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JAN 23 7986
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BRITISH WARBLERS.

A HISTORY WITH PROBLEMS
OF
THEHIR LIVES

BY

H°’ELIOT HOWARD, F.Z.8, M.B.O.U.

ILLUSTRATED BY HENRIK GRONVOLD

London

Rk. H. PORTER :
7, PRINCES STREET, CAVENDISH SQUARE, W.

Price 21s. net.

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14

WILLOW WARBLER.

Sylvia trochilus, Meyer, British Birds, folio Ed., vol. i, pl. 70
(coloured figure of adult and egg) [1835-43]; Hewitson, Eggs
of British Birds, 2nd Hd., vol. i, pp. 101-102, pl. 28, figs.
3 and 4 (eggs), 1846; id., id., 3rd Ed., vol. i, pp. 187-138, pl.
36, figs. 1 and 2 (eggs), 1856.

Sylvia trochylus, Hewitson, British Oology, 1st Ed., vol. i, 2 pp.,
pl. 115, 2 figs. (eggs), 1835.

Phyllopneuste trochilus, Macgillivray, British Birds, vol. ii, pp.
371-378, 1839; Gould, Birds of Great Britain, vol. ii, 2 pp.;
pl. 65 (coloured figures of adult male and female), 1862.

Phylloscopus trochilus, Yarrell, British Birds, 4th Hd., edited by
Newton, vol. i, pp. 432-436 (woodcut), 1873; Dresser, Birds
of Hurope, vol. ii, pp. 491-496, pls. 75 and 76 (coloured figures
of adults in early summer and autumn plumage), 1879;
Seehohm, British Birds, vol. i, pp. 430-434, pl. 10, fig. 10
(egg), 1883; Booth, Rough Notes, vol. ii, pp. 59-61, pl. 5
(coloured figure of adult and northern variety), 1883 ; Lilford,
Coloured Figures, vol. iii, p. 64, pl. 32 (coloured figure of
adult), 1887; Sawnders, Manual of British Birds, 2nd Ed.,
pp. 69-70 (woodcut), 1897.

Croatian, Brezja Zenika ; Czechisch, Budnicek vetsi ; Dutch, de Fitts ;
Finnish, Uunilintw ; French, Powillot-fitis ; German, Fitis-Laubvogel ;
Hungarian, Kézdnséges rendike; Italian, Lwi grosso ; Norwegian, Léf-
sanger; Russian, Penotschka ; Spanish, Mosquitero, Mosquilla; Swedish,
Léfsangare.

DESCRIPTION OF THE PLUMAGE.

Adult Male in Spring.—All the upper parts are ereenish
olive grey, but the crown and rump are brighter and slightly
more olive yellowish green. The flight and tail feathers are
brown narrowly edged with the same colour as the upper
parts, while the innermost and greater secondaries are broadly
edged with this same colour. The bastard wing is brown, and
the least wing-coverts the same colour as the back. The
superciliary stripe is pale olive yellow, the lores smoky grey,

i

BRITISH WARBLERS

and the sides of the head the same colour as the upper parts,
only somewhat lighter and more buffish. The throat is
whitish, the upper breast the same colour, only washed with
olive buff and striped narrowly with lemon yellow, and the
abdomen whitish. The flanks are olive grey washed with a
yellow tint, the under tail-coverts whitish washed with yellow,
and the underside of the wings and tail lavender grey.

The axillaries and under wing-coverts are sulphur yellow.
The upper mandible is horn brown, the lower yellowish buff,
and the flanges light lemon yellow. The iris is brown, the
feathers on the eyelid whitish yellow, and the feet and claws
brown, the soles being olive yellow.

The sexes are alike in plumage. |

In autumn the upper parts are richer and of a more
greenish olive brown, the primaries have narrow light olive grey
tips, and the colouring of the under parts is more intense.

Nestling.—The upper parts are olive grey, slightly brighter
on the forehead and rump. The wing and tail feathers are
darkish ash grey, the flight and tail feathers being narrowly
edged with olive buff and the greater wing-coverts and the
rest of the feathers on the wing broadly margined with olive
grey. ‘The lores are dark ash grey, sides of the head olive
brown, and the superciliary stripe—which is not very con-
spicuous—is light yellowish buff, the feathers on the eyelid
being of this latter colour. The throat is bright yellowish buff
and the pectoral tract is the same colour but suffused with
light lavender buff. The flanks are also bright yellowish buff.
The abdomen and the under tail-coverts are light yellow, and
the underside of the tail and flight feathers is light ash grey.
The mouth is orange buff, but the tip of the tongue is rather
more reddish.

The upper mandible is greyish horn colour and the lower
buff colour, the flanges being whitish yellow. The iris is dark
greyish brown. The feet are light. greyish olive, and the toes
rather more of a buff colour with olive yellow soles, the claws
being greyish brown. _

WILLOW WARBLER

On leaving the ege the bird has its eyelids completely
sealed.

GEOGRAPHICAL DISTRIBUTION,

_In England it is generally distributed and common, and to
Scotland it is on the whole an abundant summer visitor, but
in the Outer Hebrides it has only been found nesting in Barra,
and it is not recorded as nesting in the Orkneys although it
does so in the Shetland Islands. In Ireland it is common in
all suitable localities.

Throughout the greater part of Western Europe it is
generally distributed. In Spain it is found locally as far south
as Gibraltar, but is not common. Portugal appears to be
visited only on migration. We find it a common breeding
species in almost every part of France excepting the south-
eastern corner, where it is only found on migration, and it is
abundant in Belgium, Holland, Switzerland, Germany and
the Austro-Hungarian Empire. In Norway and Sweden it
is a summer Visitor, numerous in places, breeding in the moun-
tains up to the limit of the trees, and inhabiting even the
extreme north of that continent. In Italy the bird is abundant
in summer in the northern and central provinces, but rather
rare on the Adriatic Coast and occasionally visits the moun-
tains of Sardinia, though absent from Corsica. Though fairly
common in Bulgaria it does not seem to be a breeding species
in Turkey and Greece. Throughout Finland it may be said
to be generally distributed and common, the country between
St. Petersburg and Archangel is also inhabited, and we find it
breeding in the provinces of Vologda, Western Archangel,
Viatka, Perm, and the valley of the Petchora. Eastwards
from here we trace it to the valleys of the rivers Ob, Yenisei,
Lena, and Kolima. Though common in Poland, in fhe
vicinity of St. Petersburg, in the provinces of Noseored, Tver,
Jaroslav, and Moscow, in the district between the rivers Volga
and Oka, and in the province of Kasan and neighbouring
provinces, yet there seems to be some doubt as to whether it

3

BRITISH WARBLERS

breeds in the south-western provinces, although occurring
there on migration. In the south-eastern part of European
Russia we find it on the south-western slopes of the Ural moun-
tains, in the province of Orenburg, and occasionally in the
Kirghiz Steppes, and further south still in the Caucasus and
and T'rans-Caucasia. It is probable that it breeds in suitable
localities in Northern Africa. The Transcaspian Province,
parts of Persia, Asia Minor, Turkey, Palestine and Greece are
visited on migration.

Its winter quarters in Europe may be said to begin in the
south of France and to extend through Spain, parts of Italy,
Sicily, Greece and Asia Minor. The majority, however, pass
on to Africa, where they have been traced to Morocco, Algeria,
Tripoli, the oases of the Sahara, Egypt and the vicinity of
the White Nile, Abyssinia, Somaliland, East Africa, Uganda,
the Congo Free State, Rhodesia, the Transvaal, Orange
River Colony, Cape Colony and up the west coast through
Namaqualand, Damara Land, Fernando Po and Sierra Leone.

LIFE-HISTORY.

