The British Warblers A History with Problems of Their Lives/Sedge-Warbler

by Henry Eliot Howard

The British warblers - pt 1 p12

SEDGE WARBLER
ADULT MALE.

 

23

 

SEDGE-WARBLER.

 

Sylvia phragmitis, Meyer, British Birds, folio Ed., vol. i. (coloured plate figuring adult and egg) [1835-43].

Salicaria phragmitis, Hewitson, British Oology, 1st Ed., vol. i, pl. 70, fig. 2 (egg) [1836]; id., Eggs of British Birds, 2nd Ed., vol. i, p. 87, pl. 25, fig. 2 (egg), 1846; id. id., 3rd Ed., vol. i, pp. 117-118, pl. 31, fig. 3 (egg), 1856; Booth, Bough Notes, vol. ii, pp. 43-44, 1883.

Calamoherpe phragmitis, Macgillivray, British Birds, vol. ii, pp. 390-394 (woodcut of head), 1839.

Calamodyta phragmitis, Gould, Birds of Great Britain, vol. ii, 2pp, pl. 75 (coloured figures of adult male and female), 1862.

Acrocephalus schœnobænus, Yarrell, British Birds, 4th Ed., vol. i, edited by Newton, pp. 376-379 (woodcut), 1873; Dresser, Birds of Europe, vol. ii, pp. 597-601, pl. 90, fig. 2 (coloured figure of adult male), 1876.

Acrocephalus phragmitis, Seebohm, British Birds, vol. i, pp. 352-356, pl. 10, fig. 17 (egg), 1883; Lilford, Coloured Figures, vol. iii, p. 40, pl. 20 (coloured figure of adult male), 1886; Saunders, Manual of British Birds, 2nd Ed., pp. 85-86 (woodcut), 1898.

Arabian, Fisseu; Croatian, Vodarisa rogocara; Czechisch, Mysak; Danish, Sivsanger; Dutch, Bietzanger; Finnish, Buohoherttu; French, Bec-fin phragmite; German, Schilf-Rohrsänger; Hungarian, Foltos sitke; Italian, Forapaglie; Maltese, Violin; Norwegian, Sivsanger; Polish, Trzciniak rokit-niczka; Russian, Kamyschefka kamyschewaja; Spanish, Buscarla; Swedish, Säfsångare.

 

DESCRIPTION OF THE PLUMAGE.

Adults in Spring.—The sexes are alike, the male, perhaps, being a trifle brighter and rather larger, but on the other hand a bright female may surpass a dull-coloured male. The upper parts are of an umber brown tint shading into an almost unspotted rusty brown on the rump and upper tail-coverts. There is a conspicuous buffish white superciliary stripe and above that an equally conspicuous blackish stripe; the feathers in the middle part of the crown have dark centres forming three longitudinal stripes, the lores are blackish brown, cheeks brown, and the upper parts of the ear coverts slightly more dusky, these latter forming with the lores a darkish stripe through the eye. The hinder part of the neck is almost unspotted, whereas on the back and shoulders each feather has a blackish brown centre forming about six stripes on the back. The wing-coverts are blackish brown with umber brown edges to each feather, the flight-feathers are brown with slightly lighter edges, the innermost secondaries having blackish brown centres and light umber brown edges, the primaries having narrow whitish brown tips. The upper part of the tail is dark umber brown with lighter edges of the same tint, both colours getting lighter towards the outermost rectrices. The throat is whitish, the crop and sides of the neck buff shading into umber buff on the flanks and under tail-coverts. Abdomen whitish, and the under part of the tail greyish brown with a wash of lavender grey.

Immature.—The colour of the young is much like that of the adults, but richer. The crown is blackish, each feather narrowly edged with olive buff, the combined effect being, when the feathers are in perfect order, that of six fairly broad blackish stripes divided by narrow olive buff lines. There is a conspicuous light buff superciliary stripe, the lores are blackish, uppermost ear-coverts dusky, the combined effect being a dark streak through the eye; on the nape the blackish centre and olive buff edges of the feathers are of equal strength; on the back and shoulders the blackish centres are most conspicuous, forming about six fairly well defined longitudinal stripes; on the rump and upper tail-coverts the olive buff becomes slightly rusty or richer olive buff and the dark centres to the feathers are less conspicuous. The upper part of the tail is brownish slate, each feather edged with olive buff slightly lighter on the outermost ones, the shafts being dark lavender brown. The wings are darkish brown slate, each feather boldly edged with olive buff, narrower on the small coverts, and forming a sort of dark band across the wing, almost hiding the dark centres on the upper wing, making this part look uniform in colour. The sides of the face and neck are rather rich olive-buff with faint dark centres to the feathers, and there is a moustache stripe, though not very conspicuous. The throat is pure whitish buff; the crop and flanks are buff, with or without a faint olive wash, the former being furnished with brownish grey spots. The abdomen is whitish, blending into a pure buff on the under tail-coverts; under surface of the tail and wings are lavender grey narrowly edged with light buff and the feather shafts are white. The upper mandible is dark horn lavender, lower mandible light lavender flesh, darker towards the tip, and the corner and inside of the mouth orange yellow. Irides dark brown, the small feathers above are light buff, those below white. The eyelid is dark lavender flesh. Tibia olive buff. Tarsus and toes fairly light greenish lead colour; soles yellowish olive, and the claws olive grey.

