UC-NRLF

B 3 an 7DD

THE LIBRARY

OF
THE UNIVERSITY

OF CALIFORNIA

PRESENTED BY

PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID

THE MIGRATION OF BIRDS

A CONSIDERATION OF HERR GATKE'S VIEWS

BY

F. B. 1WHITLOCK

Author of " Birds of Derbyshire," <&c., <&c.

(ALL EIGHTS RESERVED)

3Lonfcon

E. H. POETEE
7, PRINCES STREET, CAVENDISH SQUARE, W.

1897

YV

PREFACE.

MIGBATION has, to me, always proved the most fascinating
feature of bird life. I therefore looked forward to the appear-
ance of Herr Gatke's long-expected work with the greatest
interest. On its first perusal, the novelty of the author's state-
ments greatly impressed me, and after careful study I found them
very difficult of acceptance. I then formed the plan of writing
a paper to one of the current ornithological journals, calling
attention to what I considered were the principal objections.

I soon found, however, that the subject was too great for this
to be practicable. After some hesitation I decided to publish this
little work on my own responsibility.

To prevent misconception, I must here state that the first
draft of my manuscript was completed before I saw Mr. W.
Eagle Clarke's "Digest of the Reports on Migration;" and
though I was glad of the opportunity the latter gave me of
strengthening my arguments, it must be understood that where
our conclusions are identical, they have been arrived at quite
independently of one another.

In writing my commentary I hope I have succeeded in guard-
ing against any expression at all likely to convey the idea that I
hold any feelings towards Herr Gatke but those of the warmest
admiration and respect.

My sole aim has been to place the other side of the question
before my readers, to the best of my ability.

F. B. W.

49, Gregory Boulevard, Nottingham.
January, 1897.

M361929

INTRODUCTION.

IT has long been known that the little island of Heligoland,
in the North Sea, is a spot especially favoured as a place of call,
by passing birds during their long migrations to and from their
breeding grounds. From time to time items of news, in the
shape of short notes, relating to the island, or the account of
a visit made by some enterprising ornithologist, have appeared
in the current ornithological journals, from which some idea of
the marvels of the place might be gathered. But at no time
has any attempt been made by a resident on the island itself,
to give a detailed account of the volume and character of the
migratory phenomena to be witnessed there. It has, however,
been no secret that one, with whose name that of Heligoland has
long been associated Herr Heinrich Gatke, has been for many
years accumulating material for such a work.

The appearance of "Die Volgelwarte Helgoland," printed in
the German language, some four years ago, was hailed with
universal welcome, and in response to a unanimous demand an
English translation was published early in 1895.

In a volume replete with interest, special prominence will be
found attaching to the author's opinions expressed in the leading
chapters relating to the direction, attitude, velocity, order, guid-
ing power, and meteorological conditions affecting the migratory
flight. The remainder of the work being chiefly occupied by
notes on the various species visiting the island, under their
separate headings.

No one has perhaps more closely studied, or had better
opportunities for the observation of the different phases of

VI.

migration, than the veteran author ; and the results of his
fifty years or more of labour, as now presented to the notice
of the ornithological world, are eloquent testimony to the untiring
zeal and energy of an accomplished field naturalist.

The opinions he expresses, on the special department of
ornithological science, for the study of which Heligoland is so
pre-eminently adapted, will naturally have the greatest weight
with all, and some in their admiration for the veteran observer
have formed the opinion, that all, or nearly all of our previous
conceptions, as to the direction, attitude and velocity of the
migratory flight, will have to be greatly modified or altogether
abandoned in favour of those he sets before us.

In the study of so complex a subject as the why and whither
of the migration of birds in general, much diversity of opinion
is naturally to be expected, and whilst the views of Herr Gatke
are entitled to the respect his' long experience demands, it will
not be surprising perhaps, if others find, in the observations
which he presents to our notice in support of the conclusions
at which he has arrived, evidence which may just as readily be
urged in favour of results quite as different.

In estimating the value of his various theories, it must not be
forgotten that they are based on observations conducted in
a very limited and somewhat exceptionally situated area ; outside
this area his personal experience seems to have been very small.

THE MIGRATION OF BIRDS

A CONSIDERATION OF HERB GATKE'S VIEWS.

ERRATA.

Page 2, line 10, for "attitude" read "altitude."
,, 19, ,, 16, for " Anglica " read " Anglia."
28, 7, for "west" read "east."
32, 21, for "Ochotok" read " Ochotsk."
,, 118, ,, 24, delete "may."
,, 131, ,, 18, for "parties" read "partner."

the general opinion Held bylhe majority ot naturalists.

This chapter also contains his remarks on the character or
breadth of the migration front, in which the flight is performed.
As the two subjects are intimately connected, his observations on
both may be conveniently examined at the same time.

It has been previously more or less generally assumed, that the
direction of the migratory flight in spring and autumn is approxi-
mately between the points of north and south. Whilst Herr Gatke
fully recognises a movement of this description it seems to him, as
may be gathered from his constant references, to be quite over-
shadowed in importance by an east to west flight or the reverse
1

VI.

migration, than the veteran author ; and the results of his
fifty years or more of labour, as now presented to the notice
of the ornithological world, are eloquent testimony to the untiring
zeal and energy of an accomplished field naturalist.

The opinions he expresses, on the special department of
ornithological science, for the study of which Heligoland is so
pre-eminently adapted, will naturally have the greatest weight
with all, and some in their admiration for the veteran observer
have formed the opinion, that all, or nearly all of our previous

THE MIGRATION OF BIRDS

A CONSIDERATION OF HERB GATKE'S VIEWS.

DIRECTION OF THE MIGRATION FLIGHT.

H AFTER I., though interesting, is to all intents and
purposes a diary, and as a whole calls for no
special comment. Such items as it contains,
which are of exceptional value, can, therefore,
readily be referred to as occasion may demand.
In a detailed examination of the whole work it will be convenient
to follow the author in his arrangement of the various chapters
relating to the different phases of the migratory movement. His
theories on the direction of the migration flight expressed in
Chapter II., which next claims the attention of the reader; will be
found of especial interest as they, to a great extent, controvert
the general opinion held by the majority of naturalists.

This chapter also contains his remarks on the character or
breadth of the migration front, in which the flight is performed.
As the two subjects are intimately connected, his observations on
both may be conveniently examined at the same time.

It has been previously more or less generally assumed, that the
direction of the migratory flight in spring and autumn is approxi-
mately between the points of north and south. Whilst Herr Gatke
fully recognises a movement of this description it seems to him, as
may be gathered from his constant references, to be quite over-
shadowed in importance by an east to west flight or the reverse
1

2

according to the season of the year. Indeed, he frankly con-
fesses that not a single bird is observed to adopt the former direc-
tion in arriving at, or departing from the island. It appears,
therefore, that he is only driven to the admission that many
species must of necessity migrate between the points of north
and south by a consideration of their geographical distribution.

It will, perhaps, be convenient to first consider the evidence
he presents in favour of this east to west flight. Before doing
so, however, it will be necessary to examine his theory relating to
the manner in which the travelling hosts of birds perform their
annual migrations. On p. 24 he writes: "The predominant
mode in which the migratory movement is performed is in a
broad front or migration column, which in the case of species
migrating to the west, corresponds to the latitudinal range of
their breeding area, and in those migrating southwards, to the
longitudinal extent of their nesting stations." It might be
inferred from this, that the author wishes to convey the impres-
sion that there are many migratory streams of birds travelling
east to west or north to south, but still leaving numerous wide
gaps in the advancing rank. That this, however, is not his inten-
tion, is pretty evident from his remarks on the migrations of the
Yellow-browed Warbler. On p. 30 he writes : " This bird ap-
pearing in Heligoland in favourable weather regularly every
autumn, two, three or more individuals being frequently observed
in one day, it surely ought also to occur in Germany with equal
regularity and in fairly large numbers." And again, on p. 33,
writing on the east and west migration in general, he remarks:
" In this long wave of migration, however, each of the many
hundreds of species which compose it, does not follow a migration
route, more or less narrowly limited of its own, but all on setting
out from their breeding area take up a westerly course which,
within the latitude of their nesting relations, they pursue to its

final goal " More to the point still are his remarks

under the heading of " Exceptional Migration Phenomena." In
discussing the question as to the justice of treating the Siberian
species which have occurred in Heligoland as erratic wanderers,
or otherwise, he writes (p. 118), "When we consider, as we are
undeniably entitled to do, that the large number of individuals of

species from far eastern regions, which are met with in Heligo-
land, must stand to the quantity of these erratics passing through
the whole of Central Europe every autumn, in the same relation
as the size of this island does to that of the continent." There-
fore, if in Heligoland alone from eighty to one hundred examples
of the Yellow-browed Warbler, have been shot or seen during the
last fifty years, it follows that the same species, but in proportion-
ately greater numbers, must also have appeared in Germany or
other parts of Europe during the same period.

The above extracts make it sufficiently clear that the author
wishes his definition of a broad migration column to be taken
in its most literal sense.

In comparing the area of Heligoland with that of Central
Europe, one naturally only compares the area of the former,
with a like area occupying the same longitude in the latter, as
the flight is supposed to travel east to west. Otherwise the
same individuals would be liable to be enumerated over and
over again at various different points. But if we are to apply
the before-mentioned theory to the rarer species, we are surely
entitled to do the same in the case of the commoner ones.

To fully realise the significance of such a theory, we have
only to take Herr Gatke's estimates of the numbers, comprising
the flocks of Hooded Crows, Starlings, Skylarks and others,
which pass the island, and multiply them by the vastly greater
extent of Central Europe in comparison with Heligoland, to
find that the results are something incredible and altogether
impossible. It must not be forgotten, too, that migration for
the most part, in the opinion of the author, takes place at
altitudes beyond the powers of ordinary vision, and that such
of it that comes within our cognisance is due to disturbances
of the normal flight. It is only fair to mention, however, that
the above-named species are amongst the few which usually
perform their journeys at a very moderate elevation. There
still remain the great majority, however, whose normal flight
is performed at heights beyond our vision.

As an illustration of what in Herr Gatke's idea is the breadth
of the migration front, his own words may be quoted. He writes
as follows : "In the case of the most different species, and in

districts so widely separated as Central Germany, Heligoland,
the eastern coast of Great Britain including the Orkney and
Shetland Islands Norway, up to a latitude of 70 N. in Finmark,
the same results as to the direction of the migratory flight have
been obtained. The latitudinal range of this migration front
covers a stretch of no less than 960 geographical miles . . ."
When it can be shown, as it undoubtedly can, that the breeding
range of certain species which according to his theories migrate
east and west entirely covers this distance, then, after also
taking into consideration the estimated numbers of these
species migrating past Heligoland alone, the full significance
of his theory of a broad migratory column corresponding to the
latitudinal area of the breeding range will be fully appreciated.

To return now to his views on the direction of the migra-
tory flight. " Direct observations in Heligoland," he remarks,
" either from watching the flight of passing migrants by day, or
by noting their call-notes during the night hours, have established
the following main results with regard to the direction of the
migration flight, viz., that in autumn the migration proceeds
from east to west and in the spring in the opposite direction.
Further, that in the cases of all the species and individuals noted
on the island, these courses are rigidly maintained during the
passage, and such rare deviations as do occur never extend
beyond one or two points of the compass. Not all birds, how-
ever, reach their winter destinations by an autumn passage
proceeding in this simple westward direction. Many on the
other hand are sooner or later obliged to turn southwards in
order to reach the lower latitudes in which their winter quarters
are situated ; in the case of some species the original direction of
flight is maintained throughout the whole immense stretch of
road from the eastern countries bordering the Amoor river to
the west of Spain." Herr Gatke here seems to have overlooked
the fact that there is a difference in the latitude of the Amoor
Valley and the west of Spain of ten degrees, or say seven
hundred miles, but of course in so long a journey this does
not proportionately amount to much. A flight, however,
between these two points can hardly be said to be performed
in a rigidly maintained east to west direction.

The words, " sooner or later," referring to a southward turn,
in the above paragraph, are very indefinite. This is unfortunate,
as it is plain, what a vast difference this turn must make in the
numbers of birds which would pass Heligoland, if it takes place
before the various flights reach the latter locality. To the
writer, Herr Gatke seems to infer in other places that the
majority do not travel southwards until they have crossed over
the North Sea to the coasts of Great Britain ; though there may
be a few exceptions to this rule.

Now there can be no reason for doubting that a vast number
of birds during their flight past Heligoland in the autumn, are
actually seen travelling in the direction pointed out by Herr
Gatke, and that their flight between these points can also be
traced over a limited distance both east and west of the island.
But a flight which has only been proved to trend in an east and
west direction over such a comparatively small proportion o
the whole journey, can hardly be held to be sufficient evidence
that its original direction, from its commencement to its arrival
at the latter locality, has been so rigidly or even approximately
maintained as Herr Gatke endeavours to prove. As to the
extreme view expressed above, that certain species perform a
flight which is maintained in this direction from countries
bordering on the Amoor to the west of Spain, there is to the
writer, only the migrations of one species, viz., Richard's Pipit,
that can be pointed to in support of such a theory, and the far
eastern origin of the individuals which reach Heligoland, will be
found, later on, to be open to doubt.

