Singing Insect Season Opens

by Carl Strang

Saturday was the spring bird count, and for the first time in recent years I was able to participate. In the early afternoon we were standing on a grassy hill, scanning a pond for water birds in Timber Ridge Forest Preserve, when my ear caught a faint, brief buzzing sound. Then, another. By then my attention had been pulled away from birds, as it seemed I had heard northern green-striped grasshopper displays. I was unable to take the time to confirm it that day, but the next day when I returned I heard many.

Male green-striped grasshopper

Male green-striped grasshopper

Those first observations brought with them the season’s first new question. I was hearing many distinct, if low-volume crepitations, enough to declare the singing insect season open. I did not see any of the grasshoppers, however. Usually their display flights are reasonably conspicuous if you are looking for them. It was moderately windy, though. Were they able to get a normal display out of a shorter, lower flight? Were they somehow rattling their wings without flying? Perhaps later in the season, when displaying grasshoppers are more abundant, I’ll be able to find out.

Incidentally, that May 4 first date is middle-of-the-road. The earliest displays I have observed for that species in DuPage County were on April 3 of last year. The latest starting date was May 16 in 2008. This insect overwinters as a nymph, and so is able to complete its development early in the season.

Northern Shoveler Species Dossier

by Carl Strang

In honor of the shovelers we saw during our Christmas Bird Count on Saturday, here is my somewhat paltry dossier of observations on this duck, which is strictly a migrant in our area. According to researchers their main direction of travel through northern Illinois is unusual: east-west, between the Atlantic coast and prairie breeding grounds.

Shoveler, Northern

Pair of northern shovelers, western Alaska

Pair of northern shovelers, western Alaska

I have seen these ducks regularly on Lake Maxinkuckee and Hawk Lake in Indiana during migration. Usually they travel as singles, pairs or in small groups. Males have a peculiar zipping call, noted in western Alaska, where occasionally I saw widely scattered individuals and pairs. There also was a call reminiscent of a flipped strip of metal. Usually they feed by sifting the surface of the water with sideways movements of their extraordinarily large bills.

15MR87. Shovelers were in a temporary pond along Geneva Road east of West Chicago.

20MR99. First shoveler of the year, IL.

26MR00. I observed 5 males and 1 female shoveler at McKee Marsh, 20 yards offshore, sticking their beak and sometimes their heads fully in the water and swinging them back and forth, but not tipping up.

24SE00. Several shovelers in small groups feeding at McKee Marsh, skimming the surface of the water.

Shovelers on May’s Lake

Shovelers on May’s Lake

14OC00. About 20 shovelers at McKee Marsh, all feeding by tipping up in contrast to their usual feeding style. No floating algae, and the water area still is large, though the entire corridor to the outlet is dry. Mainly they are in the center of the pool, though a few near the edge also are tipping up.

15DE12. A number of late-migrant shovelers were tipping up in the large pond in Timber Ridge Forest Preserve on the north side of Geneva Road.

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.

Song Sparrow 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. The song sparrow’s song is one of my favorites, evocative of my childhood in a small rural town. Hm…as I read this it is clear that I still can’t say I know all that much about this shy species.

The song sparrow is one of our common birds. The dark streaks and long rounded tail are among its physical features.

Sparrow, Song

Common in weedy to brushy old fields, railroad rights-of-way, etc., around Culver, Indiana, in south central Pennsylvania, and DuPage County, Illinois. Sings from a high perch in a bush, on a weed, or in the low branches of tree. Song consists of many short, musical chirping notes, accelerating somewhat toward the end. First song in 1980 in Cumberland County, Pennsylvania, was on 19FE. A year-round resident at Culver, visiting feeders. Also in Pennsylvania. Song sparrows at McKee Marsh, Blackwell Forest Preserve (and one I heard at Waterfall Glen) have a “chew-beecha” phrase which they include in their song (note: this seems less true in recent years). That phrase has a squeaky, raspy quality, loud and interjected clashingly.

6FE87. Heard first song of year, Warrenville back yard.

22MR87. Fish hatchery, Culver. Fights frequent between song sparrows. Tumble together on the ground between short chasing flights. Vocalizations during fight a rapid-fire mix of toops, cheeps and bits of song.

11OC87. One still singing at Pratts Wayne Woods.

Song sparrow singing posture.

