56 Booth : Migration of the Common Swallow. 
food in order to keep alive, without journeying further north 
into the bad weather. On the other hand, when conditions are 
fine and suitable in Europe to the south of us, immigratory 
birds will sometimes suddenly plunge into the most vile weather 
here. Who has not been moved to pity on seeing crowds of 
starved Swallows and other immigratory birds, all looking 
abjectly miserable, in heavy and continued showers of sleet, 
just after their arrival ? In normal seasons and shortly after 
the breeding Swallows have arrived and settled down early in 
May, very little time is lost in starting nesting operations. 
Usually a new nest is built close to, or actually upon the site 
of that of the previous year ; or at times the old nest is repaired. 
There is a belief that Swallows, etc., being called ' summer 
visitors/ are foreign birds, and come to spend a summer holiday 
and honeymoon here. This is not so. They are thoroughly 
all-British ; they first saw the light of day here, and gladly 
return many thousands of miles to make their home here again 
at the first opportunity. In fact it is doubtful if they would 
leave at all if their food supply were assured throughout the 
winter. Their food consists of insects taken on the wing. It is 
quite true that they often leave, and particularly the young birds 
of the first brood, when there is a plentiful supply of food. But 
that is a call of Nature to wise swallows to be ready and not to 
stay until the food has failed and they cannot find sufficient of 
it to give them strength to make their great journey. Every 
mild autumn and winter, laggard swallows are reported for 
almost every one of the colder months, and here and there, 
in a favourable spot, one manages to exist throughout the 
winter. Even so far north as in Yorkshire one of a pair 
managed to survive in a cowhouse at Masham, during the 
exceptionally mild winter of 1895/6. 
For a long time it has been known that Swallows, particu- 
larly the mature birds, usually return to the actual spot which 
they left the year before. Many birds have been marked in the 
past in various ways, though markings on their feathers are 
valueless, as they undergo a complete moult in their so-called 
winter quarters. Recently a more accurate system of marking 
has been practised, viz., by means of numbered and addressed 
aluminium rings being fixed on the legs. The results, par- 
ticularly with the species under notice, have been remarkable. 
In ‘ Results of a Study of Bird Migration by the Marking 
Method/ at the Aberdeen University, Dr. A. Landsborough 
Thomson says of the Swallow,* * There are three records of 
birds of this typically migratory species returning to the local- 
ities of marking in the following seasons. Two were marked 
as nestlings and one as an adult, the details being as follows 
Case 15 : Caught, marked and released as an adult bird at 
a farm in Kent on 29th June, 1909 ; recaught at the same 
farm on 14th June, 1910. 
* The Ibis, 1921, p.511. 
Naturalist 