Of the three members of the genus Phylloscopus which are
common summer visitors to this country, the Willow Warbler
is probably found in the greatest numbers, though not neces-
sarily in every district. In some parts the Chiff-chaff may be
the more numerous, or even to some extent take its place,
but on the whole the Willow Warbler is the more common
bird. It frequents localities similar to those in which we
find the Chiff-chaff common, but is not so partial in its
choice, for it can often be found in open places and even
in the centre of large woods and forests. Wooded banks,
dingles, small coppices, the outskirts of large woods, gardens,
and in fact plantations of almost every description are resorted
to, and made use of for the purpose of reproduction. If
there is any one locality for which the bird seems to show
some partiality, it is that in which a territory can be
obtained adjoining an osier-bed containing willows of some

4

WILLOW WARBLER

description, and therefore the prefix “ Willow” which has been
applied to it, and which may seem somewhat trivial, is in
reality expressive of a characteristic, though but a small one,
of the species.

In the order of migration the bird must be placed between
the Chiff-chaff and Wood Warbler, since it arrives considerably
later than the former species and somewhat earlier than the
latter. As in the case of the Chiff-chaff, the date of arrival
varies year by year—at least in the west Midlands where my
records have been kept—the earliest record I have being
March 30th, and the latest April 16th. On the average the
first males may be expected towards the latter end of the first
week in April, but all the males do not arrive on the same day
or during the same week, the migration extending over some
days. Neither do they all arrive before the females, but the
majority do so; the first females, however, are usually later by
a week or more in reaching the breeding grounds than the first
males. Meteorological conditions no doubt influence the
migration and are a cause of erratic movement. Insect life
is scarce in cold springs, and in exceptional weather almost
entirely absent for a time, and upon insects these birds
entirely depend for sustenance at this season of the year.
When, therefore, we find the smaller and more delicate-looking
Chiff-chaff a fortnight earlier still at this critical period, we
naturally seek an explanation. What difference there can be
in the constitution of the Chiff-chaff that enables it to face
such inhospitable conditions so much earlier we do not know,
and yet there must be some reason, some advantage to be
gained by its doing so. Can it be that the restless activity,
so prominent a feature of its behaviour, enables it to find a
living even under the most adverse conditions? It may be so,
for in studying the two species the Willow Warbler certainly
appears to be less active and rather more sluggish in its move-
ments. But although this may be a reasonable explanation
of the one being able to exist under more trying conditions
than the other, yet it leaves the main difficulty unsolved,

5

BRITISH WARBLERS

namely, why, in the case of two such closely allied forms living
in a similar environment, one should arrive at its breeding
ground so much in advance of the other.

The law of breeding territory forms as important a part in
the life-history of this. bird, at this particular season, as it does
in that of so many others. Similar conflicts occur, similar
petty struggles; in fact, the whole routine of the life of the
male, previous to and after the arrival of the female, may be
said to be almost identical with that of the male Chiff-chaff.
Inasmuch, however, as this law seems to be one of some
importance in the life of many species of birds, and possibly
other vertebrates, I shall describe minutely any details that
have come under my notice bearing upon the question, no
matter how small or perhaps even trivial they may seem, and
no matter how similar to those in the life of the Chiff-chaff or
any other species already dealt with. In order to observe
the behaviour of the birds during this period, it is as well
to select some wooded bank inhabited by a number of males
and divided into a number of adjoining territories. For such
territories are never very large—although they vary consider-
ably in extent, being perhaps twenty-five, forty, or sixty yards
in length—and consequently it is by no means impossible to
keep three adjoining areas under observation at the same time,
which is an advantage and often an assistance in enabling one
to interpret the actions of the different inhabitants. Moreover,
- where possible, the same wooded bank or plantation should be
selected for two or three years in succession, since by this
means alone is it possible to discover through actual observa-
tion whether the same males return to the same territories
year after year; and besides, by so doing, one commences
each season with a considerable and important knowledge
of the previous life-history of the various inhabitants of
that particular locality. As to whether the same males do
return to the same territories we know very little. There
are certain authenticated facts which show that birds do
sometimes revisit their birthplace, and, in the case of the

6

WILLOW WARBLER

adults, even appropriate the old territory, but what is of more
concern to us is the extent to which they do so. Is it a rule
for the same male to return to the same territory? And does
the female seek her former mate? These are the questions
which we should like to be in a position to answer, and they
are questions to which I have never been able through
actual observation to obtain a definite reply. The marking
of young birds may tell us whither they go, and whether
they return to the locality of their birthplace, but upon
the point in question it can clearly throw no light unless
some system can be devised whereby the owners of certain
territories are annually caught and released. In the case of
some of the migrants males are the first to reach their desti-
nation, afterwards the sexes arrive intermingled, but not
paired. A male takes up its territory and there awaits a
female, upon whose arrival pairing takes place. The young
are then hatched, and as soon as they are capable of taking
care of themselves the parents desert their territory and
appear to separate. Will they again meet the following
breeding season? Is it likely, in the first place, that both
will survive? We have no direct evidence to guide us in
estimating the average duration of life of an individual under
natural -conditions, but we can be certain that it varies
enormously in different species. However, we are here con-
sidering the migrants only; and bearing in mind the mortality
which must and does occur amongst them during migration,
from scarcity of food, from vagaries of climate, from disease
and from natural enemies, and fixing our attention on the
fact that there is no perceptible increase in their numbers year
by year, how can we regard such an existence as otherwise than
a precarious one? And are not the chances, therefore, of both
surviving somewhat remote? Assuming, however, that both
escape the numerous dangers that threaten them, and are
consequently capable of breeding the following spring, will
both male and female steadfastly make their way back to
the same few acres of ground which they inhabited the

7

BRITISH WARBLERS

previous year, and, ignoring all other opportunities of pairing,
await a happy reunion? No one, I think, would suggest
that during all these months of wandering in the wilderness
they carry in their memory the image of a former mate, and
that when the sexual instinct develops at the proper season
this image becomes the central attraction, a coal that, at any
cost, must be attained. Would not one rather suggest that a
habit which had been formed in one season would be sufficient to
bring about continued pairing without attributing to the birds
any undue powers of recognition? The whole question
resolves itself into one of expediency. Will Nature obtain the
best results if a male postpones pairing until the advent of
its former mate? Let us consider the position of a male. It
arrives alone in the spring at its destination, and takes up its
former territory. And what then? If it has no recollection
of a former mate, it must take the first opportunity that arises
of securing one, and will probably pair with the first female
that enters its territory. On the other hand, if the female
of the previous spring still occupies a place in its memory,
it must ignore all others, await its former mate that months
previously may possibly have been destroyed, and thus run
the risk of losing its chance of reproduction. While it is
difficult to see what advantage could be gained from the same
male and female pairing year after year, it is easy to see how
it might thus result in disaster. For us Nature has only
one purpose in view, namely, that the stronger individuals
shall meet, reproduce, and reproduce frequently. And here
we must bear in mind the law of territory. The male
that is capable of holding a territory and defending it from all
intruders is strong enough to reproduce, and the female that
is able to defeat her rival is algo fit to reproduce. Automatic-
ally, therefore, the stronger individuals pair. An individual
that did not seize the first opportunity offered to it of pairing
would not reproduce so frequently as one that did, and its
descendants, if they inherited a similar tendency to hesitation,
would gradually be eliminated. It would doubtless be untrue