23MR88. A song sparrow sang from the end of an oak branch, halfway up a large tree, 15 feet off the ground, at edge of woods. Song: “chick turr, turr, turr-turr-turr, chick-tee-tiddle-tump” (last part variable). Switched to another song after a while: “cheedle, cheedle” was its beginning, but it stopped after a few of those. Throughout, alternated with a nearby male.

30JE90. Willowbrook. Some song sparrow calls have close similarity, even in tonal qualities, to some of chickadees’.

30SE99. Song sparrow at Willowbrook. Also seen 11&12OC.

27FE00. First song sparrow songs of the year heard near west branch of DuPage River at North Blackwell Forest Preserve.

4MR00. Morton Arboretum. A song sparrow displaced another and then sang, in brush beside a pond.

31MR00. Waterfall Glen. A song sparrow singing in tops of isolated 8′ shrubs beside railroad. Did not lift head to sing, but held head normally at 10-20 degrees above horizontal and maintained that angle while singing.

29AP00. Morton Arboretum. The call note is sharply bounded on each end, doesn’t trail off, is very high pitched.

Song sparrow nest on the ground in meadow area, Mayslake.

18JE00. Herrick Lake. A pair was very nervous about my presence, and though one had an insect in its beak they would not go to the nest though I was 20 yards away. A pair at Willowbrook earlier in the month behaved the same way.

22OC00. Song sparrows singing at Blackwell Heron Trail area. Some also were singing in Culver yesterday and the day before.

11MR01. Song sparrow singing at Timber Ridge Forest Preserve.

13OC01. Several at McKee Marsh.

22OC01. Several song sparrows singing, sometimes seeming to answer one another. Heron Trail, South Blackwell Forest Preserve.

3NO01. A single song sparrow song at Herrick Lake F.P., near big south marsh.

12OC02. At Fermilab, 2 kinds of calls from different individuals in different places. One had calls indistinguishable from the high one of white-throated sparrow. Bits of song, too. Another individual, perched in the open on top of a bush, exposed, had a call much like house sparrow’s.

Summer 2008. Song sparrows were among the species at Fullersburg raising cowbird young.

5OC10. Mayslake. Singing: white-crowned sparrow, phoebe, cardinal, song sparrow.

Savannah Sparrow Dossier

by Carl Strang

The species dossiers I have shared to date have contained plenty of information, but such certainly is not the case for all of my files. Today I share one of the more limited examples. Though I was surrounded by savanna sparrows in Alaska where I did my graduate research, my focus was on other species. These sparrows seem to be increasingly common in DuPage County as restored prairies continue to grow and improve, but I have not had the opportunity to do much more than see them here and there, and reminisce about the Alaska days when I hear their song.

Sparrow, Savannah

Known best from summers in western Alaska, where it was the only lowland tundra sparrow and was very common. Often their noisy early morning territorial squabbles on the tent frame roof served as our alarm clock.

7OC00. Two observed near Sea of Evanescence, Fermilab. After I flushed them, they flew to exposed perches.

22OC01. One among the cattails at Heron Trail marsh, South Blackwell. Streaks on the flanks are narrow and sharp, against a yellow background that contrasts with the paler color of the undersides generally; streaks on the upper chest not as distinctive. Yellow spot at base of bill clearly visible.

4MY02. For the second spring bird count in a row, I observed savannah sparrows at the Mallard Lake Forest Preserve parking lot, singing in the small planted trees in an otherwise open, short-grass area.

15SE02. A single savannah sparrow was in a sod farm field close to 3 buff-breasted sandpipers, the only birds on the ground anywhere near that spot.

12OC02. Savannah sparrows at edge of cattails beside extensive mudflat at the south end of Lake Law, Fermilab. A couple of them were out on the open mud, well away from cover. An American pipit approached them. One of them displaced the pipit, which immediately turned and chased the sparrow in a lengthy, twisting and turning flight that took them into the cattails.

Recent springs, Timber Ridge Forest Preserve. We usually find a few savannah sparrows around the farm paddocks and fields on the spring bird count.

Black-capped Chickadee Dossier

by Carl Strang

I have mentioned black-capped chickadees from time to time in this blog, most notably when introducing the topic of mixed flocks. Today I want to share my dossier on this species. In my dossiers I try to summarize what I know of a species from my own observations, as opposed to information from the literature or other outside sources. I began writing the dossier in the mid-1980’s. Observations begin with my date codes.

Chickadee, Black-capped

Ca. 1979. I remember sitting on the hawk watch at Reineman Sanctuary in PA in fall and watching as a sharp-shinned hawk zipping along the ridge suddenly turned its course so as to enter the tree canopy and caught a chickadee.

