Selborne, Jan. 29, 1774.
Dear Sir,
The house-swallow, or chimney-swallow, is undoubtedly the first comer of all the British hirundines; and appears in general on or about the thirteenth of April, as I have remarked from many years' observation. Not but now and then a straggler is seen much earlier: and, in particular, when I was a boy I observed a swallow for a whole day together on a sunny warm Shrove Tuesday; which day could not fall out later than the middle of March, and often happened early in February.
It is worth remarking that these birds are seen first about lakes and mill-ponds; and it is also very particular, that if these early visitors happen to find frost and snow, as was the case of the two dreadful springs of 1770 and 1771, they immediately withdraw for a time. A circumstance this much more in favour of hiding than migration; since it is much more probable that a bird should retire to its hybernaculum just at hand, than return for a week or two only to warmer latitudes.
The swallow, though called the chimney-swallow, by no means builds altogether in chimneys, but often within barns and out- houses against the rafters; and so she did in Virgil's time:
... Ante Garrulla quam tignis nidos suspendat hirundo.