 

GEOGRAPHICAL DISTRIBUTION.

It is so generally distributed from the middle of April to September throughout the British Isles that it is not necessary to mention any particular locality: we find, however, that as we proceed further north it is rather more local, and does not apparently reach the Shetlands, although in the Orkneys it is by no means uncommon. In the north-west of Skye it is rare, but in the islands further south. Islay and Mull, more numerous. In Ireland it breeds in every county, and is even found on Achil Island.

Crossing the English Channel and commencing in the south-west, we find it rare in the south of Spain and in Portugal, but rather more numerous further north, especially near Aroza Bay. In the Pyrenees it is common, also in suitable places throughout France, Belgium, and the Nethrlands, especially, in the latter countries, along the banks of the Rivers Scheldt and Meuse. I did not find it as common as I should have expected in the Island of Texel: it passes over Heligoland in great numbers.

Continuing northwards, we find it generally distributed throughout Denmark and breeding in suitable localities. In the south of Sweden it is common, then becomes rarer as far as the south of Norrland, but north of this it apparently does not occur: it is unknown in Gothland. In the south of Norway it is rare, but has been observed in the Jäderen district and up to Laurgaard; north of this it disappears until we reach Dynnäsö in the Helgeland district, where it becomes more common again and reaches as far north as Finmark.

Returning to Central Europe, we find it generally distributed over Germany and especially common in the marshy parts of Mecklenburg. Holstein and Westphalia; also in Hessen and along the banks of the Rivers Moselle and Elbe; rare, however, in Sachsen-Altenburg, but very common in Silesia. In Switzerland it is fairly numerous, especially in the low-lying country and valleys round Geneva and Lake Constance, but in the central and northern parts it is rarer, although inhabiting some of the lower sub-alpine valleys, especially Hasli. In Italy it is common in all the marshy parts, but not so numerous in Sardinia, and rare in Corsica. Eastwards, we find it again common in the Austro-Hungarian Monarchy, especially in the central plains along the banks of the Danube. Whether it breeds in Montenegro is doubtful, but immense numbers pass on migration. On the east side of the Balkan Peninsula we find it common in the reed-beds of Varna and Pravadia in Bulgaria, but further inland less numerous.

In Greece it is a bird of passage only, appearing on migration in large numbers from the end of March to the end of May. It may, however, have been overlooked as a breeding species, since there are still extensive unexplored swamps in the country.

The Russian Empire is a large breeding ground. In Poland it is the most common of all the reed-warblers, and it is also numerous in the Baltic provinces. Crossing the Gulf of Finland, we find it common in suitable places in the provinces of Nyland and Tevastehus, in the neighbourhood of Åbo and Björneborg, near Lake Uleå, and on the Island of Carlö; and still further north breeding in the Kola Peninsula, but rare on the shores of Lake Enara. It occurs north-east of Lake Ladoga, in the province of Olonetz, on the banks of the River Svir and near Lake Onega. In the vicinity of Archangel it is numerous, and it also occurs in the valleys of the Petchora, Ob and Yenesei.

In the provinces of Pskov, St. Petersburg, Smolensk, Jaroslav and Kasan it is common, scarce in Novgorod, Tver and Riazan, and local in Moscow and Tula.

In the central valley of the Volga it is numerous, also in places in the Ural districts, but in the province of Orenburgh it is local, and rare in the Kirghiz Steppes, and again we find it numerous in Astrakhan and the delta of the Volga; and continuing south we find it occurring in Stavropol, Terek and Trans-Caucasia, and crossing the Caspian Sea inhabiting the Mangishlak Peninsula, Ust Urt plateau, and the valley of Amu Daria.

