es ee ey 
She fee 
$s 3 
. eva : ~ 
ae 
rd Ca, 5 ‘g pest 
4 
Vj 
\ So ee 4 m h rae 
Loggerhead Shrike |». 
‘ : oe a ee ; a 
\ c 
ty - } 4, 
Fs 
\ 
a : 
\ 
ig ai 
a ir 
ak = 
ee = 
we wy. 
SSN —— 
== WINTER Seay] ae 
B.. ra ves 
c + + + Se eee Oh 
Pos ae 
2 : 
203 400 400 800 = 
—a ax 
Fig. 3. — General distribution of the loggerhead shrike. 
ions of the state in all seasons of the year, there is a 
ectable spring influx of shrikes, even in southern IIli- 
, which has a notable winter population (Fig. 4). 
Cooke (1888) believed the shrike migration began as 
ly as January 31 in the St. Louis area, though the 
k did not arrive until March 22. Our counts of shrikes 
southern Illinois show a marked increase after Feb- 
ty 20, and a peak in late March (Fig. 4). 
Shrikes were extirpated in central and northern IIli- 
s before our censuses of the migration were made, but 
"r references indicate a spring migration season similar 
hat in the south. In central Illinois the earliest arrivals 
€ been noted in mid- and late February (DuMont 
7, Musselman 1934-1935, 1938), with more pro- 
need influxes throughout March, and largest numbers 
t March 20 (Ekblaw & Ekblaw 1916, Ekblaw 1917, 
th 1917). In the north, February records are excep- 
al, and there is almost no indication of the migration 
il March (Bartel & Reuss 1932, Gault 1901). Ford 
l. (1934) calculated the average arrival date of the 
erhead shrike to the Chicago area to be March 18, 
Ferry (1908) noted that the species became common 
March 23. 
tribution 
The general distribution of the loggerhead shrike is 
vn in Fig. 3. The Illinois distribution was never ac- 
curately known, and the absence of records in a number 
of counties (Fig. 5) may be more related to inadequate 
exploration than to an actual absence of shrikes, We are 
certain, however, based on extensive searches in the past 
few years, that most of the population in northern and 
central Illinois has disappeared since 1965. In this vast 
area there are probably only a few scattered pairs left. 
We found only one nest (Mercer County) between 1968 
and 1972 after searching large areas of central and 
northern Illinois. What is left of the state population 
today is nearly all south of the latitude of Pike and 
Cumberland counties (Fig. 5). 
Nesting Habitats and Populations 
Robertson (1942) recorded a shrike nest in oak- 
hickory forest, but this is exceptional habitat for the 
species. Most of the nests in Illinois have been recorded 
in roadside hedges in open country. Ridgway (1887) 
said the shrike liked open areas with thorn trees, such 
as the honey locust and wild crabapple. 
Most of the nests found in central and northern IIli- 
nois have been in osage orange. In the south, nest sites 
have been much more diversified, though red cedar, rose, 
and osage orange seemed most favored (Table 1). Ridg- 
way (1887), referring to the south, and Gates (1911) 
in central Ilinois both mentioned the shrike as an or- 
chard bird. 
There are also numerous references in the literature 
to the nesting of shrikes in hedges, but there has been no 
systematic study as to what truly constitutes shrike habi- 
tat, 1.e., foraging as well as nesting habitat requirements. 
Scattered young osage orange trees along the margins of 
cultivated fields would seem to be loggerhead shrike 
habitat in its simplest form, but just what and how much 
of such a combination the shrike uses is unknown. 
There have been no measurements of shrike terri- 
tories in Illinois. 
Reports that the shrike population in northern and 
central [linois was declining began at least as early as 
1910 (Hess 1910, Eifrig 1919, Work 1933, DuMont 1947 
and 1947a, Mayfield 1949, Mumford 1960). The reason 
consistently postulated for the decline was the elimination 
of hedgerows (Hess 1910, Eifrig 1937, Blocher 1933, Nice 
1945, Mayfield 1949). Osage hedges became a prominent 
feature of the Illinois landscape after 1840, partly due to 
the vigorous promotion of the plant as a living fence by 
Jonathan Baldwin Turner (Harkin 1962). With the ad- 
vent of barbed wire about 1880, removal of the hedges 
began, and though there are still many fine osage hedges 
left in the state, they are rapidly being eliminated. There 
are no records to show what plants were used by nest- 
ing shrikes before osage became so prominent, but there 
are many observations which show that shrikes definitely 
adopted the new hedges for nesting (op. cit.). 
The effect of the osage promotion on the shrike popu- 
lation cannot be assessed for lack of shrike population 
data. Kennicott (1853-1854) called the loggerhead shrike 
an abundant species in Illinois, but such a statement 
2 
