112 Notes on the Common Swift tn the Bradford district. 
‘muggy,’ or with a strong north-east wind blowing, they repair 
to the valley near to the river. During the early part of their 
arrival | have never seen any near to the nesting colony at 
Frizinghall, if, indeed, they are the actual birds which frequent 
it later. It may be, these early Swifts pass on to other districts 
to breed. Anyhow, about the r1th of May, the birds (about 
half the number that will eventually occupy it) will be seen 
circling round and flying about the nesting site. After their 
departure about the 19th of August, it is usual for several birds 
to return to the vicinity of their breeding quarters a few days 
after, and sometimes they will remain for several days, but they 
rarely stay later than the 26th or 27th of August. By their 
appearance I usually take these latter to be birds of the year. 
It is rather a curious fact that immediately the Swifts have 
finally left their feeding area at Frizinghall, several House 
Martins take their place. These latter do not breed, so far as I 
know, within about a mile away, and I have never seen them 
there when the Swifts were about. I mention that as a curious 
fact in connection with ¢A4zs colony, and not because I wish to 
impute any antagonism between the Swifts and House Martins, 
which are usually good friends, and will be seen flying and 
feeding together in many places. For the last two or three 
weeks before their departure, if the weather be fine, many of 
the Swifts again visit the higher moorlands, as the first-comers 
did in the spring. 
Last season I was greatly surprised to see a Swift hawking 
for food by the river, and evidently quite at home, on Oct. 7th. 
The weather was mild, with plenty of insect food about, and I 
watched it for half-an-hour in the morning, but it had apparently 
disappeared in the afternoon. This is more than a month later 
than I had previously seen the species in this district. Last 
year the remaining moiety of the Frizinghall colony departed on 
August 19th, but a few birds returned on the 24th and 25th, 
from which dates I had not seen any until the one on Oct. 7th. 
Almost every year very late occurrences of the Swift are reported 
from some part of the country—generally near to the coast—and 
they are most often erroneously chronicled as ‘ Late Say of the 
Swift.’ The observer usually states that none have been seen 
for some time previously, and no doubt this habit of the Swift 
in occasionally returning misled Gilbert White into believing 
that they were temporally coaxed out of their hibernating quarters 
by the mild weather. 
My observations seem to show that with this species the date 
Naturalist. 