In Turkestan it is migratory and breeds, and we trace it eastward to the Altai Mountains.

In Palestine it is common in suitable places, also in many parts of Africa, breeding in Algeria, Tripoli, Tunis and Egypt.

The winter home is principally Central and Southern Africa, but it probably also remains in some of the countries bordering on the Mediterranean, since it has been found at this season in Dalmatia.

In Lower Egypt it is common, and has been found in Somaliland and on Lake Haramaia, and we also trace it to German East Africa and as far south as Damaraland.

 

LIFE-HISTORY.

Arriving in this country about April 25th, these birds choose many varied spots for their home; osier-beds, where the various species of sedge grow in abundance, they favour most, although at times they will choose a thick and tangled hedgerow, and again, and this very frequently, they may be found amongst the dense masses of the Arando phragmitis, but in the drier portions. The arrival of the males, and perhaps of the females also, is rather irregular; that is to say, a few will appear one morning, then there will be a pause, and a few days later another batch will arrive, and so on until the migration of the males ceases, about a fortnight after the arrival of the first individual.

Their arrival can soon be detected by their babbling song, an energetic but unmusical strain, and where first heard there they will probably be found to breed, for they are by nature most home-loving individuals.

Water or swampy ground seems to be a necessity for them, for they are rarely to be found breeding in dry places. I have occasionally come across them in small dry coppices, but never very far away from water of some description. They inhabit more particularly wet osier-beds, where the different sedges, the Carex ovalis, Carex acuta and Carex riparia grow abundantly, but they seem to prefer them when rather drier, that is to say, where the willows are young and thick, and where the Juncus effusus, Spiræa ulmaria (meadow sweet) and different species of Epilobium (willow herb) grow in tangled masses. Along the banks of rivers and streams they are often common, and are abundant on pools and lakes, where aquatic plants, such as Scirpus lacustris Typha latifolia (bullrush) and the tall reeds (Arundo phragmitis) grow. Where these reeds grow to a great height, as they do in Holland and Hungary, and where the bottom is a dry mass of roots raised above the water, there I have found them exceedingly common.

The British warblers - pt 1 p19

MALE SEDGE WARBLER.
ATTITUDE DURING COURTSHIP.

The males, when they first arrive, select a certain spot of not many square yards in extent, with a tall bush or willow conveniently situated; and, moreover, they not only choose a tree but some particular branch on that tree, and this, until the young are hatched, forms their headquarters. Before the female arrives, and also, but not as much, when paired, they sit on this particular branch and pour out their song, frequently accompanying it with a pretty ærial flight, rising almost perpendicularly for a short distance in the air, turning very quickly and returning, with wings and tail outspread, to the branch. After a short rest they either start their song afresh, begin to preen their feathers, or go in search of food, wandering over the branches of the various willows, examining the under parts of the leaves for flies of the genus Chironomus, and the twigs for aphides, working lower and lower down through the branches and thick herbage till they reach the ground, and here for a time they make their way in search of aquatic insects and small spiders, only shortly to return to their favourite branch, singing as they fly. Thus they while away the days till the females arrive. The ground immediately surrounding the tree they have chosen as their headquarters they look upon as particularly their own, and when two or three have chosen positions close to one another, there they will be found to search for their food in certain well-defined directions, being most careful not to poach on one another's preserves, and consequently most jealous of any intrusion on the part of their neighbours, and not, indeed, only of their neighbours, but also—and this I have seen so frequently as to place it beyond the bounds of chance—of any other warbler, chasing them determinedly away, while frequently—I have seen them pursuing Thrushes and Hedge-Sparrows—ignoring the presence of other species so far as to allow them to nest in their favourite tree. Such powers of apparent discrimination seem very wonderful, yet we must not forget our total ignorance of all things pertaining to the sub-conscious state of animal life, and consequently of the bearing it may have on the unknown connection between different individuals, or classes of individuals, which, if known, would go far to explain such incidents, and perhaps enable us to form a truer definition of species than hitherto possible.

The courtship commences directly the females arrive, about ten days or so after the males; and as the females at this period persist in skulking in the bottom of the thickest rushes and undergrowth, it is most difficult to see what actually takes place; but the glimpses I have occasionally obtained tend to make me look upon the males when in love as rather sober-minded individuals; although the females for their part insist upon very close attention, and a somewhat servile attitude on the part of their suitors. A male pursues the female with drooping wings and erected head-feathers, uttering a rather harsh call-note; sometimes when quietly following he picks up and carries a dead leaf. If another male approaches too closely he pursues him with quick, vigorous flight. The female all the time keeps up her gentle call-note, which becomes more vigorous if her suitor, while pursuing another male, is forgetful and leaves her too long alone. Sometimes the two play together, flying at one another, the male scolding; and again they will sit close beside one another, an uninteresting couple, except when the male runs up and down the branch sideways, as he frequently does, with drooping wings and tail.

