358 RURAL GLEANINGS. 



it, and searching for food amongst its contents. Although it flew 

 away to a little distance as each successive spadeful was flung into the 

 barrow, yet it returned as soon as the dust arising from it had subsided. 

 Your very entertaining and well-read correspondent, MY. Blyth, speak- 

 ing of the robin (vide page 290), says it has "a strange tremulous 

 motion of the tail which has, I believe, never yet been noticed." He 

 does not mean by this, I suppose, the common wagging of the tail, 

 which, as White observed years ago, is always up and down instead of 

 being from side to side ; but I conceive that he alludes to what I have 

 often observed although never recorded, which is that the robin's tail 

 has a quick irregular vibration like that exhibited by a piece of watch- 

 spring (or other elastic body) when held tight at one end and struck 

 violently at the other. This motion of the tail is most frequently to be 

 observed when the bird is suddenly surprised, or when apprehensive of 

 danger. 



Not far from Leyton I observed, a few evenings ago, a couple of 

 swallows flying after a straggling rook, and snapping their bills in a 

 menacing manner close to him. This he bore very quietly without 

 attempting to retaliate, but was evidently at a loss what to do, for 

 when he directed his course one way they intercepted his retreat, and 

 when he made for another direction they did the same. By what 

 means he had offended them and excited their wrath I cannot conceive. 

 I have often read and heard, though, of swallows strongly uniting for 

 the purpose of buffetting hawks and other similar birds of prey, when- 

 ever they may consider themselves in danger from them, and to this 

 fact your correspondent Ruricola alludes in the fourth verse of his 

 prettily written poem (vide page 321), but I doubt his accuracy in 

 asserting that they treat the owl in a similar manner. I doubt the 

 truth of it for two reasons * : first, on account of owls generally flying 

 when the swallows have gone to rest, and secondly, because it is con- 

 trary to a law much observed in nature, which is that birds strictly 

 carnivorous, rarely (and then only when their usual food fails them) 

 prey upon other birds which are like the swallow strictly insectivorous, 

 and who are as equally serviceable in lessening the number of insects 

 as the former are in preventing the superabundance of noxious birds 

 and quadrupeds. It is seldom indeed that the swallow has to attack 

 the hawk, for it being thus wisely ordained that animals of similar 

 utilities shall not prey upon one another, it is rarely that the hawk 

 gives any cause for their ire. As they perform equally important and 



* If Solitarius will try the experiment, as I have done, he will find Ruricola 

 is quite correct. See Field Nat. Ma//., pncje 2. EDITOR. 



