Western Chorus Frog Dossier

by Carl Strang

An early sign of spring’s arrival is the sound of massed chorus frogs. Here are my limited specific observations of them.

Western chorus frog

Western chorus frog

Frog, Western Chorus Known in my experience mainly from DuPage County, IL, and the Culver, Indiana, area. In early spring they sing in large numbers, in crickety sounding calls, in temporary ponds. I saw one in the back yard of the house we rented in Glendale Heights. Small and striped, crawling in the grass. Closest pond where they sang was at least 200m away.

7MR87. Singing at West Chicago Prairie.

22MR87. Singing at Fish Hatchery, Culver, in first partial pond west of ditches.

12MR88. Brief song from one at McDowell Forest Preserve.

26MR88. Singing just west of Hartz Lake property.

27MR89. First song of year heard at McKee Marsh.

23AP89. Herrick Lake Forest Preserve. I water-stalked a singing frog, close enough to see it, or at least the movement caused by its singing. It was in or just above the water, which vibrated with the song. It was in a place where broken-down cattails created a small (almost completely covering) shelter. They sing in alternation: pairs, high and low. High starts. If a few calls do not involve a nearby frog in a duet, the first stops.

10MR97. Heard one singing while I ran on Prairie Path near Rt. 59.

20MR99. First chorus frogs of spring heard in 2 places.

30OC99. 1-2 (same one found twice?) found on an extensive mudflat at Fermilab.

5MR00. A few singing at Lake Law, Fermilab, in an area of shallow water and dense dead stems of cattails and grasses.

2MY00. A couple still singing.

24SE00. A few individuals singing weakly in the tall, goldenrod-dominated upland vegetation between the large lakes at Fermilab.

14OC00. Occasional song, still, at Fermilab. Much like spring peeper’s pattern of fall singing.

21MR01. First of year, a couple only, heard near Prairie Path east of Warrenville. A cold, lingering winter.

15AP01. Quite a few singing near the McKee Marsh outlet. 12SE01. I heard single brief song beside the prairie path north of Butterfield and west of Fermilab in late afternoon.

12OC02. A few weakly singing individuals at Fermilab, in low spots.

21MR05. One singer at the Hartz Lake property.

13JE06. Tri-County State Park. Chorus frogs and American toads have resumed singing after heavy recent rains have raised water levels, here and at Fermilab for chorus frogs, and here and at Fullersburg for toads.

5AP10. Mayslake. A jump in chorus frog numbers from last year. Last year they were at the stream corridor marsh only, and the maximum male count was 12. This year, up to 22. Furthermore, there were satellite groups in the parking lot marsh (3) and the reed-canary-grass pool east of the dog fence (5).

25OC10. Mayslake. Chorus frogs calling, three individuals in three places: one on top of a wooded hill; one in the middle of the meadow west of the dog area, and one a short distance south of the stream corridor marsh.

27OC10. Mayslake. A western chorus frog called from on or right beside the path N of the stream corridor marsh. No hibernaculum candidate there.

17MR11. Mayslake. First singers of the season, in stream corridor and parking lot marshes.

One reason chorus frogs can be difficult to see is that they often select sheltered places from which to sing. The edge of one’s expanded throat is just visible beneath the log.

One reason chorus frogs can be difficult to see is that they often select sheltered places from which to sing. The edge of one’s expanded throat is just visible beneath the log.

29SE11. Mayslake. At least 3 chorus frogs calling in close proximity in a reed canary grass area. Another in the main meadow W of dog fence.

Spring 2013. Mayslake. Hardly any chorus frog activity this spring, in the wake of last year’s drought, despite the re-filling of the marshes.

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Slow Day

by Carl Strang

Saturday was cool with intervals of rain, so there wasn’t much to be done with singing insects. I checked out Springbrook Prairie in the morning, and Tri-County (JPP) State Park in the evening, hoping for spring trigs, but no luck there.

Walking the trails at Tri-County, I found a dark grasshopper.

It was on the trail, had the colors of a green-striped grasshopper, but was large, perhaps an inch and a quarter long.

