The architecture of birds / [Anon].

  • James Rennie
Date:
[1831]
Catalogue details

Licence: Public Domain Mark

Credit: The architecture of birds / [Anon]. Source: Wellcome Collection.

    53/428 page 21
    always scrapes out with its feet the sand detached by the bill, but so carefully is this performed that it never scratches up the unmined sand or disturbs the plane ofthe floor, which rather slopes upwards, and of course the lodgment of rain is thereby prevented.* White says, he has frequently observed holes of different depths left unfinished at the end of summer 5 and, rejecting the first notion which occurred to him, that these beginnings were intentionally made in order to be in the greater forwardness for next spring, supposes they may have been abandoned on account of the soil proving either too hard or too loose. It appears more probable, we think, that some accident may in such cases have befallen the birds ; for they seem to be always careful in choosing the sort of bank best suited for their mode of mining. In most -of the numerous localities which we have examined, they made choice of a very hard bed of alluvial sand, in an escarpment either facing a river, a quarry, or a sand-pit, and from ten to thirty feet from the base, being evidently most in fear of enemies from below ; while above we have often seen their galle- ries within a foot of the surface. When the escarp- ment, again, is very high, they prefer a middle-height, an instance of which occurs at the chalk-pit behind the hanging wood at Charlton, in Kent.* ‘One thing is remarkable,’ says White, ‘ that after some years, the old holes are forsaken and new ones bored ; perhaps because the old habitations grow foul and fetid from long use, or because they may so abound with fleas as to become untenantable. This species of swallow, moreover, is strangely annoyed _ with fleas ; and I have seen fleas — bed fleas (Pulex wrritans) swarming at the mouths of these holes, like bees on the stools of their hives.’ * J.R. 5 + Nat. Hist. of Selborne, i, 301. White was wrong in sup-
    digitised image 1
    digitised image 2
    digitised image 3