Vi\ 



26 THE RELATION OF SPARROWS TO AaRICULTURE. 



English sparrows are also useful destroyers of weed seed. Thou- 

 sands ma}^ be seen every autumn on the lawns of the Department of 

 Agriculture feeding on crab-grass {Fanicum sanguinale) and yard- 

 grass {Eleusine indica), two weeds that crowd out good turf-making 

 grasses. They deserve further credit for their good work in destroy- 

 ing seed of the dandelion {Taraxacum taraxacum), which is a prolific 

 weed throughout the United States, especiallj^ in lawns and pastures, 

 and is also troublesome in cemeteries. In the public parks of Wash- 

 ington, D. C, the birds eat these seeds from the middle of March 

 until the middle of August, but chiefly in April and the first half of 

 May, when the lawns are full of dandelions. After the yellow bloom 

 has disappeared the head closes and a downy tuft appears at the 

 upper end; in this stage it is most frequently attacked bj^ the English 

 sparrow. The bird removes several long scales of the inner involucre 

 by a clean cut close to the receptacle or base of the head, thus expos- 

 ing the plumed seeds or akenes. It seizes a mouthful of these akenes, 

 lops off the plumes with its bill, and swallows the seeds. In many 

 cases, especially when hungry, it does not take the trouble to remove 

 the plumes. Generally it drops a score of seeds in tearing open a 

 head, and usually leaves a few clinging to the edge of the receptacle. 



The mutilation caused by the bird's beak can be detected until the 

 flower stalk dries and falls. One day I examined every stalk in a rec- 

 tangular space 6 feet 2 inches long by 3 feet 3 inches wide. Of the 

 413 stalks collected 358 showed unmistakable marks of the sparrow's 

 bill. On the next day 293 stalks were gathered from a circle 2 feet in 

 diameter on the other side of the lawn, and 275, or 93 percent, proved 

 to be mutilated. These and similar observations made with varying 

 results, covering several years, showed that at least three-fourths of 

 the dandelions that bloom in April and Ma}^ on the Department lawns 

 are mutilated by birds. In this destruction of dandelion seeds, the 

 English sparrow is aided bj^ several native birds, chiefly the song 

 sparrow, the chipping sparrow, and the white-throated sparrow. So 

 far as observed, the native birds usually do not cut open dandelions, 

 but simply feed on those left by the' English sparrow. The song spar- 

 row, however, is capable of getting out seeds alone: for one which 

 was kept in captivity manipulated dandelions in precisely the same 

 way as the English sparrow. 



Besides such lawn weeds as dandelions, crab-grass, and yard-grass, 

 several others, including pigeon-grass, knotweed, sedge, oxalis, and 

 chickweed, furnish food for sparrows. These plants are also trouble- 

 some in other places than lawns. Knotweed {Polygonum aviculare) 

 litters up paths and roads and grows in spots where turf is broken; 

 chickweed {Alsine media) occurs in plowed ground; and pigeon-grass 

 {Cha^tocloa glauca said C. viridis), which is considered one of the worst 

 of weeds in Minnesota, Is found among many crops. The seeds of 

 these weeds are eaten by the song sparrow, chipping sparrow, field 



