SPARROW FAMILY. 83 



follows: Oats in 15, wheat in 9, barley in 4, corn in 1, and unidenti- 

 fied in 1. None was taken in a harvest month. The greatest 

 amount, more than 30 percent, was eaten in March, the sowing 

 month, probably much of it from newly sown fields. 



Weed seed aggregates 61.8 percent of the food, and was eaten in 

 every month. In September it amounted to nearly 95 percent. A 

 few seeds, mostly of grass, were not identified. The following is a 

 list of identified species and the number of stomachs in which each 

 was contained: 



Ragweed (Ambrosia sp.) 1 



Tarweed ( Madia sativa) 4 



Mayweed (Anthemis cotula) 11 



Bur thistle ( Centaurea melitensis) 16 



Sow thistle (Sonchus asper) 2 



Nightshade (Solarium nigrum) 11 



Lupine (Lupinus sp.) 1 



Clover ( Trifolium sp.) 1 



Poison oak (Rhus diversiloba) 13 



Alfilaria (Erodium cicutarium) 34 



Geranium (Geranium dissectum) ■ 4 



Mustard (Brassica nigra) 3 



Miner's lettuce ( Montia perfoliata) 13 



Red maids ( Calandrinia menziesi) 2 



Purslane (Portulaca oleracea) 1 



Rough pigweed (Amaranthus retroflexus) 35 



Spurry (Spergula arvensis) 9 



Chickweed (Stellaria media) 42 



Catchfly (Silene sp.) 21 



Knotweed (Polygonum sp.) 33 



Sorrel (Rumex sp.) 26 



Wild oats (Avenafatua) 8 



Timothy (Phleum pratense) 1 



Panic grass (Panicum sp.) 3 



Sedge ( Carex sp.) 14 



Coniferous seeds not identified 4 



Unidentified 2 



Remains of blossoms were found in 1 stomach. The seeds of 

 poison oak were not discovered in the stomachs, but the characteristic 

 granules that are embedded in the waxy coating of the seeds were 

 identified, thus showing that the birds eat this wax without swallow- 

 ing the seed itself. 



SUMMARY. 



The insect food of the snowbirds is composed almost entirely of 

 harmful species, of which caterpillars form the largest item. Snow- 

 birds do no damage to fruit or grain. They eat large quantities of 

 weed seeds ? thereby rendering a service to agriculture, 



