Movcments of British Robins as shown
by ringing
By D. W. Snow
British Trust for Ornithology
L A c K ( I 944) showed from analysis of ringing recoveries that British
Robins Erithacus rubuula are partial migrants. Most of the winter
recoveries he analysed were local, but a small proportion of the birds
had migrated south to France. There was (and still is) no conclusive
evidence from ringing that any Robins breeding in England or Scotland migrate to Ireland, though the possibility was not excluded.
Earlier work (Lack 1940) had shown that most of those that migrate
are females. In a subsequent paper (Lack 1948) he discussed the
ecological aspects of Robin migration, and also presented a table which
showed, from ringing recoveries, that a considerable proportion of
young ones disperse to distances of several miles from their birth-place,
but that once they have taken up territories they become much more
sedentary.
The number of Robin recoveries has increased enormously since
Lack wrote, and justifies a somewhat more detailed analysis of the
long-distance movements. These are still far fewer than one could
wish, but the annual increment is small and it will probably be many
continued...
67
B R I T I S H BIRDS
years before anything like a complete account will be possible. It may
be noted that many of the Robin movements mentioned by N. F.
Ticehurst in The Handbook of British Birds cannot yet be substantiated
from ringing recoveries; this applies especially to those involving
Ireland and the west of Scotland.
METHODS
As we are concerned with the British population alone, only those
records have been used which show that the bird was either born, or
almost certainly breeding, in the British Isles. The following cate­
gories of recoveries have been examined:
(i) birds ringed as pulli;
(2) birds ringed as juveniles before the end of August;
(3) birds ringed as adult or full-grown in April-July, except at
south- and east-coast stations; and
(4) birds ringed at other times of the year and recovered in a
subsequent breeding season, except at south- and east-coast
stations.
Clearly the first category is the only one for which the birth-place is
known with certainty. Those in the second category are almost cer­
tainly British, since Continental Robins on passage do not normally
arrive until September, and in any case are in first-winter plumage
when they arrive. Their exact birth-place is less certain, as by July
or August they may have moved some distance from it. There is in
fact no evidence from ringing of a movement of as much as ten miles
by the first August of life, but such movements may well be made,
since by the second week of September some British Robins of the year
have already reached France. The birth-place of those in the third and
fourth categories is unknown, but they almost certainly belong to the
British breeding population. It is essential to exclude adults ringed at
south- and east-coast stations, as Continental Robins are on migration
well into our breeding season. Since the Robins that occur at westcoast observatories are overwhelmingly of the British subspecies,
distant recoveries of these have been examined; but, in fact, they are
too few to throw much light on the west-coast movements.
In attempting to determine the proportions of Robins that are
migratory or sedentary, it has been necessary to exclude all those re­
covered by the ringer at or near the place where they were ringed.
Such recoveries would greatly exaggerate the apparent proportion of
residents, as the ringer is so much more likely than anyone else to
recover his own birds. All Robins caught and released by people
other than the ringer, whether near where they were ringed or at a
distance, are included.
The same regional divisions of the country have been adopted as
68
MOVEMENTS OF B R I T I S H
ROBINS
F i G. i . Overseas recoveries of British Robins Erithacus rubecula. The Continental
recoveries were ringed as young or (in one case) as an adult in the breeding season;
the Irish recoveries were ringed on passage on the Calf of Man. Figures at the
places of recovery indicate the months of recovery; those not underlined were in
the following autumn or winter, those underlined once were in the next but one
autumn or winter, etc. The Spanish recovery was from near Cordoba (off the map)
69
B R I T I S H BIRDS
were used by Lack (1944): Scotland and the Borders (Northumberland,
Cumberland, Westmorland and Durham), Northern England (York­
shire, Lincolnshire, Nottinghamshire, Derbyshire, Lancashire,
Cheshire and North Wales) and Southern England (all the counties to
the south of these). There are still too few recoveries to warrant
finer subdivision.
Lists of all distant recoveries (ten miles or more) are deposited at the
British Trust for Ornithology and in the library of the Edward Grey
Institute at Oxford.
