758 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



respectively. Six males taken by a field party from the University 

 of Minnesota in Clay County, Minn., in July 1961, had an average 

 weight of 18.6 grams, an average length of 135.6 millimeters, and an 

 average wingspread of 236.3 mUHmeters. 



Food. — The food of this species varies with the seasons. During 

 their winter sojourn in Mexico, weed seeds must form the main diet, 

 as they do in Texas. Mrs. Harold L. Williams writes me from 

 Midland, Tex.: "They are usually seen feeding on the ground in 

 fields of maize stubble. 'Maize,' or *milo,' in Texas refers to the 

 several varieties of grain sorghum grown as food for cattle. Baird's 

 sparrows have also been seen in patches of tall 'careless weeds,' 

 (Amaranthus sp.)." 



When Richard and Jean Graber encountered Baird's migrants near 

 Norman, Okla., in April 1953, some of the common plants in the field 

 where the birds occurred were: red three-awn (Aristida), little blue- 

 stem (Andropogon scoparius), brome (Bromus), six weeks' fescue 

 (Festuca octqfiora), yellow sweet clover (Melilotus officinalis), peren- 

 nial ragweed (Ambrosia psilostachya) , plantain {Plantago virginica), 

 blazing-star (Liatris), and evening primrose (Oenothera laciniata). 



Stuart Criddle writes me that: "The food of our Manitoban 

 sparrows changes sharply with the seasons. In the spring and fall 

 a great variety of seeds are eaten. These include: "Lamb's quarters 

 (Chenopodium album), Russian pigweed (Axyris amaranthoides) , 

 Russian thistle (Salsola kali), redroot pigweed (Amaranthus retro- 

 fiexus), false flax (Camelina microcarpa), tumbling mustard (Sisym- 

 brium altissimum), and green foxtail (Seraris viridis). This last-named 

 plant probably produces more food for the sparrows, longspurs, and 

 horned larks than any other weed." 



In summer, adult Baird's sparrows take spiders and numerous 

 varieties of insects and their larvae, and Cartwright et al. (1937) 

 show that these are the only food they give the young. Part of their 

 account follows: 



Our astonishment was great when we found young birds but two days old 

 being fed with unmodified grasshoppers. * * * Later, specimens of the grass- 

 hoppers present in the area were collected and submitted to Mr. Norman Criddle, 

 together with a moth and a cricket which were occasionally fed to the young. 

 We are indebted to Mr. Criddle for the following identifications: Orthoptera: 

 Chorthippus curtipennis Harr; Camnula pellucida Scud; Arphia pseudoneiiana 

 Thoms; Melanoplus dawsoni Scud; Melanoplus bivitiatus Say; Gryllus assimilis 

 Fab; Lepidoptera: Caenurgia erechtea Cram. 



Mr. Criddle points out that C. pellucida and M. bivittatus are pests of economic 

 importance. 



It is of interest to note that, while the young are fed almost entirely on large 

 grasshoppers, the food of adults in summer consists mainly of smaller insects. 

 The examination of the stomachs of four adults reveals only one small grass- 

 hopper nymph, but many small items such as leaf-hoppers, spiders, moths and 



