EASTERN PHOEBE 
BREEDING RECORDS 
NESTS OR YOUNG ee) 
@ 1950 — 
A 1900-1949 
M@ BEFORE 1900 
PAIRS OR SINGING 
MALES (JUNE) 
O 1950 — 
A 1900 — 1949 
O BEFORE 1900 
Fig. 19. — Breeding records for the eastern phoebe in Illinois. 
Singing male records cover the period June 1 to early July. 
from the wintering grounds of the phoebe indicated that 
the phoebe population crashes represented actual 
mortality related to severe weather on the wintering 
grounds. Schafer (1921) recorded weather-induced 
mortality of phoebes in April. The phoebe population 
that crashed badly in parts of Illinois in 1957 appeared to 
be completely recovered by 1960 (T. E. Musselman, 
personal communication). Such crashes are a different 
phenomenon perhaps than any long-term changes that 
may be occurring. We need annual surveys of several 
nesting populations at locations throughout the state to 
determine if the phoebe population is increasing or 
decreasing over the years. 
Nesting Cycle 
Phoebes are already in song when they arrive in 
spring, but whether this is true of local breeding birds 
only, or also of transients passing through, we do not 
know. The song, phonetically, is slightly different than 
the sound of the name, and at different times sounds like 
“fee-burt” or “fee-bree” with emphasis on the first 
syllable. Phoebes also utter a rather soft but emphatic 
“chip,” apparently an alarm note heard often near the 
22 
nest, and a chattering call, the function of which we « 
not know. Silloway (unpublished notes, 1923) observed 
kind of flight song performance by this species on Ap 
12, 1923 in Peoria. | 
There are no published band returns to indicate t 
incidence of homing by phoebes to nest sites in Illino 
The same nest sites are often used over and over throu 
the years, but such use cannot necessarily be interpret 
as homing by the same birds either in different years, 
for different nestings within a year. Farwell (19) 
recorded phoebes nesting on her house in northeaste 
Illinois at least 15 years in succession. The same sites) 
rock overhangs are also re-used year after year (Bonn 
1917). One possible implication of these observations 
that good phoebe nesting sites are in short supply. 
We have found completed new nests as early as Mar 
23 in southern Illinois, and nest-building probably beg 
there at least as early as March 15. In central Illinois t 
earliest completed nest known to us was March 27. Int 
north, nest construction by phoebes must not begin mu 
before the first of April, but we have no firm observatic 
on this. There are no accurate measurements of the ti 
required for nest construction of early nests. We hi 
observed nests, both from an early stage of constructi 
and virtually completed, to go 5-11 days before the fi 
egg was laid. Several seemingly completed nests in 
regions of the state remained empty 7-9 days before | 
first egg was laid. Construction of complete new ne 
later in the season (second nestings) was faster, | 
shortest time being 7 days before the first egg was | 
(Fig. 22). One nest that was merely refurbished ) 
empty only 4 days before a new clutch was started, | 
more often the interval was 6-13 days (Fig. 22). 
Phoebe nests are durable and the structures often 
from one year to the next, but we know of no instanct 
which a year-old nest was used again without be 
essentially rebuilt. The nests are composed of mud, gr 
bark fiber, and moss, lined with hair, wool, and pl 
fibers (Silloway 1906; Sanborn & Goelitz 1915; Willi 
Loucks, unpublished notes). The structure is distinc 
and attractive (Fig. 23) with its covering of green m 
Phoebes occasionally use old nests of barn swall 
(Hirundo rustica), but add at least a little moss to 
structure (Fig. 24). The phoebe does not appeat 
compete directly with the swallow, but merely uses 
abandoned swallow nest. | 
Egg laying begins as early as March 28 in south 
Illinois, April 4 in the central region, and April 12 in 
north (Fig. 18). There are at least two conspicuous pe 
in egg laying in all regions of the state, and 
implication is that the phoebe attempts to raise at lk 
two broods. The two major peaks in egg production 0¢ 
about mid-April and late May in southern Illinois, « 
April and late May in central Illinois, and early Mayé 
early June in northern Illinois (Fig. 18). The egg-lay 
curves include data from re-nestings following ! 
failure, which tends to skew the main peaks and prod 
secondary peaks (Fig. 18). | 
Most phoebe nests in Illinois receive 5-egg clut 
