by Carl Strang
Today’s species dossier selection focuses on the yellow-rumped warbler, the species in its family that winters the farthest north, with a few sometimes staying through the winter in northern Illinois. Mainly we see them in migration, however, as they nest in the North Woods.
This is a very abundant warbler, observed around Culver and Lafayette in Indiana, DuPage County, Illinois, and Cumberland and Perry Counties, Pennsylvania. Usually they travel in flocks, foraging from the low understory to the canopy top. Many stay late in fall, and some appear early in spring. They retain the yellow rump patch (an obvious “follow-me” signal) year-’round. Call of fall birds “tseeet,” slight slur down in pitch early in call, then up at end, again slightly.
21AP87. Has appeared at McKee Marsh, Blackwell Forest Preserve.
26AP87. Song “tsew, tsew, tsew, tli-tli-tli-tli” (short I’s). In late morning at North Blackwell, these are sitting on perches and looking, as palm warblers did, but traveling farther between perches, working higher (mostly mid tree canopy) and not hover gleaning so much as flycatching.
29AP87. Some have songs composed entirely of the “tli” syllables, others place “tsew” syllables in the middle, others have more “tsew’s” than “tli’s.” Any combination of those two syllables seems possible, 8-15 syllables total in a song.
1MY87. Still a predominantly sit-and-wait foraging style.
4OC87. First fall migrants observed at Maple Grove.
12OC87. A yellow-rumped warbler foraged on the ground, hopping, probing, and peering under the leaves of the plants. It moved slowly, less than 1 foot per minute, turning all around.
13OC87. I observed 2 in Willowbrook’s Back 40, and on the 16th, several in the old field there.
17AP88. A couple at Blackwell Forest Preserve.
29AP88. One observed foraging in trees, spending 1-5 seconds per perch scanning, and moving 3-several feet between perches. It pursued prey once, and also tore apart a cottonwood flower. Then it sally-foraged a while. Later, it switched to reaching and probing in the flowers, moving shorter distances (mostly 1 inch-1 foot). The song was relatively weak for a warbler, accelerating through its 2-3 second duration.
7MY88. Indian Trails, Culver. One flycatching.
8OC88. Hidden Lake Forest Preserve. Abundant in woods, and in fields.
11OC88. Observed in Willowbrook Back 40.
18OC88. Observed at Hartz Lake, foraging with or at least near chickadees and golden-crowned kinglets.
17AP89. First of year seen, Willowbrook Back 40. Next mentioned 30AP, McDowell.
9MY89. One at Willowbrook, flycatching low beside stream.
21OC89. Lots of them in West DuPage Woods Forest Preserve. Foraging mainly by flycatching and hover-gleaning. Air cool, 50F or less, sunny, breezy.
17AP90. First of year seen, Willowbrook Back 40.
23AP90. One foraging in silver poplars at Willowbrook, probing etc. in canopies, with song: “we-see’-we-see -we-see -we-see -we-see” very fast, with slight emphasis on 2nd syllable and 20-30 seconds between songs. Afternoon.
19AP99. First of season noted at Willowbrook. Last spring migrant there 13MY.
30SE99. First yellow-rumped warblers of the fall, many at Willowbrook, 2 eating poison ivy berries. Also seen eating them on 5OC, 12OC.
20AP00. First spring migrants at Willowbrook. (I saw my first of the year 18AP while running near Warrenville).
22AP00. East Woods Trail, Morton Arboretum. Several yellow-rumps feeding high in forest canopy. One observed in crown of a sugar maple in flower. The bird was mainly sitting still, reaching into flower clusters for insects. They are singing the weak sounding song that alternates between two notes, beginning weakly, crescendo and decrescendo into a trailing, weak ending. Also calling: a harsh, “pick” sound, dull and flat in tonal quality but a sharply pronounced, sparrow-like note.
7AP01. First yellow-rumps of the season at Greene Valley Forest Preserve, feeding in trees in chickadee style, with much searching of twigs and bark, and a flush-and-pursuit seen.
30SE01. Many yellow-rumped warblers along the Fox River and on Island Park, Batavia. Spread out all over, some hover-gleaning, some flycatching, others getting poison ivy berries.
27DE01: Yellow-rumped warbler at Willowbrook, foraging at the edge of the open stream, seen to catch a small worm prey.
19DE03. A yellow-rumped warbler at Willowbrook feeding on poison ivy berries and calling, the first seen there in weeks.
28SE10. Mayslake. Some yellow-rumps eating cedar berries.
26OC10. Mayslake. In recent days I have found that yellow-rumped warblers can produce the common warbler call-note (high pitched, briefer) in addition to their lower species specific note.
10DE10. Mayslake. Yellow-rumped warbler eating cedar berries near the mansion.
25AP11. Mayslake. A yellow-rump singing a patterned song repeatedly, very similar to Nashville warbler song but ending just different enough to distinguish.
29AP11. Mayslake. Another distinctive yellow-rump song, this one ending like the one earlier in the week but beginning with a rising sequence of notes as in a scale.