8

WILLOW WARBLER

to say that the same male and female never meet—since
according to the law of chance a reunion must in some
instances take place—but to lay it down as a rule that the
same individuals meet again and again in consecutive seasons
and are consequently paired for life is a different matter, for
there could be no rule of that kind unless some useful purpose
were thereby served. Inasmuch, however, as the fact that the
sexes arrive at the breeding area separately admits of no
dispute, and since there is every reason to believe that a
similar condition accompanies their departure to the feed-
ing area, it is evident that they are united for part of the
year only, and whatever reunion does occur in the breeding
season must be in the nature of a casual meeting, having, as
we have already seen, little to recommend it as a conditio sine
qua non to the pairing of the stronger individuals. In almost
every part of these Islands and probably in almost every part
of civilised Europe the breeding stations of most of the
migratory species are constantly changing. The timber is
felled and the undergrowth cleared in some wood, and the
following spring it possesses no attractions for the smaller
migrants, since the new growth is insufficient to provide them
with shelter. But as the seasons pass by and the growth
increases, more and more individuals of various species take up
their territories until the whole wood becomes an important
breeding station resonant with the song of many migrants.
Slowly the bushes entwined with bramble and honeysuckle,
which used to afford shelter for innumerable nests, increase in
stature, pass into saplings, and ultimately check the growth
of vegetation beneath, and correspondingly the number of
migrants resorting thereto for the purpose of reproduction
decreases, until the wood reverts, so far as they are concerned,
to its previous state of destitution. Somehow and somewhere
these former inhabitants must obtain territories. Urged by
their sexual instinct they will wander from place to place
seeking a new home, and find, perchance, a resting place in the
same locality or possibly suffer banishment from the immediate

9

BRITISH WARBLERS

neighbourhood. ~ Nearly all the migrants are thus affected.
Hedgerows are demolished and osier-beds cleared, acres -of
reeds are cut down and beds of rushes mown; and bearing this
in ‘mind, how is it possible for us to conceive of the same male
and female meeting year after year except in a limited number
of cases? A male arrives at its former breeding haunt, finds it
unsuitable, and passes on in search of a new home; a week
later his former companion arrives on a similar errand, but in
what a hopeless position, if just that one particular male is her
ultimate goal; Nature’s purpose would surely be better ful-
filled if she seized the first opportunity of pairing.

The male Willow Warblers, like the males of other migra-
tory species, seem to arrive at their breeding ground for the
most part during the night, and to sing the morning after
their arrival. In the earlier part of the season the frequency
with which they utter their song is, to some extent, influenced
by the weather. If it is cold they are more silent and by no
means so active, but under ordinary conditions they sing
incessantly during the first few hours of daylight. They
search for food in their territories, travelling first in one direc-
tion and then in another, sometimes high up in the topmost
branches of such trees as oak or ash, at other times in the
undergrowth or bushes, and yet again upon the ground or
even along the banks of a stream, uttering their plaintive song
at intervals. When sufficient food has been found they resort
to some branch, often at a considerable height from the
ground, and there preen their feathers. In some cases one
particular tree seems to be especially favoured, and to con-
stitute the headquarters of the territory, from which excur-
sions are made in different directions within the domain.

Previous to the arrival of a female excitement may be
caused either by the question of territory, that is to say, by one
male intruding upon another’s ground, or by the presence of
a. pair of Chiff-chaffs who happen to have taken up their
habitation in the same territory. In the first of these cases
there ensue frequent pursuits or conflicts; and although such

10

WILLOW. WARBLER

conflicts vary much ‘in intensity, appearing sometimes to lack
determination and to be more in the nature of play, yet from
closely studying the conditions under which they occur I
believe that, in the majority of instances, they represent a
genuine trial of strength, and that the combatants are in
earnest. It is necessary to bear in mind the strength and
capability of the actors, and to remember that even the most
deadly of contests must always appear to us as nothing but a
fluttering of tiny wings, and might readily be described by an
onlooker, ignorant of the previous history, as a game. In the
case of the Warblers it is not probable that the conflicts often
result in the death of one of the combatants, since their bills
are not of the type that would easily inflict serious injury. The
law of territory, moreover, does not demand that the struggles
shall be fatal. That the weaker males shall be driven away
and thus leave the stronger to reproduce in peace is all that is
required. ‘This law .has but one end in view, namely, that the
strength of the species shall at all costs be maintained, and if
the conflicts were always, or in a large number of cases, to
terminate fatally this end would not be attained. For since it
can clearly not ordain which individual shall compete with
which, since, in fact, the law of chance must here be relied
upon, battles must frequently occur between. two individuals
both fit. to reproduce; in which case the death of one
member would. be. a loss, not a gain, to the species as a
whole. If, therefore, the individuals of any one species were
to develop such extraordinary pugnacity that surrender were
out of the question, and a termination were only reached
when one or the other succumbed to its injuries, that species
would be at a disadvantage in the struggle for existence,
and in the course of time would probably be eliminated.
As it is, these contests do in the case of some species.
sometimes terminate fatally, and how easy it would be, if.
truly beneficial, for a species to arise with a motto of “no
surrender’ can be seen from the fact that man for his own
amusement has in a comparatively short space of time been

iG:

BRITISH WARBLERS

able by selection to breed a race of game-cocks which fight to
a finish. Conflicts between the male Willow Warblers on
different boundaries are of frequent occurrence, and, at the
commencement of the season when two appear to lay claim
to the same territory, of some duration, the ruffled feathers
denoting the severity of the strugele. At such times their
flight is rapid. They pursue one another amongst the bushes,
or close to the ground, and when they meet there is an audible
clicking of bills and the impact is considerable. To some
extent they are oblivious of what is taking place around them,
and in their intense eagerness I have seen two combatants
pass within a few feet of where I was standing. When they
settle, after such encounters, they show signs of considerable
excitement, jerking their wings, and giving vent to their feel-
ings by a single or else by a purring note. In the case of
males with adjoining territories, the conflicts are not so pro-
longed, and perhaps on the whole not so severe; they may be
better described as incessant quarrels arising from trespass of
boundary on the part of some individual. These contests
continue for some weeks, but gradually become less and less
frequent. From this description I do not wish it to be sup-
posed that a male can never cross its boundary without being
attacked, for such is not the case. At the same time I wish
it to be clearly understood that, when I speak of a boundary,
it 18 an imaginary one fixed by myself as the result of obser-
vation. Nevertheless it is possible to establish with consider-
able accuracy the true limits of a territory, though these
limits may be intruded upon without a conflict occurring.

The second cause of disturbance referred to, namely, the
antipathy shown by this species to the presence of a Chiff-chaff
—possibly a mutual antipathy—is interesting. It results in
frequent quarrels and conflicts, for a pair of each species often
inhabit the same territory. Sometimes one is the aggressor,
sometimes the other; but the Willow Warbler seems to me to
be more often the cause of the strife. The battles resemble
those that take place between the males of the same species,

12

WILLOW WARBLER

and consist of rapid pursuits, collisions in the air with con-
siderable clicking of bills, and the usual signs of excitement
common to the bird. Generally speaking, the conditions of
existence imposed by the law of territory may at any moment
become so severe as to necessitate the individuals of not only
the same species, but also of others closely allied, struggling
together for possession of a breeding home. In the case of
the Willow Warbler and Chiff-chaff we seem to have an
instance, and in truth it would be a difficult matter to discover
two species to which such an extension of the law of territory
might be more likely to apply. So closely do they resemble
one another in structure and colouring, that expert knowledge
is required to decide whether some particular skin belongs to
the one or the other; and in life, where a close examination is
impossible, it 1s often difficult to arrive at a decision. The
resemblance, moreover, does not end with appearance ; they
live in a similar environment, require similar food, and exhibit
characteristics which have much in common. Is it not then
possible—is it not indeed highly probable that there is a con-
stant struggle between them, and that their future position,
the survival or decrease and possible disappearance of one or
the other, is gradually being worked out before our eyes ?
The case is an interesting one, but perhaps not more interest-
ing than many others if we only had sufficient facts to rely
upon. The Willow Warbler is the stouter and no doubt the
stronger of the two, and, as already mentioned, it seems more
often to be the aggressor. Physical strength alone, however,
does not decide survival; activity and power to resist
unfavourable conditions are of equal value. The Willow
Warbler may be gaining so far as direct struggle resulting
from the law of territory is concerned, but, on the other hand,
we must bear in mind the ceaseless activity which is so
prominent a characteristic in the life of the Chiff-chaff, and
remember that activity counts for much when unfavourable
conditions arise. Scarcity of food, brought about by late
frosts or exceptionally cold weather accompanied by blizzards,

13

BRITISH WARBLERS

calls forth unusual energy and effort on the part of an insect-
ivorous species; otherwise it must succumb. . And doubtless
itis this great activity which enables the Chiff-chaff in the
latter part of March to discover sufficient insect life to prevent
such am undue lowering of its vitality as might render it less
able to withstand the cold inclement weather so common at
that season of the year. Nevertheless, if we regard the relative
positions of the two species, we must conclude that the
greater strength of the Willow Warbler, which enables it with
more certainty to secure a breeding territory, is of higher
importance than the activity of the Chiff-chaff, since the
former bird is more plentiful and more generally distributed
than the latter.