It was on the trail, had the colors of a green-striped grasshopper, but was large, perhaps an inch and a quarter long.

It was unable to perform a sustained flight. Somehow I missed the fact that it had lost one or both hind legs. I am not fully confident of my grasshopper anatomy, but this individual appears to be a female, which would account for the size. It is, then, an unusual brown female of the species (typically, females are green, males brown). And that was it for Saturday’s research production.

Northern Flicker Species Dossier

by Carl Strang

The flicker was a favorite bird of my childhood; it is so unlike other woodpeckers. That’s not to say that I can offer a lengthy dissertation about them from my own experience, hence the moderate length of my dossier on them.

Flicker, Northern

Male northern flicker

Male northern flicker

This is a woodpecker of savanna and open forest. Most migrate south in winter, passing through DuPage County in large waves. They nest in tree cavities (I have seen them excavating near Lafayette, Indiana, and at Willowbrook and Meacham Grove Forest Preserves in Illinois). Nests may be near the ground or higher in trees (6 feet up at Meacham, in a 7-foot-tall stump in a clearing; 20 feet up in a large black willow at Willowbrook). Flickers frequently forage on the ground, sometimes around ant nests. They also may feed on tree trunks in usual woodpecker fashion. Their flight is strong and direct; the white rump patch is distinctive. Vocalizations are diverse: “Flicka-flicka-flicka;” “E-e-e-e-e-e-e-e-e-e,” rising in volume and perhaps a little in pitch, gradually, then dropping again the last couple of notes (staccato short e’s). A “whoop-whoop-whoop” display flight sound, made by wings or voice. Alarm: flew up from ground with whooping wingbeats, and emitted a couple of loud “kleel” sounds.

27MY86. One flicker chased another quietly from perch to perch in part of a willow canopy at Willowbrook. Chasing not too vigorous, and without vocalizations. Part of courtship?

The stiff tail feathers demonstrate this is a woodpecker. It is a little too intuitive to us that females like this one lack the male’s “mustache” marks.

The stiff tail feathers demonstrate this is a woodpecker. It is a little too intuitive to us that females like this one lack the male’s “mustache” marks.

30MR87. First of year observed.

15SE87. Several in Willowbrook Back 40. Also, 2 on 25SE, 1 on 30SE, and on 19OC.

13FE88. First flicker of the year near Culver, along S.R. 110.

17MR88. First arrival at Willowbrook.

16AP88. A flicker at the Morton Arboretum displaced a red-bellied woodpecker which landed on a major branch of the same tree the larger flicker was in. It chased and displaced the red-bellied twice, and uttered a faint “flicka-flicka-flicka” series, then the red-bellied flew off.

27SE88. Still present at Willowbrook. Also seen 3OC, 6OC, and one on 11OC.

17AP89. Lots of flickers in Willowbrook’s Back 40.

17JE89. A broad-winged hawk called repeatedly, in the north end of Maple Grove. Jays, flickers and grackles were highly agitated, flickers the most continuously vocal with “keels” every 2 seconds (2 birds).

11FE90. Flicker near Hartz Lake, IN.

7OC99. Last flicker of season at Willowbrook.

21NO99. Flicker perched at edge of Fermilab along Kirk Road.

18DE99. Very late flicker at Fermilab.

17JA00. Even later flicker at Greene Valley Forest Preserve. This individual looked very dark.

29-31AU01. Flickers fairly common at Algonquin Park, Ontario. Feeding on ground, usually in groups of 2-3.

Flickers consume many ants, like other woodpeckers, but unlike them often feed on the ground.

Flickers consume many ants, like other woodpeckers, but unlike them often feed on the ground.

2005-7, Greene Valley and Tri-County. Flickers overwintering in open areas.

20AP09. Flicker drumming in W part of Mayslake savanna. Drumming relatively light but very fast.

As the dossier reveals, it took me a while to figure out that flickers winter here more regularly than I had thought. They especially like prairies and other really open areas in that season.