Boiling Springs, PA, 1980. A pair nested in hollow Ailanthus branch. One bird was electrocuted by a nearby electric fence. The other completed incubation and at least began to rear the brood alone. “Cheeseburger” call (more formally known as the fee-bee call) used early as apparent territorial signal.

Lombard, IL, 1981. A pair nested in a wren house, raised a brood, then returned and raised a second brood in the same house. In both cases, the pair traveled the neighborhood with their groups of fledglings.

Maple Grove Forest Preserve (F.P.), 1986. A pair was cleaning out an old cavity in a 10 foot snag in the maple forest. The excavating bird periodically removed beaks full of sawdust. Other bird remained nearby, giving occasional “chickadee” contact call.

Meacham Grove F.P., 24MY86. For the first time, I saw a chickadee taking advantage of tortricids hidden in folded leaves. One individual moved from one folded leaf to the next, vigorously tearing them open. I expected to see it more frequently than I have, given the lack of other birds with the appropriate foraging behavior in their repertoire, and the abundance of this food resource.

Willowbrook F.P., 1984-86. Chickadees have broods in the wooded riparian strip each spring. One pair appears to control the entire 1/4 mi. X 100-foot strip. Groups of more than 2 chickadees stay together through the winter. “Chickittaperk” vocalization appears to be an interspecific agonistic (dispute) display.

Chickadees weren’t common in Culver, Indiana when I was growing up. I remember being pleasantly surprised that a pair was present, nesting, at Miracles’ house in summer. This implies they were more easily seen in winter, at the feeder. Old trees and branches were scarce in our neighborhood.

Alarm call: one used a sharp “chiburr,” another answered with the same call.

11FE87. Willowbrook. Widely scattered chickadees in the Back 40 old field are maintaining contact mainly via the feebee call.

28FE87. A group of a half-dozen chickadees in trees: much sneeze-calling and chick-chick-chick-chick, but few chickadee calls, with much chasing and displacement. Later, many individuals made chickadee calls from widely separated perches. Then a period of silence followed.

14MR87. Maple Grove F.P. Seven chickadees moved together with a mix of chickadee and sneeze calls, occasionally briefly chasing one another. The group spread out widely, then used very high-pitched brief “cheeks” for contact.

29AP87. Chickadee caught adult noctuid moth, pecked body (scales puffed into the air), removed wings one at a time and they drifted to the ground, landing at least 3 feet apart.

1JL87. Willowbrook F.P. Chickadee pecking at mulberries.

10SE87. 0.5-3 seconds per perch in foraging, flying or hopping a few inches to 6 feet or occasionally 10 feet between perches, acrobatic hanging or hover-gleaning, pecking at dried leaves, turning and lowering body almost to upside down position to peer different ways.

13SE87. At West DuPage Woods F.P., several chickadees in a mixed flock with a redstart and a bay-breasted warbler.

17JE89. A broad-winged hawk callied repeatedly, in north end of Maple Grove F.P. Jays, flickers and grackles were highly agitated, flickers the most continuously vocal with “keels” every 2 seconds (2 birds). Grackles gacking frequently, too. A great crested flycatcher near, also vocal, but not clearly in response to the hawk; same with chickadees. Robins definitely disturbed, with nervous dee-dee-dee’s every 20 seconds or so. Jays in bursts, with several birds mobbing.

10JE90. Warrenville Grove. Chickadee saw me at sit near edge of woods. Alarm call “chicka-chicka-…(rapid)-dee-dee-dee”

3JL90. Chickadee plucked 2 unripe (white) mulberries from the branches. Dropped the first, then went for the second. Worked on it several seconds, holding it against a twig with its toes. I couldn’t tell if it ate the whole berry or just extracted seeds. Suspect latter.

7SE90. 2 chickadees eating dried crabapples, eating, pulling out and eating little bites.

30SE90. Chickadee and downy woodpecker eating poison ivy berries at Ann’s business property near Lafayette.

8FE00. Chickadees heard singing for the first time of the year at Willowbrook, and continuing in the following days. Also vigorously chasing each other this day, with agonistic vocalizations.

10FE00. Chickadees singing (feebee song) at Willowbrook.

