5 
0 
10 
10 
2ue 30 
AUGUST 
<0 30 
AUGUST 
20 30 
AUGUST 
CENTRAL 
9 I9 29 
SEPTEMBER 
9 IS) ee 
SEPTEMBER 
8) I95 29 
SEPTEMBER 
NUMBER OF BIRDS 
9 19 
OCTOBER 
NUMBER OF BIRDS 
9 19 
OCTOBER 
9 19 
OCTOBER 
29 
ZS) 
NUMBER OF BIRDS 
ae) 
CATBIRD (Dumetella carolinensis) 
(Fig. 10 and 11) 
Spring Migration 
So far as we know, catbird migration in Illinois is 
strictly nocturnal, spring and fall, but the only direct 
indication of the night flight in spring is a catbird killed 
with other night migrants at a television tower in Cham- 
paign County on the night cf May 28-29, 1963. 
Though there are a few winter records of catbirds in 
Illinois, the onset of the spring migration is conspicuous, 
and, in marked contrast to the early migration of the 
thrasher, shows little disparity in timing between the 
eornenn and the northern regions of the state (Pig 12)). 
There are a few March (26— 29) records of catbirds in 
Illinois (Blocher 1921, Schwager 1961, and others), and 
a few for early April (Beech: 1937, Cooke 1888, and 
others), but the early arrival dates recorded by most ob- 
servers fall between April 17 and May 1, with usually no 
more than a week between early arrivals in the south 
(April 17) and the north (April 24). Definite influxes 
are often noted, April 26-28, and May 1, and, quantita- 
tively, May is the month of catbird migration throughout 
the state (Fig. 12). 
As in the case of the thrasher, the catbird’s spring 
migration is particularly conspicuous in west-central TIli- 
nois, and least notable in the south (Wien 125 perhaps 
reflecting the large amount of concealing cover in the 
south, 
Nothing has been recorded on specific habitat require- 
ments or Dicterences if any, of migrating catbirds, nor are 
there published data on the destinations of transient cat- 
birds which pass through Illinois in spring. 
Distribution 
The general distribution of the catbird is shown in 
Fig. 10. The species probably nests in ev ery township in 
Lincs but published records are lacking for many 
counties (Fig. 13). 
Nesting Habitats and Populations 
Like the thrasher and mockingbird, the catbird is an 
edge species, but unlike them it is not nearly so tolerant 
of open spaces. Where the thrasher follows linear hedge 
plantings far out into the open cultivated fields, the cat- 
bird stays closer to more wooded areas. Still, on the basis 
of population density, edge shrubbery is the favorite 
habitat in most of northern and central Illinois (Table 3). 
Compared with thrashers, catbirds are much more toler- 
Fig. 12. — Nesting and migration seasons of the catbird in 
different regions of the state (see Fig. 1). Spring and fall graph 
lines show the highest daily counts of each 2 days (left hand 
scale). The lines are interrupted where data have not been 
collected. Encircled points represent censuses in the Illinois val- 
ley; other points represent east-central Illinois. Shaded block 
indicates length of the nesting season and level of adult nesting 
population. Egg-laying graph line (right hand scale) is based 
on repeated searches of roadside habitat throughout the nesting 
season. 
17 