Beaver Species Dossier

by Carl Strang

The species dossier idea came from my realization in the 1980’s that much of what I “knew” about wildlife came from the scientific and popular literature rather than personal experience. I went species by species, writing what I could remember about each one from memories of my own observations. Then I built the dossiers with added notes. The dossier begins with the initial paragraphs, followed by notes dated by a code that uses two-letter combinations to signify months.

Beaver

Beaver, Salt Creek at Fullersburg Woods

This aquatic rodent lives in ditches, rivers, and lakes. Observations to date have been in the Culver, Indiana, area (Maxinkuckee, Tippecanoe, Yellow River, Fish Hatchery), southern Ontario, and DuPage County, Illinois. The signs are seen much more often than the animals themselves; they are crepuscular/nocturnal for the most part, although the Canadian ones occasionally appeared in daytime, and I have seen them during the day in northern Lake Michigan and the West Branch of the DuPage River (mid-winter). Alarm signal: dives noisily, augmenting the splash with its flat tail.

Stand-alone lodge, Canada

They feed on bark and twigs of willow and other woody plants, storing large underwater piles of branches in fall for winter use. They also stripped bark from the 1-4″ diameter X 1-3′ long sticks used in building dams and lodges. The den can be in a bank or in a stand-alone built lodge. Bank dens are used in larger, deeper rivers and lakes, although built lodges also can be seen in such places. I have seen built lodges in Canada, Lake Maxinkuckee (Venetian Village), DuPage Co. (e.g., Churchill F.P.), Isle Royale. They have a distinctive appearance because of the white sticks, though some lodges on riverbanks are not rounded and so at first glance resemble piles of drift from the last flood. Mud also is used in construction. Lodges have been 8-15′ in diameter, 2-4′ high, usually on a bank.

Beaver dam, Tri-County State Park

Small streams may be dammed to create a pool (the most ambitious dam I’ve seen was on the West Branch of the DuPage River at Blackwell in mid-winter). Dams, like lodge coverings, are built of stripped sticks, mud, vegetation, usually have a slight U-shaped bend pointing downstream, and are not particularly high above the contained water level, though some on Isle Royale were taller than me on the downstream side. Very long dams can have a more sinuous shape; I’ve seen them more than 50′ long.

High beaver dam with trail, Canada

Beavers will carry branches from other bodies of water to the home pool. Cut trees are distinctive with large tooth marks and pointed (cone-shaped) ends. Beaver tracks are large, and have the rodent formula (4 toes front, 5 back), the webs of the hind feet not always making noticeable marks.

Beaver front footprint

31AU86. Beavers at Culver’s fish hatchery have reinforced the base of their dam with a heavy plastering of marl.

18DE86. Month-old beaver sign, Willowbrook Back 40: several black cherry trees had their bark chewed off on the stream side of the trunk. No others in the vicinity (willow, box elder) were damaged.

11JA87. At the mouth of Sawmill Creek, Waterfall Glen F.P., beavers this morning fed on bark of a box elder 7″ dbh, they had cut down earlier. They had made a trenchlike single path in 6″ snow between stream and trunk.

8MR87. 2 ash trees 8″dbh cut down but only some bark removed from trunk. Otherwise untouched, for months.

Beaver-felled tree, Fullersburg

28MR87. Beavers at Waterfall Glen cut three 8″ dbh bur oaks, ate much of the bark from 2 of them, in an area with much willow.

23JA88. McDowell F.P. Beavers built a long winding dam on Ferry Creek, 20-30 yards long

15MR90. McDowell. Beavers were active in the evening dark during my night hike program. We heard one chewing: identical to the sound of a squirrel gnawing a nut, and as rapid, but much louder. Several of us shined lights on it. It was on the opposite side of the river, standing up on its hind feet, against the tree. After at least 30 seconds of being illuminated, it abruptly ran into the river. It swam for another 20-30 seconds, still in lights, then walked up the bank back to the same tree, and resumed gnawing. The alarm splash is like a big rock being thrown in. I didn’t detect a tail slapping component.

13NO99. A beaver dam has been built across the very low West Branch of the DuPage River, Elsen’s Hill at the eastern horse ford.