There seems to be some connection between the song—or the
sounds that answer to song—and the territory. The actual song
is in the case of many species so remarkable and beautiful that
it at once arrests our attention, and we naturally ask ourselves
the meaning of it, whence it originated, or how it developed.
To these questions no satisfactory answer has yet been forth-
coming. Just why a Blackcap can produce such very beautiful
notes and a Grasshopper Warbler such peculiar and mono-
tonous ones is as great a mystery to-day as ever, and I do not
pretend to be able to throw any light on the mysterious aspect
of it, but only to indicate one direction in which it may be of
some use. We must dismiss from our minds all ideas of
esthetic value, for it is clear that if there be any utility attached
to the various cries, those which may sound to our ears harsh
or even repulsive must, if uttered under similar conditions and
at. a similar season, be of equal importance to those which
delight us with their beauty. The males of the summer
migrants reach their destination many days before the females,
take possession. of their territories, and there remain: singing
incessantly during the first few hours of daylight, and ina
lesser degree throughout the remainder.of the day. The
males of some of the resident species, the Chaffinch for instance,
take possession of their territories very early in the year, and

“14

WILLOW WARBLER

there they will be found for the first two hours or so of day-
light singing incessantly, but for the remainder of the day
they behave as they do during the winter months, roaming
about in flocks; it is-not until some weeks: later that the
females become sexually developed and commence to’ seek for
mates. Territory is an essential to reproduction... By some
means a male must proclaim the fact that he is in possession
of a territory, and by some means the female must be made
aware of the presence of a male fit to reproduce. I see no
difficulty therefore in believing that all the particular sounds
emitted at this season are thus of some use. And since, on
the average, the stronger males only will be capable of obtain-
ing a territory and thereby attaining to reproduction, may it
not in justice be argued that a gradual increase in their power
of producing sounds will automatically result ? Itis difficult to
obtain any concrete evidence in proof of this. I will mention
a few facts which may be used in support of it, and there leave
it. The males we hear in full song in the spring are those
which own territories and ultimately reproduce; I can recall
no instance of a wandering male, that is to say, a male without
a territory, in full song in the height of the breeding season.
Males in search of territories sometimes pass through those
already occupied and, as far as I have been able to
observe, they remain silent during their transit. In the case
of many species the song is uttered less frequently upon the
arrival of the females and in some instances practically ceases.
When two males occupy adjoining territories, and one of them
utters its song whilst on the boundary, the other not infre-
quently attacks it forthwith. —

The migration of the females extends over some days.
The first females arrive about a week or ten days after the
first males, but this interval is subject to variation - according
to the seasons. Thus it happens that males with adjoining
territories. do-not necessarily all- obtaim a female on the same
day. The. difference is sometimes considerable, and may even
amount to as much as a week. ‘This discrepancy in the time

15

BRITISH WARBLERS

of arrival of the females is often the cause of much quarrelling ;
for although she seems to pair with the owner of the territory
in which she first makes an appearance, yet throughout the
first morning or the first day of her arrival she does not
confine herself so strictly to the boundaries as she is wont to
do later on. It is clearly impossible for her to know the limits
of the territory in which she has settled; she must learn by
experience; and this experience is probably gained under
compulsion, for a male can sometimes be seen pursuing a female,
who has crossed the boundary, and driving her back again into
his territory. Her arrival in a territory is the cause of extreme
sexual excitement on the part of the male who is its owner,
and, if she crosses the boundary, on the part of the adjoining
male. This excitement expresses itself similarly in both
sexes, and results in much pursuing and frequent mock con-
flicts. During the pursuit the flight is often rapid, the birds
twist and dart in and out of the bushes, momentarily settling,
but only to commence their round again. These outbursts of
excitement are by no means continuous, but spasmodic, and
may be commenced by one sex or the other. Thus the female
at one moment appears to call the male by singing, when he
either approaches her slowly, or flies at her more abruptly,
uttering at the same time a quiet purring sound. ‘This act of
flying at her is of common occurrence, and when it takes place
she may on his approach spread her tail, assuming an attitude
of defence which results in a fluttering of tiny wings and a
momentary clicking of bills. Or he may fly towards her
apparently with the object of presenting her with food—an
attention on the part of the male which is common amongst
many species—and he then warbles quietly or rather sings his
song continuously. When the male overtakes her during the
pursuit, both birds may fall fluttering to the ground in their
excitement.

The manner in which sexual emotion is expressed varies
in different, and even in closely allied, species. Why it should
be so we cannot tell; yet the difference is often striking. I

16

o.

. MALE AND FEMALE WILLOW WARBLER

5

ATTITUDE DURING THE PERIOD OF

' ; SEXUAL ACTIVITY 5
4 PUBLISHED BY R.H. PORTER ‘ SWAN ELECTRIC ENGRAVING C2

WILLOW WARBLER

have already mentioned that the habits of the Willow
Warbler and those of the Chiff-chaff are so similar that it
is well-nigh impossible to distinguish between them in actual
life. This is true of their habits as a whole, but the expression
of sexual emotion differs considerably, and it is possible to
recognise the peculiar wing-flapping of the Willow Warbler
at some distance. This wing-flapping is not confined to
one sex only, but forms part, though a lesser part, of the
sexual manifestation of the female. It can be seen to the
best advantage—for the peculiarity is then more strikine—
when both sexes perform at the same moment, an occur-
rence by no means unusual. Settling a few feet apart, they
face this way or that, often in opposite directions, and
standing in an upright position on the branch, partially
extend their wings, and flap them at a moderate speed.
Whilst thus performing they carry their heads rather high,
slightly expand their tail, and become so completely absorbed
in their performances, which may last for fully half a minute,
that they take little or no notice of one another. At this
period during the first few hours of daylight the wine-flapping
is of frequent occurrence on the part of one sex or the other;
and when a number of territories adjoin and a female is present
in each one of them, this curious but interesting behaviour
can be observed with but little difficulty. Hven when the
female is not in his immediate presence, the male may be
seized with sexual emotion and express it in this manner.
In its details the performance varies but little, the wings are
not always expanded to a similar extent, and the tail is
sometimes slightly raised. Silence is often maintained, but
may be replaced by a highly pitched twittering sound uttered
in sympathy with the bodily movement. Although apparently
so absorbed when performing alone, it is quite clear that the
male is very much on the alert and knows the whereabouts
of the female, for in the midst of his emotion he will dart off
without hesitation towards her, when the usual fluttering of
wings and rapid pursuit follow.

