SELBORNE, _Sept._ 9_th_, 1781.
I have just met with a circumstance respecting swifts, which furnishes an
exception to the whole tenor of my observations ever since I have
bestowed any attention on that species of hirundines. Our swifts, in
general, withdrew this year about the first day of August, all save one
pair, which in two or three days was reduced to a single bird. The
perseverance of this individual made me suspect that the strongest of
motives, that of an attachment to her young, could alone occasion so late
a stay. I watched therefore till the 24th August, and then discovered
that, under the eaves of the church, she attended upon two young, which
were fledged, and now put out their white chins from a crevice. These
remained till the 27th, looking more alert every day, and seeming to long
to be on the wing. After this day they were missing at once; nor could I
ever observe them with their dam coursing round the church in the act of
learning to fly, as the first broods evidently do. On the 31st I caused
the eaves to be searched, but we found in the nest only two callow dead,
stinking swifts, on which a second nest had been formed. This double
nest was full of the black shining cases of the _hippoboscae hirundinis_.
The following remarks on this unusual incident are obvious. The first
is, that though it may be disagreeable to swifts to remain beyond the
beginning of August, yet that they can subsist longer is undeniable. The
second is, that this uncommon event, as it was owing to the loss of the
first brood, so it corroborates my former remark, that swifts breed
regularly but once; since, was the contrary the case, the occurrence
above could neither be new nor rare.
P.S.--One swift was seen at Lyndon, in the county of Rutland, in 1782, so
late as the 3rd September.