29MR00. While running past the borrow pit at McDowell Grove Forest Preserve, I frightened a beaver into the water. It swam under the surface for 20 feet or so, a stream of bubbles revealing its position, then surfaced. Immediately it dove again, but as it did so I saw it deliberately lift its tail and slap it on the water. I could detect the sound of it, but the splash made by the posterior part of the body (spread feet?) was the louder sound. Perhaps the double sound makes it a communication for beavers, to distinguish it from other splashes.

11MR01. A beaver lodge is on the shore of the old gravel pit on Timber Ridge Forest Preserve (at the intersection of County Farm and Geneva Roads). There has been much recent gnawing of nearby woody plants.

8AP01. At around 8:30 a.m. at Red Oak Nature Center I heard a gnawing sound down near the edge of the Fox River. It was a beaver, sitting in the shallow water and feeding on the twigs of a shrub or small tree overhanging the river (intervening brush too thick to get an ID of the plant). The beaver was reaching up, biting off a branch, then consuming the twig. Less than about 3/16″ in diameter, the twig was consumed by the beaver holding it like a piece of stick candy and nibbling on it with gnawing sounds reminiscent of a squirrel working on a nut but more rapid. After 2-3 seconds of biting off the end, the beaver chewed with its molars for a few seconds, swallowed, then worked on the end some more. When the diameter of the remaining twig became greater, approaching 1/4″, the beaver turned it sideways (always holding it in the front feet) and quickly stripped off the bark.

22OC01. Beavers have been very busy in recent days at the marsh beside South Blackwell’s Heron Trail (marsh full of water thanks to heavy rains in recent weeks). They have trampled a path through the cattails all the way to Heron Trail, and have been cutting the small willows and cottonwoods into pieces, eating the bark from some of the bigger chunks, and hauling the tops into the water (drag marks visible in the mud).

6JL07. Fullersburg. A beaver swimming up the main channel along Sycamore Peninsula went to the shore at 8:30 a.m. and ate some root bark and twig bark from American elms. It continued upstream past the Visitor Center.

Red-bellied Woodpecker Dossier

by Carl Strang

I established my vertebrate species dossiers in the 1980’s as an antidote to relying too heavily on the scientific literature and the stories of others for my natural history knowledge. I wrote everything I could remember about each species from personal experience, which generally was embarrassingly little. Then I began to add notes as I made new observations to beef out the files. Each subsequent entry begins with my date code: the day of the month, two-letter month code, and year. Today’s example still is nothing to brag about, but on the other hand woodpeckers can be shy and resistant to casual observation.

The lack of red on the front of the head indicates that this bird is a female.

Woodpecker, Red-bellied

Frequently seen in Indiana, Pennsylvania and Illinois. Stays in forested areas most of the year. Frequently goes into towns to visit feeders in winter. I found a nest at Meacham Grove Forest Preserve in the large hollow branch of a live tree. They search for food on tree trunks and large branches. Their voice is similar to that of the red-headed woodpecker. Harsh vocal quality, difficult to render, “yooch yerch,” (short oo’s), sometimes the latter syllable repeated several more times. Very quick to call when a person comes into its vicinity in winter, more so even than the blue jay.

2AP88. Near Hartz Lake, Indiana. Call between chasing intervals, apparently expelling a rival: “rook-tik.” Haven’t noted that vocalization before.

31MR99. An excavation started by one of the red-bellied woodpeckers at Willowbrook on the 29th now is a full-sized hole and goes into the tree an undetermined amount. Near the creek.

14JA00. Red-bellied woodpecker drumming repeatedly.

22MY00. Red-headed woodpecker’s trill call is flatter in tone, not rising or falling like red-bellied’s.

A nestling, close to fledgling, is anticipating its next meal.

5JL00. Willowbrook. Many robins, adult and first‑year, on the preserve today. A young one, and also a red‑bellied woodpecker, sally‑foraging for insects, possibly flying ants, from the top of a tall dead tree near the stream. (One passing insect was observed for a few seconds before the robin flew out and caught it).