1AP00. Morton Arboretum, Heritage Trail. A mixed flock with at least 1 brown creeper, 2-3 chickadees; juncos and robin in area. Chickadees longer on each perch than golden-crowned kinglets observed yesterday. A lot of looking around, not so constantly moving between perches, and making larger jumps between perches, 3′ common. Later, another association of chickadees, golden-crowned kinglets and a white-breasted nuthatch. These mixed flocks stand out because after going through a long segment of forest path where there are essentially no birds, suddenly there are many at once of several species. Again, chickadees sitting longer in one place and moving farther between perches. All moving together in same direction through forest, and moved away from me as I observed them. Later still, a couple of chickadees without associates. Perhaps this is the kind of observation that led to the local core species idea.

25JE00. This spring I have observed 3 chickadee groups with parents and fledglings, one at the Arboretum on 1JE, one yesterday at Willowbrook, and a third in another part of the Arboretum today. Instead of being spread out, in each case the groups were clustered in a small area no more than 20 feet in diameter, and they moved only very slowly. Feedings were frequent, so apparently the parents directed or led their young to food-rich locations.

11MR01. A chickadee at Timber Ridge Forest Preserve with a variation on the fee-bee song: the “bee” syllable is repeated, and each syllable has the usual hinged quality, i.e., “fee-bee-ee-bee-ee.”

More recent observations have focused on the role of black-capped chickadees in mixed flocks.

29AU01. Algonquin Park, Ontario, Mizzy Lake Trail. Flock 1: Golden-crowned kinglets, a young-of-the-year black-throated green warbler, black-and-white warbler, black-capped chickadees. Flock 2: At an edge between mixed forest and a lake. Black-capped chickadees, several black-throated green warblers (appear to be sticking together to form their own group within the flock), at least 1 blue-headed vireo, 1 female or young blackburnian warbler, 1 chestnut-sided warbler, and 1 Tennessee warbler. The black-capped chickadees are very abundant here, the most apparently numerous birds in the forest (because of their frequent calling and frequent presence). It is easy to see how migrant birds accustomed to forming mixed flocks with them here in the north could attach to resident birds they encounter on the trip south. Flock 3: Black-capped chickadees, Swainson’s thrush.

30AU01. Algonquin Park, Bat Lake Trail. Flock 1: Black-capped chickadees, a black-and-white warbler, the latter singing. Flock 2: Black-capped chickadees, red-breasted nuthatches, golden-crowned kinglets, 1 or 2 black-throated blue warblers, at least 1 Tennessee warbler, yellow-rumped warbler. The first three species are the vocal ones. These flocks are distinctive: you go for hundreds of yards seeing or hearing no small birds, then suddenly there is one of these diverse groups in a small area.

31AU01. Algonquin Park, Spruce Bog Trail. Flock 1: Yellow-rumped warblers, black-capped chickadees, red-breasted nuthatches, golden-crowned kinglets. Do more northern birds, living in more open forests, either not have chickadees to associate with, or perhaps the scattered trees (if they are) remove the advantages of mixed flocks? See if it’s true that the non-mixed-flock species tend to be more northern.

12SE01. Willowbrook. Flock 1 around west end of cross trail. 2 chickadees and 1@ of black-throated green, magnolia, Tennessee (sang a couple times), and 1 unidentified species. Flock 2 near the NW corner of nature trail, a magnolia warbler apparently alone.

13SE01. Willowbrook. A large but difficult to view mixed flock near office building: 3 chickadees, 2 redstarts, a blackpoll warbler, a red-breasted nuthatch, and many others.

14SE01. Willowbrook. Flock 1 around NW corner of nature trail: redstart, chickadee, downy woodpecker, Tennessee warbler, black-throated green warbler, magnolia warbler, red-eyed vireo. Flock 2 between eastern part of animal exhibit and bridge. Chickadee, 3 redstarts, downy woodpecker, blackpoll warbler (it is possible that the one seen earlier joined this flock; it was near this location).

17SE01. Willowbrook. Flock 1: 3 chickadees, 1 redstart, others perhaps; near west end cross trail. Flock 2, base of savanna, 2 palm warblers only. Flock 3, brush area east of Nature Trail, 2 chickadees only. Flock 4, another part of same brush area, 2 chickadees, a magnolia warbler, 1 other unidentified.

19SE01. Willowbrook. Flock 1, east exhibit area to bridge: 2 chickadees, 1 black-throated blue warbler, 1 redstart, possibly others. Flock 2, west end cross trail: staying around berry-feeding robins, waxwings and catbird, with no chickadees around: a black-and-white warbler, 2 downy woodpeckers, a redstart, a blackpoll warbler, possibly others.