MIGRATION TO THE C O N T I N E N T
Five Robins ringed as nestlings, and five ringed as juveniles before the
end of August, have been recovered in France (nine) or Spain (one),
and one ringed as a nestling has been recovered in Holland. In
addition, one ringed as an adult inland in the breeding season (21st
July) has been recovered in France. As mentioned above, there is
still no conclusive evidence that any Robins born in Great Britain
migrate to Ireland, though this now seems very likely from recoveries
of migrants ringed on the Calf of Man in August and September: four
of these have been recovered in Ireland, three of them in the following
winter—December to early March—and the fourth in a later winter
Fig. 1 shows that the migrants to the Continent came mainly from
the south, and especially from the south-east, of England, and that
their recovery localities mostly lay between south and SSW of the
ringing localities. Though the numbers are small, there appears to
be a difference between the age groups. The six most southerly
recoveries were all in their first-year, whereas the recoveries of older
individuals were more to the north-east. Thus the extreme easterly
recovery (Hook of Holland) was in its third winter; the next most
easterly (Rouen) was in its fourth winter; and the age of the next (near
Tours) was unknown, but it was not in its first winter as it was the
only one ringed as an adult. Whereas five of the seven first-winter
Robins were recovered in September (four) and October (one), the
older ones were all recovered in November, December and January.
These records could be interpreted as indicating that adult Robins
F I G . 2 (opposite). Recoveries of British Robins Eriihacus rubecula at ten miles or
more within the country. Solid lines: ringed as nestling or juvenile and recovered
in the following autumn or winter. Broken lines: ringed as adult in the breeding
season and recovered in the following autumn or winter. Dots and dashes: ringed
in autumn (August-September) and recovered in the following winter. Dotted
lines: ringed in winter and recovered in the following breeding season (arrowhead in
this case indicates the direction taken in previous autumn)
7°
MOVEMENTS OF B R I T I S H ROBINS
71
B R I T I S H BIRDS
follow a more easterly course than juveniles, but a more likely explana­
tion is perhaps that all of them take a more or less south-easterly
course across the English Channel, and that the heading is then
changed to SSW—as in the Swallow Hirundo rustica (Davis 1965) and
probably many other small passerine migrants (Lack 1963)—and that
the adults tend to stop sooner and winter farther north, while the
juveniles continue farther south, not stopping long enough in the
north to give much chance of recovery.
L O N G - D I S T A N C E MOVEMENTS W I T H I N THE COUNTRY
All the recoveries that give some indication of the directions taken in
autumn by migrants within Great Britain are plotted in fig. 2 (see fig. 1
for movements from the Isle of Man). The picture is confusing, with
no simple pattern emerging, but the following trends seem significant.
Recoveries of Scottish Robins tend to fall into two groups: those
showing long movements in a southerly direction, and those showing
shorter movements, of which six out of nine are in north-easterly
directions and suggest an avoidance of the inland mountainous areas.
There is only one long movement of a Robin known to have been born
in the north of England, from Lancashire to Devon. It is difficult to
account for the other long movement, from Lancashire (22nd Septem­
ber) to Midlothian (same November).
There is a marked lack of records involving Robins from the English
midlands, which contrasts with the considerable number for southern
England. Nearly all the longer movements in the south of England
are orientated transversely to the north-south axis: five show move­
ment to the east, and two to the west. Both of the latter were re­
coveries from hard winters (1961/62 and 1962/63), which suggests that
Robins do make hard-weather movements—a debated point (discussion
in Lack 1948), for which the evidence is still meagre. It may be
significant that all the four records which show movement in a nearly
southerly direction to the south coast of England were ringed in the
autumn (August and September), and so were not necessarily southern
English breeding birds. They may well have been on passage from
further north when ringed.
There are six records (not shown on the map) indicating shifts in
breeding locality between years. For instance, one ringed in July 1961
at Banbury, Oxfordshire, was recovered in July 1962 at Hemel Hemp­
stead, Hertfordshire, 41 miles ESE. These shifts may well involve
long-distance migrants which failed to return to their previous breeding
locality.
WEST-COAST MOVEMENTS
As already mentioned, there is little evidence from ringing for the
migrational movements on the west coast of Great Britain and the
72
MOVEMENTS OF B R I T I S H ROBINS
Irish coasts summarised in The Handbook. Fig. i shows the five
records of Robins ringed on the Calf of Man and recovered at a dis­
tance. Since Robins are overwhelmingly passage migrants on the Calf
of Man, one may reasonably interpret these records as indicating that
some from southern Scotland and northern England winter in Ireland;
but it is curious that ringing on the Calf of Man has produced these
records in four years, whereas ringing in England and Scotland for 5 5
years has not yet produced any.
