) as the population has built up again after the very serious reduction in numbers caused by shooting during the war. This recovery in population and the increased proportion of birds present during the last two months of the year are clearly shown in Figure 2. This is reminiscent of the behaviour of the Fulmar (Fulmarus glacialis), where birds return to the nesting 30 - zo- 10 J ^ Z J, Z Z f +q49 rqsb 1qs1 tgsz ig53 ig54 gss Figure 2. Counts of Woodpigeons in Central London Squares (2-monthly averages). s f Z

4 1958 WOODPIGEON BEHAVIOUR 57 ledges much earlier in the larger breeding colonies than in the small ones (Fisher 1952). Coulson and White (1956) have reported similar behaviour at the colonies of the Kittiwake (Rissa tridactyla) studied by them, but they argued that this was because the larger colonies were usually older than the small colonies and consisted of older birds, which tended to commence breeding earlier in the season than young birds. The average age of the Woodpigeons in central London has almost certainly risen in recent years with the growth in population and as they appear to maintain the same territory year after year in many cases a similar explanation probably holds, but it appears probable that the present high density may also act as an incentive to secure a good territory as early as possible. A further contributing factor in the case of the Woodpigeon is the probability that the increased numbers in recent years have exhausted the supply of acorns, etc., more quickly, so leading to an earlier return to the centre. By December many more birds are back, and when they are not feeding (and this takes up a surprisingly small part of their day) they perch in trees or, less frequently, on buildings. As well as the males, and occasional pairs, in territorial trees, small groups of Woodpigeons, from three to ten, may be seen perched in other trees and these are, I think, unmated females or males which have not yet taken up a territory. The males occupying territory are mainly silent and undemonstrative, and it appears that they mark their ownership of a territory primarily by just being there and a Woodpigeon perched in a tree bare of leaves is a large and conspicuous object. The first song is usually heard in December, but it is relatively rare then and even into January. Indeed, as Table I shows, the volume of song continues to rise in February and remains at the highest levels from March until June, although most territories are being staked out and fought for in the first three months of the year, and by April many nests have been started. TABLE I SEASONAL OCCURRENCE OF SONG AND DISPLAY FLIGHTS Month Song Number % Display Flights Number % January February.. I March April May o June July August September October November 1 0.I December TOTALS

5 58 WOODPIGEON BEHAVIOUR 5(2) In December the males are most likely to be seen in their territorial tree (or trees, for, as is described later, the majority have several trees in their territory and defend them all) around noon or early afternoon, but by January their visits usually extend to the mornings and evenings also. Thus, in early January the male holding territory in the small piece of land outside my flat will normally arrive in the tree about ten minutes before sunrise on a fine morning (but often much later in dull weather) and as the days lengthen he tends to arrive a little later in relation to sunrise until in February and March he is not usually seen until sunrise or just after. It would seem certain that on most mornings he flies from the communal roost (usually, from the direction of his arrival, the long-established roost on the island in Regent's Park lake, about one and a half miles away) direct to his territory before feeding. On most mornings, but not all, he sings two or three times on arrival and then soon afterwards goes to feed, although at times he will remain silent in the tree for as much as half an hour before doing so. Ownership of territory is also proclaimed by the well-known Display Flight. This occurs much less frequently than song, but, as is shown by Table I, is most frequent earlier in the year, above all in February and March, when territorial squabbles are most frequent. The flight takes place over a much wider area than the territory, but is usually centred on it. It affects other males strongly, often causing them to fly up and display in the same way, and sometimes making another bird in its territorial tree begin to sing as the displaying Woodpigeon flies overhead. I have not heard the wing `clap' in central London as frequently as some authorities suggest. Thus T. A. Coward (192o) wrote as though it was invariably heard and the Handbook of British Birds (Witherby et al., ) states that it occurs commonly, but not always, whereas I have heard it on less than five per cent. of the display flights in central London. It is interesting that Heinroth ( ), who studied the Woodpigeon in similar urban surroundings near the Berlin Zoo, said that wing-clapping occurred very rarely. PAIR FORMATION From November onwards then, and more regularly by January, the unmated male Woodpigeons may be seen sitting in the trees in their territories, occasionally singing and less often launching themselves into display flight, but more often perched silent and motionless, save for infrequent bouts of preening. Sooner or later they acquire mates. It is most difficult to watch the initial stage in pair formation in any species, but I believe I have been fortunate enough to see it three times in the Woodpigeon. The unmated females must be well aware, in their wanderings around the area, of the trees occupied by unmated males with territories. Sooner or later one visits a tree where a male is perched and, as in other species where the plumage of the two sexes is similar I believe the male recognises the female largely by her behaviour. When another bird lands in his territory he at once wakes from his lethargy and flies over

