pulations in urban habitat, but there are no good data 
show the effect. Red-headed woodpeckers (Melanerpes 
ythrocephalus) have also dominated cresteds in 
mpetition for a nesting cavity (Ridgway 1915). On the 
ver hand, at an established nest in northern Illinois, a 
ested flycatcher fearlessly attacked red-headed 
odpeckers, blue jays (Cyanocitta cristata), and 
low-shafted flickers (Colaptes auratus) (Pattee 1931): 
ese few observations on competition for nest sites, etc. 
olve urban habitat. There are no data on the question 
competition in natural habitats. 
Musselman (1932) noted crested flycatchers taking 
session of nest boxes in central Illinois as early as April 
and Gault (unpublished notes, 1899) witnessed nest 
Iding in the north as early as May 18. There is little 
ormation on the season of egg laying. In central 
nois, the region for which there is the most 
ormation, egg laying extends from at least May 17 to 
y 12 (Fig. 14). 
Data on 25 clutches of crested flycatcher eggs from 
tral and northern Illinois showed the following 
ribution of clutch size: 7 eggs — 4 percent, 6 eggs — 
percent, 5 eggs — 36 percent, 4 eggs — 24 percent, 
| 3 eggs — 4 percent. These data may not be truly 
resentative of the species, as they are nearly all from 
TABLE 2. — Breeding populations of great crested flycatchers 
old oological collections and old literature. There is one 
record of cowbird parasitism of the crested flycatcher in 
Illinois (Blocher 1936). 
Nesting success, productivity, causes of nest failure, 
and, in general, the basic biology of the crested flycatcher 
in Illinois, are unknown for any population. 
Fall Migration 
The fall migration of the crested flycatcher is 
unspectacular to the field observer (Fig. 14). As with a 
number of other species, the crested population seems to 
slip away almost unnoticed. In northern and central 
Illinois we have seen cresteds that were nearly through the 
postnuptial or postjuvenal molt as early as August 18, 
and others apparently in fresh plumage on August 26. 
The fall migration probably begins at least as early as 
mid-August. 
Most observers record the last cresteds of the year in 
mid- or late September (Fig. 14), with little variation 
from region to region (Clark & Nice 1950, Dillon 1968, 
Schafer 1917-1918, Cooke 1888). Our peak fall counts 
occurred in August and September, and we have no 
Illinois records of the crested later than October 1. The 
fall counts are very low, particularly in the south, but 
they are actually more uniform than the spring counts, 
in various Illinois habitats. 
OO —— 
Habitat Acres 7 ead Years pa ean Reference 
irban residential 8 50 1916 Nest Richland (S) Cooke 1916, Ridgway 1915 
in residential 98 5 1958 Strip South Graber & Graber 1963 
maple forest 55 7-40 (avg 20) 1927-1972 Nest Champaign(C) Kendeigh 1944, Kendeigh & 
Stubbs 1951 
maple forest 64 19 1947 Nest Champaign (C) Johnston 1947 
le-elm forest 63 22 1950 Nest McLean (C) Calef 1953 
63 19 1951 McLean (C) 
nd second growth hardwoods 56 32 1941 Nest Sangamon (C) Robertson 1941 
56 21 1942 Sangamon (C) Robertson 19426 
56 ai 1944 Sangamon (C) Robertson 19446 
46 14 1948 Sangamon (C) Robertson & Snyder 1948 
ad growth hardwoods 15 27 1937-1938 Nest Rock Island(N) Fawks 1937, 1938 
ed bottomland woods 93 24 1955 Nest Macon (C) Chaniot & Kirby 1955 
n floodplain forest 77 12 1948 Nest Sangamon (C) Snyder et al. 1948 
lplain forest 50 20 1946 Nest Piatt (C) Fawver 19476 
nd oak-hickory forest 24 4 1967 Nest Hancock (C) Franks & Martin 1967 
) oak forest interior 40 4 1968 Nest Mason (C) Johnson 1970 
odified woodland 27 15 1937 Nest Lake (N) Beecher 1942 
fied woodland (human housing) 28 7 1937 Nest Lake (N) Beecher 1942 
t (all types including edge) 98 3 1958 Strip North Graber & Graber 1963 
97 8 1957 Central 
117 5 1958 Central 
20 20 1907 South 
40 28 1909 South 
174 5 1957 South 
166 1 1958 South 
shrub 21 14 1966 Nest Vermilion (C) Karr 1968 
) areas 7, ll 1907 Strip South Graber & Graber 1963 
39 2 1909 South 
67 3 1957 South 
ard 19 5 1907 Strip South Graber & Graber 1963 
26 4 1909 South 
a ere ee ee Hee ee IS ee ee 
All figures were converted to read birds per 100 acres (territorial males or nests X 2) 
15 