25SE01. Elsen’s Hill, plateau above river. Flock 1: at least 8 vocal, active yellow-rumped warblers, and a ruby-crowned kinglet. Flock 2, very large and diverse, only some individuals identified: 2 chickadees, black-throated green warbler, blackpoll warbler, 2 Nashville warblers (1 low in an aster thicket another in low tree branches), downy woodpeckers, a parula behaving like the Nashville, 2 redstarts, a chestnut-sided warbler.

26SE01. Willowbrook, between bridge and animal exhibit. 2 chickadees, and at least one @ of vireos (Philadelphia, red-eyed, yellow-throated), warblers (Tennessee, magnolia, parula, black-throated green), scarlet tanager, red-breasted nuthatch.

27SE01. Willowbrook. Flock between bridge and exhibit fence. 2 chickadees, 1 Tennessee and 1 magnolia warbler.

30SE01. Fox River and Island Park, Batavia. Many yellow-rumped warblers spread out all over, some hover-gleaning, some flycatching, others reaching for poison ivy berries. With them, a chickadee, a male Cape May warbler in the top of a silver maple, very active in the short time I saw it.

14SE02. Elsen’s Hill. I walked for several minutes, seeing apparently independent Tennessee warblers (2 together) and a Nashville warbler before encountering a large flock. This flock seemed to be changing composition over time, i.e., after my initial observations I walked a short distance away, then returned, and when I came back, some birds were the same but there were several new ones, as well. Later, after following the flock for 50 minutes or so and losing them in a direction I did not want to pursue in the brush, I returned to the starting point and a small mixed flock was there, with some of the birds I saw initially (apparently, none were marked of course) and a couple added ones. Initial group: a blackpoll warbler, 2 red-eyed vireos, 2 redstarts, an essentially silent chickadee, a black and white warbler, a Tennessee warbler, a Swainson’s thrush, a female or young black-throated blue warbler that was the only flock member calling consistently, all foraging in brush understory within 15 feet of the ground (the redstarts were the only ones consistently going above 10 feet; this was after 9 a.m.). Flock after my return: golden-winged warbler (like the redstarts, up higher, and very active, including flush and pursuit), a male and 2 female or young black-throated blue warblers, 2 Tennessee warblers, a black-throated green warbler, 3 redstarts, 2 blackpoll warblers, a black and white warbler, a blackburnian warbler. After it had warmed up some, later, a magnolia warbler foraging 20-25 feet up and the other birds also have gone higher. Doing a lot of reaching, and spending much time looking from each perch. At 10:45 I returned to the starting point: 4 noisier chickadees, 2 red-eyed vireos, a blackpoll warbler, a male redstart, a magnolia warbler, all except the chickadees foraging higher, throughout the tree canopies. Also a downy woodpecker, black-throated green warbler, Swainson’s thrush.

25AU08. Fullersburg Woods. First mixed flock of the fall migration has 2 chickadees, a downy woodpecker, a Tennessee warbler and a Canada warbler.

28AU08. Fullersburg Woods. Mixed flock just S of Willow Island bridge: 2 chickadees, 2 Tennessee warblers, 2 magnolia warblers, a gnatcatcher.

29AU08. Fullersburg Woods. Mixed flocks: One with four chickadees, two Tennessee warblers, a magnolia warbler and a black-and-white warbler. Also, 2 Tennessee warblers together apart from mixed flock. At mid-day a mixed flock near the junction of trails with 3 chickadees, 3 Tennessee warblers, a white-breasted nuthatch, a magnolia warbler, a parula. Chickadees were doing a lot of hanging upside down, Tennessees less acrobatic running along tops of branches and reaching, magnolia and parula more rapid movements, hopping between branches, nuthatch on bark, all in top half of canopy.

13SE08. Kettle Lakes Provincial Park, Ontario. Large, mixed flock in an area around 75 yards in diameter: at least 2 black-capped chickadees, 5 golden-crowned and 4 ruby-crowned kinglets, 4 yellow-rumped warblers, 2 red-eyed vireos, downy woodpecker, black-and-white warbler, black-throated green warbler, redstart, red-breasted nuthatch. I’m hearing white-throated sparrows, but they seem all near the ground rather than up in the trees with the others. Weak songs from ruby-crowneds, the black-throated green and the black-and-white. This is mainly an area of aspens with some jack pines. Mixed flock: at least 2 chickadees, at least 2 golden-crowned kinglets, 2 ruby-crowned, and a yellow-rump. Aspen grove again with some jack pines and a couple white pines.