We are not expressly told what are the species which adopt
this east to west line of flight, though they are said to amount
to many hundreds. It is, however, possible to gather that
amongst the most important are the following: Buzzards,
Starlings, Hooded Crows, Books, Jackdaws, Larks, Swifts,
Plovers, Curlews and Geese. These species are mentioned on
p. 25, and God wits, Oystercatchers, Greenshanks, Sandpipers
and Thrushes are enumerated in addition on p. 30. This list,
however, leaves the remainder of the " many hundreds " men-
tioned on p. 33 to our imagination. It may be here pointed out
that the majority of the smaller species, such as the Bluethroat

and other warblers, Wagtails, Flycatchers, Chats, &c., arrive and
depart from the island in a manner which precludes the possi-
bility of realising in what direction they are travelling at all.

On p. 37, however, we are also told that the direct north and
south flight is peculiar to a large number of species (though it
must not be forgotten that none are said to be seen to adopt this
line of flight), more especially such as have their breeding
quarters in high northern latitudes. In the face of this remark
are we to eliminate from the above list the following, or not ?
Shore Lark, Grey Plover, Dotterel, several species of Geese,
Bar-tailed Godwit, Greenshank, Dusky Eedshank, Green Sand-
piper, Wood Sandpiper, Little Stint, Knot, Sanderling, and a
few others. We know also that many of these species are seen
during the migratory periods on both coasts of Scandinavia and
also in the Baltic, and we should expect numerous flocks from the
latter localities to touch on Heligoland. It must not be forgotten
too that the breeding ranges of most of the species recorded as
visiting the island, extend far to the north of the latitude of the
latter. As instances, the Kedwing, Fieldfare, and Hooded Crow
may be mentioned. In considering from what regions the enor-
mous flights passing Heligoland are derived, these facts are of the
utmost importance. It is a pity, therefore, that the author is
not more definite in his remarks as to the particular species
following this east and west route, especially as some already
mentioned are found during the winter season on the Mediter-
ranean coasts. It would be interesting in the light of this theory
to learn how these birds are supposed to reach the latter
locality.

It may here be as well to quote Herr Gatke's definition of
what he terms migration proper, or normal migration. On p. 46
he remarks " Here I ought to remind the reader, that when
I speak of migration proper, I mean those large extensive
movements which, on the one hand in autumn, conduct our
migrants from their breeding homes to or very near to their
winter quarters in one uninterrupted, and for the most part
nocturnal flight ; and on the other hand, in spring, convey them
in the opposite direction from their winter quarters to their
breeding haunts the uninterrupted continuity of the flight being

still more marked in this latter phase of the migratory pheno-
menon." From the above passage, read in conjunction with
others on the altitude and velocity of the migratory flight, it
will be clearly evident that the author's theories on the direction
of the flight are based on observations made, when this migration
proper has been interrupted and has therefore become in the
light of his remarks, at any rate disturbed; but we may fairly
assume that the direction is not affected in any case. Before
going any further it may be as well to take a brief glance at
the total number of species enumerated by Herr Gatke, as
having occurred on the island. A convenient summary, by the
late Henry Seebohm, appeared in the Ibis, vol. iv., 1892, pp.
1-32, and will be found sufficient for the purpose.

The total number known, or supposed to have visited
Heligoland, is 396 (one or two more have been added since the
publication of Herr Gatke's work). Of these some forty or more
are admitted into the list, on evidence not quite conclusive. But
if we remember that so many of the inhabitants of Heligoland
are familiar with all the usual visitors, we shall not err, perhaps,
in attaching more credence than usual in the case of these reputed
occurrences, especially such as have the endorsement of Herr
Giitke. At the same time one may be perhaps excused a feeling
of envy towards Aeuckens, who possesses a memory which
enables him, on the skin of a Warbler being submitted to his
notice, to declare the species of the latter identical with the
mutilated remains of another which passed through his hands
some twenty-seven years previously. Seventy-five other species
have been shot only once, though in a few instances other
examples have been reported as seen near enough for identi-
fication. There still remain some 280 species which pass with
greater or lesser regularity both in spring and autumn. A truly
marvellous number if Herr Gatke's theories are borne in mind,
and the small area under notice is not lost sight of. The
total European avi-fauna, including Neartic and other stragglers,
amounts to, in round numbers, 600 species, so that Heligoland
can claim fully two-thirds.

In considering Herr Gatke's theory of a rigidly preserved
east to west flight, it will be useful to learn what species have

8

reached the island which are not yet known to breed on the
western side of the Urals, and to also learn in what numbers
they have appeared.

As the result of upwards of fifty years' observation, we find
the following have been recorded :

Geocichla varia. Thirteen examples caught, most of them
in September and October. Seven or eight others seen.

Geocichla dauma. An example in Lund Museum which may
have been obtained on Heligoland.

Turdus Fallens. A bird seen June 3rd, 1881, supposed to
have been of this species.

Turdus fuscatus. A young example caught in 1880.

Turdus ruficollis. A young bird caught in November, 1843.

Turdus atrigularis. An adult male once seen.

Phylloscopus fuscatus. A bird supposed to have been of this
species seen in October, 1876.

Phylloscopus superciliosus. Seen about eighty times during
fifty years. More than thirty examples shot.

Phylloscopus proregulus. ODC killed October, 1845. A
second seen October, 1895.

Phylloscopus coronatus, One killed October, 1843.

Phylloscopus viridanus. Three shot.

Phylloscopus nitidus. One shot 1867.

Hypolais caligata. One shot September, 1851.

Locustella certhiola. One shot.

Cinclus Pallasi. Supposed to have been seen twice.

Saxicola morio. Two shot (this is, more correctly speaking, a,
south-eastern species).

Anthus Eichardi.K few in spring, pretty numerous in autumn.

Alauda sibirica. Two shot.

Alauda tartarica. One shot.

Emberiza pityornis. One caught.

Emberiza luteola. Two birds seen are supposed to have
belonged to this species. (This is also more of a south-eastern
species).

Parus kamschatkensis. An example seen by Herr Gatke, but
not obtained.

Charadius fulvus. Three shot.

9

Charadius caspius, Two shot, two supposed to have heen
seen.

A total numoer of twenty-four species. On the face of it this
appears to be a remarkable record for so small an area. But out
of the whole list only two can be looked upon as regular visitors,
viz.:

Phylloscopus super ciliosus. Average visits for fifty years, two
per annum.

Anthns Richardi. Fairly regular in spring, occurring in some
numbers in the autumn.

Of the others Geo. varia occurs on an average once in two
years. So far from the rest of Central Europe having produced
the foregoing species in numbers proportionate to its vastly
greater area, the exact converse is the case, and that these rare
birds in such theoretical abundance have escaped notice, is highly
improbable. This especially refers to the cases of Eichard's
Pipit and the Yellow-browed Warbler. Several other species are
included in the European avi-fauna on the strength of single
examples having been obtained on Heligoland alone. Of the
remainder of the list, one or two, have been included on the
evidence of supposed captures before Herr Gatke's time. About
a third of the whole number have only occurred once. What the
many other species from eastern Asia are which visit Heligoland
in such large numbers every autumn (p. 33), one would be
interested to learn.

If we take away the evidence of the far eastern origin of the
vast nights of birds annually passing Heligoland in the autumn,
afforded by the regular occurrence of Anthus Richardi and PhylL
superciliosus , but little remains to prove that any species in such
distant countries, on setting out from their breeding area, take up
a westerly course, which they maintain until they arrive at the
coasts of western Europe and Spain. If the foregoing species men-
tioned, as only breeding east of the Urals, are not to be regarded
as accidental stragglers, then, one cannot help being struck by
the different manner in which Herr Gatke treats the occasional
appearance of certain others, whose breeding grounds are much
nearer Heligoland, but whose migratory flight, he admits, is per-
formed from 7iorth to south. These individuals, on the contrary,

10

are pointed to as evidence of the undeviating character of the
latter movement, their appearance on the island being described
as of the rarest, though like the Siberian examples several have
been obtained more than thrice.

So far, however, from treating the Siberian species as erratics,
though their normal line of flight is also admitted to be north to
south, they are supposed to be affected by some law or impulse to
abandon the route pursued by the vast majority of their fellow-
travellers, and to turn to the west by a voluntary act, which is
not to be interpreted in the light of an accident, but in another
place is explained as due to the prevalence of certain peculiar
meteorological conditions at the time of their departure.

It must not be forgotten, too, that the flight of these Asiatic
species, in common with the European, comes equally under the
definition of the "broad migratory column" as before described.
Many should, therefore, be found passing through or wintering in
western and southern Europe in considerable numbers.

In Herr Giitke's opinion, the lack of evidence that such is the
case is due to the fact that certain of them are so inconspicuous
in size and appearance that the chances are all in favour of their
escaping detection. This, he especially insists upon, is the case
with the Yellow-browed Warbler, which, he thinks undoubtedly
occurs in some numbers in Great Britain every year. In con-
sidering the chances of this contingency he overlooks one fact
however. This species has most often been obtained in Heligo-
land in the month of October. Now in Great Britain, at this
period of the year, all the other Phylloscopi will have already
retired to their winter quarters. The appearance of a solitary
example, therefore, would be sure to attract the attention of any
observer interested in bird-life, and probably lead to the detec-
tion of the stranger. The call-note, too, has been described by
Seebohm as quite distinct from that of its European congeners.

The case of Anthus Richardi is still more striking, though
this species has been far more frequently detected in western
Europe than the former. But, whereas, if by Gatke's rule the
Yellow-browed Warbler should occur in hundreds, Richard's
Pipit should be wintering somewhere in tens of thousands, or as
he puts it himself, in incomputable numbers, and that such a

11

fine species, with its loud clear call-note, should be overlooked
under such circumstances is simply incredible.

It will be seen at once that our acquiescence in the statement,
that we are undeniably entitled to assume that these Asiatic
species pass through central Europe in numbers proportionate to
the larger area of the latter in comparison with the area of
Heligoland, will depend in the first place on our acceptance of
the theory that their western flight is performed in a broad
column corresponding to the latitudinal extension of their
breeding grounds ; as their normal migrations are admittedly
north to south, and in the absence of confirmatory evidence, the
application of such a theory to these particular species seems to
be quite unwarranted.

In perusing the contents of Herr Gatke's work, one is being
continually struck with the high estimates he places on the
numbers comprising the migratory flocks of birds passing the
island.

Curiously enough it will be found, in the first place, that the
species which migrate from east to west in autumn are said
to amount to many hundreds (p. 33), and also that as many,
if not more, preserve a line of flight from north to south. As
the whole ami-fauna, of Heligoland only amounts to some 400
species, one is rather puzzled how to account for these large
figures.

It will be readily admitted that to arrive at an accurate
result in calculating the numbers of rapidly moving objects is
very difficult. It is equally difficult to arrive at a proper esti-
mate of the value we are to place on the author's computations.
In particular instances the reader can hardly fail to be struck
by evidence of the grossest, though no doubt unintentional,
exaggeration. This must perhaps be attributed to the artistic
element in Herr Gatke's nature. As an instance of this ex-
aggeration, the case of the Hooded Crow may be pointed out.
On page 64 he writes of this species migrating "in millions,
nay, billions " an impossible estimate in any case, but still
more incredible if we bear in mind his theory of a " broad
migration column," and if we are also to assume that this state-
ment refers to the neighbourhood of Heligoland alone. It is

12

doubtful if any species of bird exists in numbers approaching a
billion. It is perhaps hardly necessary to point out that for one
billion of Hooded Crows to cross a given longitude in the sixty
days which Herr Giitke assigns as the duration of the migratory
iiight of this species, it would be necessary for no less than six-
teen thousand six hundred millions to pass each day. It will
also be observed that Herr Gatke is not even content with the
singular number. Whatever the breadth of the migration column
may be, such myriads are inconceivable.

In the article on "The Guillemot" also, we have another
instance in which he allows his enthusiasm to run away with
him. Eef erring to this species on p. 578 he writes of " countless
myriads of birds swarming about in all directions in the air ;
equally innumerable long-extending companies are seen swimming
near and far upon the sea" an artistic description truly, but
on further reference to the text we find that these " countless
myriads " and " innumerable companies" resolve themselves into
some fraction of a breeding colony of only 2,000 birds.

These remarks are not intended in any hypercritical spirit,
but merely to serve as a warning to the reader not to attach
too great an importance to statements that such and such species
pass Heligoland in numbers which can only be derived from a
breeding-range extending throughout the whole of Eastern
Europe and Asia.

