INDIRECT BENEFITS DERIVED FROM INSECTS. 243 



part of the creation with a sufficient supply of food. The 

 number of birds that derive the whole or a principal part of 

 their subsistence from insects is, as is universally knov\^n, very 

 great, and includes species of almost every order. 



Amongst the Accipitres the kestril {Falco tinnunculus L.) 

 devours abundance of insects. A friend of mine, upon 

 opening one, found its stomach full of the remains of grass- 

 hoppers and beetles, particularly the former, which he sus- 

 pects constitute great part of the food of this species. One 

 of the shrikes, also, or butcher-birds (Lanius collurio) — and 

 it is probable that other species of this numerous genus may 

 have the same habits — is known to feed upon insects, which 

 it first impales alive on the thorns of the sloe and other 

 spinous plants, and then devours. If meat be given it, when 

 kept in a cage, it will fix it upon the wires before it eats it. 

 Lanius excubitor also impales insects ; but Heckewelder 

 denies that it feeds upon them. If he be correct, the object 

 of this singular procedure with that species may be to allure 

 the birds which it preys upon to a particula^r spot.^ 



Amongst the PiccB or Pies the Crotophaga, called the Ani, 

 which is a native of Africa and America, lives upon the 

 locust and Ixodes ricinus, which it picks in great numbers 

 from the backs of cattle ; but none are greater devourers of 



1 According to Mr. Heckewelder ( Trans. Amer. Phil. Soc. iv. 124.), L. excu- 

 bitor, called in America the nine-killer, from an idea that it transfixes nine 

 individuals daily, treats in this manner Grasshoppers only ; while L. collurio 

 would seem to restrict itself chiefly to Geofrupes, two of which Mr. Sheppard 

 once observed transfixed in a hedge that he knew to be the residence of this bird. 

 Kugellan even thinks that it impales only G. vernalis, which he has often found 

 transfixed, but never G. stercorarius. (Schneid. Mag. 259.) I must remark, 

 however, that I last summer observed two humble-bees quite alive impaled on the 

 thorns of a hedge near my house, which had most probably been so placed by 

 this species, L. excubitor being rarely found except in mountainous wilds. 

 (Bewick's ^«rc?s, i. 61.) And Prof Sander states that on opening this bird 

 (L. collurio) he has sometimes found in its stomach nothing but grasshoppers, 

 and at others small beetles and other insects. (^Naturforscher, Stk. xviii. 234.) 

 Mr. Dunlop, in a letter in 'LonAovi's Gardener's Magazine for May, 1842 (No.cxlvi. 

 p. 259. ), states, that upon examining a branch cf hawthorn on which he had for 

 some days observed a pair of fly-catchers feeding their young, he found upwards 

 of a dozen humble-bees (Bombus terrestris) fixed upon the spines as securely as if 

 done by the hand of man, some being alive, and others dead and partly devoured. 

 Mr. Dunlop, after removing the bees to watch the process of the birds in placing 

 them, had soon the satisfaction of seeing the fly-catchers catch them on the wing, 

 carry them direct to the branch (which was a dead one, apparently on account of 

 the greater hardness of the spinas), and thrust them on the spines as above 

 described. Mr. W. W. Saunders found a number of the yellow underwing moth 

 ( Triphcena pronuba) thus fixed. 



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