Fig. 27.—General distribution of the gray- 
cheeked thrush. 
collections) taken June 10 in southern Illinois must be con- 
sidered accidental. 
Spring numbers of gray-cheeked thrushes show a fairly 
uniform distribution through the state (Fig. 28), but phe- 
nomenal aggregations have been recorded in northeastern 
Illinois especially (Eifrig 1913, and Lewis 1923). Eifrig 
saw hundreds of gray cheeks in late May and felt that Du 
Page County was on a major “highway” for the species. 
Gray-cheeked thrushes sing as they pass through Illi- 
nois, but their song is much more subdued than the song of 
Swainson’s thrushes, and in general gray cheeks appear to 
be less vociferous. Nelson (1876-1877) noticed that gray- 
cheeked thrushes are more likely to sing at times of misty 
weather. We translate the call notes most often given as 
“peeeur” and “peee-oort,’” but occasionally gray cheeks 
also call ‘‘whit,’? a note much more characteristic of the 
Swainson’s thrush. We cannot differentiate, with certainty, 
28 
the migration calls of gray cheeks and veeries. Th 
piercing calls are uttered both at night, during activ 
ration, and during the day, when the birds are groun 
There are no published band recoveries of Illinoi 
sients, but telemetered gray cheeks have tended to fly 
ly east of north from Champaign (Cochran et al. 196 
Fall Migration 
In nearly 50 years of observations, Benjamin ( 
earliest fall record for the gray cheek in northeaste 
nois was August 11, an abnormal arrival date. Usui 
first gray cheeks do not reach northern Illinois unt 
August 20, and most of the population has passed 
Illinois by the end of September, though a few! 
found almost every year until mid-October (Fig. 
extreme southern Illinois the species is consistently ' 
mon in fall. We have no records of more than one s 