In presenting evidence of his theory of an east - to - west
migration, Herr Gatke has wisely called attention to the flight
of several species which are either conspicuous from their
abundance, or from special interest attaching to their history.
It will, therefore, be convenient to follow him in his remarks
on each of these species in turn.

Before doing so, however, it may be as well to ascertain what
portions of the continents of Europe and Asia we are fairly entitled
to consider as belonging to the east. Of course, if we are to include
all the vast territory lying to the east of the longitude of Heligo-
land, from the Mediterranean in the south to the Arctic Ocean in
the north, and in like manner throughout Asia, then the theory
of an east-to-west flight may be very easily accepted. But if,
on the other hand, and bearing in mind the author's definition

13

of a rigidly maintained westerly flight, we take as our standpoint
the latitude of Heligoland as constituting the only true east,
then all points north of this latitude must be considered as only
approximating to the east in lessening degree, until at last true
north of the island is reached in Scandinavia. The same
remarks, of course, apply to the south. It follows, therefore,
that birds breeding in the north of Europe, and which may
happen to pass Heligoland on autumnal migration, must travel
in a direction more or less partaking of a direct southerly
character, even should they at the actual time of passage be
observed to be travelling due west. According to Herr Gatke,
however, the southward turn is only adopted towards the end
of a long westerly flight.

If we adopt, however, the definition of the east in its narrowest
sense as we might not unreasonably do in the light of the
author's remarks on the rigidly-conducted line of flight it follows
necessarily that any species migrating from the east, and adhering
to this course until it reached the longitude of Heligoland, will
only be observed at the latter locality if the latitude of its nest-
ing station corresponds with that of the island. "All on setting
out from their nesting stations take up a direct westerly course,
which they pursue to its final goal," he writes (p. 33). This is
an important point in considering the undeviating character of
the flight, as described by Herr Gatke, and in face of the enor-
mous numbers of birds annually recorded as passing his observa-
tion. For are we not told to use his own words that at Heli-
goland migration takes place in " extraordinary and unexampled
grandeur" (p. 4). If we accept the theory of a broad migratory
column, advancing due west from regions in the far east, we
should naturally expect to find, in like manner, birds passing
other points to north and south of the island in equal abundance.

These remarks especially refer to a well known species, viz.,
the Hooded Crow. The migration front of this species has on
one occasion, according to the author, been known to cover a
longitude of thirty-six miles in the immediate neighbourhood of
the island, and possibly further still. But this distance is insig-
nificant in comparison with the latitudinal extent of the breeding
range. Eoughly speaking, the latter includes Scandinavia and the

14

greater part of Europe east of the longitude of Heligoland, extend-
ing as far north as the limits of forest growth, and about as far
south as lat. 48 ; colonies also exist to the west and in north-
eastern Africa; but it is not necessary to take the latter into
account at the present juncture. Writing on the Hooded Crow,
Seebohm remarks : " Though the area of its distribution is
intersected by the narrow belt of Carrion Crows, which connects
the East Siberian colony with the Turkestan colony, and the
latter with the west European colony, it cannot be said to be
discontinuous. On the continent the Hooded Crow is found
throughout Europe east of long. 10, and in Asia extends north
of Turkestan as far as the valley of the Yenesay. . . . The
Scandinavian birds migrate to Holland, Belgium, and Northern
France, and even to England, in winter; and many of the
Siberian birds, together with hybrids of every degree, winter in
Turkestan." Amongst the millions of this species which pass
Heligoland every year, many of which, in Herr Giitke's view, are
derived from regions in the far east, he has not detected any of
these hybrids alluded to by Seebohm. Now what a remarkable
fact it would be if the individuals breeding beyond the region
where the former are produced, when migrating to the west, were
not frequently accompanied by many examples of the latter.
In the absence of these hybrids, it appears very unlikely that
any of the great flights passing from Heligoland are really
derived from a breeding area in far Eastern Asia. It will be
observed that Herr Gatke assigns the Lena as the limit of this
breeding area. On the other hand, most authorities mention the
valley of the Yenesay.

Even if these hybrids were unnoticed by reason of their not
passing directly over the island, they would hardly escape detec-
tion on their landing on the eastern coast of England, which
Herr Gatke informs us is the next destination of the vast flights
which pass his observatory.

What numbers of so voracious a species as the Hooded Crow
any given area could support is very difficult to say. But if we
consider the great quantities of Books which find a thriving
living in a limited district like the Midland counties of England
where every village has its rookery we may perhaps not deem

15

it necessary to have recourse to a country extending beyond the
Urals to sustain even the millions of Herr Gatke, as he himself
suggests.

How are we to account for the accumulation of these vast
flocks, if we accept the theory that all on setting out from their
nesting stations travel in a rigidly maintained westerly direction
and in a broad column corresponding to the latitudinal area of
the latter? Except at the periods of migration the Hooded
Crow is not a particularly gregarious species, and though con-
siderable numbers may be present in a small district, yet at their
winter quarters small parties, rather than flocks, are met with
as a rule. With regard to the breadth of these flights, the most
that has been proved is, that on a certain occasion, viz., October
24th, L884, the present species, in company with Rooks and
Jackdaws, was observed to be passing over and near Heligoland
in vast numbers, and in a flight having an ascertained frontage
thirty-six or forty miles in extent, though we are not told this
was an unbroken front. Now no country, due east of Heligoland,
of this breadth, even if it extended as far as the Yenesay, would
have been large enough to have produced the millions comprising
this flight. Herr Gatke also further attempts to prove that
this migration front covered a vastly greater breadth. At the
same time, he writes, that an extraordinary migration was taking
place " over the North Sea, on the eastern coast of England and
Scotland up to the Orkney and Shetland Islands." On referring
to the "Report on the Migration of Birds for 1884," it will be
found that whilst there certainly was a large movement in
progress on the east coast of England, within or around a latitude
corresponding to that of Heligoland ; further north, however,
the numbers arriving were insignificant and not more than the
normal. In support of this statement those portions of the same
report relating to the east coast of Scotland may be quoted. On
p. 28 we read " In autumn, a more decided movement of
Hooded Crows (this in comparison with spring, when less than
usual were observed). Records from Sumburgh Head, North
Ronaldshay, Pentland Skerries, Girdleness and Isle of May (none

noted at Bell Rock) Decided rush between October

llth and 26th at Pentland Skerries (14th), and at Isle of May."

16

It will be observed that these dates do not altogether coincide
with those recorded at Heligoland.

Now let us also see what constitutes a rush on the east coast
of Scotland. Again quoting from the same source we find
" The numbers recorded are, on llth and 12th one shot by
J. A. H. B. ; no more till 23rd ; eighteen flying north (and
Books), forty on 24th, and forty on 25th, with one Carrion Crow.
Continued on 26th. Again in November, a number for some
days at Sumburgh Head on 10th ; also at Pentland Skerries
a few, and the indication of a rush at Isle of May, on 12th and
15th, flocks of nine and twelve having been seen on these dates."
Compared with the myriads recorded from Heligoland these
numbers are utterly insignificant. [Though too long to be
quoted here, the remarks of Messrs. Harvie Brown, and Cordeaux,
on the stretches of coast on the east of Great Britain most
favoured as points of arrival by immigrant birds will be found
especially interesting in connection with the theory that migra-
tion is performed in a broad front (see reports for 1885).]

It may here be remarked with reference to this rush of
Hooded Crows in October, 1884, that the chief lines of flight
were S.E. to N.W., E. to W., and S. to N.W., as observed at
various light vessels and lighthouses adjacent to the east coast
of England; thus showing if we grant the identity of the flocks
passing Heligoland with those arriving on our Lincolnshire coast
that the rigid east-to-west direction, which this flight is originally
supposed to have possessed, had undergone a certain amount of
deviation before reaching the latter locality.

The above evidence will perhaps justify our assumption that
over whatever breadth the migration front extended at the time
of its inception, it had become considerably contracted by the
time it reached our shores, and bore no adequate relation to the
latitudinal area of the breeding range. And with regard to the
general direction of the flight we cannot conceive that a district
thirty-six miles, or fifty miles in breadth, even if it extend to
the valley of the Lena, could produce the species in such great
abundance. Does it not follow, therefore, that at some period
of the journey, there must be concentration on to some common
fly-line of all the migratory individuals of this species, from

17

districts intermediate, between the north-east and east of the
latitude of Heligoland. If so, shall we be justified in calling
a flight, which under these circumstances would trend more
or less from N.B. to S.W. ; a rigidly preserved westerly flight ?

In suggesting a " concentration on to some common fly-line,"
it must not be inferred that this implies any special intention on
the part of the flocks to meet together with this purpose in view,
bub to point more to a fortuitous circumstance, brought about
possibly by the configuration of the country as the Hooded
Crow is a low flyer.

It is easy to see how this concentration may occur. If we
glance at the map of Europe we shall find that the land reaches
its highest northern latitude in Russia, at the extreme north-
eastern boundary of the continent, and that as we travel west-
wards from thence, the coast line, as far as the shores of the
White Sea, gradually falls away towards the south-west. If we
grant for the moment that the Hooded Crows breeding in the
regions above the arctic circle migrate due west from their
nesting stations and rigidly preserve this direction of flight, they
will sooner or later reach the shores of the Arctic Ocean. Now
we have no reasons for thinking that at any point in the far
north, they leave the land to migrate across the sea to the Kola
peninsula. If, however, this actually takes place, then a con-
tinuance of their journey would take them to the west coast of
Norway, where they must either turn south or cross the North
Sea, and their further flight, in this case, would tend either to
miss Heligoland altogether, or, at the most, to cross the island
in a north to south direction. It seems, however, far more
reasonable to suppose, that such migratory flocks which breed in
the far north still assuming that they take up a direct westerly
course would, on reaching the sea, follow the coast line to the
delta of the Dwina, where other flights, from lower latitudes,
would coalesce with them, and thus continue their further
journeys in company. A similar concentration may very well
take place at many points along the eastern shores of the Baltic ;
whether individuals in the first instance migrate due west or south-
west ; and we can thus see how the immense hosts observed at
Heligoland may be marshalled together. The flocks comprising a
2

18

migration conducted in a broad front, and travelling west, would,
on turning south at an identical longitude, naturally be converted
into a comparatively narrow flight, and bearing no relation what-
ever to the latitudinal area of the breeding ground. It seems
more probable that these migratory Crows would follow the
eastern shores of the Baltic in preference to making an attempt to
cross to the opposite coast in continuation of their westerly flight :
for, as has been pointed out before, if they still persisted in a
flight in the latter direction as far as shores of the Atlantic, they
would hardly be likely to touch at Heligoland at all. Birds are
very conservative in their habits, and there can be little doubt
that inheritance comes largely into play when the locality of their
winter home has to be determined. If we grant that the nature
of migration at its first inception is to-day best represented by
the intermittent movements of those species which may be said
to hang about the fringe of the severest cold, we can understand
that the habit of crossing wide seas, as is the practice of birds
at the present time, must have been a later development; not
from any lack of powers of flight, but more from a reluctance to
attempt a journey leading to some unseen and unknown goal :
indeed, the pioneers in a movement of this nature must, as far
as we can see, have first undertaken such a flight through an
accident or by force of circumstances, rather than design. We
cannot imagine birds to have been gifted with a sense which
enabled them to detect the presence of land in the far distance,
and beyond their range of vision at this early stage of the develop-
ment of the migratory habit. Thus the flights of Hooded Crows
are more likely at this early period to have followed the coast
line of such seas as they encountered, and have continued to do
so to the present day. According to Herr Gatke's view, how-
ever, it is not the sight of the sea which turns birds to the
south, though he does not tell us his reasons for coming to this
conclusion. In bringing forward evidence in favour of the far
eastern origin of these great flights of Hooded Crows, Herr Gatke
is apt to lay too great stress on the fact that their direct westerly
flight can be traced over a distance of six hundred miles, i.e.,
from the shores of Schleswig Holstein to the interior of England ;
but it can readily be proved that only a small proportion, if any,

19

of the vast hosts he alludes to, ever reach the latter country;
and even such as may do so, turn to the south soon after their
arrival on the east coast. But in any case a westerly flight of
some 600 miles is only a moderate fraction of the distance
between central England and the valley of the Yenesay.

With regard to the ultimate distinction of these hordes, it
seems to the writer, after considering all the evidence bearing on
the subject, that soon after passing Heligoland the great majority
turn towards the south or south-west, some passing inland into
Germany, and the remainder wintering in Holland, Belgium and
France, or, perhaps, still further south as examples have been
met with in Spain.