15SE08. Nagagamisis Provincial Park. On trails, encountered a little flock of at least 7 ruby-crowned kinglets. Nothing up with them first time through, but white-throated sparrows lower down in that area (on the way back a chickadee, a brown creeper, 3 golden-crowned kinglets and a Swainson’s thrush added). Birds have been few, and I cannot discount the possibility of an association of the white-throated sparrows with this group. On the Time Trail, balsam fir the dominant tree with plenty of white spruces, some black spruces, white cedars, paper birches. Another mixed flock with at least one chickadee, 2 ruby-crowns, 3 golden-crowns.

21SE. Mayslake. A mixed flock at edge of Area 9 and grounds containing a black-throated blue warbler (new preserve species), black-throated green, 2 redstarts, 2 blackpolls, chestnut-sided, Nashville, black-and-white, magnolia, and a chickadee.

Two-spotted Tree Cricket

by Carl Strang

One of the goals in my singing insects study this year is to sort out the songs of three arboreal tree crickets. In the field I have found that their songs are not as distinct from one another as reference recordings and descriptions seemed to suggest. Two of the three species I have seen, and so confirmed their presence in DuPage County. Today I begin with what I suspect may be the only one singing as early in the season as late July and early August: the two-spotted tree cricket.

Two-spotted tree cricket 1b

This photo shows a female, with the two large spots on her back that give the species its name (males lack them, and are pale). She sits on the arm of one of the 2006 Roger Raccoon Club  kids, who brought her to me for identification. Until two weeks ago, she was the only one I had seen. Certainly the references were correct in saying these are not easy to find. They live in trees, often well above the ground. The male’s song, which you can find here  or here, is a strained, often dissonant sounding trill that is interrupted fairly frequently by brief pauses that often are filled with stuttering sounds. Unfortunately, the same description applies more or less to the songs of Davis’s tree cricket and the narrow-winged tree cricket, though the tone of the last seems more melodic to my ear.

Two-spotteds begin to sing at dusk. On August 6 I was at Timber Ridge Forest Preserve, strolling the Great Western Trail with ears open for insect songs, when scattered tree crickets in this target group began to sing. All had identical songs, but one in particular seemed to be closer to the ground and just off the trail. After a short time I found him.

2-spotted singing b

He was on the underside of a big grape leaf. Here he is close up.

2-spotted singing cropped b

He was using a trick for which some of the tree crickets are known. He had chewed a circular hole in the leaf, and was using it to amplify and possibly direct his song (tree crickets sing by elevating their wings and vibrating them against one another).

2-spotted wings down b

I made a recording, then prepared to collect him for identification. But when I put my flashlight on him again I found this was unnecessary.

2-spotted pair 2b

A female had arrived on the scene, and there was no mistaking her identity. The male kept his wings elevated, and continued to vibrate them occasionally in song. She was palpating her way slowly up his back in search, I believe, of secretions that some of the tree cricket males provide as nuptial food gifts in a prelude to mating.

2-spotted pair 1b

The next evening at dusk I was at Springbrook Prairie Forest Preserve. I heard the same song coming from near the top of a 15-foot-tall bur oak beside the trail. Looking up toward the point from which the sound seemed to be coming, I noticed that one of the leaves had a circular hole in the middle. When I illuminated it with my flashlight, sure enough, there was another male two-spotted tree cricket. So, at least with plants having relatively large leaves, I now know to look for distinctive circular holes that may help me to find these elusive insects.

American Robin Dossier

by Carl Strang

 

Today’s post is another in my series of species dossiers. It begins with the summary paragraph written when I established the dossier in late 1986 or early 1987. I have edited out some less informative entries.

 

robin-1b

 

American Robin. Familiar bird of natural and artificial savannas. Primarily a summer resident, although small numbers remain in northern IN and IL around fruit-rich areas as long as winter weather is not too severe. Waves of migrants seen each spring and fall. Nest typically on branches of broadleaf trees, or in shrubs. Nest of grasses and mud, with deep inner cup. Sometimes grasses dipped in mud before delivery to nest. Eggs deep sky-blue. Young may get out of nest a short distance a couple of days before fledging, but after early-morning departure from nest they tend to travel some distance and do not return. Young scattered, tended individually by parents, who swoop and may peck at people or mammals which approach the young. Fledglings have dark spots on breast. Worms and insects hunted on ground in summer; fruit the winter food. Mulberries eaten by both adults and young in early summer. Winter berries include buckthorn, mountain ash. Song dominates habitat in early morning and dusk. A musical series of phrases, each composed of 2-3 clear, slurred whistling notes sung from mid to high perches in trees, on aerials, etc. Alarm call “cheet’-der-der-der-der.” Occasional battles, presumably territorial, take place. Striking white spots on tips of tail feathers may be “follow-me” signals. Preyed upon by cats, on occasion. When hunting worms, run 2-20 feet over the ground, stop, then may move a short distance, lean down with side of head turned toward Earth, then possibly reach down and pull up worm with beak.