Three Robins ringed on Great Saltce, Co. Wexford, in late August
and September, when there is an annual influx, have subsequently been
recovered on the mainland of Ireland. Two were recovered in a later
breeding season (Co. Dublin, about 1st May; Co. Louth, 20th June);
the third was first reported in early January and recorded as still present
on 2nd May (Co. Kerry). These records indicate that Irish breeding
Robins migrate south, but the winter quarters of these migrants offer a
problem, since only a small number can winter on the Saltee Islands
themselves.
THE PROPORTION OF THE POPULATION MIGRATING
In his study area in south Devon, Lack (1940) found that nearly all the
males were resident; 70% of the females apparently migrated, but some
certainly moved only short distances and, since they returned in
January and February, they may all have spent the winter within a few
miles. At the other extreme, Robins normally leave some breeding
areas at high altitudes in Scotland completely, and all must move
several miles at least. The proportion of the population migrating, as
assessed from ringing recoveries, can therefore at best be only a very
rough average figure.
Table 1 sets out the numbers of local and distant recoveries in
autumn and winter for the three regions into which the country has
been divided. Altogether, 6% of the Robins born in Southern
England were recovered abroad, and another 4$% at distances of ten
miles or more within the country. The figures for the two northern
Table 1. Recoveries during September-February of Robins Erithactts mbecula
ringed as young in die three main divisions of Great Britain (page 70)
Where
ringed
Scotland and Borders
Northern England
Southern England
Recovered
locally
Recovered at
10 miles or more
in Great Britain
27
50
143
6
}
7
73
Recovered
abroad
1
I
'
I0
B R I T I S H BIRDS
regions combined, though rather small, leave little doubt that rela­
tively fewer Robins from the north of the country migrate abroad
(altogether two out of 88, or 2f %), though more of them move to a
distance within the country (altogether nine out of 88, or 10%).
In spite of the fact that local recoveries by the ringer have been ex­
cluded, the chances of recovery of a Robin which remains near where it
was ringed must still usually be better than the chances of one that
migrates away, since so many are ringed in suburban areas where dead
Robins are more likely to be found, and if found reported, than in rural
areas or abroad. Hence the totals of about 10% and 12% given above
for the migratory fraction of the population are probably too low, and
may well be much too low.
ACKNOWLEDGEMENTS
I am grateful to Robert Spencer and Peter Davis for helpful criticism
of this paper in an earlier draft, and to the staff of the B.T.O. Ringing
Office for help in checking and locating some of the records.
SUMMARY
The long-distance ringing recoveries of British Robins Erifhactts rubemla are shown
on two maps. A proportion of the population, mainly from the south-east of the
country, migrates south to the Continent. The records, though few, suggest that
older individuals migrate less far than first-year ones, and that the direction of migra­
tion is perhaps south-east to northern France and then SSW to south-western France
and the Iberian peninsula.
Long-distance movements within Britain present a more confusing picture.
Scottish Robins tend to move either long distances to the south or shorter distances
in directions which suggest avoidance of mountainous areas. Southern English
ones tend to make their longest journeys in west-to-east or east-to-west directions,
the latter (only two records) indicating hard-weather movements.
Ringing still throws little light on west-coast movements, but recent recoveries in
Ireland of Robins ringed on migration on the Calf of Man suggest that some from
north Britain winter in Ireland.
The apparent proportions of migrants to non-migrants for three divisions of the
country, as shown by ringing, are set out in a table. It is pointed out that the true
proportions of migrants may be considerably higher than these figures indicate.
REFERENCES
DAVIS, P. (1965): 'Recoveries of Swallows ringed in Britain and Ireland'. Bird
Study, 12: 151-169.
LACK, D. (1940): 'The behaviour of the Robin. Population changes over four
years'. Ibis, (14)4: 299-324.
■
—-(1944): 'The problem of partial migration'. Brit. Birds, 37: 122-130,
143-150.
(1948): 'Notes on the ecology of the Robin'. Ibis, 90: 252-279.
(1963): 'Migration across the southern North Sea studied by radar. Part
4. Autumn'. Ibis, 105: 1-54.
WITHERBY, H. F., JOURDAIN, F. C. R.,
TICEHURST, N . F., and
(1938-41): The Handbook ofBritish Birds. London,
74
vol.2."
TUCKER, B.
W.