SPAKROW FAMILY. 85 



Caterpillars, while taken in nearly every month, were eaten very 

 irregularly and to the extent of 4.3 percent only. There was a fair 

 percentage from March to August inclusive, but in other months a 

 trifle or none, except December, in which 5 percent were found. May 

 shows the greatest amount, 14 percent. Grasshoppers are apparently 

 not relished by the song sparrow. A mere trace of these insects was 

 found in a few stomachs collected in February, May, June, and August. 

 They do not form an appreciable percentage of the food. A few 

 insects too finely pulverized for recognition, some spiders, and a few 

 snails make up the remainder of the animal food, 2.5 percent. 



Vegetable food. — Evidence of fruit eating was found in 19 stomachs 

 as follows: Seeds of Rubus (blackberries or raspberries) in 9, elder- 

 berries in 4, cherries in 2, figs in 1, and fruit pulp or skins in 3. In 

 all it amounts to a trifle more than 2 percent of the food. Grain was 

 absent in all stomachs collected from February to June inclusive, and 

 in November. What was eaten in the other months comes to a little 

 more than 3 percent for the year. The most, 1 1 percent, was taken 

 in January, but July shows very nearly the same. This last was 

 perhaps gleaned from the field. The varieties are as follows: Barley 

 found in 7 stomachs, oats in 5, and wheat in 2. 



The chief food of the song sparrow is weed seed. This amounts 

 to 73 percent of the year's food, and varies from one-fifth to very 

 nearly the whole of each month's diet. In September, when animal 

 food is at its minimum, weed seed reaches a little more than 93 per- 

 cent. On the other hand, in May, when animal food is at its maxi- 

 mum, weed seed shrinks to a little less than 21 percent. Of the 321 

 stomachs, 302, or 94 percent, contained weed seed. Of these, 171, 

 or 53 percent of all, were completely filled with it. There were only 

 19 stomachs that did not contain more or less of this food. The 

 record of this sparrow for eating weed seed is excelled by only four 

 species of California birds — the linnet, the two goldfinches, and the 

 white-crowned sparrow. 



Following are the species of weed seeds identified and the number 

 of stomachs in which each was found: 



Sunflower (Helianthus sp.) 1 



Lesser tarweed (Hemizonia fasticulata) 1 



Tarweed ( Madia sativa) 9 



Mayweed (Anthemis cotula) 7 



Bur thistle ( Centaurea melitensis) 36 



Sow thistle (Sonchus asper and oleraceus) 5 



Salsify ( Tragopogon porrifolius) 1 



Henbit (Lamium amplexicaule) 1 



Nightshade (Solanum nigrum) 35 



Nine bark (Opulaster opulifolius) 1 



Turkey mullein (Eremocarpus setigerus) 1 



Poison oak (Rhus diversiloba) 3 



Alfilaria (Erodium cicutarium) 23 