2 17

BRITISH WARBLERS

As the time passes by and sexual activity wanes, so the expres-
sion of the emotion subsides, until it finally disappears when the
full complement of eggs is laid, except in the case of polygamy
or a second brood. Let this, however, be noted, that it is not
of uncommon occurrence even after the nest is completed and
the first few eges are deposited. When in the case of adjoin-
ing territories a female arrives in one of them while the owner
of the other is still unpaired, and when, as is often the case,
she is inclined for a while to overstep the boundaries of the
territory in which she has settled, the male on to whose
eround she wanders becomes excited, and may even commence
wing-flapping. I recollect a case of this description which
was interesting merely if we regard the actions as of direct
biological significance, and as appealing to the female accord-
ing to the degree in which they are executed, for it was
evident that the more demonstrative male was rejected. The
female in this particular case wandered from the territory
in which she had settled, and from her mate who was showing
little excitement, into an adjoining one, and was confronted by
the owner who was apparently under the influence of sexual
emotion. There she remained for a short time, while he
displayed the usual signs of excitement, included in which
was considerable and vigorous wing-flapping ; eventually she
returned to her undemonstrative husband. ‘To such an
episode I attach but little importance. The sexual instinct
must vary in the same individual from day to day and even
from hour to hour, and the corresponding emotion must vary
with it. Incidents of this kind are therefore no more than
we should anticipate under the circumstances.

Of four adjoining territories, which I had under observation
one season, the behaviour of the inmates of one, which I
marked as No. 2 on the rough plan made at the time, was so
interesting that I offer no apology for describing it in detail,
though it entails a repetition of some of the features in the
life-history already mentioned. All three territories were
situated upon a long wooded bank divided by a public foot-

18

WILLOW WARBLER

path which extended throughout its entire length. In some
places it was more or less open, in others thickly covered with
undergrowth consisting principally of hazel, bramble, and
honeysuckle, and scattered here and there were such trees as
oak, ash and beech. The territory I am speaking of more
particularly, and to which I shall refer as No. 2, was about
fifty yards in length and embraced a portion of the wood
thickly covered with undergrowth. Being away from home
for a few days about the middle of April, I do not know the
exact date upon which the male arrived, and any initial
struggle which may have occurred over the question of terri-
tory was consequently missed. On April 20th three males
occupied the three adjoining territories, and the scenes which
have already been described as usual previous to the advent
of a female were constantly occurring between the three
individuals. An oak tree situated at one end of No. 2
territory was often resorted to by the owner and may have
been his headquarters; in any case he made considerable use
of it, and there passed much of his time in song. From it,
too, and from other parts of his territory, he was wont to
make excursions into the willows. Here also he sometimes
encountered No. 3 male, when a struggle usually ensued. -On
the morning of April 23rd three birds were in No. 2 territory,
one of which I believed to be a female. This was soon con-
firmed, for the owner of the territory summoned by her quiet
singing approached, and the usual scenes of excitement then
followed. For short intervals she left him, and once wan-
dered into No. 3 territory, but soon returned to No. 2. In
the evening she was on the edge of No. 1 territory, from
which she was pursued by No. 2 male, who followed her back
into his own territory. Another single bird now entered and
remained in this territory for a time, being sometimes pur-
sued by the owner. ‘April 25th found the pair together,
excitement subsiding, and the male not singing so much as
usual. On April 26th the female was building, the nest being
situated in one corner of the territory on the boundary of

19

BRITISH WARBLERS

No. 3 territory and a considerable distance from the footpath.
The male at times was excitable, showing it in the usual
manner, but the principal feature was his conflicts with the
owner of No. 3 territory, the attacks coming first from one and
then from the other. On one occasion both birds were
hopping about the ground within a few feet of one another, and
when one retired the other did likewise. Upon examination I
found the outer part of the nest formed. The next morning
both sexes showed signs of excitement, flapping their wings in
the usual way; the nest had been added to, but neither bird
approached it while I was present. On April 28th the female
was constructing a nest in an entirely different part of the
territory, and an examination of the first one revealed the fact
that nothing had been added thereto since the previous day.
The second nest was situated within a few feet of the footpath.
Throughout the morning of April 29th the female was busy
building, and considerable excitement was shown by both
sexes. After this date nothing unusual occurred until
May ‘th; there were then five eggs in the nest, and soon
after my arrival the male pursued the female and together
they fluttered about the ground, coition probably taking
place. A third bird now entered the territory and followed
the female, who was excitable and kept flapping her wings.
The male forthwith flew at this new arrival and appeared to
drive it away, but later it returned, when again it seemed
to be attacked by the male. At this time I thought that
the intruder was the female from No. 1 territory; that it
was a female I had little doubt. On May 8th this third
bird again appeared, when the male, instead of attacking,
followed it flapping his wings in the usual manner; this
action on his part confirmed my opinion that the intruder was
a female. Upon the male thus following her she retired, but
presently returned and commenced to search for food close to
the first female. The latter bird seemed to resent her presence
and consequently flew at her, upon which she again retired.
In the evening the second female was again present. On the

20

WILLOW WARBLER

morning of May 10th, noticing that a female was wing-
flapping and that the male was close beside her, I examined
the nest and was surprised to find the female sitting; she
fluttered off in fact at my approach. The mystery, however,
-was soon explained, for the second female, the bird that was
excitedly flapping her wings on my arrival, was rapidly build-
ing a nest. ‘This was situated in the centre of the territory,
about fifteen yards from the second nest of the first female.
Later on in the morning [ noticed the male in the presence of
this second female excitedly wing-flapping, while the first
female was actually sitting on the nest. Throughout the
morning of May 11th the second female was occupied in
building, and by May 13th she had laid the first ege. The
full clutch of eggs was completed by May 19th, and on the
morning of that day I found that the eggs which were on the
point of hatching in the first female’s second nest had been
taken. On May 21st the first female was again building
within a few feet of the footpath, this being her third nest,
and in it was deposited one malformed ege on May 29th, and
on June 9th she was building yet again, but this, her fourth
nest, was never completed, although sufficiently advanced to
allow of removal. The young were hatched in the second
female’s nest on June Ist. The behaviour of these three birds
is interesting from more than one point of view. At the
outset we have the curious fact of the first female building two
nests, not taking into account the third and fourth ones which
were the result of the second being destroyed. Why should she
not have been content with the first nest? Some birds, it is
true, commence one or even two nests before the final effort,
but I am not aware of this habit in the case of the Willow
Warbler. The position chosen for the first nest was at a con-
siderable distance from the footpath, and the female could not,
therefore, have been disturbed by passers-by. The actual
situation was in a bank close to the roots of a large beech
tree, where the soil was perfectly dry, and was consequently as
suitable a one as could possibly be found, but it was close to

21

BRITISH WARBLERS

the boundary; this proximity gave rise to constant warfare
between her mate and the owner of No. 3 territory, so long as
she adhered to that situation, and, I believe, explained her
desertion and the construction of another home in the centre
of the territory. A bird may desert its nest on account of
disturbance, but this particular female forsook a position of
security for one of great danger. And, as if to leave us proof
that the question of safety did not enter into her con-
sideration, she constructed a third nest within a few fect
of her second, and in as dangerous a position. Is there no
significance in her building a second, a third, and a fourth nest
in the centre of the territory, and the second female doing
likewise with regard to her one? Interesting as this desertion
of the nest may be, it is not so peculiar as the polygamous
habit of the male. Amongst certain birds polygamy is not
uncommon, but it is contrary to the general practice of the
smaller birds, and this one instance is the only evidence that
so far has come under my notice of any tendency in such a
direction amongst the Warblers. I cannot, therefore, help
thinking that the case is an unusual one. On the appearance
of the second female scenes ensued similar to those which
occurred upon the arrival of the first; that is to say, the
expression of emotion was identical in both cases. The male
again flapped his wings and again pursued and fluttered in
the wake of his second mate, and she likewise went through
' the customary process of wing-flapping. It is noteworthy
that the male attacked the second female on her first appear-
ance, but ultimately yielded to her persistent intrusion, and
also that the first female seemed to object always to her
presence. The single malformed egg laid by the first female
in the third nest is possibly not without meaning. May it not
point to sexual exhaustion on the part of the male, and may it
not consequently be indirect evidence that polygamy is not
customary on his part? It must be within the power of most
species to rear two broods at least in one season, and thus be
able to replace the destruction of the first. Indeed, it is not

22

WILLOW WARBLER

unusual to find a late second brood in the case of this species,
and the fact of the first female building a third nest points
in the same direction, and is evidence of expectation on her
part. Failure, however, was the result, brought about, I
believe, solely by abnormal conditions.

