American Tree Sparrow Dossier

by Carl Strang

Today’s feature is my dossier of the American tree sparrow, a wintering bird that still is with us but soon will head back to the northern nesting grounds. The following notes reveal my interest in the complex range of this species’ vocalizations.

American tree sparrow. The black spot in the clear chest is a helpful identification feature.

American tree sparrow. The black spot in the clear chest is a helpful identification feature.

Sparrow, American Tree

This songbird is a common winter resident in old fields and residential areas with some bushes, in Culver, around Lafayette, in south central Pennsylvania and in DuPage County, IL. Usually they occur in loose flocks, often mixed with juncos. They feed on the ground, especially, taking seeds. Note: “tsew,” “tsoo” or “tsee” in a slightly melancholy minor key, hint of downward slurring. Has a 3-syllable call, a hair slower and more flowing than junco’s, very musical and pleasant in contrast. Single-note call has a descending tail, is much like white-throated sparrow’s.

26FE87. Song heard in Willowbrook Back 40: “Tsoo-too-doo-doo-dee-chew-chew-chew-chew.” Song loud and clear, of water thrush quality.

7MR87. Another song: “tsee-tsoo-bye-tsee-tsoo-tsoo.” First note held longer than others. Tsee syllables highest pitched, tsoo’s lowest. Sang from perch in top of willow clump, 6 feet up, at West Chicago Prairie.

13MR87. Still hearing them singing.

22MR87. Still present and singing at Culver Fish Hatchery.

15OC99. First tree sparrow of the season at Willowbrook.

20DE99. Tree sparrows eating Indian grass seeds at Fermilab. Sometimes their call notes are simple and flat, but sometimes they add a trailer that so far I cannot tell from white-throated sparrow’s. In conflicts they have beautiful, musical clusters of notes.

29JA00. A flock of 30 tree sparrows and 2 juncos feeding on the gravel berm edge of Swenson Road, Fermilab.

5MR00. A single still at Fermilab, in thick grass area with a few shrubs, beside trail.

The red on the top of the head, the white wing features and yellow lower bill mandible are additional distinctions.

The red on the top of the head, the white wing features and yellow lower bill mandible are additional distinctions.

23NO04. Willowbrook. A flock of tree sparrows in tall prairie vegetation using a call I don’t remember hearing before, a pardalote-like “wee’dah.”

16NO10. Mayslake. Many tree sparrows are in the west stream corridor along the southern edge of the mansion grounds. Giving an unusual call, less than a second long, beginning at a high pitch, slurring to a lower one, and quickly back up to the starting pitch.

6JA11. The more complex tree sparrow call can be difficult to pick out when many birds are producing it at once. When a single bird is isolated, the call has the rhythm of a quick, “tit willow,” i.e., three dominant syllables with the last two close together and a little more separated from the first.

2FE12. American tree sparrow call: dedjidu, quickly pronounced.

15NO12. Mayslake. Tree sparrows eating seeds of Canada goldenrod and annuals.

25JA13. Mayslake. On the ground in the off-leash dog area, an enormous flock of at least 100 tree sparrows, 30 juncos with at least one white-throated sparrow mixed in, doing the double-foot scratching to get through the snow and then reach, presumably for seeds.

Friary Prairie Grasses

by Carl Strang

A prairie is in its early stages of developing on the site of the former friary at Mayslake Forest Preserve. On my most recent check, I was pleased to find scattered prairie grasses in seed, both Indian grass and big bluestem. There is some risk when introducing Indian grass so early in a restoration project, as it can spread quickly and dominate an area. The plants appear to be few and widely scattered, however, so there may not be a problem in this case.

Seeing them reminded me that I need to resume my project of photographing the preserve’s plants in winter. This week’s example will be that big bluestem. Here in its still intact winter mode is a fruiting top.

Note how tightly the seeds are pressed against the branches of the inflorescence, which gave this plant its alternate (and November-appropriate) name of turkey foot.

Here is an inflorescence in bloom, back in the summer:

The flowers are more relaxed out from the stem, and the anthers are releasing their pollen to be wind-carried to other plants.

This is one of the characteristic species of the tallgrass prairie.

Big bluestem can tower above many other of the prairie plants.

So, this made for an easy start. Not all plants are so recognizable in their winter form, as we’ll see.

Gray Ground Cricket

by Carl Strang

The south unit of Illinois Beach State Park is closed. I found that out when I arrived there, having taken a vacation day and driven the hour and a half or so it takes to reach Zion. That squelched singing insect research Plan A, though it turned out for the best, as we’ll see. I would not be able to achieve all my goals, but I could at least try to find gray ground crickets at the north unit.

Grassy area just inland from the beach at Illinois Beach State Park’s north unit.

Between the parking lot and Lake Michigan, this grassy area is protected enough from wind and waves to support tall prairie grasses including big and little bluestem, and Indian grass, as well as a few forbs. The soil appears to be nearly pure sand. All I was hearing at the parking lot were some fall field crickets and Allard’s ground crickets, but I followed a path toward the beach and soon, in the sandy prairie shown in the photo, was hearing scattered gray ground crickets. I kept hoping I might see one out on the path, but no such luck, and I didn’t want to be too intrusive at an area that already gets much use. I’ll hope for a photo opportunity some other time.

The gray ground cricket’s song is distinctive, though in part that is because of the connection to the habitat. There was one place where an Allard’s was singing close enough to a gray to allow a direct comparison. Both ground crickets have long trills, but that of Allard’s is noticeably slower, the individual notes fully distinguishable if a little too rapid to count. The gray ground cricket’s trill is much more rapid, though still audibly composed of distinct notes (i.e. they don’t blend into a single tone). The song is higher pitched than that of Allard’s. In addition, the gray incorporates characteristic pauses here and there. A recording can be found on-line here.

It was only mid-day, so I decided to check another Lake County site on my fall research list, which I had thought would have to happen on another day. I’ll report on that tomorrow.

Native Grasses

by Carl Strang

We are moving into the second half of summer, and late season prairie grasses are beginning to bloom at Mayslake Forest Preserve. Big bluestem has the tallest stature.

The stems reach above your head.

Another name for this grass is turkey foot.

The spikes radiate like a big bird’s toes.

My favorite among the common prairie grasses is Indian grass.

The beautiful color of the coppery spikelets contrasts with the yellow anthers.

Drier places in the prairie support side-oats grama.

Here the anthers are bright red.

Earlier in the season a grass began to flower that I could not identify. Now, with the seeds well developed, I find that it is an unusual species in DuPage County.

A couple clumps of slender wheat grass, Agropyron trachycaulum, are growing at the very edge of the prairie adjacent to the parking lot. I assume the seed came in with a vehicle.

It is native to the area, but apparently seldom finds suitable soil in DuPage.

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