6 I958 WOODPIGEON BEHAVIOUR 59 to the intruder. If the intruder is another male it usually flies off immediately on this approach, though fighting may sometimes occur, as is described later. If it is a female, however, and ready to obtain a mate, she will stand her ground, though often rather Figure 3. The Bow. (a) On left, halfway position with tail spread ; (b) on right, complete position with tail closed. nervously. The male then gives the deep bow (Figure 3), with head low, neck inflated to show the white patches and the adjoining iridescent green, wings closed, the tail spreading as it is raised, but closed as it reaches the highest position, accompanied usually by a quiet, rather variable call. I have heard a double call, `coo, coo', a triple call `coo, coo, coo', and a longer `coo, ke, ke, coo, coo'. This call appears to be more frequently uttered when bowing takes place on the ground, but the note is often so soft that it may be missed when the birds are in a tree. On these three occasions when I think this was the initial step in pair formation, the female did not display in return (except once to turn around on the branch) but she overcame her fear of the male's aggressiveness sufficiently to stay with him in the tree. The bow is found in the display of many pigeons, and has been discussed at length by Goodwin (1956a). He considers it likely that the elements of the bowing display `originated in, and may still indicate, a conflict situation in which aggressive or sexual impulses inhibit an impulse to escape' and that the bow of the Woodpigeon has the same significance as that of the Stock Dove (Columba cenas) where `self assertiveness and threat are always dominant over any escaping tendencies'. In the cases described I consider that the bow may have served to persuade the female to overcome her fear and remain. In the male there often appears to be a clear conflict between sexual and aggressive impulses. Thus, on one typical occasion, a male approached a female on a branch, and when some three feet away bowed low four times. He then began to move closer, making strong pecking motions. She at first stood her ground, then with brief head noddings, moved away. He then flew to another branch, bowed low once, and she at once flew to join him, landing within a foot of him on the same branch. He again started to move towards her, with the same pecking motions, and she at once flew back to the original branch. He then joined her, bowed again three times and once more moved close, but this

7 6o WOODPIGEON BEHAVIOUR 5(2) time she flew to another tree in the territory and he desisted. In these situations it seems to me that the bow is in many ways reminiscent of the Head-Flagging posture of the Black-headed Gull (Lanus ridibundus). Tinbergen and Moynihan (1952) have described how this with the bill and brown face turned away is the opposite of the Forward Display, a threat posture. It always occurs with partners or prospective partners, and they suggest it may mean something like `No offence meant'. In the Woodpigeon the bow appears to be the opposite of the aggressive posture (discussed later) with both offensive weapons out of action, the bill down and the wings closed, and, because of the lowered body, useless for striking. The bow has become ritualised to some extent ; the neck is distended and marked with white and green, while the tail, probably raised originally for balancing, is spread as it is raised. The cementing of the pair bond may take some time, especially with early pairs, for all forms of sexual and territorial behaviour may be inhibited or almost brought to a stop by cold spells. Still, after this first approach the female will often join the male in the territory, but in the early stages tends to keep away from him, often perching on another branch. This applies even to the few birds which appear to return to the territory already paired. Thus in 1955 a pair returned together to a territory in one of the squares on 14 November, but not until early December, although they were both present every day, did I see them perched close together. Usually also at this early stage of pair formation, the female arrives each morning from the roost some time after the male, and even on occasion apparently from a different roost. It may be that such pairs were paired in the previous season, but as my birds were not colour-ringed I have no proof of this. Some species of pigeon do pair for life, and the choice by Woodpigeons of some highly unusual nest sites year after year suggest that at least one of the pair had previous knowledge of the territory. Gradually, however, the female overcomes her initial fear of the male, while his aggressiveness is reduced. This appears to be done particularly by repetition of the bowing ceremony, and generally perhaps by the presence of both birds together in the same tree for long periods each day. They then reach the stage when they are able to approach close to each other, and at the same time the pair bond is strengthened by two further displays. The first is mutual caressing the birds in turn nibble the plumage of the j^ \ Figure 4. Caressing.

