Taste 4. — Plants used by catbirds as nest sites. 
Percent of Total Nests 
Species North Central South 
(121 Nests) (31 Nests) (27 Nests) 
Grape (Vithspyhn eee eee 21 23 
Dogwood (Cornus racemosa), C. 
qugosa and G.$Dataq- seer 17 3 4(ficrida) 
Sassafras (Sassafras albidum)......  .. on 26 
Hawthorn (Crataegus sp.)....... 7 6 ti 
Virginia creeper (Parthenocissus 
QUINQUesOlG) ecw teen ee 3 at 18 
(Biker (OUMUS Soo) onc eck eoacoco: 3 10 4(alata) 
Gooseberry (Ribes sp.)). 3-2 12 6 24 
Crabapple and apple (Malus sp.) 1 10 + 
Multiflora rose (Rosa multiflora) 
= ROSA SD aon ae eee ee 6 5 4 
Osage orange (Maclura pomifera).. 1 13 
\WNbUl Koni (BAER SO) os oo oo bcc ace 2 10 a 
Red cedar (Juniperus virginiana). . 2 di 
Black locust (Robinia pseudoacacia ) 1 3 4 
Dkiren CHMWS BO sone. csa05cce0. Po oe 7 
Box-elder (Acer negundo)........ 2 8 
Oak (Quercus spo) jan*. ae 4 
Soaee (CUS RD Ino ap ode ok 00 ce 4 
1 
1 
Bramble (Rubus sp.)..........- 5) 
INS (SE AOUIS GOs). o a cp oa se snk 1 
4 
4 
oe 
Honeysuckle (Lonicera sp.).....- 
Mulberry (Morus sp.)........-- 
River birch (Betula nigra)....... 
LilaG (Syringe spi) eee eee 
Golden-bell (Forsythia sp.)...... 
Elderberry (Sambucus canadensis). . 
62 OO OO: 
Norway spruce (Picea abies)... . . 
Hazel (Corylus americana)........ 
Spirea (Spiraea'sp.) ti a ao ase 
New (lacus spe) sree are 
PR RR ND - 
from mid-September to mid-October, with most falling 
in late September and early October. The catbird migra- 
tion is almost over by October 10, but there are a few 
records for November and even fewer on into the winter 
(hig st 2) 
Our censuses indicate a definite increase in catbirds in 
August over the summer population (Fig. 12), and we 
judge that the southward movement begins by at least 
mid-August in northern and central [linois. Our data 
show many more migrating catbirds in northern Illinois 
than in the south, with central Illinois intermediate in 
volume. 
Only in northern Illinois did the total fall count ex- 
ceed the spring count of catbirds. The low fall counts 
are enigmatic, for we would expect a population increase 
during the summer, and, hence, a high fall count. There 
are several possible explanations of the paradox. Among 
other things, the census method may be faulty, or the be- 
havior of the birds so different in fall that they go unde- 
tected. The gradation in the fall population from high 
in the north to low in the south suggests the possibility 
that many of the northern catbirds are migrating east- 
20 
Tasie 5.— Clutch sizes of catbirds in northern and cen- 
tral Illinois. 
Percent of Nests 
Total . 
th Clutch if 
Months, Years Number aes Oe eee 
of Nests ute 5 At 3 2 
Eggs Eggs Eggs Eggs 
May-June, 1967-1968 38 3.7 5 58 37 
July-Aug., 1967-1968 9 3.1 22 67 
ward as well as southward (see below under Specimen 
Data). 
The only fall recovery of an Illinois-banded cathind 
that we know of was reported by Laskey (1961). The 
bird, banded at Lisle, Illinois, May 19, 1960, by Dr. 
Edmund Jurica, was killed September 28, 1960, at a 
television tower at Nashville, Tennessee, southeast of the 
place of banding. 
Catbirds are common victims at television towers and 
other high structures during night migration. Even long 
ago Gastman (1886) recorded catbirds among the casual- 
ties at an electric light tower in late September at Decatur, 
Cathbirds comprised 3 percent of about 6,500 bird speci 
mens picked up at television towers in central Illinois be 
tween 1955 and 1967. This is about 30 times the kill ol 
thrashers in the same period, notwithstanding the fact 
that more thrashers than catbirds were seen during the 
fall censuses when the kills occurred. The highest kills ol 
catbirds occurred September 20-30 (Fig. 15). This was 
also the period of high peaks in our fall ccunts (Fig. 12). 
There are no data on location of the wintering 
grounds of Illinois catbirds. 
Winter Records 
The distribution of winter records of catbirds in Illi 
nois is shown in Fig. 16. There were very few winte 
records prior to 1950, but more have been found in re 
cent years as participation in the Christmas counts ha: 
increased. The frequency of occurrence during the pas 
25 years (1944-1968) has been only | percent in thi 
north (192 censuses) and south (124 censuses) zones 0 
the state and 3 percent in central Ilinois (140 censuses) 
How often catbirds actually remain through the winte 
in Illinois is unknown. Nor is it known how well the’ 
survive. 
Food Habits 
There is little information on the foods of catbird 
in Illinois other than the studies of Forbes (1880) base 
on specimens collected in northern and central Illinoi 
(Fig. 17). Forbes found that in May catbirds fed almos 
entirely on animal matter. Ants, caterpillars (Lepidop 
tera), crane flies (Tipulidae), ground beetles (Carabi 
dae), and spiders were quite regularly important consti 
tuents of the diet, but beginning in June, fruits we? 
increasingly important on into the summer (Fig. 17) 