26FE01. McDowell Grove. A male red-bellied woodpecker spent over half an hour excavating a cavity previously begun (it could stick its entire head in the hole). The tree was a dead stem, 20 feet tall, at the edge of the creek, the hole was facing south, away from the creek, and was surrounded by other trees. The hole was 6-8 inches from the squared, broken-off top of the stem, and the stem there was 6-8 inches in diameter. The bird paused to call frequently.

16-17MR06. On the 16th, a red-bellied woodpecker was drumming at Fullersburg. Drumming very rapid. The next day, a hairy woodpecker drumming at Tri-County State Park was drumming, similar in length but even more rapid.

Red-bellied woodpecker nest at Mayslake Forest Preserve.

27MR06. Downy woodpecker drumming is so rapid that individual strikes cannot be followed. Hairy woodpecker drumming very rapid, individual strikes can be distinguished. Red-bellied rapid but slightly less so.

9NO09. Female red-bellied eating an apple in the Mayslake mansion orchard.

Cedar Waxwing Dossier

by Carl Strang

One delightful bird which can be seen in northeast Illinois throughout the year is the cedar waxwing. Today I share my dossier for the species, consisting entirely of my own observations. Though references are valuable it also is important, I think, to keep track of one’s own experiences with a species.

Cedar waxwings are smaller than robins but larger than sparrows, crested, soft brown and yellow in color with bright yellow follow-me bands on the tail tips.

Waxwing, Cedar

My principal childhood memory is of waxwings that nested around brushy thickets and willow clumps along the Tippecanoe River near Monterey, IN. Adults hunted insects in flycatcher fashion from bare twigs over the river. In DuPage County they are evident in wandering flocks through all parts of the year except the breeding season. They travel in flocks, staying one to many days in an area and feeding on berries in fall and winter. This also occurred in Cumberland County, PA. Mountain-ash berries were a favorite food in both places. Also consumed are dogwood, and buckthorn berries. Flock cohesion is aided by the bright-yellow tips of the tail feathers, and by the unique high-pitched thin contact call. First winter birds have breasts striped longitudinally with cream and the soft brown adults’ breast color. At the Willowbrook Wildlife Center clinic, waxwings frequently came in with broken wings and other injuries suffered in collisions with windows. In the cages they showed an open-mouthed threat display, possibly made more effective by the black facial markings. In mid-September at Herrick Lake, a single waxwing perched in an old-field treetop gave a single loud note and flew away into thicker trees. Several seconds later a sharp-shinned hawk flew by the waxwing’s original perch, heading in the same direction. (This first paragraph, written from memory, established the dossier in the early 1980’s. Subsequent additions begin with date codes.)

When not feeding, cedar waxwings typically perch high in trees.

30OC86. Willowbrook Back 40. Waxwings feeding heavily from honeysuckle (berries and leaves still on bushes).

16OC87. First autumn appearance of a flock at Willowbrook Back 40.

13JA88. Lots of waxwings in Back 40.

27OC88. Feeding on honeysuckle berries, Willowbrook Back 40.

13DE88. Waxwings abundant in Back 40, stuffing down rose hips.

3SE89. Mixed young and old waxwings eating honeysuckle berries, Island Park, Geneva.

JA99. Waxwing flocks frequently at Willowbrook. Eating, among other things, Asiatic bittersweet (Celastrus) berries.

11MR99. Last of winter waxwings noted. Not seen again at Willowbrook until 25MY. Then after 1JE another gap until 12&20JL. Became a frequent visitor again in early August.

These waxwings are drinking meltwater where snow is being warmed on a roof at Mayslake Forest Preserve. Much energy is saved by drinking, even if the water is cold, instead of eating snow.

7JA00. Waxwing eating buckthorn berries.

31JA00. Waxwing, again at Willowbrook, again eating buckthorn berries.

8FE00. Waxwings eating buckthorn berries at Willowbrook.

17FE00. Several waxwings on the ground eating snow (buckthorn berries available on bushes nearby).

19MY01. Many flocking waxwings spread out over a large area at the Arboretum, mainly in treetops in forest as well as more open areas.