8 1958 WOODPIGEON BEHAVIOUR 61 partner's head and neck, and, much more rarely, other portions of the body (Figure 4). This caressing is often frequent and prolonged in the early months of the year. The second is billing, when the female, with her head slightly below the male's, inserts her bill in his. During this, the throat muscles of the male can often be seen to move, but it is impossible to say whether any food is passed. Billing is the normal prelude to coition, but often occurs in the early months without leading to this. During both these displays, the birds frequently intersperse the caressing or billing with displacement preening, in which the bill is quickly inserted behind the scapulars or under the front of the wing and withdrawn. Goodwin (1956b) describes displacement-preening as occurring in many species of pigeons. I have seen these two displays, caressing and billing, only in trees, but bowing often occurs on the ground. There it may be done, perhaps, by unmated males in search of a mate or by already paired males approaching strange females. On the ground, the male follows the female, sometimes walking, but in the more intense form hopping, and then pausing to bow and call. At times, a partial bow, with the head half-lowered and the tail raised little, is given. There is also a rather high intensity version, which I have called Kangaroo Hopping, when the male leaps at least a foot in the air, with his legs tucked well into the body, and jumps forward up to two feet at a time. Thus, once in April, I saw a male hopping after a female and bowing, when suddenly another male flew near and bowed to her from the front. She moved towards him aggressively, with neck raised and wings half open, and he retreated, but the first male then continued to follow her with these strange, kangaroo leaps. TERRITORIAL FIGHTING The territorial area defended by Woodpigeons varies considerably, but I believe that they will always defend at least one territorial tree however dense the population. The land outside my flat is barely a third of an acre, with only two trees, and the pair not only defend both trees, but the ground itself, the adjoining buildings (where they have a favourite nest site on the fire-escape) and the roofs (and especially the chimneys) of the houses across the street (where they have never nested). The nearby square, almost an acre in extent, has always held two pairs in recent years, but never more, despite the steady increase in population and the attempts of others to squeeze in. The trees in the square are divided fairly evenly between the two pairs, although they are only really aggressive about certain trees with good nest sites. Until 1949, the square held only one pair, and they would drive intruders from all trees, the ground and adjacent buildings. Now, other birds are usually tolerated on the ground or buildings. In the larger squares and parks, with big Woodpigeon populations, I think that only the trees are defended with full vigour and that much of the ground is regarded as a neutral feeding area, although some of the frequent fights on the ground probably have a territorial significance. In Lincoln's Inn Fields each pair defends a group of trees, and the

9 62 WOODPIGEON BEHAVIOUR 5(2) nests are well spread out, but in St. James's Park nests may be found in adjoining trees at times. It seems that most pairs try to keep a territory containing more than one tree if they can ; this is clearly advantageous for a species which may make up to three nesting attempts in a season, and more if some are unsuccessful. A nest may be used twice, or even three times in a year, but more frequently a new one will be built, and most trees seem to have only a limited number of sites which Woodpigeons regard as satisfactory. It has already been mentioned that most intruding males will leave at once when the territorial male flies over to investigate. Sometimes the trespasser is more persistent, and merely flies to another branch in the same tree. The owner then follows and lands near, the intruder flies to a third branch, the owner follows and so on until, tired of this persistent chasing, the intruder leaves. The great majority of territorial squabbles appear to be of this nonviolent kind, but if these harrying tactics should fail the owner will threaten with pecking movements and half-opened wings. Intruders may carve out a territory by sheer persistence, as a second pair did in the nearby square already mentioned. In January 1949, when the second male first appeared, the resident male launched himself into the air with a loud clatter of wings as soon as the other began to glide down, causing him to swerve and flee without attempting to land. The intruder persisted, however, on succeeding days, and eventually acquired some of the trees, and later a mate. The first male gradually gave way, though every now and then he would fly up to the new pair, only to retreat when threatened. Gradually the new male won possession of the buildings overlooking the square on the east, while the first retained those on the west as song posts. Twice when the first male flew off after an unsuccessful attack, the other flew after him for a little way, then swung back in a peculiar floating flight, with strong, slow wing-beats. The fiercest battles I have seen have taken place in hawthorns in the parks. These hawthorns seem to be especially favoured ; they provide good cover for the nests, with protection against the Carrion Crows (Corvus corone), which rob so many of the early nests in the leafless planes, and enable the birds to build below a height of 15 feet, which Colquhoun (1951) found to be the preferred height amongst rural Woodpigeons, whereas most nests in planes are of necessity much higher. I have seen long and persistent battles in hawthorns, with repeated and powerful blows from the wings. Each bird tries to get on top of the other, and when it succeeds it batters its opponent fiercely with both wings. Owing to the thick cover it is often difficult to see whether much use is made of the beak, but sometimes the opponent's head is pecked and in a fight in the open I have seen a Woodpigeon tear a feather from its rival's back. When fighting on the ground the two birds stand side by side, facing the same way and two or three feet apart, and, with heads raised and wings half-opened, they eye one another like boxers sparring for an opening. Then they leap into the air each as if trying to land on the other's back, but I have never seen this actually

