)17), is saddled on a horizontal branch and is a very 
eresting structure (Fig. 41). It is composed of weed 
ms, dry grasses, hair, and cobwebs, and covered with 
hens (Loucks unpublished notes, and Sanborn & 
elitz 1915). At a distance the nest resembles a knot on 
» branch. The time required for nest construction has 
t been recorded. 
_Egg laying by wood pewees begins at least as early as 
\y 23 in northern Illinois and May 17 in central Illinois, 
1 probably earlier in the south even though present 
ords do not show it (Fig. 43). Egg laying has been 
orded at least as late as August 12 in central Illinois, 
ing the wood pewee an egg-laying season about as long 
that of the phoebe, but much later (Fig. 18 and 43). 
‘do not know if the wood pewee is double brooded. 
Egg data on 35 Illinois nests (north-13, central-17, 
th-5) indicate that most nests (69 percent) receive 3 
s (Fig. 45). Other clutch sizes were 4 eggs (17 percent), 
ggs (11 percent), and a few nests (3 percent) with 5 
s. These data represent mainly old museum records or 
literature and may not constitute a truly 
resentative sample, especially for recent years. The 
e requirements for incubation and nestling life have 
been studied in IIlinois. 
Nice (1961) studied parental care of nestlings at a 
od pewee nest in northern Ilinois. She observed that 
y one parent — probably the female — brooded the 
ng, but both adults shared, about equally, the task of 
ling the young. When the nestlings were about 12-13 
s old, the parents brought food to the nest at rates 
ying from 14 to 55 times per hour (average: 29). The 
ling rates were lower (average: 16 times per hour) 
‘n the nestlings were younger (5-11 days old). Nice 
)1) found that most of the nestlings’ food was minute, 
Fig. 45. — Eastern wood pewee nest and eggs. 
but there were a few relatively large items such as a 
cabbage butterfly, a damsel fly, and a crane fly. 
Nice (1961) also observed that the parent wood 
pewees were very belligerent in the vicinity of the nest, 
driving away gray squirrels (Sciwrus carolinensis) and 
birds larger than themselves as well as other pewees. They 
were particularly aggressive toward squirrels, grackles 
(Quescalus quzscula), blue jays, and robins (Turdus 
migratorius), but tolerant of the smaller species such as 
house sparrows and red-eyed vireos (Vireo olivaceus ). In 
central Illinois Fawver (19476) saw wood pewee conflicts 
with cardinals (Cardznales cardinalis), and black-capped 
chickadees (Parus atricapillus). In the south we have seen 
wood pewees vigorously chasing Acadian flycatchers. 
There have been no measurements of nesting success or 
productivity of pewees, and there are no data on causes of 
nest failures. Neither is it known whether wood pewees 
attempt to rear more than one brood. The wood pewee 
has been recorded as a victim of cowbird parasitism in 
Illinois (Green 1917, Friedmann 1963), but the incidence 
and effect of parasitism is unknown for any Illinois 
population. 
Fall Migration 
The eastern wood pewee has been an uncommon 
victim in the kills at television towers. The four fall 
specimens, which have been retrieved from central 
Illinois towers, were killed between September 17 and 
October 1, indicating that active migration was in 
progress at least during that period. 
Our highest fall counts, as well as those of Swink 
(1960) and Dillon (1968), for the wood pewee (Fig. 43) 
came in August, and we believe that the fall migration of 
the pewee is well underway at least by mid-August, a time 
when some nests are still being initiated (Fig. 43). 
An adult wood pewee found dead just south of Illinois 
in Kentucky was in extensive body molt on August 2, and 
in Illinois on August 20 we have seen some wood pewees 
in badly worn plumage and others apparently in fresh 
plumage. A pewee killed at a tower in central Illinois on 
the night of September 16-17 was almost through the 
post-juvenile molt with only a few pin feathers on its 
head. 
Illinois observers usually record the last wood pewees 
of the fall in late September or October (Fig. 43, DuMont 
1947, Blake 1941, Brodkorb 19266, Kleen & Bush 
1972a), and a pewee at Springfield on November 8, 1972 
observed by H. D. Bohlen (Kleen & Bush 1973) was 
exceptionally late. 
Our fall counts of wood pewees seem low (Fig. 43) 
when we consider that the fall numbers should show the 
productivity of the preceding nesting season. The ratios 
of our spring to fall counts were: 1.0 in the spring to 2.0 
in the fall (north), 1.0 to 1.0 (central), and 1.5 to 1.0 
(south). The low fall counts, which we have seen in other 
flycatchers also, are perhaps related to the fact that 
nonsinging fall birds are less conspicuous than the more 
vociferous spring birds, but we cannot explain the 
commonly observed pattern of a progressively descending 
ratio of fall birds from north to south. 
51 