12MR06. Cedar waxwings delicately picking anthers from silver maple flowers in the yard. [Note: studies have shown that waxwings use protein from pollen to render certain berries more digestible]

13JE06. Tri-County State Park. Cedar waxwing working on a nest in the topmost leaf cluster in a 25-30-foot box elder within 30 yards of Brewster Creek. Weaving, using long slender strands, at least some of which are stripped from grape vines. Spending considerable time with each strand. Mate perched in same cluster of trees. Bird completely concealed when weaving.

This is the tree where waxwings built a nest at (then) Tri-County State Park in 2006.

16JE06. The nest looks complete, a significant lump in the first branching of twigs about a foot from the tip.

22MY08. Fullersburg. An interesting display between 2 cedar waxwings, appears highly stereotyped. They were perched side by side well up in a tree in SW Butler Woods. They took turns quickly hopping away from the other bird a few inches, and returning, at which point the two birds touched or nearly touched beaks, which were angled up. Each of these cycles (or half-cycles, for each bird) took 1-2 seconds, and there were perhaps 20 reps that I observed (i.e. at least 10 per bird). At first they faced the same way, at some point one turned to face the other way and they continued. Eventually one moved to a different twig, but still was close. [Note: this is called the Side-hop display in the Stokes bird behavior guide, and is part of courtship].

6JL09 Mayslake. 14 cedar waxwings foraging like swallows out over May’s Lake. (This was repeated over several days.)

1JA10. Hidden Lake. Waxwings and robins feeding on buckthorn berries.

Great Blue Heron Dossier

by Carl Strang

It has been a while since I posted one of my species dossiers. The idea is to make a record of what I know of a species from my own experience rather than what I have learned from others. This is a valuable exercise. When I got the idea and started it, I was embarrassed by how little I could write even for common species. It has forced me to pay more attention, to observe more, to be more discriminating in what I can claim to know about natural history. Even books and, yes, Internet sources like this blog need to be read skeptically. Today I choose the great blue heron, a species that played an important role in inspiring my interest in natural history studies. Records are dated with my code that begins with the day of the month, followed by a two-letter month code (usually the first two letters of the month’s name) and a two-numeral year. The code 16JE99 would indicate June 16, 1999.

Great Blue Heron

First observed at Hawk Lake, where several fished along the east side each evening in summer during my childhood. These were an early inspiration for my bird watching interest. Also observed in PA, along the Tippecanoe River in IN, in DuPage County, in Florida. Seek food usually in relatively deep water, sit-and-wait foraging. They quickly extend the neck to seize or spear fish or other prey. On rare occasions I have seen them briefly swimming on the surface of water too deep to wade. One in FL waited for fishermen to catch fish, then ran up in hope of getting the catch.

They have loud raucous squawking calls, a brief one in flight (often when disturbed) and a longer more rattling one when handled (i.e. at Willowbrook’s wildlife hospital).

Rookery established around 1967 south of Culver, Indiana, near the Tippecanoe River, in several large sycamores at the edge of a small woodlot near S.R. 17. That site still was used through 1986. Birds appear standing in nests in mid-March, radiate out in many directions to feed. Great blue herons then also reached all parts of DuPage County, IL, despite no rookeries there (a large rookery south of the county at Plainfield).

24JA89. A great blue heron flying east of Lake Maxinkuckee, IN.

10MR00. Several herons have returned to the new, small (10-nest) colony at Danada Forest Preserve.

7MY00. Great blue herons croaking in flight, traveling above West DuPage Woods Forest Preserve. An extended string of them, so the calls may be communication between flying birds.

13NO01. I count 25 nests, now, in the Danada rookery. The trees are at the edge of a pond. They are not sycamores, but I didn’t get close enough to ID. Elm shape.

21FE02. A single heron was standing on a nest in the Danada rookery at 4p.m. The winter has been mild, and it’s not inconceivable that a GBH could have survived the winter locally.

1SE02. At 10:30 p.m., a great blue heron in Geneva, standing in shallow water in the Fox River, apparently fishing in the street lights.

16JE03. This year I know of 2 large nesting colonies in DuPage County, both established in recent years. One is at Danada Forest Preserve, the other at Pratts Wayne Woods, near the intersection of Rt. 59 and Stearns Road and visible from both.

