18 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 



In the first analysis of the food components the two principal 

 elements are found to be : Animal matter, 2.4 a percent ; vegetable 

 matter, 97.6 percent. 



Animal food. — This brings into strong relief the linnet's sins of 

 omission. Living in a country where constant war against noxious 

 insects is necessary, the bird takes little or no part in the contest, and 

 in return for benefits derived from man renders but slight service in 

 this direction. 



The small portion of animal food it takes, however, consists almost 

 wholly of insects and a large proportion of it of plant-lice (Aphi- 

 didse), which from their small size do not attract the notice of many 

 species of birds. They appear, however, to be the favorite animal 

 food of the linnet, and it is noticeable that a large percentage of them 

 are the woolly species. Many of the birds when killed had their 

 beaks smeared with the remains of woolly aphides. As these insects 

 are notoriously harmful to many trees and other plants, any bird that 

 destroys them is a benefactor. It is to be regretted that the linnet 

 should not indulge to a greater extent a taste so well directed. Were 

 25 percent of its food made up of woolly aphides the fruit it destroys 

 would be well paid for. The other contingent of animal matter 

 found in the linnet's stomach consists of small caterpillars and a few 

 beetles, chiefly weevils. Most birds that feed on plant-lice eat also 

 the ants that are usually in attendance upon them, but the only trace 

 of ants or of other Hymenoptera in the stomachs of linnets was one 

 ant's jaw. Grasshoppers, the favorite food of so many birds, were 

 represented by a mere fragment in one stomach. 



Vegetable food. — The most interesting part of the food of the lin- 

 net is the vegetable portion. This naturally falls into three cate- 

 gories : Weed seed, which amounts to 86.2 percent of the annual food ; 

 fruit, 10.5 percent; and other miscellaneous vegetable matter, 0.9 per- 

 cent. 



Fruit. — Fruit is represented in stomachs taken in January by a 

 mere trace. This was probably of no value, only ungathered fruit or 

 perhaps belated olives. In stomachs taken in February no fruit was 

 found, but in ensuing months it appears in small quantities, increas- 

 ing irregularly until August, when a maximum of 27.4- percent was 

 eaten. In September a trifle less was taken than in August, and after 

 that the quantity decreases until December, in which month a little 

 less than 2 percent was eaten. In March the fruit amounted to 

 about 6 percent, a quantity hard to account for except on the suppo- 

 sition that it was waste fruit left over from the previous year. The 



« While percentages are sometimes given in fraction, it need not be assumed 

 that extreme accuracy is intended ; such figures must be taken as only an 

 approximation to the truth. 



