| | | <——— Empidonax 
‘| 
| | CENTRAL 
20 30 
AUG 
SOUTH 
DEE 
OCT 
I9 
lentified Empidonax flycatchers; solid line represents counts of 
itified Acadian flycatchers. 
ACADIAN FLYCATCHER 
BREEDING RECORDS 
NESTS OR YOUNG 
AE] ony 
g Me RY) LAKE 
@ 1950 — at “¢- 
A 1900-1949 et cl ae 
|JouAxae| 
™@ BEFORE 1900 at | 
if Be ty 71 
5 — canon eee 
PAIRS OR SINGING ie Aiea 
MALES (JUNE) [ eee 
Luvin GSTO els oe 
O 1950 — Pay | rey | 
iMcOONOUGH € ORO, =} 
IX 1900 = 1949 nancod| Le ¢ 
mala T Tp 709! 
a CEM T / CHal VERMILION: 
Jas POG lg gay 
Be an 
Y Ams = ieee 
N IN DOUGLAS ; 
Lelio ss ena) 
ee | | 
UO BEFORE 1900 
Scale 
0 i] 10 20 30 40 SOMiles 
SSS 
Fig. 31. — Breeding records for the Acadian flycatcher in IIlinois. 
Singing male records cover the period June 1 to early July. 
per 100 acres in different years, with adjacent upland 
forest populations as high as 24 Acadians per 100 acres 
(Fawver 19476, Holmes 1950, Weise 1951). In excellent 
bottomland forest habitat in southern Illinois we have 
recorded Acadian populations as high as 32 birds per 100 
acres (Table 5). 
Four territories of Acadian flycatchers measured in 
floodplain forest in Piatt County varied in size from about 
1.7 acres to 4.3 acres, averaging about 2.6 acres (Allison 
1947, Fawver 19475). 
The Acadian flycatcher has undergone some notable 
population changes in the past century. Gault’s 
unpublished notes of 1884-1927 indicate that the species 
was fairly common in DuPage and Cook counties. 
Woodruff (1907) also considered it not uncommon in 
northeastern Illinois. Ford (1956) called the Acadian an 
uncommon summer resident in the Chicago region. 
Judging from the frequency of reports of Acadians in 
literature, a population decline of the species took place 
in northern Illinois in the 1930’s. In 1968, with extensive 
fieldwork in Whiteside, Carroll, and adjacent counties, 
we did not record a single Acadian flycatcher. The 
species may always have been rare (or absent) in 
northwestern Illinois, as up to 1904 Burtis Wilson had 
33 
