SPARROWS IN THE FIELD. 43 



from a false buckwheat vine. But these were isolated lustanees, rare 

 exceptions to the general rule of ground feeding. 



It should be stated, however, that there was snow on the ground 

 during onh' one of the visits, and then it was barely an inch deep, 

 while there was a big bare place along the tributarj^ where spar- 

 rows spent much of their time feeding on crab-grass and pigeon- 

 grass. Had the snow been a foot in depth all of this food supply and 

 much of the ragweed would have been rendered unavailable, in which 

 case it seems probable that the birds would, for a time at least, have 

 been obliged to take ragweed akenes from the plants, and perhaps, 

 like the snowflake (see p. 53), to resort to the seeds of amaranth and 

 lamb's-quarters, which appeared to be less palatable to them. 



The snow afforded very useful records of the actions of the spar- 

 rows. A few footprints far out in the middle of the ragweed field and 

 man}' in the weed}' garden above showed where the birds had been 

 feeding. In many places much chaffj^ debris gave additional evidence. 

 It appeared more frequently under plants of lamb's-quarters than 

 under those of the more abundant amaranth, showing the birds' pref- 

 erence for the former species; and in most instances bending plants 

 just grazing the ground had been resorted to, while sometimes the 

 birds had apparently been feeding from the stalks. Similar debris, 

 consisting of parts of flowers and broken shells of akenes, were found 

 under many ragweed iDlants. It might be supposed that weed seed 

 destruction by mice would be of more value than that by sparrows, 

 but the records left in the snow did not justify any such conchision. 

 Xot only were mice tracks extremel}^ few couij^ared Avith those of the 

 birds, but no evidence appeared of the eating of weed seeds by the 

 few mice that had been in the fields. One track tliat I carefully 

 inspected ]3assed directly through the ragweed in the wheat stubble, 

 but nowhere could I find any indications that the mouse had eaten 

 seeds of any kind. 



Some notes were made of the destruction of ragweed akenes. In 

 the snow beneath a ragweed 3^ feet high a song sparrow was feeding. 

 Subsequent examination showed about 50 imprints of its feet, 3 whole 

 akenes, and the broken pieces of the shells of about 20 more, together 

 with some of the debris of floral parts. On another day a hundred 

 juncos, white-throats, and song sparrows had been feeding busil}' for 

 half an hour in a patch of ragweed, and a few minutes' careful inspec- 

 tion of the ground disclosed only 6 whole akenes among a hundred 

 empt}' half akenes. At anotlier time a dozen fox sparrows were busilj- 

 scratching on the ground tinder a patch of giant ragweed and picking 

 up the large akenes. Here I found a large number of empty entire 

 akenes, at the smaller end of each of which was a rent through which 

 the meaty seed had probablj" been squeezed by pressure from the 

 birds' beaks. This method of manipulation seems to account for the 