10 1958 WOODPIGEON BEHAVIOUR 63 happen in ground fights, for either the one still on the ground moves away in time, or they fly up together and almost crash in the air. This fighting attitude is reminiscent of the Upright Threat posture in the Herring Gull (Larus argentatus), as described by Tinbergen ( 1 953) the raised neck, the beak ready for attack, and the wings half-opened for the same purpose. As with the Herring Gull, anxiety is mixed with aggressiveness shown in the Woodpigeons by the withdrawing movements of the head as the opponents face each other. Goodwin (in litt.) has suggested that the raising of the wing in pigeons is the intention-movement of fleeing, not fighting, though it also serves as a threat display. In the Feral Pigeon (Columba livia) he has found that a bird which raises both wings is more likely to flee than to fight ; the opposite has, however, been my experience in Woodpigeon battles. In many cases, especially where the fight has been on the ground, the defeated bird has been seen to give the deep bow to the victor. When an intruder arrives at a territory with a pair present, it is usually the male who deals with him, although the female will also join in on occasion. Battles between two pairs may also occur, and here each bird usually takes on its opponents of the same sex. After such battles I have on several occasions seen the female bow deeply to her mate. CHOOSING THE NEST SITE From early January, and often soon after the pair is definitely formed, the male begins to mark suitable nest sites by Nest Calling. He crouches on the proposed site (which may be a bare fork or branch, or an old nest) and makes short, sharp, downward pecking motions, accompanied by the special nest call a deep, double note, `coo, coo' (Figure 5). In low intensity versions the neck is lowered only Figure 5. Nest calling. Two positions assumed by the male. slightly, but as the intensity increases the head issteadily lowered more and the back slightly arched, until the bird is pecking right down at the branch, or into the twigs if it is an old nest. At the same time, the tips of the wings, and sometimes the tail are jerked rhythmically. Once a male `nest-called' so violently soon after driving away a trespasser that his tail jerked up and down like a semaphore. Sometimes nest calling takes place when the female appears to be absent, though it is probable that she is somewhere near just out of sight ; normally she is present and flies to the male as soon as he begins to call. She then perches near, making the same

11 64 WOODPIGEON BEHAVIOUR 5(2) nodding movement, but less violently, then moves close to him and pecks at his head, usually in a gentle way, but on occasion quite fiercely. This ceremony appears to arouse strong emotions in both birds and undoubtedly plays a most important part in cementing the pair bond. Goodwin (1955) states that nest-calling is found with many species of pigeons, and normally soon gives way to actual nest building. In the Woodpigeon, however, I have often observed nest-calling in January, many weeks before any nests are built, although it undoubtedly becomes more widespread as the nesting season approaches. The male may `nest-call' at several sites, and I imagine that the female normally makes the final choice, for the nest is by no means always built on the site where her mate has `nest-called' most persistently. The first nests are seen normally towards the end of March, and the majority start to sit in April. Occasionally earlier nests are found, but it is probable that many of the reports of very early nests of the Woodpigeon (save in such exceptional circumstances as the mild spell in February 1957) are due to the common habit of False-Sitting on an old nest. This is quite unlike Nest- Calling, for the bird (always in my experience a female) does not crouch in the nest, but sits in the normal incubating position, and does not display or call. Sometimes the male will perch next to her and gently caress her head and neck. In one extreme case this false-sitting began on 3 March and continued for periods almost every day until 17 April ; the nest was readily visible, and no eggs were laid during this period. Then, the pair moved to a new site on an adjoining building, and within two days built a nest and started laying. Usually, false-sitting is more sporadic and lasts for a much shorter time. Tinbergen (1953) has described how the Herring Gull will also sit as if incubating `days in advance of the appearance of the first egg'. MATING Mating usually begins with displacement-preening. Thus, in one instance, the two birds were about fifteen feet apart on different branches of a tree, when the male began to preen, back behind the scapulars and forward under his left wing. He then walked four quick steps forward and then back again. This was repeated several times, causing the female at first to peer at him and then to fly down to join him. She approached him along the branch, crouching slightly and put her bill inside his. After this both birds preened, then there was a further bout of billing and coition followed. Often the female appears to take the initiative in this billing, and if the male is unwilling to mount when she crouches in readiness, she will bill again and caress his head and neck. I have also seen the male bow as a preliminary to billing and mating. Several times I have seen the female begin billing as a prelude to mating, without an y sign of an invitation from the male, though this may have been overlooked. Behaviour after coition varies greatly ; the birds may sit quietly in a hunched-up attitude, or preen, or, as on one occasion, the female may caress the male. In my experience mating always takes place in a tree in the territory, although not necessarily