That any large proportion of these millions reach the east
coast of Great Britain which is the case, according to Herr
Gatke there is no evidence to prove. What would be the effect
in East Anglica of an incursion of a voracious species like the
present, in numbers approaching those observed at Heligoland ?
They could hardly fail to create a sensation, even if they were
distributed over the whole littoral between the Humber and
Thames. Certainly the species is observed in the late autumn
in considerable numbers in our eastern counties ; but there are
no records referring its appearance in even tens of thousands.
It is simply impossible that such huge numbers could escape
observation. Neither do Hooded Crows on reaching the coast
line pass very far inland to the extent Herr Gatke imagines.
The following remarks of his, quoted from p. 26, are based on
mere assumption. He writes : " Now the Eastern and Mid-
land counties of England cannot by any possible means afford
sufficient room for furnishing winter quarters to .the millions of
Hooded Crows, which every autumn pass this island across the
North Sea; and since, according to Eodd and Thompson, they do
not reach either the West of England or Ireland, ... it
follows that they must very soon after reaching England pass
across the channel to France." On p. 25 he further writes:
"The Hooded Crow does not get to the Western parts of Eng-
land, but turns to the South as soon as it reaches the central
portions of that country." These statements are rather contra-
dictory, too, after having previously quoted Mr. Cordeaux's

20

remarks, to the effect that the species still flies directly inland
to the west on arriving at the Hum her. For if they pass inland
in Lincolnshire, it follows that they must cross a wide district of
England before they can reach the Channel to cross into France.
There is also no evidence to show, nor any reason to suppose,
that they suddenly alter the character of their flight and pass over
the central parts of England at a great elevation, and thus escape
notice. For in the light of the author's theories on the altitude
of flight, this would mean a sudden change of meteorological con-
ditions immediately on their arrival ; and the Hooded Crow is
one of the few species which always fly low. That the present
species is seen in moderate numbers, crossing England from north-
east to south-west every autumn by certain well-known routes,
will be readily admitted ; but the evidence in favour of an
immediate turn to the South on their first making the land, all
points to its being the course adopted by the majority ; for very
large numbers (though not millions) have been observed following
the line of the sand hills due south, on the Norfolk coast, in com-
pany with Books and Daws (see Migration Committee's Eeport).
The Hooded Crow at its winter quarters seems to be a very aquatic
species, and is very fond of wading in shallow waters in search
of food. It appears natural for a species possessing these tastes
to hug the coast line as much as possible during its migratory
journeys, and in passing inland to follow the course of rivers
not as guides to its destination, but as convenient routes where
food can be readily procured when required. That all the Hooded
Crows observed in the eastern and midland counties reach us
via Heligoland is, however, very improbable ; for, according to
Seebohm, many individuals breeding in Scandinavia winter in
this country, and we should hardly expect Norwegian examples
to travel past the island on their journey here. Confirmation of
this may be found in the Migration Committee's Eeport, 1884,
p. 53, where it is recorded that: "During the latter half of
November the rush (of Hooded Crows) seems to have been con-
tinuous night and day" thus differing in character from the
migration observed at Heligoland, which ceases about 2 p.m. ;
" at the outer Dowsing light vessel on November 1st, 2nd and
3rd, a continuous rush N.E. to S.W., and also at other stations;

21

but in less numbers to November 15th. . . ." A continuous
rush N.E. to S.W. seems to point to the Scandinavian origin of
this flight. As will be seen later on Mr. Eagle Clark, in his
digest of all these light-house and light-ship records, has come
to the conclusion that direct migration from Heligoland to our
East coast only takes place on rare occasions. If the Hooded
Crows seen in Lincolnshire are identical with those passing the
former locality, they must reach us by a somewhat circuitous
route. This is important in view of the fact that Herr Gatke
bases one of his computations on the speed attained by migra-
tory birds on the identity of these flocks.

We are not told much about the return migration of the
Hooded Crow in spring; but we learn that the species passes
Heligoland, travelling towards the west, in rare instances at a
vast height, but usually at no greater elevation than 100 feet, and
in smaller numbers than those observed in the autumn; there
is also no evidence set before us to prove that the breadth of
flight is so great as at the former period. There will, perhaps,
not be much tendency on the part of the flocks to break up
until the eastern shores of the Baltic are reached ; any inclina-
tion to scatter, and thus present a broad migration front until
later in the journey, would be thus avoided at the time of passage
by the island.

After weighing all the evidence in favour of the far eastern
origin of these great flocks- of Crows, and the supposed westerly
course of their flight, one is inclined to agree with Herr Gatke
that the foregoing considerations have gone no further (or even
so far) than to prove that they have maintained a westerly flight
over a stretch of some 600 miles. But whether this is enough to
justify our assuming that all these countless hosts of wanderers
have regularly maintained this direction from the commencement
of their migration, is, in the light of the evidence adduced, very
much open to question.

In further considering the theory of a migration conducted
in a broad front, we pass from the evidence afforded by a very
common species to that presented by a comparatively rare one,
viz., the Honey Buzzard. We are also told that this species
furnishes further proof of a migration in a direction from the far

22

east to the far west. Whether the latter fact be true or not, the
acceptance of the theory that the migration is conducted in a
broad front corresponding to the latitudinal area of the breed-
ing grounds will be found to be very difficult. Indeed, it may be
at once remarked that the evidence of other observers quoted on
p. 28 by Herr Gatke all points to the opposite conclusion.

The spring migration of this species, as observed at Heligoland,
is described as being performed in very small parties, but in the
autumn almost always in assemblages of varying numbers, but
which sometimes during the first weeks of September, assume
considerable dimensions. An unusually marked migration
occurred on September 19th, 1858. This movement commenced
with small parties in the forenoon, and increased towards sunset
to one incessant stream of flocks of fifty, eighty, or even larger
numbers. These approached the island from the east and
disappeared from view in the far west, just as the majority of
species do. Now, though this migration, as regards numbers,
was abnormal and not likely to occur again for many years, yet
there is no reason to suppose that it was conducted in any but
the normal manner of flight. The author's theory of a broad
front should, therefore, still apply, as in the case of other
species.

On witnessing a phenomena of this nature, Herr Gatke might
well express his wonder as to how such extraordinary numbers
of an uncommon species had banded themselves together, but
perhaps he had in view his theory of the " broad front " when
he hazards the opinion that only the endless forests of Euro-
pean and Asiatic Eussia could have given birth to such a
throng. For we must assume, to be in harmony with the above
theory, that still greater numbers were passing other localities
both north and south of the island a fact impossible of realisa-
tion in the case of so rare a species without concurring in his
remark on the necessarily vast area requisite to produce such
multitudes ; and in the latter case one is also impelled to
ask What became of all this great host and in what country did
its constituents find winter quarters?

Though this migration was evidently of an exceptional
character as regards numbers, and perhaps akin in nature to that

23

of the Jay described elsewhere ; it seems impossible to realise
how so many of a rare species whose nesting stations must have
been scattered over a wide country can have come together
unless they had gradually concentrated themselves on to some
customary fly line. It may be surmised that many small flocks
had accumulated at some point where their further progress had
been delayed by unfavourable weather. Herr Gatke's description
of the flight seems to point to this small parties at first, then
larger ones, then a steady stream of flocks, and lastly the main
body in one continuous procession. Had an advancing column
of Honey Buzzards in a rank corresponding to the latitudinal
area of the breeding range suddenly set out from the Asiatic
forests to Western Europe, gradually augmenting its numbers
as it progressed, it could hardly fail to have attracted notice in
many parts, whereas in the present instance, Heligoland seems
to have been almost the only spot where such large numbers
were observed. On the theory of a direct east to west migration
many of this throng should have reached the coasts of Great
Britain unless a southerly turn was made soon after passing the
island. In the former country, owing to the persecution meted
out to all the larger birds of prey and other rare species, an
event of this nature could hardly have failed to have excited
remark. We know what has happened during the visitations of
Pallas' Sand Grouse.

If on the other hand these large flocks had become gradually
concentrated through the configuration of the country, the
following of river valleys or shore lines into a narrow stream
the chances of their escaping notice would have been vastly
increased, especially as their ultimate destination seems to have
been some part of North-Western Africa. It is well known that
the Honey Buzzard passes the Straits of Gibraltar in large
numbers every year (Irby). It is only evading the difficulty in
suggesting that a further westerly flight may have been con-
ducted at a great elevation and thus have escaped notice. It
has already been pointed out in the case of the Hooded Crow ;
that, such a change in altitude really means, according to the
author's theories, a sudden variation in meteorological conditions
necessitating an ascent to higher regions of the air. That in

24

Herr Gatke's view this migration of Honey Buzzards was con-
ducted in the normal way, i.e., in a broad front, the following
extract from his notes will illustrate. He writes, p. 29 :
"The fact that the Honey Buzzard does not reach Portugal
, also proves what has been already called attention
to, in regard to Hooded Crows, that it is not the sight of the sea
which induces birds migrating in a westerly direction to turn
suddenly south, but that this deviation forms, from no account-
able cause, the concluding stage of the westerly course of
migration. A similar phenomenon is presented by the same
bird in England. In that country the Honey Buzzard is met
with as a breeding species only in solitary instances, but arrives
in tolerably large numbers on the east coast during the autumn
migration. Such examples as originate from the northern limits
of their breeding zone in Europe and Asia, bring their westerly
flight to an early close in England, when, then turning south, they
pass, via Western France and Spain to their winter quarters in
Africa."

It will certainly be news to British ornithologists to learn,
that the Honey Buzzard arrives in tolerably large numbers on
the east coast during the autumn migration. Surely Herr Gatke
is thinking of the Bough-legged Buzzard. Furthermore, to the
writer, it does seem to be the sea that turns these northern bred
birds to the south, otherwise they would reach the Shetlands,
Orkneys and North of Scotland coasts rather than the east
coasts of England. If taken at all the turn no doubt actually
takes place in Scandinavia.

In further consideration of an east-to-west migration we may
now turn to another interesting, but more common species,
viz., the Shore Lark. As can be readily proved from pretty
conclusive evidence, this species within the last fifty years
has undoubtedly been extending its breeding range westward.
In the light of this fact its gradually increasing abundance
on passage at Heligoland is significant, for it is one of those
species occurring in great flights to which Herr Gatke attributes
a far eastern origin. With regard to its former breeding
range he has collected the following facts " According to
Pallas (" Zoogr. Eoss. Asiat.," pub. 1811), the bird was in

25

the last named year already distributed over the whole of
Siberia, but in 1835 had not been met with as a breeding bird in
Scandinavia." Now if Herr Gatke's contention is correct that
a great proportion of the Shore Larks passing Heligoland are of
Asiatic origin, as he describes 011 p. 32, it is a remarkable fact,
bearing in mind that the species had already spread over the
whole of Siberia, that this bird was at that particular period
unknown as a visitor to the island. It is still more remarkable
that not until ten years after the discovery of pairs breeding in
Eastern Finmark, viz., the year 1847, that examples were met
with in Heligoland in any numbers. " Since that time adds
Herr Gatke the Shore Lark has rapidly multiplied and it has
become one of the most common breeding birds in Lapland and
Finmark." Some idea of its abundance in Scandinavia even as
much as thirty or more years ago, may be gathered from
"Wheelwright's experiences. The latter observer states that
during his stay at Quickiock he secured about fifty examples
and could have obtained many more had he so desired.

Now what a curious coincidence must have taken place in
regard to the extension of the breeding range and the migratory
habits of this species if, as soon as it had become numerous
in a region lying to the north and north east of Heligoland,
whence its migratory flights might reasonably be expected to
carry it over the island that the Asiatic individuals should
suddenly develop a tendency to abandon their old winter
quarters lying to the south or south-east of their breeding
range and to seek new ones in the west or south-west of Europe ;
a district where we should only expect the breeding birds from
Northern Europe to find a winter home. In the light of the
evidence brought before us by Herr Gatke, if we accept his
theory of the far eastern origin of the large flights of this species
which now pass his observatory, this is really what must have
taken place.

The locality of the winter quarters of the Shore Lark is
involved in some obscurity, which Herr Gatke's speculations
will hardly tend to dissipate. After commenting on the enorm-
ous numbers comprising the above flights which in his opinion
can only be derived from a country far larger than the whole of

26

Northern Europe, he next calmly assigns them a winter home in
the comparatively tiny area of the mountain regions of France
and Spain.

Suppose for the moment we admit that Herr Gatke is correct
in assuming an eastern origin of these large nights of Shore Larks,
and we also try to trace their further westerly flight after passing
Heligoland. We shall find, as far as Great Britain is concerned,
that not until the period between the years 1860 and 1870, or
ten or twelve year after the first considerable numbers were
observed at the former locality, that flocks of any importance (say
comprising fifteen to twenty birds) were observed on the east
coast of England, though the species, in the meantime, since its
first occurrence, was yearly passing Heligoland in ever-increasing
abundance. It will at once be apparent that, as in the case of the
Hooded Crow and Honey Buzzard, though more markedly in the
present and latter species, that only an insignificant proportion
cross the North Sea, as indeed is the case at the present day.
If the facts were otherwise, they could hardly fail to come under
observation, and it is only evading the difficulty to suppose that
these individuals suddenly alter the altitude of their flight and
pass over at a great elevation (see p. 367). Larks, as a rule, on
migration, as Herr Gatke himself tells us, fly comparatively low,
and we may take it for granted that this is especially the case
in passing over large areas of land. Even if these Shore Larks
really increased the altitude of their flight in travelling across
England, we should expect them at times to meet with adverse
meteorological conditions, and on such occasions we might
reasonably look for many stragglers or even small flocks in
inland localities. But up to the present time this species has
been a bird of the rarest occurrence in the latter country away
from the coast.

