280 USEFUL BIRDS. 
to the weeds and take the seeds from the stalks; while Song 
Sparrows and Chipping Sparrows subsist largely on such 
seeds as they can find on, or reach from, the ground. Song 
Sparrows, Fox Sparrows, and Tree Sparrows are persistent 
scratchers, and dig out seed that has already fallen, and is 
buried by dead leaves, straw, earth, or other litter. Meadow 
Larks and Quail are useful in digging out seed from the 
ground, which, already buried, would otherwise spring up 
and grow. When the snow is deep, a large proportion of 
the seed-eaters must of necessity go south; but as soon as 
the ground is bare, they return to scratch and dig for their 
favorite food. Thus, as various species of differing habits 
and different haunts frequent the fields and their borders, and 
as the work of one supplements that of another, they exert 
together a constant repressive influence against the undue 
multiplication of weeds. The birds most actively employed 
in consuming weed seed in field and garden are Sparrows 
and Finches, Blackbirds, Cowbirds, Meadowlarks, Doves, 
and Quail. 
Dr. Judd found about five hundred and twenty-five birds 
eating weed seed from a single acre of truck land on a Mary- 
land farm, and estimated that they destroyed forty-six thou- 
sand seeds for their breakfast. About the last of April he 
attempted to learn what proportion of the weed seed on the 
place had been destroyed by birds during the fal] and winter. 
In a wheat field where ragweed was plentiful it was difficult 
to find half a dozen seeds in a fifteen-minute search. Ina 
growth of pigeon grass the examination of an area where 
there had been hundreds of seeds the year before would 
sometimes fail to disclose one ; and in some crab grass in the 
same field not one seed out of a thousand was left. 
The following list of seeds eaten by birds, taken from Dr. 
Judd’s interesting account of the “Birds of a Maryland 
Farm,” will serve to indicate the habits of the same birds in 
Massachusetts. It will be noted that most of the weeds in 
this list are common here, and some of them are very abun- 
dant, widespread, and troublesome. Chickweed seeds ma- 
ture very quickly, and purslane has to be dug up and carried 
out of the field, else it will persist in spite of the gardener. 
