44 THE BELATIOI^ OF SPAREOWS TO AGRICULTURE. 



fact tkat giant ragweed seeds are rai^elv met Avith in sijarrows' stom- 

 ^aA^ks in a condition allowing identification. 



The grain of spreading panicum, being inclosed in sheaths, rattles 

 'out on the ground a little at a time throughout the winter, and thus 

 affords several species of sparrows a constant supply of food. Under 

 some of these plants Avhere a song sparrow had been hopping about 

 were found 12 grains, 6 of which proved to be empty, and under 

 others ^hefe a junco had been picking from the ground 5 out of 6 

 ■gMins found were empty. Sparrows appear to make a practice of 

 ?removMg the outer glumes of these grains before swallowing them, 

 whil^ those of the closely related crab-grass they seldom, if ever, 

 ^i^j-fi^jve. 



"Climbing false buckwheat rains down multitudes of its seeds, which 

 furnish an abundant and accessible supplj^ of food. In one sandy 

 l^lace thick with birds' tracks 52 of the seeds were found within a 

 radius of 2 feet, and all but 6 were empty^ Seeds of this plant are 

 shiny black and look like miniature beechnuts. In some cases one 

 of the three sides of the seed had been cut away, while in a much 

 greater number one of the three edges had been slit so as to leave 

 the empty seed shell entire and apparentl}^ uninjured. 



Part of the investigation on this farm was directed to the ques- 

 ttion of the dissemination of weed seeds b}- sparrows. One hundred and 

 ^fifty bird droi)pings were collected on each side of the brook, in the 

 ragweed field and in the weedj^ garden above. Examination of these 

 revealed but 7 uninjured seeds, one of crab-grass and 6 of amaranth, 

 certainh' a very insignificant proportion of the number consumed. 

 Ai¥(i it is not unlikelj^ that many of those thus voided uninjured are 

 ^^te^NVards taken a second time. Most of the dung consisted of the 

 ipn-b/erized remains of seeds, among which the most conspicuous were 

 ^'^fnall fragments of the akenes of ragweed. The finely comminuted 

 fragments of grass seeds Avere also very abundant. Among these 

 crab-grass occurred often, but the remains of pigeon-grass and spread- 

 ing panicum Avere positivel}' identified in onlj^ a few instances, proba- 

 bly because these two seeds are usuallj' hulled before they are 

 swalloAved (see p. 49). Amaranth and lamb's-quarters were easily 

 recognized by the characteristic texture of the coats of their seeds, 

 t-ij and in one instance b}' the emptj^ half shells of the seed. Bits of the 



shiny seeds of climbing false buckwheat f requentl}^ appeared in the 

 dung. The seeds of sedge and oxalis were comparatiA^ely rare, 



Winter obserA'ations on the District of Columbia farm brought 

 out several points which it is to be hoped may proA^e to be general. 

 Under favorable conditions the entire farm was Avorked over thor- 

 OUghl}^, cA^en at a season when birds require more or less accessible 

 f cover for protection. The sparrows took their food chiefly from the 



ground, in contrast to other species, which they thus supplement. 

 They appeared to have manipulated a large portion of the seeds left 



lil! 



s; 



