SPARROW FAMILY. 93 



and bushes. The service it performs in destroying the seeds of weeds 

 should be sufficient to cover a number of sins, but fortunately there 

 are none serious enough for consideration. 



BLACK-HEADED GROSBEAK. 



(Zamelodia melanocephala.) 



During the six months from April to September inclusive, the 

 black-headed grosbeak occurs throughout the State of California, 

 excepting the arid deserts and boreal mountain summits. Like its 

 eastern relative, the rose-breasted grosbeak, it takes readily to 

 orchards and gardens, and is common in agricultural districts. It is 

 a bird of beautiful plumage and sweet song, and is a welcome addi- 

 tion to the attractions of rural life. It often nests in orchard trees, 

 and, as is perfectly natural, gets much of its food there. While this 

 consists mainly of harmful insects, a goodly part of it is fruit. The 

 grosbeak, as its name indicates, has a very powerful bill, and has no 

 difficulty in cutting the skin of the firmest fruit. It feeds upon cher- 

 ries, apricots, and similar fruits to a considerable extent, but on the 

 other hand it habitually consumes some of the worst insect pests, 

 such as the black olive scale, the 12-spotted diabrotica, and the 

 codling moth. The destruction of this trio alone should entitle the 

 bird to great consideration, but it eats also other destructive insects. 



For the laboratory investigation of this bird's food 225 stomachs 

 were accessible. They were collected in the six months from April 

 to September inclusive, a fair number in each, except the last, when 

 only 3 were obtained. These stomachs contained about 57 percent 

 of animal matter to 43 of vegetable. The animal matter is composed 

 of insects and spiders, with a few traces of vertebrates. Insects, such 

 as beetles, scales, and caterpillars, constituted nearly 53 of the 57 

 percent of animal food. 



Animal food. — Of the animal food, beetles are the largest item. 

 They were found in 190 of the 225 stomachs. Of these, predatory 

 ground beetles (Carabidse) were found in 16 stomachs, and ladybird 

 beetles (Coccinellidse) in 2. To offset the destruction of these useful 

 insects, the 12-spotted diabrotica, which often does serious injury to 

 fruit trees, was found in 109 stomachs. Many weevils were found, 

 and great numbers of several species of leaf beetles (Chrysomelidae). 

 To this family belongs the notorious Colorado potato beetle, which 

 at one time seemed likely to ruin the potato industry of the East. 

 The bird which attacked this pest constantly and systematically was 

 the rose-breasted grosbeak, a near relative of the one under considera- 

 tion. When the potato beetle finds its way into California, as even- 

 tually it undoubtedly will, the black-headed grosbeak is the bird most 

 likely to become its active enemy. 



Hymenoptera in the form of bees and wasps with a few ants aggre- 

 gate less than 2 percent. A worker honeybee was found in one 