The nest, placed low down amongst the thick tangled undergrowth in the fork of a willow, or on the low branches of a bramble, especially when the latter entwines amongst a thick growth of Juncus effusus, is built up as follows: The foundation is dead grass of various kinds mixed with small pieces of dead thistle; on this is a thick layer of the fluffy seeds of the various species of Salix, bound together with fine dried grass, the lining being usually of the latter substance only. The female does most of the building, flying backwards and forwards to the Salix nigricans, carrying billfuls of the seeds, followed closely by the male, who never makes the slightest effort to help her, but, whether she be on the willow tugging at the seeds or actually building, sits close beside her, and in the same manner flies within a few feet of her on her journeys backwards and forwards.

The young are hatched as a rule about the middle of June, but the date varies considerably; I have found them as early as the first week of that month, and first broods as late as the first week in July. When the young are hatched the parent birds will allow you, if well concealed, to watch their domestic arrangements very closely. Peering through the sedges within a few feet of the nest, I have frequently watched them feeding their young, and cleaning their nest. The female at this time is less suspicious than the male. She it is who seems to be aware of the necessity of a constant supply of food to the nestlings; the male in this respect not working nearly so hard, and when suspicious only occasionally, and that very hurriedly, bringing a small billful of insects: the greater part of his time appears to be spent in keeping guard. The female, on the other hand, feeds her brood continually, every few minutes coming to the nest with a large billful of insects, which she distributes amongst some of the young. When startled she will sing a few notes of the song of the male, but will on no account drop the food she may be holding at the time. I have startled her in many ways, even going so far as to touch her with a stick, in order to make her drop the insects that I might be able to see to what species they belonged, but in no case have I been successful. The fæces, enclosed in a membranous sac, is carried away by the female each time after bringing food, and is dropped twenty or thirty yards from the nest; occasionally, but not as frequently as amongst other species, it is swallowed by her. The young leave the nest when about ten days old, and until able to fly keep well hidden amongst the undergrowth, occasionally uttering their very small call-note, which is answered by the parent birds, and enables them to keep in touch with their scattered offspring.

When fully grown the young ones are soon taught to find food for themselves. They follow their parents amongst the bushes and undergrowth, each being fed in turn, but occasionally taking the trouble to pick off a few aphides for themselves, giving one the impression that they prefer to be lazy as long as possible. Their difficulty no doubt lies in their want of experience, and consequent lack of power to distinguish between what is food and what is not; thus, even when they have left their parents. I have seen them in doubt trying to swallow the ragged ends of a broken twig. They are very playful at this age, their games sometimes taking the form of a tilting match. Three take part, two sit on convenient twigs facing one another, and the third from his central position might almost be called an umpire. Numbers one and two then lower their heads, each in anticipation of the other moving; one of them, call him number one, then springs into the air, and darts at number two; number two dodges and occupies the position vacated by number one, each of them then face round ready to continue the fray, the change of positions becoming quite rapid.

Although I have never found a second brood, yet I think it probable that two are sometimes reared, for this reason, that some of the males in July indulge in a second courtship. When a female is present the male will spread out his wings and tail, and walk sideways up and down a branch, the female for her part also spreading out her wings and tail, but not moving up and down the branch. After performing thus for a short time she will fly off, pursued by the male, calling to him with her low quiet note if he does not immediately follow. Sometimes two or three males join in the pursuit, apparently for the fun of the thing and the annoyance of the real lover.

It will be seen that this courtship is really identical with that performed in spring, and is therefore somewhat of a mystery, the more so as it is not indulged in by all males, for

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MALE SEDGE WARBLER,
ATTITUDE DURING COURTSHIP.

some at this period, after they have reared their young, begin to wander, and can be heard singing even in the middle of the cornfields.