26AP80. Pennsylvania. Robins, when startled into flight across the path of an approaching car, appear to use body-twisting and turning tactics more appropriate to flight from a hawk.

14JE87. Young-of-year eating mulberries at Culver Fish Hatchery.

9SE87. Large flock in Willowbrook Back 40. One ate grapes.

16SE87. In the evening, within a half-hour before sunset, robins were migrating south over Willowbrook. They flew just above treetop level, in flocks of 3-30, occasionally perching to rest for a time in the treetops, then moving on. The birds occasionally called to one another in flight, alternately flapping in short bursts, and gliding.

29AP88. A robin on a nest at Pratts Wayne Woods Forest Preserve, 6 feet up in crotch of a 15-foot, 3″dbh fencerow box elder.

7AU88. Young robin, apparently independent but still with spots, eating black cherries in Willowbrook Back 40.

30AU88. Lots in Back 40, mostly on ground but 1 in black cherry going after fruit.

5OC88. Robins eating grapes, Back 40.

6OC88. Robins eating gray dogwood fruits, Back 40.

12OC88. Robins eating honeysuckle fruits, Back 40.

17JE89. A broad-wing calling repeatedly, in north end of Maple Grove Forest Preserve. Robins definitely disturbed, with nervous dee-dee-dee’s every 20 seconds or so.

28AU89. Robins eating gray dogwood fruit, Back 40.

21OC89. Robins eating buckthorn berries, West DuPage Woods Forest Preserve.

3JA90. A robin singing very softly at Herrick Lake Forest Preserve. Temperature ~40F, sun.

 

robin-b

 

14JA90. A large robin flock, scattered in woods on ground, moving as they do when hunting worms. Ground frozen. Saw occasional reaches to turn over a leaf, but no feeding.

7AP90. Robins in forest at Winfield Mounds Forest Preserve, throwing leaves with beaks to find food.

2JE90. Culver. A robin foraging on lawn (20 feet from nearest shrub) singing, 7:30am.

14SE90. Willowbrook, robin ate a couple small grapes, swallowing them whole.

JA99. Robins present on Willowbrook preserve all winter. Heavily fruiting asiatic bittersweet (Celastrus vine) a particular attraction.

6FE99. At Morton Arboretum, in an area thick with honeysuckle beneath a mesic forest, many robins feeding on the ground, vigorously throwing leaves aside and eating very small things too quickly to identify. I dug, found a mix of insects and fruit-like items.

9SE99. 2 robins eating buckthorn berries at Willowbrook.

13OC99. Robin occasionally singing at Willowbrook.

8FE00. Robin eating buckthorn berries at Willowbrook. They are fewer and more intermittent than last winter, 1 or 2 at most at any time.

13AP00. Willowbrook. One robin chasing another in the savanna. Could robins have nested in prairie savannas in years when fire burned off the tall plants beneath the trees? They might have fledged an early brood before the new plants got too tall for them.

16AP00. Willowbrook. A robin carrying nesting material.

1JE00. Arboretum. Along the Joy Path, a robin was perched in the lower branches of a maple, well concealed from above by leaves, sitting absolutely still and barely opening its beak at intervals to give a high-pitched note, somewhat waxwing-like but louder, better defined, that was difficult to locate.

15JE00. Arboretum. Near Parking Lot 7, when I arrived around 8am, 3 robins were giving the high‑pitched thin call repeatedly, and the forest otherwise was relatively quiet. After 10 minutes, a Cooper’s hawk started calling nearby, then flew out away from the forest edge until an eastern kingbird started to chase it. It immediately turned around and flew back the way it had come, and kept going. The robins then were quiet.

16JE00. Willowbrook. In the afternoon, a Cooper’s hawk perched near the west edge of the prairie, drawing alarm calls from a robin (the hawk‑whistle warning call) and a cardinal, and a chorus of 7 loudly mobbing jays.

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).

11MR01. A robin singing loudly, Timber Ridge Forest Preserve.

