200-400 400-80 
miles 
ig. 17. — General distribution of the eastern phoebe. The outlined 
© may include large sections in which populations of species are 
or even absent because of the nature of the terrain and paucity of 
ble habitat. 
nbers in east-central Illinois between March 22 and 
In northern IIlinois there is evidence of a peak in the 
ebe migration in late March (Brownell 1916, Rogers 
4), but Swink [1965] called April the month of 
atest concentration of phoebes. In southern Illinois 
highest spring counts of phoebes came in mid-March 
early and late April. 
ribution 
The eastern phoebe has an extensive breeding range 
astern and central North America, and a winter 
3¢ in southern United States and eastern Mexico (Fig. 
In Illinois the phoebe probably nests in every county, 
igh there are a number of counties in which breeding 
t still be verified (Fig. 19). In addition to the records 
ted on the map, there are June records for recent 
S in Jersey and Madison counties (personal 
munication from Dick Anderson, no specific 
lities given), 
ting Habitats and Populations 
: 
3rewer (in Ridgway 1889) felt that phoebes were 
acted to two kinds of places — the vicinity of 
lings and the vicinity of water. An important factor 
omitted from his statement is the need for some kind of 
woody cover, something more than just a hedgerow. We 
have never found nesting phoebes more than a few yards 
from substantial woody cover, even where there were 
excellent nesting sites and good streams. This means that 
there are sizable (and expanding) tracts of agricultural 
land without nesting phoebes. 
Gates (1911) considered the species to be common in 
bottomland forest. Robertson (1941, 1942a, 1944a) 
found one pair of phoebes nesting each year on about 64 
acres of “swampy prairie” in Sangamon County. This 
“prairie” habitat did, however, contain some woody 
cover. Fawks (1937) found one pair in 15 acres of upland 
woods near Rock Island. In Piatt County Fawver (19476) 
found two pairs of phoebes per 100 acres in floodplain 
forest, and determined the size of one territory to be 0.7 
acre. 
Because of the phoebe’s requirement of a shelf or wall 
of some sort for nest placement, phoebe territories are 
often not contiguous. Usually there is but one pair (if any) 
nesting at a bridge or a farmyard, for example, and the 
spacing of phoebes may thus often be more dependent 
upon the spacing of bridges than upon the size of the 
territory of the bird. This spacing is not true however of 
rocky bluff areas, where numerous nest sites may be 
available through miles of continuous forest habitat. In 
such situations phoebes may be closely spaced. At One 
Horse Gap in Pope County, where there are extensive 
rock bluffs in forest areas (Fig. 20), we found six 
contemporaneous nests in an area of about 30 acres. The 
two most closely spaced of these nests were about 270 feet 
apart. This area had a particularly dense population of 
phoebes. Other rock areas we visited in southern IIlinois 
had only one or two pairs in 30 acres. Some large areas 
(100 acres or more) of suitable-looking habitat were 
without phoebes. Phoebe habitat has never been precisely 
defined, and we cannot account for the variation in 
populations. We suspect that there may be a relationship 
between the humidity in rock canyons and phoebe 
populations, but this suspicion needs testing. 
Away from rock bluff areas, the usual nesting places 
are bridges, culverts, and buildings. Phoebes nest both on 
and inside buildings. They appear to choose nest sites 
offering some measure of overhead shelter, and nests on 
rock walls are nearly always placed under an overhang 
(Fig. 21). As the phoebe’s nest contains a large amount of 
mud, protection from rain may be essential to keep the 
nest from washing away. Some naturalists feared that 
phoebes might suffer a great loss of nest sites as bridges 
with iron I-beam girders gave way to cement culverts 
(Ford 1956), but phoebes adapted to the cement 
structures successfully (Blocher 1933). 
Phoebe nests in natural rock settings vary in height 
from about 214% feet to more than 20 feet, but are 
generally under 6 feet. Nests on buildings are usually 
about 7-9 feet high, the height of porch braces. The 
heights of bridge and culvert nests are similarly incidental 
to the birds’ choosing. 
Swink (1960) observed that hawthorn (Crataegus), 
19 
