126 NATURAL HISTORY 



LETTER XLI. 



TO THOMAS PENNANT, ESQUIRE. 



T is matter of curious inquiry to trace out how 

 1 those species of soft-billed birds, that con- 

 tinue with us the winter through, subsist 

 during the dead months. The imbecility 

 of birds seems not to be the only reason 

 why they shun the rigour of our winters ; for the robust 

 wryneck (so much resembling the hardy race of wood- 

 peckers) migrates, while the feeble little golden-crowned 

 wren, that shadow of a bird, braves our severest frosts 

 without availing himself of houses or villages, to which 

 most of our winter birds crowd in distressful seasons, while 

 this keeps aloof in fields and woods ; but perhaps this 

 may be the reason why they may often perish, and why 

 they are almost as rare as any bird we know. 1 



I have no reason to doubt but that the soft-billed birds, 

 which winter with us, subsist chiefly on insects in their 

 aurelia state. All the species of wagtails in severe weather 

 haunt shallow streams near their spring-heads, where they 

 never freeze; and, by wading, pick out the aurelias of the 

 genus of Phrygancce, &c. 2 



Hedge sparrows frequent sinks and gutters in hard 

 -weather, where they pick up crumbs and other sweepings : 

 and in mild weather they procure worms, which are stirring 



1 The golden- crested wren and the common brown wren are both 

 very impatient of cold. In confinement, as observed by the Hon. arid 

 Rev. W. Herbert, the least frost is immediately fatal to them. In a 

 wild state, they keep themselves warm by constant active motion in the 

 day, and at night they secrete themselves in places where the frost cannot 

 reach them ; but numbers doubtless perish in severe winters. ED. 



2 See Dei-ham's " Physico-Theology," p. 235. G. W. 