28JL01. A newly on-its-own robin chased a cicada through the air, the insect giving its predator-discouraging call, but broke off the chase and flew back the way it came. The robin was never close to the cicada during the part of the chase I saw.

13MR02. First morning of robin (or any) dawn chorus at my house.

Woodcock Dossier

by Carl Strang

 

After yesterday’s account of woodcocks at Mayslake, I thought I’d share my dossier  on that species. As always, I began with my observations of the species prior to setting up the dossier in 1987, then added observations coded by date:

 

Once I got a close look at one beside the Tippecanoe River. It walked slowly, with a peculiar bobbling gait, teetering on its short legs. Courtship display observed near Purdue in IN, in PA, and in DuPage County, IL. Male usually flies to his dancing ground in mid-late dusk, with distinctive mothlike flight (continuous flapping of round wings, with some curves and turns in course). Display begins with male on ground, emitting a flat, buzzing call, “beezt,” at 2-8-second intervals. A close observer hears a faint hiccup preceding (coupled to) this “peent” call. The bird turns occasionally to face in different directions. After several minutes of peenting the woodcock takes off, flying low with a whistling titter sound, then turning and flying upward in a spiraling or zigzagging climb. When the bird is near the apex of his flight he still is roughly over his ground site, and the whistling becomes more frantic and labored, in bursts rather than continuous. Finally he hovers or zigzags at an altitude of at least 300 feet, singing a beautiful plaintive whistling song with repeated phrases of separate notes going up in pitch, then down (usually 3 notes, with increasing emphasis, then 3 notes down with lower emphasis). Finally the bird becomes silent and zigzags steeply back to Earth, usually landing where he started, in a little arena of short grass within an early-shrub-stage old field near heavier brush. Often a bird will have 2-3 alternate ground sites. Began late March, ended by 1MY in northern IL, often extending later (even into June) in Indiana, e.g. at Hartz Lake. One bird was observed dealing with an intruder on 2 different nights at Pratts Wayne Woods Forest Preserve, in 1986. Intruder peented a couple times, resident made a loud long buzzing call, then flew toward the intruder, who took off. The pursuing bird escorted the intruder away the first time, but chased it closely for a long time the second night, eventually returning to his initial site. In NE IL the birds danced for around 45 minutes, going up 3-12 times during that period. As the season grew late, they went up fewer times.

12JL87. Flushed 2 in nearly dry artesian-well pond at Culver Fish Hatchery. Looked a little unsteady in flight: youngsters?

8AP89. No woodcocks flew at Pratts Wayne Woods (I heard 7-9 the previous week, and they flew for a program 4 days before that). Weather cold after a cold front, with snow. Also failed to fly 4 days later. Weather cold through that period. A couple peents each night, no more.

15AP89. Hartz Lake, IN. I approached 2 displaying woodcocks. One walked around a lot, over a 10-15 foot area, stretching up and walking slow or fast, between flights. Other walked only a little. First’s peenting frequency became very rapid once, when another woodcock flew over.

13MY89. Still going strong at Hartz Lake. After quitting in dark, one began peenting intermittently later (I was camping), well after dark, and even flew once, at ~11pm. No moon, dark with intermittent showers.

26-29MY90. Hartz Lake. Display still strong on 26th, with about 5 flights in evening. But number of flights tailed off daily. Both morning and evening displays. Morning pattern the reverse of evening’s. Only peented morning of 30th.

2JE90. Woodcock tracks in muddy rut of path at Pratts Wayne Woods. Interspersed with many beak-probe holes. Holes 1/8″ in diameter, sometimes soft mud produces a little larger hole. Middle toe 1.25-1.5″ long, side toes around 1-1.25″.

 

woodcock-track-drawing1

 

28FE00. 3 woodcocks peenting in north part of Warrenville Grove Forest Preserve. At least one did complete display at least once.

27MR00. As I ran the prairie path near the Northwoods subdivision at Timber Ridge Forest Preserve, I heard 2 peents from a marshy area at around 6:15pm, well before the light was dim enough for the usual beginning of the courtship display.

27AP06. Fullersburg. Woodcock probed in wet soil near edge of Salt Creek on Willow Island. Caught a large worm, pulled it out, cheeks bulged as it swallowed. Resumed probing after rocking from foot to foot several times. Later, when approached by a red-winged blackbird, it severely cocked its tail up beyond vertical. When the blackbird moved on the woodcock flew across the creek to a brushy area to the south.

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