8AU03. I kayaked between Willow Springs Road in Cook County and Route 83 in DuPage on the Des Plaines River. There is a strung-out colony of great blue herons nesting over a 2-mile stretch of river that spans the county line. The nests are in scattered dead trees close to the riverbank, taller than the surrounding trees, 2-5 nests in half a dozen trees total. Though separated sometimes by more than a hundred yards, the trees each seem to have one of the others in view.

28MR06. At Tri-County State Park, the 2 nests from last year (a new satellite of the Pratts Wayne colony) gradually had lost most of their sticks. On the 23rd, herons returned (later than in the larger colonies), and now are building the nests back up. One seen carrying a long thin stick in its beak, flying up to a perch beside the nest and giving it to its mate standing in the nest, who then added it. Two additional pairs perching in those trees, but no new nest starts yet.

18JA09. Danada. Checked great blue heron rookery. Most of the 15-20 nest trees were living cottonwoods, and 90% of the nests were in these. Two were dead trees, and three were willows. One cottonwood had 16 nests, a couple had 13, one had 11. Total nests counted 142. The rookery is in a swampy area around a large pond. Last summer I also learned of a rookery at Churchill Forest Preserve, on the islands in the East Branch of the DuPage River.

11OC10. During a dragonfly monitoring run on the Des Plaines River I noticed that, in addition to the scattered great blue heron nests in tree tops along the shore, there is at least one group of trees with a number of nests in a more concentrated colony. There are more than a dozen nests in at least 3 adjacent trees. This cluster is on the river’s south bank, east of Route 83.

Red-winged Blackbird Dossier

by Carl Strang

Here’s another example of a species dossier. The idea is to separate what I have learned through my own observations from what I have learned through the literature or others’ observations. It is a tool that has enriched my understanding and improved my focus in the field. The initial summary, written when I established the dossier in the mid-1980’s, is followed by entries marked by my date code. Each month is represented by the first two letters of its name, except when two months begin with the same letter. Then, the second letter is unique to that month (JA, JE, and JL for January, June and July, respectively).

Blackbird, Red-winged

Nests seen in cattail marshes, attached to cattails, although birds also defend territories in dry, tall grass meadows. Out of breeding season may show up anywhere, though usually in open areas. Male advertizes with song (kong-la-ree’-er), either while perched or descending to perch on, say, tall cattail head. Capable of hiding or elevating and exposing red shoulder patches. When people approach nest, male especially but also female get highly excited, hovering overhead with sharp dry “keck” notes. Some individuals swoop down at intruders. Also chase crows, hawks. Hunt insects in breeding season, visit cornfields in flocks in fall. Gone from the north in winter.

5MR87. In morning, first of year on perches beside Butterfield Rd.

6MR88. Numbers of them at Winfield Mounds.

12MR89. First of year seen on way to Hartz Lake.

15AP89. Males often seen swiftly and closely chasing females, this time of year. Is she testing him, listening for wheezing, etc.?

1NO99. Last of the season seen at Willowbrook.

21FE00. Among several Brewer’s blackbirds at Fermilab’s buffalo feeders, a single male red-winged blackbird which called, once.

18JE00. A female flushed from a nest when I was about 10 feet away. Nest with 3 eggs, a woven grass cup ~3″ deep by 4″ across, attached to a dead woody stem in its fork, in a canary reed grass area and within the level of the grass, ~3 feet off the ground. Near edge of Herrick marsh.

22OC01. Some red-wings singing in the morning at south Blackwell.

31OC01. Flocks of red-wings and grackles remain (Nelson Marsh, Kane Co.)

4NO01. An enormous flock of red-wings and grackles along Kirk Road in eastern Kane County. The species were staying apart, on the whole, and there were mainly grackles, but there were hundreds of each. They were landing in a harvested corn field.

16MY06. Tri-County S.P. A male red-winged blackbird took flight and went straight for a pair of cowbirds foraging on the ground, more than 50 feet away. It chased them away, turning back as they kept going.