12 1958 WOODPIGEON BEHAVIOUR 65 the one where the nest is. It usually occurs when the nest is being built, but I have seen isolated instances (not followed then by nesting) in January and even in late November. As soon as the eggs are laid and incubation begins, a striking change occurs in the behaviour of the pair. Prior to this, often for three or four months, they have both spent long periods each day in the territory, but now the bird which is not sitting disappears completely from the territory. In the larger squares and parks, of course, it may be feeding somewhere close by, but in the isolated territories (such as the one outside my flat or those in the planes in busy streets) it leaves the area altogether. The full advertising song also ceases, although occasionally an incubating bird will sing a little. PURPOSE OF TERRITORY It has been shown that the Woodpigeon has highly developed territorial behaviour, operating for up to nine or ten months of the year, and it may be wondered what purpose is served by territory in this species. Food is unlikely to be of great importance for even those birds with small isolated territories which defend the ground as well as the territorial trees rarely feed in the territory, and the majority of pairs defend only trees, which provide food at limited periods of the year, when buds or seeds are suitable for eating. Again, in rural areas, Woodpigeons tend often to nest at high densities in suitable woods (in an extreme case reported by Colquhoun (1951) a density of 11.3 nests per acre was reached) but range widely over the surrounding countryside for food. In the case of the Herring Gull Tinbergen (1953) has suggested that the spacing of nests by territorial behaviour reduces the loss from predators, but it is doubtful if in London this much affects the losses from the Woodpigeon's main predator, the Carrion Crow, while in the country Colquhoun suggested that the exceptionally heavy losses he found at the egg stage in this species were mainly due to natural predators. Territorial behaviour certainly helps to ensure sufficient suitable nest sites for repeated nesting attempts. Its main function, however, appears to be to provide a place where the displays which strengthen the pair bond and later mating itself can take place without interference from other Woodpigeons. It is interesting in this connection that the highly developed Driving of the female by the male, which occurs regularly in the Feral Pigeon, and some other species, shortly before the first egg is laid, is not found in the Woodpigeon although when a pair of Woodpigeons are feeding out of their territory, the male will sometimes drive its mate away from another male he fears to attack. Goodwin (1g56b) has demonstrated convincingly that the function of Driving is to prevent the female being fertilised by other males and to give the pair opportunity to mate undisturbed. I have never witnessed any instance in which the coition of Woodpigeons has been disturbed by others and with the safe refuge of the territorial trees the full development of Driving behaviour in this species has been unnecessary.

13 66 WOODPIGEON BEHAVIOUR 5(2) ACKNOWLEDGEMENTS I am much indebted to Derek Goodwin for his generous assistance and encouragement, and for providing the sketches of Woodpigeon displays. REFERENCES colqul oun, M. K. 195I. The Wood Pigeon in Britain. London. COWARD, T. A. 192o. The Birds of the British Isles and their Eggs. London. COULSON, J. C. AND WHITE, E A study of colonies of the Kittiwake. Ibis, 98 : FISHER, J The Fulmar. London. GOODWIN, D Notes on European wild pigeons. Avicult. Mag., 61 : GOODWIN, D. 1956a. Observations on the voice and some displays of certain Pigeons. Avicult. Mag. 62:17-33, GOODWIN, D. 1956b. The significance of some behaviour patterns in pigeons. Bird Study, 3: HEINROTH, O. AND M Die Vogel Mitteleuropas. Vol. II : 46. Berlin. TINBERGEN, N The Herring Gull's World. London. TINBERGEN, N. AND MOYNIHAN, M Head flagging in the Blackheaded Gull ; its function and origin. Brit. Birds, 45 : WITHERBY, H. F. et al The Handbook of British Birds. Vol. 4. London. TREATMENT OF SICK AND WOUNDED BIRDS by F. B. LAKE Received 24 September SUMMARY 1. The problem of the exhausted, sick, or injured bird is discussed, mostly with regard to the small passerines, with brief notes on other types of birds. 2. Elementary principles of cage and aviary management of such cases are described, stressing the necessity of a period of rehabilitation before release. 3. Some common treatable illnesses and injuries are described. 4. The problem of when and how to destroy ill birds is considered. Most of us who are known to be interested in birds occasionally have a sick or injured one brought to us in the belief that we will know what to do to help it, and an embarrassing problem it may well be. It is not the purpose of this essay to deal in any detail with bird diseases or their pathology, but simply to try and describe what can and cannot be done in such a situation. A bird that has been overcome by adverse conditions on migration, or cut off from its food supply by hard weather, should recover if given rest and shelter and food, and Exhaustion and Starvation is therefore the first and much the most hopeful diagnosis