I have not yet noticed any striking variation in the duration
of the period between the arrival of a female ina given territory
and the laying of the first egg. So far as my observation goes
this period is from seven to nine days, but since there is con-
siderable variation in this respect in the case of other species,
it is possible that it is really greater than the above figures
represent it to be.

The female commences to build about two days after her
arrival. Deducting these two days from the normal period of
fertilisation, which is approximately eight, we get six days for
the actual construction of the nest. This need not necessarily,
and probably does not, represent the building capabilities of
the bird; for with regard to rapidity of construction the
female must be guided by the development of her ovaries. It
will be remembered that the first female in No. 2 territory
constructed her second nest in less than four days, and the
second female her one nest in less than three. Under ordinary
conditions a female builds rapidly for a short time and then
ceases, and the greater part of the work seems to be done
during the first few hours of daylight, for, before leaving a
territory, I have taken particular notice of the details of a
certain nest, and upon arrival the following morning have
found nothing added thereto. The ereater part of the actual
construction is the work of the female, the male seldom, if
ever, attempting to share this duty with her, but it is no
uncommon occurrence for him to interrupt the process by
flymg at her and pursuing her through the bushes. Sexual
desire is the cause of this, as it is the period of fertilisation.
Although dead grass and dead leaves are made use of to a large
extent in the construction of the nest, it is worthy of notice
that in many instances the bark of the honeysuckle is utilised,

23

BRITISH WARBLERS

and in fact appears to be a favourite material. If the branches
of the honeysuckle are examined, it will be noticed that the
bark of itself peels off and splits up into long soft strands.
The female consequently has little difficulty in tearing off the
smaller shreds, with which she forms the foundation of the
nest; and so much does it resemble decayed grasses that it is
often a difficult matter to distinguish it. Honeysuckle abounds
in many places resorted to by the Willow Warbler, and its
bark is easily collected. It formed the foundation of all three
nests constructed by the first female in No. 2 territory, and
also of those in the adjoining territories. In fact it is con-
stantly used both by this species and the Chiff-chaff. What
particular merit can there be in its use? Why should it be
preferred to dead grass? The use of it cannot be of “‘selection”
value, for bark is not obtained more easily than decayed grass ;
the weaving of it into the foundation of the nest cannot make
for stability, and an individual that persistently ignored the
use of it would be in no worse a position, since other material
in abundance is always close at hand. No doubt an earlier
generation would have regarded the habit as an intelligent
modification transmitted from parent to offspring, but such a
view cannot now be entertained, and the behaviour of the birds
does not admit of an appeal to tradition. It is just one of
those details which so readily escape our attention on account
of their triviality. We ask ourselves how comes it that this
material should be used by different individuals and so fre-
quently, call to our aid known laws and theories which in
other directions successfully explain certain facts, apply them
one by one, and finally lay them aside as unsound or insuffi-
cient, humiliated by the vastness of that which we deemed
unimportant. ‘The interior part of the nest is formed of the
decayed stems of finer grass, intermingled with moss and dead
leaves, the lining being usually feathers, but the third nest of
the first female in No. 2 territory contained no feathers. All
the nests that have come under my notice were situated on the
ground, and, where possible, a sloping bank seems to be pre-

24

WILLOW WARBLER

ferred, although level ground is occasionally chosen, and in a
flat country must often be resorted to. As, a rule one egg is
laid every twenty-four hours, but it sometimes happens that
a day is missed, in which case the loss of time is made up by
two being produced during the ensuing twenty-four hours.
Six or seven eggs represent the normal clutch, but if the first
nest is destroyed, the second clutch may consist of only three
or four eggs. Incubation lasts from twelve to thirteen days.
It is possible to tell from the behaviour of the birds when
the young are hatched, since there is a marked increase in the
excitement they then show. This excitement may be said
to be almost equal to that shown during the period of sexual
activity. ‘The period of incubation is a quiescent one; the
male has nothing to do except to find food for himself, and
for the female it is a time for rest. The energy to some
extent exhausted during sexual activity is replenished, and
upon the appearance of the young finds an outlet. A com-
parison of the manner in which this energy asserts itself at
different periods forms one of the most interesting studies in
bird life, a study to which in the future considerable time and
attention must be devoted if we are to attain to a fuller know-
ledge of the meaning of the complex modes of behaviour,
which are comprised under the term “expression of the
emotions.’ I have just mentioned that, in the case of the
Willow Warbler, the excitement shown at the period of
parental care almost equals that at the period of sexual
activity, and I do not think this is an exaggeration, for it
would be a difficult task to draw a line between the two, or
even to point to a single action which could be regarded as
characteristic of only one period. It may be remembered
that during sexual activity both sexes flap their wings in a
peculiar manner. Upon the birth of the young I have seen
the parents behave similarly; the female when near the male
flapped her wings in the manner indicative of a desire for
coition, and what is more curious still, coition appeared to be
the result. But it is perfectly clear that this could not have

25

BRITISH WARBLERS

been the case, since the young were but a few hours old and
required the care and assistance of a parent for some weeks.
The approach of a member of another species is sometimes the
signal for an outburst of excitement, and may result in a
spirited attack upon the intruder. Of no bird is the approach
so much resented as that of the Cuckoo, and so long as it
remains in the neighbourhood of the nest the excitement,
of the male especially, knows no bounds. If it happens to
pass amongst the trees above the nest the male follows in
pursuit, uttering a curious jumble of sounds intermingled with
which are parts of his song, and upon his return moves
uneasily from bush to bush, expressing his excitement by
jerking, fluttering, spreading, and waving his wings, and at
the same time fully expanding his tail. His attitude at such
a time differs only in degree from that during sexual activity, the
wings being more fully expanded and the tail fanned out instead
of being slightly spread. It is curious that in the case of both
the Willow Warbler and the Chiff-chaff there should be such
resentment shown at the presence of a Cuckoo, and interesting
also that the resultant expression of the emotion should be
identical. If these two species were especially singled out by
the Cuckoo as foster-parents for its young we could better
understand their behaviour, but according to my experience
this is not the case.

Of the two the female is the more timid. She it is who is
suspicious when one approaches the nest, fluttering around
for some time before she can gain sufficient courage to
enter. The male is not so easily perturbed; he may hesitate
before he carries food to his young and performs the necessary
duties, but it is not for long. The female often finds courage
in following in his wake, and therefore enters the nest imme-
diately after, if not at the same time with him. She, however,
shows all the while by her actions that her suspicions are not
allayed, casting frequent hurried glances this way or that.
The young remain in the nest about eleven days. For the
first few days the female spends much of her time brooding,

26

WILLOW WARBLER

the male supplying a great deal of the necessary food. With
the growth of the young these conditions alter, and about the
sixth day the necessity for a constant supply of food being
paramount both parents are consequently indefatigable in
searching for and bringing larve to their hungry offspring. I
cannot recollect having seen a male brooding the young,
although he sometimes, for the purpose of cleaning the nest,
remains for a few moments in it after having actually delivered
up the food he was carrying. The feces enclosed in a mem-
branous sac are carried away by the parents and eaten or
dropped some distance from the nest. For the first two days
or so the young develop slowly, but afterwards the growth
becomes more rapid. On the fourth day the primaries begin
to show and the eyes are partly unsealed. On the sixth day
the eyes. are fully open, and by the seventh the young are
active and make use of their call note, and the feathers on all
the feather tracts show colour. ‘The primaries are about a
quarter of an inch long on the eighth day, down being still con-
spicuous on the head. By the eleventh or twelfth day the birds
are sufficiently fledged to be able to leave the nest and fly
moderately well, but for a while they remain on, or close to,
the ground, being unable to rise to any height or to grasp the
branches securely. Their strength, however, soon develops,
and they follow their parents, who now roam beyond the
boundaries of their territory, until able to find food for them-
selves. During July and August the males sing less and less,
ultimately becoming silent, but after the moult is finished
their plaintive song can again be heard occasionally until they
leave the country in August or September.