Towards the middle of July, while watching them in osier-beds, where they happened to be very plentiful. I have noticed curious commotions, the origin of which I have not been able to satisfactorily explain. As many as eight or nine collect together, some adult, some immature, the adults apparently very angry, scolding vigorously, their feathers ruffled and their tails spread out; the onlookers also join in the scolding, the commotion being quite unusual for bird-life. So absorbed have they sometimes been that I have crept into the middle of them before they have noticed me, when they have reluctantly dispersed. I once found an empty nest from which the young may have been taken, but there were no dead bodies round it to show that a tragedy had occurred; and it is generally the case, when a rat or a weasel has attacked and destroyed the young, that the bodies lie round or perhaps even remain in the nest, with no sign of ill-usage on them except two small punctures at the junction of the head and neck, indicating the marks of the teeth, the blood having evidently been sucked. Hitherto, I have seen these scolding parties in July only, but it is quite likely that they may be of frequent occurrence at other times.

On his arrival in this country the male sings at all hours of the day, especially in the morning, frequently at night, and continues until pairing is over and incubation commenced, when to a great extent he ceases, but recommences after the young have flown. His song is loud, cheerful and babbling, sometimes harsh, and perhaps might be described as lacking education. He has also considerable powers of mimicry, the call-notes and parts of the song of different species being often introduced. This mimicry will be heard more frequently when any commotion is going on amongst the bird-life around, owing, no doubt, to the alarm-notes of the different species engaged in it being then more pronounced. At such times I have heard them imitate the Whitethroat, Blackbird and Chaffinch, and at other times the Tree Pipit, while once I remember hearing one imitating the call-note of the Partridge perfectly. They can also, when singing, produce a ventriloquistic effect, but do not do so very frequently. The ordinary call-note used by both sexes is a rather harsh crackling note, difficult to describe; the female when mating has rather a different note to the male, and the young when fully grown differ again somewhat from both their parents.

The call-note—this is rather a vague term, in reality meaning very little—is used by both sexes all the summer, and when listening by the side of a reed-bed on hot summer afternoons it is frequently the only expression of bird-life one hears. Thus they keep calling, sometimes with the single note, sometimes with a treble note quickly uttered in a descending scale, as they wander along in search of food, apparently not troubling about an answer to their call, but uttering it mechanically at varying intervals. Any sudden noise or disturbance, even the throwing of a stone into the rushes, is often enough to cause them to sing.

In the latter part of August and the first half of September, that is to say, in the last few weeks before they leave this country, they are much quieter, rarely singing, but instead skulking in the undergrowth, and are therefore difficult to see. As they move about you can hear them occasionally calling to one another, but showing themselves very little, evidently finding plenty of food amongst the stems of the reeds and rushes.

Climatic conditions do not seem to affect them very much, but during very wet weather their song is not so frequent nor so vigorous, neither do they appear to be very happy themselves, but are rather more inclined to mope and are considerably less active.

Their food seems to consist entirely of insects, and during the few months they are with us food of this description is never lacking. They search for it chiefly low down amongst

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MALE SEDGE WARABLER.
ATTITUDE DURING COURTSHIP.

the roots of the herbage, often hopping on to and along the ground in swampy places, where small worms and spiders are abundant, and since they generally inhabit swampy places, swamp-loving insects form a great portion of their food. It is common to see the adults hunting the willows and small alders (Alnus glutinosa), but never the high trees. The young in July when fully grown are not so particular in this respect, often searching in the tops of large alders, especially during the swarming time of the aphides. It is no doubt the pursuit of food that leads the adults into the middle of cornfields, but I have not been able to determine what the special food they are following consists of.

Flies belonging to the Chironomidæ, of which I have identified the following, are frequently taken: Chironomus viridis, Chironomus brevitibialis, and Tanypus choreus.

These insects can be seen, especially in the morning, both early and late in the season, clustering under the leaves of the willows, hazels and alders. A slight tap on the branches will frequently produce incredible numbers, where before few could be seen.

In June and July they feed, amongst other insects, on the following:—

Genus.			Species.
Homoptera	. . .. . .		Cicadula septennotata.
Hemipteron	. . .. . .		Macomma ambulans.
Coleoptera	. . .. . .		Cyphon coarctatus.
Diptera	. . .. . .	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Dolichopus ungulatus. Tipulæ. Limnobiidæ. Empidæ.

The young, especially when still in the nest, are fed largely on these insects, occasionally also on the larvæ of certain moths and butterflies. During all the summer months great numbers of aphides are devoured, in fact, these insects appear to constitute the great food supply, not only of this species, but of many others also. A close inspection of the twigs and leaves of the different species of Salix will reveal these insects clustering in great numbers, and will at once explain what, at a distance, looks like the aimless pecking at nothing of these birds.

When inhabiting swamps where the Arundo phragmitis grows, they seem to find, early in the season, a quantity of food amongst the fluffy seeds at the top of these reeds.

 

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FEMALE SEDGE WARBLER.