The evidence of other observers quoted by Herr Gatke
(pp. 32, 366) does not lessen the difficulty of accepting the
theory of an east- to- west migratory flight on the part of the
Shore Lark. He writes: " These birds arrive in East Finmark
from the east and are consequently known there under the name
of Bussian Snow-Buntings. Collett says (see Dresser IV.) that
they travel from Norway east, and thence down through

27

Sweden, and are seen in lower Norway only in exceptionally
rare instances. In Southern Sweden they unite themselves
with those coming from Asia, hence have arisen the innumer-
able hosts seen in Heligoland within the last decades." What
evidence there is that the flocks met with in southern Sweden
come from Asia, is very difficult to see; but the case of those
migrating from Norway a latitude due North of Heligoland
affords a striking instance of how easily a species migrating
really north to south, or south-west, may be erroneously
regarded as one performing the whole journey in an east-to-
west direction, simply because, at the moment of observation,
it may be passing a particular locality in the latter line of flight.
It may even be the case that those individuals exceptionally met
with in Southern Norway, may be identical with the birds which
reach our eastern coasts, for it is difficult to see to what other
country their journey, if any, further prolonged, would carry
them.

There is not much to be learnt with regard to the theory of
a " broad front " from the migrations of the Shore Lark, as its
breeding grounds, for the most part, lie above the limits of forest
growth ; but Herr Gatke apparently has the idea in view when
he writes respecting flocks from Asia being met in southern
Sweden by others from the north of Norway. As he points out
a southern turn must be taken by flocks breeding east of the
Baltic, up in the far north, otherwise we should expect to find
the species in greater abundance in the most northern parts of
Great Britain, i.e., in the Shetlands, Orkneys and north of
Scotland, or perhaps still further north, away in the Faroes and
Iceland. It seems, however, to be carrying the theory of a
westerly flight to an absurdity in suggesting the probability of the
species occurring as an occasional visitor from Europe on the
Atlantic coasts of America. Herr Gatke seems to think that the
Shore Lark must have displayed, even from its origin, a strong
inclination for a westerly autumn migration, for otherwise, it
could never have got across into Asia and finally to Lapland and
Finmark. What he means by the remark " even from its origin "
is not easily discernable, unless he intends to convey the idea that
as the evolution of the species progressed, a supposed innate

28

desire to migrate westward was also developed, until it found
vent in a voluntary move into eastern Asia.

It is curious to read on p. 122 that, whereas, all species in
Western Europe have a strong disinclination to migrate to the
east, this objection ceases to exist on the American shores of
the Atlantic. The Nearctic birds are said to evince as strong a
tendency to turn to the west, as Asiatic species are said to be
given to migrating in the reverse direction. The northern Blue-
throat occasionally appears in Alaska. Are we therefore to
assume a tendency on the part of this species to migrate in the
opposite direction to the Shore Lark ? In the case of the latter
it will be noted that Herr Gatke writes of a westerly autumn
migration. It seems hardly likely, however, that a species whose
normal flight must have been north to south in its original home,
should have suddenly developed a tendency to migrate westwards
on first establishing itself on the Asiatic continent ; a proceeding
more likely to have led to the extinction of the colonists than to
their future increase. Is it not more probable that these first
visitors to Asia accidentally * found their way thither in the
spring, and after having bred there, wintered in China or some
country in the south-east ; returning again to their new breeding
homes the following year, being guided in their movements by
surrounding species ? In passing it may be noted that the Shore
Lark breeds fairly numerously in Novaya Zemlya. A westward
autumnal migration would hardly have colonised this locality,
especially in view of Herr Gatke' s theories as bo the direct
manner in which birds that adopt this course return to their
breeding grounds in the spring (see p. 42). With regard to the
latter theory, the present species so far from adopting a straight
course from its winter quarters to its breeding grounds, passes
Heligoland at this period in considerable numbers. Wherever
these last are derived from, it is evident that their line of
flight is circuitous ; as in no locality so far south as the latitude
of the island is the species known to nest. It is a curious fact
that the Lapland Bunting, a species having a similar distribu-
tion in the breeding season to the Shore Lark should be of so
uncommon an occurrence in Heligoland, especially as of late
years considerable flocks have migrated to our east coast. But

29

I the latter fact only emphasises the opinion that much of our

| east coast migration is quite unconnected with that occurring

in the former locality. As the Lapland Bunting also breeds

; throughout Northern America, its spread westward has probably

been accomplished in a similar manner to that of the Shore Lark.

But those individuals breeding in North- Western Europe seem to

have a tendency to migrate in the autumn to the south-east

rather than to the south as, no doubt, was the habit of the Shore

Lark until comparatively recent times.

From species having a breeding range extending throughout
Northern Europe and Asia, we must now turn to two others,
which have up to the present, not been detected nesting in the
former continent, viz., the Yellow-browed Warbler and Eichard's
Pipit, to both of which Herr Gcatke makes very frequent allusion.
Though neither have been known to breed, on unimpeachable
evidence within the boundaries of Europe, it cannot be said with
truth that the full extent of their breeding areas is at all
completely known.

In the case of the Yellow-browed Warbler, the late Henry
Seebohm was the first to take authenticated eggs in the valley
of the Yenesay, in lat. 66. He found the birds breeding up to
about lat. 68, as we learn from his work " Siberia in Asia."
Since his memorable journey little or nothing has been added, to
our knowledge, of any further westward extent of its breeding
range ; but that the valley of the Yenesay forms the limit is very
unlikely. It must not be forgotten that several Asiatic species,
such as the Petchora Pipit, Siberian Stonechat, Yellow-headed
Wagtail, Siberian Chiff-Chaff breed in North-Eastern Europe;
the same observer having met with them in the valley of the
Petchora. It seems, therefore, not unreasonable to suppose that
the Yellow-browed Warbler breeds very near to, if not within,
the European portions of the Russian empire. In any case, Herr
Giitke is hardly justified in alluding to it as " a little East Asiatic
species," or as a species from the extreme east of Asia (p. 77)-
The Yenesay in lat. 66 is within 700 miles of the Urals.
Such a description seems to quite over-state the facts of its
distribution. A similar exaggeration is apparent in the author's
remarks on its occurrence in Heligoland. On p. 288 he writes :

30

" The migration of this Warbler commences in Heligoland
during the last ten days of September, and continues until the
end of October. On several occasions the bird has been met
with as late as the beginning of November." And, again, on
p. 43, he further states that this bird may be met with almost
daily in favourable weather during the autumn migration. From
these assertions it might be inferred that the bird appeared during
this period, more or less every day. But when the records of
the examples shot and seen, or reputed to have been seen, are
examined, it will be found that the average occurrences have not
exceeded two examples per year. It is true that in certain
years as many as half-a-dozen have been reported ; but, on the
other hand, at certain times none have appeared at all. It may
also be the case that, when the species has been most numer-
ously noted, that the same individuals have been reported more
than once, as in one or two instances the records refer to con-
secutive dates. In any case, the average occurrence of two
individuals per year, of an Asiatic species whose distribution is
very imperfectly known, furnishes but little proof of a general
east to west autumnal migration. As an instance of how our
knowledge of the geographical distribution of these smaller spe-
cies may be at fault the case of the Sedge Warbler may be
pointed out. Until Mr. Seebohm visited the Yenesay valley this
noisy and conspicuous species was supposed not to breed east of
the Urals, except in Western Turkestan. Commenting on this
fact, Mr. Seebohm pertinently asks, " Where do the Yeuesay
Sedge Warblers find a winter home?" No rigidly adhered to
north-to-south or east-to-west line of flight would convey them
to Africa, the only locality known at present. Again, even so
experienced an observer as this gentleman overlooked Pallas'
House Martin on his Yenesay journey. It was not until he
returned home that he discovered he had been amongst thou-
sands of this species.

The contemporary records of the appearance of the Yellow-
browed Warbler relating to other parts of Europe, throw some
light on the theory of migration being conducted in a broad front.
According to Herr Gatke's views, the species should pass through
central Europe in numbers proportionate to the vastly greater

31

extent of the latter country, in comparison with the area of
Heligoland. That such is not the case has already been shown,
and also that the numbers obtained on the island exceed the
total captures for the whole of the former country. As the lati-
tudinal area of the breeding range extends beyond the Arctic
circle in the north, we should expect, if individuals from those
portions of the latter exhibited a tendency to turn to the west
immediately on setting out from their nesting stations, in the
manner described by Herr Gatke, that the majority of the occur-
rences in Europe would have been recorded at points far to the
north of Heligoland. As a matter of fact the evidence all points
to a probable considerable flight to the south before the western
turn takes place, assuming that the Heligoland examples come
from such a distant region. It must not be forgotten, too, that
the normal migration is from north to south; or south-east
with those individuals known to nest the nearest to the Euro-
pean boundary. If, therefore, the examples occurring in Heligo-
land are derived from the Yenesay, or some region further east,
and not, as is more probable, from a locality very much nearer
to or within North-Eastern Eussia ; then the so-called westerly
migration seems to be conducted in a comparatively narrow
front, and not in a column at all related to the latitudinal
extent of the known breeding area.

Another theory as to the manner in which these Asiatic
stragglers reach Heligoland may be here advanced. It is a well-
known fact that many species of birds, whose breeding-ranges
are confined to the South or Central Europe, are occasionally
captured many hundred miles to the north of their customary
haunts. The Roller, Bee-eater, Golden Oriole, and certain
warblers, may be pointed to as instances ; some of them having
been met with in the Shetlands, and the Oriole as far north as
the Faroes. It cannot be doubted that similar straggling goes
on over the whole of the Palaearctic region. There seems to be
no difficulty in imagining individuals or small parties of Yellow-
browed Warblers, Siberian thrushes, and others, after passing
the summer in some haunts to the north-west of their customary
breeding range, joining those large flights of other species whose
normal migrations carry them over Heligoland.

32

After considering the above evidence, it may be asked in
conclusion, " Does the migration of the Yellow-browed Warbler
whose appearance on Heligoland is said in another place to be
due to the prevalence of meteorological conditions of a peculiar
nature, and therefore more or less accidental, afford proof of any
value that the normal course of migration is due east to west, and
that many other species having their homes in far Eastern Asia
travel to their winter quarters by an identical route ?

In the case of Eichard's Pipit to which Herr Gatke also
refers so very frequently, we have another species whose breeding-
range is very imperfectly known, and we find the same ten-
dency on the part of the author to refer to the extreme eastern
limits of its known extent, as the district from which the remark-
able nights passing through Heligoland are derived. To the
writer there seems to be absolutely no need to assign the
countries east of Lake Baikal and those bordering on the Sea
of Ochotsk as the summer home of these particular individuals.
Herr Gatke seems to have quite overlooked the fact that the
late Hy. Seebohm found this Pipit very common at Yenesaisk,
some 800 miles nearer Heligoland than Dauria and 1,600 miles
nearer than the Sea of Ochotok. True, he did not take a nest,
but then at the time of his visit the breeding season was over,
and if it is objected that the individuals he met with were
already on migration, then their presence at Yenesaisk throws
considerable light on the leisurely manner in which the species
performs its flights. To the writer there can be little doubt
that Eichard's Pipit breeds much nearer to Europe than even
Yenesaisk and possibly within its boundaries, for it seems highly
improbable that any species could have acquired the habit of
crossing half of the continent of Asia and the whole of Europe in
search of a winter home. Like the Yellow-browed Warbler, the
normal course of migration in the case of Eichard's Pipit is from
north to south or thereabouts. Why certain meteorological
conditions should effect such small numbers of the former
species in comparison with the latter is incomprehensible. To
the writer the prevalence of south-easterly winds at the time of
migration does not afford at all an adequate explanation of the
fact that only a limited number of individuals should be induced

33

thereby to forsake their normal course, when the great body of
their fellows remain unaffected.

With regard to migrations of Kichard's Pipit being conducted
in a broad front corresponding in width to the latitudinal area of
the breeding-range, no more telling facts against such a theory
than those related by Herr Gatke could well be adduced.
Remarking on the numbers of the species occurring in Heligo-
land, he writes (p. 118) : " Again, if twenty, fifty, or even a
hundred examples of Eichard's Pipit occur here in one day,
these numbers can only represent a minute fraction of the
quite incomputable quantity of these birds which are travel-
ling at the same period from Dauria to Western Europe."
Whatever the probabilities are of the Yellow-browed Warbler
or other species being overlooked in their European winter
quarters, it is quite impossible that a much larger species
with a loud clear call-note and in " incomputable quantities "
could escape observation in like manner. For, apart from its
much greater size, the present species frequents the open
country and not bushes and thickets like the former, as Herr
Gatke points out. It is more, perhaps, on account of these habits
and general conspicuousness, that Richard's Pipit has been so
frequently observed in Western Europe than by reason of its
occurrence in any supposed vastly greater abundance than the
Yellow-browed Warbler. No doubt it does actually occur in
larger numbers than the latter, though not to anything like the
extent Herr Gatke' s theories require. One also wonders what
becomes of these supposed vast flocks, or in what particular
country they find winter quarters. Perhaps, like several other
species, they are assumed to pass over those districts where they
are unknown, at a great elevation, though even under these cir-
cumstances, they might reasonably be expected to be observed
on the theory of a rigidly performed east-to-west flight.