In the life of the Chiff-chaff I remarked upon its peculiarly
inquisitive behaviour, and since the Willow Warbler is so
closely allied, it may well be asked whether it too possesses a
similar trait. I can recall but little evidence pointing to its
presence, for although a Willow Warbler sometimes shows
excitement for no apparent reason at the presence of a member
of another species, yet it is difficult to recognise that constant

27

BRITISH WARBLERS

intrusion upon, and apparent desire to be a spectator of, the
quarrels and tragedies in the bird life of the surrounding
district, so inseparable from the habits of the Chiff-chaff. At
the same time it is not likely that it is altogether absent,
but it is safe to say that it is by no means present in a
similar degree, for whereas the inquisitive nature of the Chiff-
chaff is constantly forcing itself upon our attention, that of
the Willow Warbler has to be sought for, and can only be
observed with difficulty, which of itself is evidence of con-
siderable difference in the character of the two species.

The vocal powers are more highly developed than those of
the Chiff-chaff. The song is unusually plaintive and sweet,
appealing to some ears in a manner in which no other song is
capable of doing. This is not difficult to understand, for in a
wood inhabited by a number of different individuals the constant
singing in reply to one another results in a concert which no
one could fail to enjoy. When in full song early in the spring
the bird utters its complete song from five to seven times a
minute, and continues often for many minutes in succession
without a pause, but when busily engaged in searching for
food its song is heard more intermittently. Between the song
of different individuals there seems to my ear to be a certain
amount of variation, but I do not feel competent to judge
Wherein exactly it lies, although the difference often appears
to be connected with the pitch; and I am not at all sure
that the same individual does not at times vary its song, in
addition to its frequent habit of commencing in the middle
and leaving out the higher notes. The song really consists
of so few notes and the difference between the notes is so
slight, that any attempt to resolve it into its constituent
parts is very difficult. In different localities there is consider-
able variation, which is in a great measure due to alteration in
the pitch. On the west coast of Ireland, for instance, the
tone is deeper, whereas in Hungary it is higher, and, to my
ear at least, not so pleasing. In addition to the song there are
sundry call notes, and the most common one to which I have

28

WILLOW WARBLER

not yet alluded is uttered at times of anxiety, or seemingly
for no ostensible reason. It is very similar to the correspond-
ing note of the Chiff-chaff, and very difficult to distinguish
therefrom, consisting of two notes uttered in a plaintive key,
but more slowly or rather not so briskly as those of the other
bird.

Their food is similar to that of the Chiff-chaff, and consists
almost entirely of insects. Occasionally they peck at the fruit
in gardens, and can often be found in the autumn in the
elder bushes, but I do not recollect having seen them actually
feeding on the berries. Their principal food when they arrive
consists of the various species of Chironomde ; these they
seek for diligently, examining large and small branches, buds,
and leaves. Since they are later than the Chiff-chaff in
arriving at their breeding grounds, they probably do not suffer
so much from scarcity of food brought about by abnormal
climatic conditions. Nevertheless they are compelled some-
times to face frost and even snow, and they then lapse into
silence, less able apparently to withstand the cold, or more
probably less capable of replacing their usual diet by more
minute and hardy insects. Later in the season larve form
their staple diet, especially those of the oak-leaf roller moth
(Tortric viridana). ‘he young are principally fed on larve.

29

Risyaa Ama,

UAL EOE NS ad Tehershae

16
RUFOUS WARBLER.

Aédon galactodes, Gowld, Birds of Great Britain, vol. ii, 2 pp.,
pl. 53 (coloured figures of adults), 1870; Yarrell, British
Birds, 4th Ed., vol. i, edited by Newton, pp. 355-359 (wood-
cut), 1873; Dresser, Birds of Europe, vol. ii, pp. 547-552,
pl. 85 (coloured figure of adult), 1874; Luilford, Coloured
Figures, vol. iii, p. 30, pl. 15 (coloured figure of adult), 1883 ;
Saunders, Manual of British Birds, 2nd Ed., pp. 73-74
(woodcut), 1897.

Sylvia galactodes, Seebohm, British Birds, vol. i, pp. 418-422, pl.
10, fig. 8 (egg), 1883.

Arabic, Bou-Djeha ; French, Bec-fin rubigineux ; German, der rostfarbige
Sanger; Italian, Rusignolo levantino; Spanish, Alzacola, Rubita, Vinadera.

DESCRIPTION OF THE PLUMAGE.

Adult Male.—The upper parts generally are rusty isabelline,
rather darker on the crown, rump, upper tail-coverts and two
central tail-feathers. ‘The rest of the tail-feathers are rusty
brown, the three outer ones being broadly tipped with white
followed by a band of blackish brown, while the two next ones
are tipped with blackish brown only. ‘The least wing-coverts,
medium, and larger secondary coverts are the same colour as
the upper parts. The flight-feathers are brown, the secondaries
being edged with the same colour as the back and tipped with
whitish brown, and approximately two-thirds of the outside
edges of the primaries is rusty isabelline. The primary coverts
and bastard-wing are brown edged with sandy buff. ‘There is
a distinct creamy white superciliary stripe, the lores are smoky
brown and under the eye is a creamy white space, the cheeks
being light rusty isabelline. The underparts are buffish white
and the flanks buff. The abdomen proper is whitish, the

1

BRITISH WARBLERS

under tail-coverts whitish buff, the underparts of the tail rusty
mauve and the shafts of the feathers whitish buff. Avxillaries
and under wing-coverts are whitish isabelline and the under-
side of the wing the same colour as the underside of the tail,
only paler. The bill is horn brown, the posterior part of the
lower mandible being dark flesh colour. The iris is dark
brown and the feet greyish buff.

The autumn plumage is similar but rather paler.

The young resemble the adults but the upper parts are
rather more reddish, the eye stripe yellowish, and the lores a
little lighter brown.

GEOGRAPHICAL DISTRIBUTION.

There are only three records of the occurrence of this
warbler in England, two from Devon and one from Sussex ;
the only other record for the British Islands being a specimen
which was obtained at the Old Head of Kinsale, Co. Cork.

This bird is a southern species not found in France and
apparently not visiting the northern parts of the Peninsula.
However in the south of Spain and Portugal it is common,
especially in Andalucia, Murcia, Valencia, Castellon and the
Balearic Islands. Occasionally it reaches Italy, Malta is
passed on migration, and it is found breeding in parts of
Palestine. Throughout Morocco, Algeria, Tripoli and Egypt
it is generally distributed and it is found in the Egyptian
Soudan and on the White Nile both in winter and spring,
visiting in addition Abyssinia and Somali Land in winter.

26

SAV?S WARBLER.

Salicaria luscinoides, Hewitson, Eggs of British Birds, 2nd Ed.,
vol. i, pp. 89*-90*, pl. 25* (ege), 1846; id., id., 38rd Ed.,
vol. i, pp. 115-116, pl. 31, fig. 2 (egg), 1856.

Lusciniopsis luscinioides, Gould, Birds of Great Britain, vol. ii,
2 pp., pl. 77 (coloured figures of adults and nest), 1866.
Acrocephalus luscinioides, Yarrell, British Birds, 4th Ed., vol. i,

edited by Newton, pp. 389-397 (woodcuts of adult and nest),
1873 ; Lilford, Coloured Figures, vol. iii, p. 46, pl. 23 (coloured
figure of adult), 1886.
Locustella luscinioides, Dresser, Birds of Europe, vol. ii, pp. 627-
- 632, pl. 93 (coloured figure of adult and nestling), 1875;
Seebohm, British Birds, vol. i, pp. 346-349, pl..10, fig. 20,
1883; Saunders, Manual of British Birds, 2nd Ed., pp. 91-
92 (woodcut), 1898.

