VEERY 
BREEDING RECORDS 
NESTS or YOUNG 
@ 1950- 
A 1900- 1949 
@ BEFORE 1900 
PAIRS or SINGING 
MALES (JUNE) 
O BEFORE 1900 
LIVIN IN H 
Se ae 
i —— iROQUOIS | 
ail al L__4 | 
FULTON MAZE We | Me LEAN Foro L_ rial 
eee ene a 
aaa os ) wl 
MASON 2 j vt 
AN | py Boe 
D 
A 1900 - 1949 
O 1950— 
7 i 
GREEN! j i ie 
est | alii rf - FumeenLsvo CLARK 
Me | | EFFINGHAM e ~ 
Se a ve Ra | pee? |cnawrond 
J. ie a 
Fig. 32.—Breeding records for the veery in Illinois. Singing male 
records are for June only. 
EASTERN BLUEBIRD (Sialia sialis) 
(Fig. 33 and 34) 
Spring Migration 
Though there are winter records of the bluebird for all 
regions of the state, and there is a sizable winter population 
vn southern Illinois, the migrations are conspicuous (Fig. 
35). The arrival dates most often given are around Febru- 
ary 20 for central Illinois and February 26 for the north. 
Arrivals in early February are apparently infrequent in 
both regions, but in some years bluebirds are common in 
central Illinois even in January (Musselman 19395 
1934-1935, and 1939), with groups of 30 or more being 
seen. 
The largest numbers of bluebirds in the spring have 
been recorded in March, and most of the migration proba- 
bly occurs in that month (Fig. 35). Zimmer (1922) ob- 
served “hundreds” near Rock Island on February 22, but 
noted that such aggregations were unusual. Populations in 
34 
the spring, as well as in other seasons, are highest in s¢ 
ern Illinois. 
Judging from the literature, the actual migration fl 
are rarely witnessed. Van Duzer (1922) and Schafer (l 
recorded diurnal flights, possibly migrations, in nort 
Illinois in late February and in March. We have 
definite diurnal migrations of bluebirds only in the 
(Fig. 35). There is no evidence of nocturnal migration, 
as nightcalls and television tower kills, as there is for | 
thrushes. 
Distribution 
The general distribution of the bluebird is shoy 
Fig. 34. The available breeding records for Illinois 
36) do not truly indicate the state distribution. Large 
in the state, especially intensively cultivated tracts, a 
sentially devoid of bluebirds. We estimated that 80 pe 
of the Illinois bluebird population was in the southern 
of the state (Graber & Graber 1963). 
Nesting Habitats and Populations 
The bluebird’s usual habitat includes woody vege 
in or adjacent to open fields, especially grasslands. 
treeless areas, even where nesting boxes have been p 
ed, are unlikely to have significant bluebird populz 
Large blocks of forest are also poor for the species (\ 
1964), though forest edge supports low population 
(Table 6). Residential habitat was more important 
bluebird prior to 1900, but the species has been dis 
by house sparrows and wrens (Nehrling 1880, Ri 
Lot 
The earliest successional stages of forest are nots! 
for bluebirds (Brewer 1958, and Karr 1968). In so 
Illinois Brewer found no bluebirds in strip-mined 
that had been abandoned about 14 years. | 
Bluebird habitats must have suitable nesting ¢i 
and the elimination of rail fences and wooden fenc 
has had a detrimental effect on the bluebird pop 
(Musselman 1940). Bluebirds seem to have underge 
transitions with regard to nesting sites in the pz 
years. Many of the early references (before 1900) 
nests in cavities of dead trees, stumps, or the dead br 
of cottonwoods (Populus), willows (Salix), or orchal 
(Gault, unpublished notes, 1876-1889; and Loue 
published notes, 1888). From dead trees to fence po 
4 natural transition, and most of the nests recordec 
literature were in fence posts until recent years, ©] 
since 1950, when most of the records have been fre 
boxes. Bluebird nesting box routes like tHtose establi 
Musselman (1944), and Varner (1964) are now Pp 
important to the species. There are no data on the 
bility of natural cavities. 
Bluebird nests in natural cavities have been rece 
low as 1% feet above ground and as high as 11 feet 
have undoubtedly been much higher nests, but m 
ords, even for natural sites, are below 7 feet. 
The only territory measurement we have seen 
