a ‘In other a the number of gregarious ‘birds to the observa- 
i tion: was less than three times the number of the more abundant solitary 
_ species ; but it follows from even this fact that for equally valid averages 
and generalizations the number of observations of gregarious birds 
way further examination of the details of our tabulated data concern- 
ing the most abundant gregarious birds leads us to believe that, with 
_ three exceptions, the variations in numbers at different times and in the 
several sections of the state are not unusual as compared with the range 
of corresponding variations in the numbers of the solitary species, and 
ACREAGE OF SURVEY 
AND NUMBERS OF MOST ABUNDANT GREGARIOUS BIRDS, 
SUMMERS or 1907 anv 1909 
1907 h 1909 Both years 
aay Acreage of Survey: 
Southern Illinois 2504.08 3023.11 5527.19 
Central Illinois 2017.09 3806.80 5823.88 
Northern Illinois 3172.39 4794.14 7966.53 
Totals : 7693.56 11624.05 19317.60 
<- 
_ Numbers of gregarious birds recorded: 
: English sparrow 1414 4239 5653 
Quail 91 224 315 
Mourning dove 461 670 1131 
Crow : 89 287 376 
Bobolink 119 631 750 
Cowbird 102 1845 1947 
Red-winged blackbird 347 573 920 
Bronzed grackle (crow-blackbird) 900 2455 3355 
Goldfinch 158 231 389 
< Totals | 3681 11155 14836 
Birds per square mile 306 614 492 
_ Numbers of above birds with three 2560 6224 8784 
doubtful species omitted 
Birds per square mile 213 | 343 | 291 