It will be interesting to compare Herr Gatke's notes on the
migration of Richard's Pipit, published in another place, with
the foregoing. Since the appearance of the first edition of his
work writing in the Zoologist, 1893, p. 164, in reply to a
communication from the late Henry Seebohm he remarks :
" Widely different stands the case with Anthus Richardi, a
3

34

native of the far east of Asia, from Lake Baikal to the Sea of
Ochotsk ; its regular line of autumnal migration runs south, and
it consequently is a common winter resident in South China and
the eastern parts of India Bengal, for instance being in
Calcutta a plentiful market bird during the winter months.
Such individuals, therefore, as under exceptional and undoubtedly
meteorological influences adopt at irregular periods, though in rare
instances in comparatively considerable numbers, a western instead
of their normal southern autumnal migration flight, can reasonably
be pronounced only accidental visitors to Europe. The more so
since even the cases of appearance in greater numbers of this Pipit
have occurred mostly at intervals of from six to ten years, viz., in
1839, 1848, 1849, 1859, 1868, 1869, 1870, 1876. On account of
prevailing westerly ivinds A. Bichardi has during the last fifteen
years been obtained here but once or twice about every third year."
The above passage is directly at variance with the statement
on p. 29-30 to the effect that " Nor must such individuals be
in any sense regarded as isolated rarities or ' stragglers,' for
not only are they met with regularly every autumn, but they
frequently attain to the comparatively large numbers of from ten
to fifty, and in two or three instances of even a hundred in-
dividuals in a single day." After the above admission that A.
Bichardi should only be treated as an accidental visitor to Europe,
we shall undoubtedly be justified in placing a very small value
on the evidence its occurrence affords, of a general migration from
the far east of Asia to the west of Europe ; and as this is by far
the most numerous of the Asiatic visitors to Heligoland we may
fairly treat the casual visits of those species, only occurring once
or twice during a period of fifty years, as still more accidental.

What the many other species are from far eastern Asia which,
to use Herr Gatke's own words " visit Heligoland in such
large numbers every autumn " (p. 33), one is at a loss to know.

A few words must be written on the autumnal migrations of
the Goldcrest, for from a cursory examination of Herr Gatke's
remarks on this species, they might appear to confirm the theory
that the flight sets out from the breeding grounds in Norway in
the manner he describes. There can be no doubt that the large
numbers or rushes of this species which have at times arrived on

35

our eastern coasts are derived from the former country, as at
these particular periods there has been either no corresponding
rush over Heligoland, or the species has occurred there in smaller
numbers than usual. Indeed it will be gathered from a remark
of Herr Gatke's on p. 15, that mass migrations of this species
rarely pass the island.

To enable these large flights to collect together, a certain
amount of concentration on to particular stretches of the
Scandinavian coast-line must of necessity take place. It cannot
be imagined that all the individuals in a particular district, which
might have an area of many square miles, set out from their
nesting stations at an identical moment. Probably the first
move is down some broad and well-timbered river valley to the
sea. On arriving at the latter, the various flights are banded
together whilst waiting the advent of the anti-cyclonic conditions
so necessary during the migrations of so feeble a species.

On these conditions becoming prevalent the majority will
probably take early advantage of the opportunity to at once
undertake their flight over the North Sea. In crossing the latter,
however, there can hardly fail to be a considerable amount of
spreading amongst the flocks. From this fact, and also from the
probability that there are many starting points, the flights on
reaching our islands will affect a considerable length of coast line.
Moreover, all do not proceed directly inland ; many will continue
the journey by following the latter to the south, and as these
rushes occasionally extend over a period of several days, flocks
which have really arrived in the north, and have since travelled
many miles further, may come to be regarded, in other localities
1 through which they may pass, as new arrivals from over the sea.
I Thus so far from having conducted the migration in a broad front
| corresponding to the latitudinal area of the breeding grounds,
the flight has been really performed in several narrow columns,
which have become partially dispersed in crossing a wide sea.

Herr Gatke in later chapters of his work alludes to large
flights of Plovers, Curlews, Godwits, Sandpipers, Oyster-catchers
and other species occurring late in the year, at times quite beyond
the ordinary migration period of these species. These supplemen-
tary migrations are usually accompanied by the advent of severe

36

weather. In the manner of their performance, however, they
do not differ from the flights at the normal periods of the year.
These individuals, moreover, have long since left their nesting
stations, and there can be nothing suggestive of a broad front
corresponding in breadth* to the latter, in the manner in which
these late birds pass the island. Why, therefore, should Herr
Gatke conclude that the latter mode of flight is characteristic
of the migrations of the same species which take place in the
ordinary course, but which do not visibly differ in the manner in
which they are conducted from those under notice.

As further evidence of, and in confirmation of his theory of an
east-to-west autumnal flight, Herr Gatke frequently refers to
the observations of a well-known ornithologist, viz., Mr. John
Cordeaux, a gentleman living near the Lincolnshire coast in a
locality almost due west of Heligoland, and whose opinions he,
in common with all naturalists, holds in high respect. As an
example, on p. 26 he writes : " Mr. John Cordeaux ....
informs me that the bands of migrating Hooded Crows do not
alight immediately upon reaching the coast, but continue their
journey inland in a westerly direction," and other notes to the
same effect. That the latter gentleman, however, does not
intend his remarks to apply to all immigrants arriving on our
east coast may be readily shown from his writings in other
places. Eeferring to two great rushes of birds in 1892, com-
prising Eedstarts, Whitethroats, Eobins, Pied and Spotted
Fly-catchers, Wheatears, Hedge Sparrows, Goldcrests, Grey
Shrikes, Larks, Eing Ousels, Blackbirds, Eedwings, Thrushes,
Willow Wrens, and a few others, he remarks : " In both
these cases of great rushes, which I have cited under similar
meteorological conditions, great flights of immigrants were evi-
dently passing the North Sea, probably from north-east to south-
west, when the easterly gales caught them on the flank and drove
them helter skelter on to the east coast " (Zool., 1892, p. 420).
And again in the same journal (p. 227, 1893) he expresses the
opinion that the migratory Eock Pipits which visit the east coast
in the autumn are almost exclusively the Scandinavian form from
the north-east.

Still more to the point are further remarks bearing on the ques-

37

tion of an east-to-west flight, which appeared in The Naturalist,
1894 (p. 420). He writes: "As a rule the small summer
visitants to northern and central Europe, such of them as reach
the coast of Great Britain in the autumn passage, do not pass
inland or cross the country, but follow the coast line south. This
is the case with the Eing Ousel, Wheatear, Eedstart, Willow
Wren, Pied Flycatcher, Yellow Wagtail, and a great many other
small species far too numerous to mention, and so much is this the
rule that an observer residing a few miles inland will be ignorant
of the immense movement going forward within so short a
distance." The latter remark also throws some light on the
question of migration in a broad front.

The above extracts will be sufficient evidence to prove that
Mr. Cordeaux fully recognises a strong migratory movement
travelling between the points of north and north-east to south
and south-west, and that the opinions expressed in his writings
referred to by Herr Gatke are only to be applied in a limited
sense.

Further references to the opinions expressed by the same
gentlemen, that many of the migrants arriving in north Lincoln-
shire from over the sea reach the latter locality from a due
easterly direction, though somewhat contradictory to those
previously quoted, may possibly be explained in the following
manner. Birds crossing the North Sea from north-east to south-
west, on first catching sight of the land when out at sea, will very
probably so alter the course of their flight in order to reach it as
early as possible, as to give an observer the impression that they
I fibre coming in directly from the east.

Mr. W. Eagle Clarke, however, on whose shoulders has fallen
the labour of digesting the immense amount of material fur-
nished by the observations of light-house keepers and others
at the instance of the Committee appointed by the British Asso-
. ciation to study the question of migration has expressed himself
very decisively on the supposed identity of the migration over
Heligoland with that affecting our east coasts by a direct east-to-
west flight. On p. 7 of his digest he remarks : " Much prominence
i has been given in some of the Annual Keports issued by the
Committee, and in Herr Gatke's book, 'Die Volgelwarte Helgo-

38

land,' to an inter-migration between Heligoland and the east
coast of England by a direct east-to-west autumn, and, it is to
be presumed, west-to-east spring, movement. Herr Gatke most
obligingly communicated details of tbe bird movements observed
on Heligoland for four years (1883-1886), during which the in-
quiry was being prosecuted over the British area. These two
sets of data have been carefully examined and compared, and it
has been found that the dates of the chief movements of the
species common to Heligoland and eastern Britain seldom, if
ever, correspond, and do not bear out this theory ; that particular
species which are irregular as migrants in Britain, such as the
Ortolan Bunting, and others, occur regularly, often indeed in
' rushes ' at the more favoured isle off the mouth of the Elbe ; that
other species which are very rare on our British shores occur in
Heligoland as regular migrants and in considerable numbers, as
Motacilla flava, Anthus Eichardi, &c., while species common to
both islands occurs in 'flights like clouds,' in 'hundreds of
thousands, * thousands upon thousands,' in ' marvellous numbers,'
' astonishing flights,' and so on, at Heligoland, at periods when
there is not a single observation for the same species on the
English shores. A study of the phenomena of migration com-
pels the investigator to come to the conclusion that Heligoland
and Britain draw their migratory hosts from different sources."
Mr. J. H. Gurney has been at some considerable pains in
drawing up a comparative list of the occurrences of certain species
which have arrived at various times on Heligoland and on our
east coasts in exceptional numbers, and whilst the result might
appear to some extent to confirm the view that a close connection
exists between the migratory streams affecting both localities, still
he does not fail to point out that in the greater number of in-
stances there is no connection whatever. Mr. W. Eagle Clarke
further expresses the opinion that as " the ordinary movements
of any common migratory bird occur in each month of its
seasonal flight-periods, and the mere coincidence of the species
being observed simultaneously in ordinary numbers on both sides
of the North Sea, has no significance whatever. It is not im-
possible or improbable that birds may occasionally cross the
German Ocean by an east-to-west flight in the latitude o\

I 39

Heligoland, but our data lead us to believe that such cases are
the rare exception, not the rule." According to the same gentle-
man, the records kept at the Outer Dowsing Lightship, the most
isolated of the stations in the North Sea, situated thirty-eight miles
E.S.E. off the mouth of the Humber, or almost in the exact lati-
tude of Heligoland, strikingly confirm this opinion.

It is difficult to see on what grounds Herr Gatke has based
his theory that the general course of migration trends from east to
west. Apart from his own observations conducted on Heligoland
he brings forward very little confirmatory evidence. He, how-
ever, in one place refers to a statement of the late John Wolley's
as furnishing the most northern illustration of an autumn migra-
tion proceeding in this direction. It appears that the latter
observer, after only a year's residence at Muonioniska, in lat. 68
N., came to this conclusion on account of the large numbers of
the Yellow Bunting he met with at the close of summer. These,
in his opinion, could only have come from a district lying to the
east. Mr. Seebohm, however, considered this species rather rare
in the Petchora district ; whilst Collett states that even in the
extreme north of Norway a few individuals remain throughout the
winter ("Bird Life in Arctic Norway"). If follows, therefore,
that the present species is an abundant summer migrant in the
latter locality. Herr Gatke, however, even in this instance, is
constrained to admit that the further course of migration on the
part of this Bunting must be to the south, otherwise it should
visit the Shetlands in large numbers, whilst the reverse is actually
the case. Compared with the distance travelled in the latter
direction any westward flight, which, moreover, would be hardly
likely to comence further east than the shores of the Kola Penin-
sula, is very trivial.

Herr Gatke also calls attention to the presence of countless
droves of land birds, both of the larger and smaller species, as
well as of Ducks, Geese, Swans, and other water birds, which
may be seen in the aatumn months on the coasts and interior
parts of the west of Scotland. All these, he states, are hasten-
ing to their winter quarters in a southerly or south-south-easterly
course. This may be true of the land birds, not only at that par-
ticular time and locality, but may equally well refer to the whole

40

journey. It is difficult to see what evidence there is to show,
however, that these droves consist in part of birds which, like
the Brambling, after arriving on the east coast, have traversed
the latter country in a westerly direction. The flight of these
flocks, according to the evidence afforded by the observations of
light-keepers and others, either stih 1 maintains its south-westerly
course, or follows the eastern coast line into England.

