310 AGRICULTURE. 



ously considers them his enemies. To this 

 class belong the crow, the blackbird, and many 

 species of hawks and owls.* Examination of 

 the stomach contents of many of these birds has 

 proven that they are more beneficial than harm- 

 ful, destroying many insects as well as injurious 

 rodents, such as mice and gophers. 



Again, some birds eat more or less weed seed 

 throughout the year, even when insects are 

 abundant. But their work practically extends 

 from early autumn until late spring. During 

 cold weather most of the birds about the farm 

 feed extensively upon seeds. It is not uncom- 

 mon for a crow blackbird to eat from thirty to 

 forty seeds of smartweed or bindweed, or a 

 field-sparrow one hundred seeds of crab-grass, 

 at a single meal. In the stomach of a Nuttall's 

 sparrow were found three hundred seeds of 

 amaranth, and in that of another three hundred 

 seeds of lamb's-quarters ; a tree-sparrow had 

 consumed seven hundred seeds of pigeon-grass, 

 while a snowflake from Shrewsbury, Mass., 

 which had been breakfasting in a garden in 

 February, had picked up one thousand seeds of 

 pigweed. 



Among the weeds which are troublesome in 

 fields, especially among hoed crops, may be 

 mentioned ragweed (Ambrosia artemisicefolia}, 

 several species of the genus Polygonum, includ- 



* Year-book, 1897. 



