22 CUCKOOS AND SHRIKES IN RELATION TO AGRICULTURE. 



has observed the loggerhead impale snakes on a barbed- wire fence. 

 At times loggerheads feed upon fish. The stomach of a bird killed in 

 Utah on a cold winter's day contained nothing but minnow's bones; 

 and Bachman speaks of the shrike's impaling fish that have been left 

 by fishermen. 



INSECTS EATEN BY THE LOGGERHEAD. 



The larger part of the insect food of this shrike consists of Orthoptera 

 (grasshoppers and crickets), and the remainder is principally beetles. 

 In summer, when grasshoppers are abundant, the loggerhead does not 

 seem to attack birds. The fact that in time of ])lenty more insects are 

 killed and impaled tlian can be utilized indicates that the percentage 

 of these pests destroyed is much greater than the laboratory examina- 

 tions show. The same statement would not hold good in the case of 

 the destruction of birds, because during cold weather when birds are 

 kill«;d there is a scarcity of food, and all the spoils of the chase are 

 probably utilized, (Grasshoppers and crickets were found in tliree- 

 fourths of the stomachs examined, and 14 of the 88 shrikes had fed 

 exclusively upon these pests. Most of the Ortlioptera eaten are grass- 

 hoppers, though some crickets are taken. ^lost of the grasshoppers 

 found in stomach contents are Hying species, among which have been 

 noted the dtist-colored Dissosteirti curoUnu which, when rising from the 

 road, sliows beautiful yellow underwings, and the red-legged grass- 

 hopper (MehoiopluHfemur-nibyum] which is so conspicuons in hay fields. 

 The i)ellacid grasshopper {Caininihi atrox), which is somewhat migra- 

 tory, is frequently captured, and also an ugly grasshopper {Ilippiscus). 

 In Arizona Dr. Horn has seen loggerheads catch grassiioppers and 

 impale them on cactus spines. One of the largest insects devoured by 

 this bird is a sand cricket, the so-called Idaho devil. The mole cricket, 

 likewise a large insect, is attacked and eaten by the shrikes of the 

 southeastern United States. The fact that they take these enormous 

 insects shows that whatever food becomes available in any locality is 

 generally utilized. 



Beetles and their hirvie are found in about one-fourth of the 

 stonuichs, and constitute 20 per cent of the bulk of the food. Most of 

 the beetles are eaten in spring before gra8shoi)pers become abundant. 

 Half the beetles and their larva* destroyed are useful carnivorous 

 si)ecies that prey upon insect pests. Some of the largest of these 

 beneficial beetles have been found stuck upon the splinters of the 

 stump of a felled tree. There were taken from one loggerhead's 

 stonuich 112 jaws of the larva- of a large i)redaceous beetle, and from 

 another stwmach the remains of the useful tigei- beetle. It is probable 

 that the killing of useful beetles is more <letrimental to agricultural 

 interests than the destruction of birds. Although half the beetles 

 eaten are beneficial, most of the others are injurious. Among this 

 latter class may be mentioned large, bright-colored, wood-boring bee 