With regard to the Brambling. The movements of this
species from Northern Scandinavia are said to first conduct them
to the southern parts of Sweden. Possibly this is correct, but
that they then turn directly west is very doubtful. It will be
evident if they merely follow the general trend of the land their
course must necessarily be to the south-west, and if again they
leave the coast of Norway at its most westerly extension, this
same direction of flight need merely be still maintained to
eventually land the travellers on the mainland of Scotland, and
not on the Orkneys and Shetlands.

Herr Gatke, however, has quite overlooked the presence of
many migratory species in the Faroe Isles, and still far greater
numbers in Iceland. It is absurd to suppose that birds from
either of these localities migrate in autumn to the west. It
therefore naturally follows that the hordes of water-fowl and
shore-birds observed on the west of Scotland must in great
measure be derived from these northern islands, and not from
districts in the north-east of Europe, as he supposes. When,
however (p. 31), he is driven, in support of his theory of an east-
to-west line of flight, to allude to the fact of the Gannet having
been observed passing in a westward direction for six or eight
days together at Cape Wrath, its weakness will be apparent ;
for it is well known that no breeding places of this species exist
to the east of Scotland, the movements in question being merely
due to wanderings in search of food.

It is on evidence of this nature, and in conjunction with his
own Heligoland notes, which have already been discussed, that
be bases the assertion that "the flight of these migrants has
thus been followed from Eastern Asia to the Atlantic shores of
Europe. In the case of the most different species, and in dis-
tricts so widely separated as Central Germany, Heligoland, the

41

eastern coast of Great Britain including the Orkney and Shet-
land Islands Norway up to a latitude of 70 N. in Finmark,
the same results as to the direction of the migratory flight have
been obtained."

Why certain species should follow such a course, and the
remainder should fly from north to south, he offers not a word in
explanation, and he quite ignores the results of inquiries con-
ducted by ornithologists like the late Dr. Severzoff, as regards
Central Asia ; and Dr. Menzbier as regards Eastern Europe ; or,
again, by Von Middendorff, who, after selecting seven typical
species, found that in the middle of Siberia the general direction
of the usual migrants is almost due north, in the east of Siberia
from south-east to north-west, and in European Russia from
south-west to north-east. Prof. Palmen's conclusions are similar.
Whether we accept the theories of the latter as to the manner
in which birds are guided, or not, is of little importance at the
present juncture, and does not affect the accuracy of his state-
ments on the direction of the migratory flight.

It is no doubt true, as pointed out by Dr. Menzbier, that there
are no such things as fly-lines. Probably every species goes its
own way, and what is called a migration route is only the co-
incidence of the way taken by many (Newton, "Dictionary of
Birds "). How Herr Gatke, however, can formulate a theory of a
migration carried out in a broad front, corresponding to the lati-
tudinal area of the breeding-ground, and rigidly conducted in an
east-to-west direction, in the face of the heterogeneous assem-
blage of individuals and species which pass with such regularity
and in such wonderful proportions at his little island, is im-
possible to imagine. With regard to the confirmatory evidence
of a general migration in an east-to-west direction, afforded by
the capture of a few Siberian species during a period of more
than fifty years, as well might it be argued, from the occurrence
of over 250 American birds in Great Britain in the same lapse
of time, that the general tendency of migration in the latter
continent is in the reverse direction.

In objecting to the theory that birds follow coast lines as
guides during their migration, Herr Gatke, referring to Eichard's
Pipit, and others, inquires " Are we, therefore, to assume that

42

when arrived at the Baltic they suddenly become incapable of
continuing their journey except by following the comparatively
small span of coast to Holstein?" To this one might fairly
retort Are we to assume that, because birds in passing Heligo-
land are either seen or heard to be travelling in an east-to-west
direction, that this is the course of flight maintained throughout
the whole duration of their journey ?

We turn now to the consideration of Herr Gatke's remarks
on those species which he tells us travel to and from their breed-
ing-grounds in a direct north-to-south, or the reverse, line of
flight. There will not be the difficulty in accepting his conclu-
sions as to the general direction of this flight as in the previous
case, but exception must be taken to the assertion that it is per-
formed in the rigid and undeviating manner as described; and
also to the theory that it is conducted in a broad front, in a
similar mode to the east-to-west flight.

In considering Herr Gatke's arguments, his admission that
not a single bird is seen to arrive at or depart from the island in
either a north or south direction must not be forgotten. Yet
he tells us that this north- to-south line of flight is " peculiar to
a large number of species, more especially such as have their
breeding-quarters in high northern latitudes, and, in respect to
the individuals taking part in it, fully equals the great east-to-
west migration, while, as regards the distance traversed, it in
many cases even surpasses the latter movement." We are,
therefore, driven to the conclusion that it is the consideration
of the breeding-ranges of the species which are said to comprise
this movement rather than the result of actual observations on
which he bases his theory. One is rather puzzled to know what
species are comprised in this flight, as, on pp. 25 and 30, several
having their breeding-grounds in the high north are included in
the list of those said to be derived from the far east ; others such
as " the Bluethroat, Wagtails and Warblers we are told
appear on and depart from the island in a manner precluding
the possibility of our being able to realise by our senses the
direction of either their arrival or departure."

Amongst the species specially singled out in illustration of
this north-to-south flight is a very well-known one, viz., the

I 43

Red-spotted Bluethroat. Referring to its geographical distribu-
tion Herr Gatke writes : " This species breeds in high northern
latitudes of the old world from Kamschatka as far as the
central and northern portions of Norway, while its winter
quarters range throughout the whole of Southern Asia and over
the eastern half of North Africa." It may here be pointed out
that most authorities refer to Egypt as the winter quarters of
the Northern Bluethroat, as Herr Gatke himself does in other
places. This point is of importance in view of the fact that
Herr Gatke makes such special reference to the undeviating
character of the flight. As the latter part of North-eastern Africa
is the only locality where this species is found in winter, it is
difficult to see how a rigidly performed south-to-north flight
would cross Heligoland at all. He further adds: "In Heligo-
land, as well as in Germany and Italy, it is of quite regular
autumnal occurrence ; in England, on the other hand, only
solitary examples of the bird have ever been met with, and
these only at intervals of many years . . . ." With regard to
the latter remark, Herr Gatke's information is certainly not up
to date, for he quite overlooks the occurrence of the species in
North Norfolk where over a hundred were observed at one time.
In the opinion of Professor Newton, the Bluethroat probably
occurs on our east coast with regularity, but is, no doubt, over-
looked (" Dictionary of Birds ") . Reference also to Mr. Cordeaux's
notes in the Naturalist will prove that hardly an autumn passes
without one or two being observed in the Humber District ; other
occurrences are alluded to in the reports issued by the committee
on the migration of birds. It has also been recorded from
Malaga and Valencia in Spain (Irby). One cannot help specu-
lating whether, if Herr Gatke had not overlooked these facts,
he would not have been tempted to include the Bluethroat
amongst the species migrating by the east-to-west route, for its
distribution is very similar to that of several species comprised in
the latter. His following remarks will afford good evidence,
after noting the above omissions, of the danger of attributing
a rigidly-maintained direction of flight to any species whatever.
He writes : " It hence follows most decisively that the bird,
in autumn, rigidly adheres to a southerly course of migration

44

and travels in a broad migration front which corresponds to
the longitudinal range of its nesting area, and of which Heligo-
land forms the most western limit. Even a slight westerly
deviation from their southerly course of such species (indivi-
duals ?) as breed in the west of Norway could not fail to convey
large numbers of these birds to the east coast of England,
and their all but total absence there furnishes, therefore, an
undoubted proof of the persistence with which the southerly
course of migration in this instance is adhered to." It has
already been pointed out that the Bluethroat is not of so
casual an occurrence in England as Herr Gatke supposes, and
if we bear in mind that the winter quarters of this species in
North-eastern Africa are limited almost to Egypt, it becomes
evident that the individuals breeding in the westernmost parts
of their range would, on their return journey, if they took a
direct route, fly from north-west to south-east. The pretty
regular appearance of examples in England is, therefore, still
more worthy of note. One would naturally expect the species
to occur fairly numerously in central Europe on the return
journey, owing to the proportion of young birds which would
then be travelling, and also on account of the more leisurely
manner in which the latter flight is conducted. But, judging
from the evidence placed before us, it appears to be rather local,
even in this large area.

The difficulty of accepting the theory of a migration conducted
in a broad front is perhaps more apparent in the case of the
Northern Bluethroat than in any other species to which Herr
Gatke refers. Writing on the spring flight he remarks (p. 265) :
" In the absence of cold and dry northerly winds at the end of
May and April, it appears here [i.e., Heligoland] , as a daily visitor,
and if, in addition, the weather be warm and fine, with a light
south-east wind, it frequently occurs in such large numbers that
on days of this kind Oelrich Aeuckens and myself have succeeded
in obtaining as many as from thirty to fifty male individuals."
He also tells us (p. 44) that on May 26th, 1880, the species
occurred on the island in thousands. In certain preceding
passages Herr Gatke lays special emphasis on the fact that the
Northern Bluethroat has only been obtained during its spring

45

flight, in very exceptional instances, in Italy, the north of
Germany, and in other localities south of the latitude of Heligo-
land. This he regards as strong evidence of the unbroken
character of the flight. But may not these facts be quite as
reasonably cited in evidence of the narrowness of the migrating
column ? The paucity of observers in south Europe, too, must
not be overlooked. Herr Gatke seems to be quite certain in his
own mind that the Bluethroats passing his observatory in spring
are identical with those which breed in western Norway. To
the writer, however, the evidence is all against the accuracy of
this assumption. In the first place we are confronted with the
remarkable fact if such were the case, and if the assertion is
correct that these Norwegian individuals occupy the extreme
westerly extent of the advancing column that it is only the
latter individuals that take a rest during their flight, though they
have the shortest distance to travel. This is a curious circum-
stance in view of the statement that the Bluethroat migrates
at the rate of 180 miles an hour, and also that by the time
it reaches Heligoland it is rapidly nearing its destination in
western Norway. Furthermore, this rest appears to be taken ai>
times when the meteorological conditions are most favourable to
the performance of an unbroken flight, i.e., during the prevalence
of light south-easterly winds with warm weather. If the species
migrates in a broad front, how do those individuals dispense with
a rest who must, of necessity, travel over the whole length of the
Baltic and Gulf of Bothnia, if they rigidly confine their flight
between the points of south and north ? One cannot help here
remarking on the inconsistency of Herr Gatke's arguments. In
the case of the Shore Lark and Hooded Grow, we are told the
vast hosts which pass Heligoland can only be derived from a
country extending from the Atlantic to the Pacific, but in the
present instance, a species, which has always been looked upon as
only moderately common, occurs in thousands on one day alone,
viz., May 26th, 1880, and, moreover, on a tiny island. In the
face of these facts we are asked to believe that these large
numbers are journeying north to breed in a very limited area in
the most southern and western extension of the breeding range.
Does not the above evidence point in a far stronger manner to

46

the fact that the Northern Bluethroat migrates at any rate in
spring in a very narrow column or columns, and bearing but
little relation to the extent of the winter quarters and breeding
range ? Shall we not also be much safer in assuming that the
large numbers occasionally noted on the island late in May are
individuals breeding in the far north ? We should expect those
whose nesting homes lie in the most southerly portions of the
breeding range to have already commenced operations by May
26th. Even in the Petchora valley, Messrs. Seebohm and Harvie
Brown note that the Bluethroat arrived in this northern locality
quite a week earlier. Again, the winter quarters of the Blue-
throat in north-eastern Africa are very much more confined in lati-
tudinal extent than are the breeding grounds in northern Europe,
so that there must be considerable spreading of the flocks, and,
consequently, no rigidly adhered to, south-to-north direction of
flight during the spring migration, if conducted either in many
narrow, or in one broad column. To the writer there seems to
be little doubt that the Bluethroats calling at Heligoland during
May form a succession of flocks travelling in a narrow flight over
a customary route to breeding grounds in the north of Scandinavia
and Lapland, and that their non-appearance in certain years is
due to a deflection of the stream which may readily miss so tiny
an area as the island, or even break the journey at other points.
The fact of individuals so rarely occurring in intermediate
localities, though surprising in itself, is much less difficult of
comprehension on this theory. Herr Gatke himself perhaps
gives a clue to this mystery in his charming opening words,
referring to the progress of migrants, where he speaks of our
" sharing in their joy when some high mountain valley offers a

portion some temporary rest and refreshment " (p. 3).

But the paucity of observers in southern Europe must by no
means be overlooked in accounting for the absence of spring
visits of this species.

