TaBLe 5. — Breeding populations of Acadian flycatchers in various I}linois habitats. 
Birds Per 
ee ————_—. t—~—s 
Habitat Acres 100 hee Years 
Virgin floodplain forest 77 18 1948 
Floodplain forest 50 8 1946 
Bottomland woods 15 46 1968 
Bottomland woods 13 32 1973 
10 30 
Floodplain forest 16 6 1973 
20 10 
21 14 
Oak-maple forest 55 2 1948 
55 4 1949 
55 4 1950 
55 4 1953 
55 4 1956 
55 4 1958 
55 ae 1964 
55 4 1966 
55 4 1970 
Forest (all types including edge) 79 1 1957 
97 5 
174 17 
166 12 1958 
@ All figures were converted to read birds per 100 acres (number of territorial m 
b Less than one. 
recorded only one Acadian flycatcher in the Davenport, 
Iowa area (Hodges 1954). The Acadian population may 
now be increasing in the north. Petersen (1964) reported 
that the species was spreading into new areas near 
Chicago, and Gauthreaux (1971) stated that the species 
is making a recovery in northeastern United States. 
Acadian flycatchers almost always place their nests 
near the end of a horizontal limb of a sapling, often along 
a rivulet or stream and sometimes over the water. 
We have nest-site data on 41 Acadian nests in 
southern (mainly) and central Illinois. Over half the nests 
(22) were in maples, particularly sugar maples (Acer 
saccharum). Six nests were in ironwood (Ostrya 
virginiana), five in oaks (Quercus stellata, Q. alba, Q. 
muhlenbergit), four in blue beech (Carpinus 
caroliniana), two in elms (Ulmus rubra), and two in 
willows (Salix sp.). Whether the high proportion of sugar 
maples used represents definite selection on the part of 
Acadians, or only a high incidence of that tree species in 
the habitat we cannot say. 
Nest heights varied from 5 to 35 feet, and averaged 12 
Leet. 
Nesting Cycle 
As there are no published banding data on the 
Acadian flycatcher in Illinois, homing has apparently not 
been demonstrated for any Illinois population. 
The Acadian flycatcher has at least two song forms. 
The most commonly heard is an unmusical, quick, high, 
emphatic ‘“flee-deet” or “flee-eetit” of two or three 
syllables often so run together that they sound like one, 
with rising inflection on the second part. The earliest 
34 
Type of Region or 
Census County Rela 
Nest Sangamon (C) Snyder et al. 1948 
Nest Piatt (C) Fawver 19476 
Nest Vermilion (C) Karr 1968 
Strip St. Clair (S) (This paper) 
Washington (S) 
Strip Franklin (S) (This paper) 
Clinton (S) 
Jackson (S) 
Nest Champaign (C) Kendeigh 1948 
Champaign (C) Kendeigh & Fawver 1949 
Champaign (C) Kendeigh et al. 1950 
Champaign (C) Kendeigh et al. 1953 
Champaign (C) Kendeigh & Brewer 1956 
Champaign (C) Kendeigh & West 1958 
Champaign (C) Kendeigh & Brooks 1964 
Champaign (C) Barnett & Balda 1966 
Champaign (C) Kendeigh & Clemens 197 
Strip North Graber & Graber 1963 
Central 
South 
South 
ales or nests X 2). 
Acadian arrivals sing this song, and we have heard it | 
late as September 25 in southern and central Illinois. 
The second song is part of an entrancing display, ar 
consists of a prolonged, high, soft, twittering sound, | 
trill, uttered by the male as he flies a somewhat circul: 
course through part of his nesting territory, alightir 
here and there, usually briefly, on twigs as he goes. T) 
fight is distinctive, a kind of fluttering, slow-motic 
flight, and the song is not interrupted when the bis 
perches. 
Besides the songs, Acadians commonly utter a sha’ 
call note, a “quip” or “squeep”’ sound, which is probab 
an alarm note. It is most often heard near the nest. 
Nesting activity must begin shortly after the fema 
arrive, as we have observed nest building as early as M 
5 in southern Illinois. The nest, constructed of grass 
fine branchlets, forest duff, moss, spider web, and ster 
oak catkins, is unique in form (Fig. 28). Though Acadi 
nests are often rather fragile looking, they have a toug 
rigid construction from the interlacing of branchl 
which are almost wire-like. The nest is almost alwi 
somewhat pensile, suggesting the structure of a vireo ne 
but shallow. It is usually placed in one of the termi 
forks of a horizontal branch of a sapling. Some Acadi 
nests are so thin walled that the nest contents can be se 
through the bottom from below the nest. Some lin 
nests also have a much more massive, thick-wall 
construction, like nests of the species from | 
southeastern United States, as illustrated in Bent (194 
There is almost always some trailing material hangi 
from the nest. The material, usually grass stems, ™ 
hang as much as 1-2 feet below the nest (Hess 1910). T. 