Dutch, Nachtigaal-Rietzanger ; French, Fawvette des Saules ; German,

Weidenrohrsinger; Hungarian, Déli hddifiilemile ; Italian, Salciajola
Pagliarol.

DESCRIPTION OF THE PLUMAGE.

Adult Male in Spring.—All the upper parts are uniform
olive brown. ‘There is a distinct superciliary stripe, the lores
are smoky grey, and the sides of the head are the same colour
as the upper parts, but rather lighter. The shafts of the ear-
coverts are cream colour. The flight and tail feathers are
brownish, the latter being marked by faint transverse bars.
The throat and abdomen are white, the rest of the under-
parts together with the long under tail-coverts being pale
rusty brown, the latter having greyish white tips. The
underside of the tail is greyish brown, the axillaries pale
chocolate colour, and the underside of the flight-feathers light
greyish brown. ‘The upper mandible is dark horn brown,

1

BRITISH WARBLERS

lower rather more whitish, the iris light brown, and the feet
light brownish flesh.

The colouring of the female does not, as a rule, appear
to be so intense.

The young bird after the first moult is richer on the
upper parts, and the white on the under parts is less intense.

GEOGRAPHICAL DISTRIBUTION.

In former times this bird nested regularly in Norfolk,
Cambridgeshire and Huntingdon, but since the draining of the
Fens these districts have been deserted, and it is now many
years since it was last recorded as a breeding species in Great
Britain. ‘I'here is, however, one recent record in this country,
a specimen having been obtained on Fair Isle in the spring
of 1908. |

Formerly it must have been very plentiful in Holland, but,
as in our en districts, recent drainage has affected its num-
bers and banished it from many localities. Yet it has by
no means deserted the country, being still almost common
in places. In Belgium it is very rare, but is said to be
found near Antwerp. Heligoland possesses no record of it on
passage, and from Denmark and North Germany it is absent.
In Spain it is common in places, especially in parts of
Andalucia. There are records of its occurrence in Portugal,
and the south and south-western parts of France are visited,
especially the Camargue and the country round Bordeaux.
To Italy the bird is a local summer visitor, being found more
especially in the Venetian bogs, the Po Valley and in Tuscany,
From Sardinia there is only one record, but it occurs locally
in Sicily and Malta. It is not found in Switzerland, but east-
ward becomes plentiful, more particularly in Austrian Galicia
and in many parts of Hungary. Probably it occurs in all
suitable localities on the lower Danube, but from Montenegro
and Greece there are no records. In the southern and

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central parts of Russia eastwards to the Volga delta it is
generally distributed, Poland being the northern breeding
limit, where it is locally not uncommon in the provinces of
Plock, Lublin and Warsaw. In Southern Russia the most
favoured provinces are Volhynia, Podolia, Khiev and Kharkov,
and specimens have been obtained on the River Don and in the
Crimea. In the Volga district the bird is common, and there
is a record of its occurrence in the province of Orenburg. In
Turkestan it occurs in Sir Daria. In Palestine we find it a
scarce summer visitor, but in Egypt a common breeding
species, and we meet with it again in Tunis, Algeria and
Morocco. The winter appears to be passed in the northern
parts of Africa.

LIFE-HISTORY.

The few days I spent in studying this beautiful bird
on the Valencze Lake in Hungary were sufficient to show
that its habits are of unusual interest, and as a naturalist
I cannot but regret the altered conditions, the necessary
progress of civilisation, which have banished this bird from
its old home in the Eastern Counties. It inhabits the dense
masses of the common reed (Arundo phragmites), where the
roots are sufficiently thick to afford protection for its nest,
and such situations must have been plentiful before the fens
were drained. |

With regard to the date of arrival in different Huropean
countries I have no information, but on April 25th, 1904 many
males had already arrived on the Valencze Lake, and as the
females commenced to arrive on the following day, it is prob-
able that the former had been there some little time. The
question of breeding territory seems to be of importance
to the males, but since I have had so few opportunities of
studying the birds, and none of studying a male immediately
upon arrival at its destination, I am unable to produce
evidence of any struggle for possession ; nevertheless from the

8

BRITISH WARBLERS

behaviour of the male after the female has arrived I infer that
this question is of importance, since he confines himself more
or less to certain boundaries, and moreover possesses a head-
quarters, usually a prominent dead reed, to which he returns
after following the female, and from which he pours forth his
sone.

Before the arrival of the females the song of the males can
be heard in every direction throughout the day, though the
“ trills”” are longer and the song more persistent in the morn-
ing and the evening. Climbing up some dead reed and sitting
near the top the male utters his peculiar note, turning his head
first in this direction and then in that, and thereby producing
a similar ventriloquistic effect to the song of the closely allied
Grasshopper Warbler. Perched thus on the top of some tall
reed he is a conspicuous figure early in the season before the
new reeds have attained to any considerable height, and where
the species is plentiful there is consequently little difficulty in
locating the males and watching their movements.

Upon the arrival of the females, excitement is consid-
erable, and a great deal of restless movement then takes
place. One can trace the quarrelling and pursuing, and
observe without difficulty the general excitement reflexes
inseparable from the behaviour of most species when the
sexual instinct is dominant. What the direct stimulus to all
this varied behaviour is I am unable to say without further
detailed observation, a short description therefore of the
behaviour of both sexes as it actually appeared to me must
suffice under the circumstances.

The actions of both sexes during this period are very
beautiful, and in many respects interesting, but especially so
for the reason that they are identical with those of the Grass-
hopper Warbler at a corresponding period. ‘The two species
are Closely related, and we might reasonably expect to find a
similarity of behaviour, but it is a curious fact that identity of
structure does not necessarily imply identity of emotional
expression. The Chiff-chaff and Willow-Warbler, the Reed

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and Marsh Warbler, and the two Whitethroats are severally
very closely allied, but by no means adopt a similar method of
expressing their emotion. Therefore the identity of expression
of the Grasshopper and Savi’s Warbler is the more interest-
ing. Both sexes are very excitable at this period, the male
sings persistently, and while doing so seems to be watching
the movements of the female. She runs about, mouse-lke,
amonest the thick masses of dead reed, and the male espying
her climbs or flutters down the reed upon the top of which he
was singing and pursues her, running in and out amongst the
reeds, at one moment spreading his wings and flapping them
up and down and then expanding his tail like a fan, and
at another following her in a stately way carrying his head
erect, or yet again creeping after her with his head lowered,
threading his way in and out of the stems. The tail when
expanded may be either raised or lowered, and a dead leat
of the reed is often searched for, picked up, and carried in
the wake of the female. In this way the male pursues her
around his territory, eventually returning to the reed which
forms his headquarters, up which he climbs, and then again
commences his peculiar song. When on the ground both
sexes are able to run with considerable speed, but sometimes
they move by hopping. Like the Grasshopper Warbler they
have the peculiar habit of walking along a horizontal reed,
and the male does so even when with wings and tail outspread
he is pursuing his mate. The behaviour of the female during
this period is unusually interesting, for she not only sings but
also pursues the male, and even opens and closes her wings
when close beside him.

The nest, which is rather deep and solidly constructed, is
placed at the base of the reed stems and is composed of the
interwoven leaves of the common reed.

The song is similar in type to that of the Grasshopper
Warbler, but far more musical, and in a way resembles the
tinkling of numerous tiny bells. ‘The bird produces the notes
with its bill widely opened. At the commencement there is a

5

BRITISH WARBLERS

peculiar rattling sound, the clear notes then follow and con-
tinue for some minutes in succession. In addition to the song
there are numerous call notes, difficult to express in words, but
the one most frequently used resembles the call note of the
Hawfinch, so that when a number of males are close together
the sound produced reminds one of a small flock of that
species in flight. To my ear the call note of the female
appears to be somewhat different from that of the male.

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