As before noted, Herr Gatke does not devote much space to
the consideration of the autumnal flight of migrants which pass
from north to south. In addition to the Bluethroat, however, he
refers to a few other birds. Amongst the latter is the Eed-
throated Pipit, a species breeding abundantly above the Arctic

47

circle from Norway eastwards; but whose winter quarters lie
to the south-east, rather than the true south, of Heligoland.
Colonel Irby, however, met with two examples at Gibraltar, and
expresses the opinion that it passes that point regularly on
migration.

Referring to the geographical distribution of this bird,
Saunders writes (Manual of British Birds) : " It breeds in
many parts of Scandinavia, especially in East Finmark ; while
eastward we find it in increasing numbers, beyond the limits of
forest growth, across Siberia to Kamtschatka and Bering Island.
It is even said to have straggled across the Pacific to Lower
California ; but, be this as it may, the migrations of this Pipit
undoubtedly extend to southern China, Borneo, Burma, India,
Persia and Egypt. In the latter and in Nubia the bird is
exceedingly abundant in winter ; westward in North Africa it
becomes rarer ; but it is found on migration throughout the basin
of the Mediterranean from Asia Minor to Gibraltar."

This Pipit from its similarity to A. prateusis is very likely to be
overlooked. This view is strengthened by Herr Gatke's further
remarks. With regard to its occurrence on Heligoland, he
writes : " I obtained the first example of this Pipit on the
island on 28th September, 1854, and the second on 20th
September, 1857. Soon after, Glaus Aeuckens learned its call-
note, and in consequence managed to see and frequently shoot
one or other of these birds regularly every autumn. In 1884
they occurred here in unexampled frequency ; from 15th to 30th
September thirteen examples were seen, and for the most part
shot, on some days as many as three examples " (p. 345).

The above account, however, will be found to be quite at
variance with a reference to this species on p. 37. In the
latter place the author writes of the Eed-throated Pipit as
only occurring in Heligoland in the most exceptional cases,
having only been shot there more than six times within the
last fifty years. The latter fact having been brought forward as
evidence of the extreme rigidity with which the north-to-south
line of flight is adhered to, its value will be apparent when com-
pared with the previous statements. The admission, too, that as
soon as one of Herr Gatke's best assistants became acquainted

48

with the call-note, the species should be noted- afterwards as
of regular occurrence, is significant, and points to the fact of its
having been previously overlooked. The same has probably been
the case on our east coasts. So experienced an observer as Mr.
Cordeaux has expressed the opinion that it would be almost
impossible to detect the Bed-throated Pipit amongst a flock of
Meadow Pipits even with the aid of a good field glass. Further-
more, in various parts of the text the author includes A. Cervinus
amongst those species which are brought forward in evidence of
an east-to-west line of flight (p. 116). It is odd to read, there-
fore, that it "likewise adheres to a most rigid southerly course "
in its autumn migrations.

In considering the migrations of this species Collett remarks :
" Like most of the genuine migrants of the order Passeres,
the small birds do not reach their northern nesting-places across
the southern parts of Norway, but by the eastern route across
Eussia and the Baltic provinces. One consequence of this is
that the Eed-throated Pipit and Siberian Willow Warbler are
either not met with at all during migration in the southern
parts of the country, or appear there only occasionally and
accidentally " ("Bird Life in Arctic Norway").

Turning now to two other species singled out by the author,
viz., Eversmann's Warbler (Sylvia borealis) and the Northern
Nightingale (Sylvia philomcla) we find that the former of these is
stated *' to direct its migration flight in an equally unswerving
southerly line." Unfortunately but little of the winter distribu-
tion of this tiny species is known, but it seems to be identical
with that of the Eed-throated Pipit and several other species
breeding in Northern Europe, lying rather to the south-east than
the true south of the western limit of the breeding range. In
whatever manner the migration is conducted it will trend in the
former direction, and the chances of the species turning up in
Heligoland are thereby much reduced. Writing on this species,
Collett remarks : " In Finmarken it is a recent immigrant, and
its migrations therefore do not pass southwards along the Baltic
provinces, like that of our other Arctic small birds, but it migrates
across the large river basins of Siberia, in order to reach down tc
the Pacific Coast, China and India, where its chief winter home
is" (" Bird Life in Arctic Norway," p. 30).

49

The absence of records from neighbouring countries points
rather to the fact that the flight is conducted in pretty compact
flocks and not in a broad front. If the latter were the case, more
straggling might reasonably be expected. In this instance,
apparently, the author does not apply the rule that the species
should occur in numbers proportionately greater in Central
Europe as the size of the latter area is to that of Heligoland,
though to be consistent he should do so. He does not even
suggest that Eversmann's Warbler has been overlooked in other
parts. This is a fair example of the varying treatment identical
evidence, in support of divergent theories, receives at his hands.
The very casual appearance in Heligoland of the Northern
Nightingale is not difficult to account for ; the breeding range of
this species extends but little further north than the latitude of
the island. On leaving their nesting stations in the autumn,
migratory individuals are far more likely to deviate from their
normal course in the middle or latter part of their journey than
at its commencement. It must not be forgotten, too, that as the
limits of the breeding grounds are approached birds become much
scarcer than in the central portions. In the present case an
early westward deviation of Swedish individuals would be far
more likely to be observed on the coasts of Denmark, where such
stragglers would probably unite with local examples of their own
species. It may be further remarked that the single record of the
Northern Nightingale in Heligoland was noted on the night of
May 4-5 at the lighthouse lantern. It seems quite possible that
this was an individual which had overshot its breeding grounds
in the Rhine Valley, where, according to Seebohm, the species
occasionally nests.

The remaining species alluded to by Herr Gatke as conducting
their migrations strictly between the points of north and south,
viz., Siberian Chiff-Chaff, Yellow-headed Wagtail, Yellow-breasted
Bunting, Terek Sandpiper, and Eed-footed Falcon, are all birds
having their winter quarters for the most part in the south-
eastern portions of the Palaearctic or oriental regions ; and their
breeding ranges extend but rarely any distance further westward
than long. 25 E. It would therefore require a very considerable
deviation from a direct southerly flight to carry individuals over

50

Heligoland. Still for all that, such a contingency occasionally
happens in the autumn months. In such instances the explana-
tion, to the writer, seems to be that these stragglers have
accidentally attached themselves to flocks of other species whose
ordinary flight passes the island.

In the case of the Yellow-headed Wagtail, it may be remarked
that up to the present this species has not been found breeding
west of the valley of the Petchora. That it should have occurred
on migration no less than five times in so distant a locality as
Heligoland is remarkable, and forms additional proof that many
of the migrants which according to Gatke, are derived from the
east really come from northern and north-eastern regions.

The above remarks also apply to the Siberian Chiff- Chaff and
Yellow-breasted Bunting ; though their breeding ranges extend
further west. The latter species, it may be noted, has occa-
sionally been found in Southern Europe.

As an exception to the rule of a migration rigidly performed
between the points of north and south, or rather in accounting
for the regular appearance on Heligoland and in other parts west
of the ordinary limits of such a flight, Herr Gatke makes especial
reference to the Little Bunting. On page 34 this species is said
to migrate in a direct north-to-south line of flight, but later on in
bis work the author includes it amongst those which are supposed
to migrate westward from Eastern Asia. On page 34 he remarks :
" More or less considerable numbers of individuals turn to the
west on quitting their nesting stations, and migrate to Western
Europe instead of Southern Asia." He further adds : " This
tendency is by no means peculiar to those species whose breeding
range extends to Western Asia or North-eastern Europe, as is
proved by the cases of the Siberian Chiff- Chaff, the Yellow-
breasted Bunting, and the Terek Sandpiper. On the contrary,
all our experience goes to show that it is more especially mani-
fested by species whose breeding homes are furthest removed
from Europe. . . . Moreover this tendency is generally confined
to particular species only of a genus, being entirely absent in
others of the same genus. In proof thereof we may cite the case
of the Yellow -breasted Bunting and the Little Bunting two
species breeding in the north-east of European Russia, whose

51

nests may be found almost side by side. Of these the former
has only been seen in Heligoland on three occasions within more
than fifty years, and with the exception of an example met with
at Genoa, has never been observed in Central or Western Europe.
The Little Bunting, on the other hand, appears in Heligoland
every autumn, and is frequently shot. ... In the south of
France it is said to be the commonest of the rarer Buntings,
small companies of it wintering at Marseilles. [He might also
have added that nine examples were obtained near Malaga, in
Spain, December 28, 1874 (Irby)]. Inasmuch, then, as both
species are found breeding in about equal numbers in the neigh-
bourhood of Archangel, both, too, belonging to the group whose
autumn migration is directed south, we are confronted by the
question as to what may possibly be the cause which determines
the one the Little Bunting annually in large numbers to turn
west on starting from the common nesting home, while the other
the Yellow-breasted Bunting is hardly ever induced to swerve
in this manner from its normal southerly course."

After reading the above and comparing it with further re-
marks on the Little Bunting in other parts of the book, one is
somewhat puzzled as to whether Herr Gatke intends we should
gather that the Little Buntings met with on Heligoland are sup-
posed to be derived from the neighbourhood of Archangel, or from
far eastern breeding grounds in Asia. If from the latter locality,
then, according to the author's treatment of other species, their
flight would come under the category of an east-to-west descrip-
tion, and not, as previously stated, of a north-to-south type. A
reference to the records of the Little Bunting on Heligoland
seems to point to the fact that the individuals touching there are
derived from two districts, as there is a break in the continuancy
of migration, not a regular dribble of individuals during the
autumn as with other species. As the species breeds throughout
Northern Russia, east of the White Sea, it may perhaps be the
case that the later arrivals come from the Petchora, or other river
valley in the north-east. In any case there is no evidence of a
flight rigidly performed either from east to west or north to
south, though the general direction appears to be from north-
east to south-west, or thereabouts.

52

Herr Gatke seems to think that the appearance of certain
species on Heligoland, whose breeding grounds for the most part
lie in Asia, is due either to an innate tendency to wander, or to a
deliberate turn to the west on setting out on their migrations.
In other places, however, it must not be forgotten that he
attributes this westward wandering to meteorological influences
prevailing at the period of autumnal migration. If the former
supposition is correct, it is difficult to see how this tendency has
been inherited without producing a more general effect on the
particular species which are said to be subject to its influences.
It is significant that those which are supposed to be so affected
have, as Herr Gatke admits, for the most part only been detected
on the island in single instances ; but as the Yellow-breasted
Bunting and Yellow-headed Wagtail have occurred more fre-
quently, it is remarkable that he has not brought them forward
too in illustration of this tendency rather than treating them as
species, which prove how rarely a certain other group of birds
deviate from a rigidly performed north-to-south flight. The
probability of the fact, that because certain species have occurred
on Heligoland in small numbers, therefore they should in like
manner occur in much larger numbers in Central Europe, seems
to the writer to depend entirely on our acceptance of the theory
that birds migrate in a broad front. Whether this is so or not, '
it seems very unlikely, however, that the small number which
are apparently induced to travel westward should adopt such a
form of migration.

With regard to the progress of the spring migration from south
to north, Herr Gatke's remarks are very interesting, and form
a striking example of how the habits of birds differ in various-
localities. On page 41 he writes: "Here we nowhere meet
with any attempts at dividing the long migration flight into short
convenient stages such as is often the case after the first great
advance during the autunm migration ; nor do the birds at this
time anywhere exhibit a tendency for taking long spells of rest
in the course of their journey. Unrest and an impelling haste
are everywhere the prominent characters of the movement dur-
ing its whole progress." Observations conducted on Heligoland
no doubt bear out this statement, and we can hardly imagine

53

birds lingering at such an uninviting spot especially uninviting
in the spring unless their need for food or rest were very urgent.
But in other localities the observations of naturalists point to
quite a different conclusion. In our own country, for instance,
at various points on the east coast, certain species make their
appearance with great regularity at particular times, and so far
from evincing any of this unrest and impelling haste, are content
to linger for days together before further continuing their
journeys.

The Fieldfare may be singled out as a species illustrating this
fact ; even those flocks which pass through the Midlands at so late
a period in the spring as the first week in May, so far from
exhibiting any of this restless haste, may be seen lingering in the
same fields for several days at a time, instead of at once passing
on. The case of the Dotterel a species breeding in the far north
of the Palaearctic region too, is similar, flocks of which are known
to tarry in certain districts, not for days, but for whole weeks
together. Again, at Gibraltar, Col. Irby as early as March llth
met with very large numbers of the Common Crane migrating due
north. In the course of a single hour he calculates that at least
four thousand must have passed by. As the Crane breeds only
very locally and very sparingly in Spain, there can be no doubt
that these flocks were en route to the north of Europe. But at
this period their breeding grounds would not be fit for habitation.
No doubt the journey would therefore be broken at some convenient
locality in Western Europe. To the writer the very fact of so vast
a number of birds visiting a little spot like the island which Herr
Gatke describes as a most unattractive residence for birds, points
to the probability that the greater number certainly of the smaller
birds, if not the larger also conduct their migrations in compara-
tively short stages. The fact of the greatest number calling during
periods which we are told are the most favourable to an