18MR09. Mayslake. Both red-wing and grackle include tail fanning and wing spreading in their displays. In the red-wing, these movements accompany the song but are expressed in a range from not at all or nearly so, slight fanning of tail, slight tail fanning and spreading of wings, much tail fanning and wing spreading.

Forbes’s Tree Cricket

by Carl Strang

DuPage County is one of the few documented places where Forbes’s tree cricket occurs. That is not because it is particularly rare. It probably is quite widespread and common. The problem is that at present the only way to identify a tree cricket as a Forbes’s is to measure the number of pulses per second in its song (which is a long, nonstop, fairly loud trill). Forbes’s tree cricket is a sibling species of the better known black-horned tree cricket. In fact, where both are known to occur together the only way to distinguish them is by song pulse rate.

Black-horned or Forbes's 2b

Sibling species don’t interbreed, but visually are indistinguishable or nearly so. Black-horned and Forbes’s tree crickets are able to avoid interbreeding because the different pulse rates are recognized by females, who approach only males with the correct song for their kind. Sibling species are a recurring theme in all our major groups of singing insects: crickets, katydids and cicadas. That fact underlines the importance of song as opposed to visual recognition in these groups.

Black-horned or Forbes's male 1c b

You can’t distinguish their songs by ear; we’re talking about pulse rates that can approach 90 per second on a warm day. I use my home studio equipment to slow the recorded song, step by step, until the pulses are countable.

Forbes’s tree cricket was recognized as a species by Thomas J. Walker of the University of Florida, who runs the Singing Insects of North America website . As far as I know he has not published this distinction outside that website, but in his 1963 monograph The nigricornis Group of the Genus Oecanthus  he showed data that demonstrate black-horned tree crickets have two very distinct song pulse rates. With further study after that publication he concluded that these were in fact being produced by separate, sibling species. The “fast-trilling nigricornis” now is labeled Oecanthus forbesi, Forbes’s tree cricket.

These two species are distinguished from other tree crickets by being relatively dark, though they are quite variable and individuals at the paler end of the spectrum have to be studied with a hand lens focused on the pattern of spots on the two basal antenna segments (partially visible in the photo below).

Black-horned or Forbes's male 1a b

These two species prefer prairies or meadows with lots of forbs (flowering herbs other than grasses, sedges and the like), though some sing from vines or shrubs within such meadows. Given their recent recognition as separate species, little is known about their variability and possibly distinct habitat preferences. It is painstaking work, as you have seen, but in coming years I hope to build a database on this species pair in DuPage County. In my limited study so far I have found black-horned tree crickets at Blackwell Forest Preserve, and Forbes’s at Danada Forest Preserve and Tri-County/James Pate Phillips State Park.

American Toad Dossier

by Carl Strang

It has been a while since I have shared one of my dossiers. The idea, which I began in the 1980’s, is to make a written record of everything I have learned about a species from personal experience. Some dossiers have grown to be relatively large over the years. Others, like this one, have remained small.

Toad 2b

American Toad

Terrestrial most of year, in wooded areas, hunting for insects at night, catching them with long-thrown, sticky tongue. Sing in numbers in ponds in spring, song a trill. Sings later than chorus frogs, spring peepers and wood frogs. Smaller males ride on females’ backs, clasping with forearms. Eggs laid in long strings, hatch into tiny black tadpoles which develop in a few weeks into tiny toads that disperse, sometimes in great numbers, into the surrounding landscape. Common near home in Culver when I was a child. Once the dog grabbed one but spit it out and showed distress, salivating excessively afterwards.

10MY87. Singing at McKee Marsh.

30AP88. Singing at McKee Marsh.

12-13MY99. Singing at Willowbrook.

30AP00. I can hear them singing from the house on Briarwood, Warrenville.

21AP01. First of year singing, heard from the house. On 22nd, also, many singing at Pratts Wayne Woods.

13JE06. Tri-County State Park. Chorus frogs and American toads have resumed singing after heavy recent rains have raised water levels, here and at Fermilab for chorus frogs, and here and at Fullersburg for toads.

21MY09. Mayslake. A toad moving through the savanna, mid-day. Earlier in the season several sang in the marsh just west of the stream, but only there on the preserve.

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