Photo Bag

by Carl Strang

Time to shake out some miscellaneous photos from 2015 that didn’t make other posts.

I liked this October scene of sumacs contrasting with pines.

I liked this October scene of sumacs contrasting with pines.

This buck checked me out as I explored a remote area of Hidden Lake Forest Preserve at the end of October.

This buck checked me out as I explored a remote area of Hidden Lake Forest Preserve at the end of October.

The classic pose of a gray squirrel gnawing into a walnut at Fullersburg Woods in November.

The classic pose of a gray squirrel gnawing into a walnut at Fullersburg Woods in November.

The highlight of my group’s Christmas Bird Count was a merlin at West Branch Forest Preserve.

The highlight of my group’s Christmas Bird Count was a merlin at West Branch Forest Preserve.

I hope your 2015 was a great one, and that 2016 will be as well.

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Sound Ideas: Variegated and Cuban Ground Crickets

by Carl Strang

One of the highlights of the field season just past was finding variegated ground crickets, a long sought species, right under my nose, as described earlier.

Variegated ground cricket

Variegated ground cricket

Here is a recording I made in 2011 in the lawn at Mayslake Forest Preserve. I have trimmed out all but the critical end portion, which includes the abrupt end of one trill and the crescendo beginning of another:

I had made the incorrect assumption that these crickets, living in cracks and holes in the lawn, were Say’s trigs. Here is a recording of one of the trigs from nearby Fullersburg Woods Forest Preserve. The ending likewise is abrupt, but the next trill has a “chuwee” beginning.

In both cases the trills are extended, longer in the trig as a rule. A third species worth comparing here is the Cuban ground cricket. I have not encountered this species in the Chicago region, yet, but I need to be alert for it. Previously known only as a southern species, Lisa Rainsong has found it to be common in the Cleveland area. Ecologically it seems to resemble the variegated ground cricket in liking wet areas near lakes, rivers, and marshes, but is active on the surface rather than remaining out of sight in gravel or in soil crevices. Here is a partial recording of a Cuban ground cricket living in a terrarium in Lisa’s home:

The repeated brief scratches or chirps are from a striped ground cricket in another terrarium. The Cuban ground cricket, a member of the same genus as the variegated, likewise has a crescendo beginning, an extended high-pitched trill, and an abrupt ending. The pitch is just a little lower than that of the variegated, but otherwise they are much the same.

A final note on this topic is that my analysis allowed me to identify a recording from Illinois Beach State Park as belonging to a variegated ground cricket.

The singer was located beneath this vegetation, a few steps from the Dead River. I could not find it, and now realize that it must have been beneath the surface.

The singer was located beneath this vegetation, a few steps from the Dead River. I could not find it, and now realize that it must have been beneath the surface.

Here is an excerpt from the recording (you may need to turn up the volume):

All of this has me primed to document variegated ground crickets elsewhere in the coming season, and to be alert for Cuban ground crickets.

 

Some Final Insect Photos

by Carl Strang

The arrival of snow flurries and skim ice on the lakes and marshes means that insects are pretty much done for the year. Today I will share some photos of a couple late season observations. One of these was at Fullersburg Woods Forest Preserve.

This is the red flat bark beetle, with the musical scientific name Cucujus clavipes.

This is the red flat bark beetle, with the musical scientific name Cucujus clavipes.

I recognized that little critter thanks to the Observe Your Preserve website, through a contributed photo by Linda Padera.

Some of us in the Education department participated in a morning bioblitz at the Lemont Quarries at the beginning of November. It was a chilly morning, but we found a few insects, including a new species for me, Walsh’s grasshopper.

Not a singing species, this short-winged hopper is in the spur-throated group.

Not a singing species, this short-winged hopper is in the spur-throated group.

The hind tibia are orange or red with yellow bases.

The hind tibia are orange or red with yellow bases.

This grasshopper turned up in its typical habitat, a mix of forbs and brush at the edge of a woodland.

Ruby-crowned Kinglet Dossier

by Carl Strang

Our two species of kinglets are early season migrants. Today’s featured species usually shows up a little later than the golden-crowned kinglet.

Kinglet, Ruby-crowned

Ruby-crowned kinglet

Ruby-crowned kinglet

I have seen this little northern-breeding bird in migrations, in northern IL and IN. Usually they travel in flocks. In 1986 they moved north later than golden-crowned kinglets, in mid-late April, mainly, in DuPage County.

26OC86. Single seen in brush at Willowbrook.

18AP87. First of year seen at Dunes State Park, IN. Has louder, harsher voice than golden-crowned. More chatter. Resembles goldfinch with a burr.

24AP87. Pratts Wayne Woods (Prairie Path). Moving from bush to bush. No vocalizations. Also, little or no probing; foraging by sight only.

21AP89. First migrants of year seen in the little park across from the Newberry Library, Chicago.

22AP89. Both kinglets at Willowbrook, using a mix of hover-gleaning and even more pursuit. Also, this is the kinglet with the song, high and thin, that has one section of accelerating notes flowing into a “chee-chee-per-chi-bee” section.

24AP89. Still at Willowbrook.

25AP89. Lots of them at Willowbrook today. First warm early morning of the year.

26AP89. A few present at Willowbrook.

3MY89. Still a few.

21OC89. Present in West DuPage Woods Forest Preserve.

17AP90. Observed at Willowbrook.

22AP90. Winfield Mounds. Has song “tsee-tsee-…(accelerating)…tsee-tsurd-tserber-tsee-tsurd-tserber-tsee.”

15OC90. Ruby-crowned kinglets at Willowbrook.

23SE91. IL Beach State Park. Kinglet in black oak, reaching, lunging, and very short-flight hover gleaning. 3-12″ per move, less than 0.5 second per perch.

12AP99. Willowbrook. Golden-crowned kinglets nearly gone (saw only 1), but ruby-crowneds have arrived.

20AP99. Ruby-crowneds are showing their red crests today (first time since they started arriving), defending little feeding areas along the stream at Willowbrook. Flycatching and flush-pursuit foraging.

21AP99. Today they still are foraging with much aerial pursuit, but are moving together in groups. No crests showing.

7MY99. A second major wave of ruby-crowned kinglets, probably females, at Willowbrook. None seen after this date that spring.

1&11OC99. Migrants at Willowbrook.

12AP00. Migrants at Willowbrook, singing occasionally.

16AP00. Willowbrook. Several ruby‑crowned kinglets on the preserve, some singing. Two observed showed much more flycatching than golden‑crowneds showed this spring, and some hover‑gleaning. Longer pauses on each perch while searching for an insect to pursue.

22AP00. Morton Arboretum. Both kinglets still present.

14OC00. The past week at Willowbrook, and today at Fermilab, ruby-crowneds foraging mainly in prairie areas with scattered shrubs, concentrating on the shrubs but occasionally visiting goldenrods as well. This open area foraging contrasts with their usual spring woodland preference. Golden-crowneds this fall have been sticking to the woodlands.

7AP01. A couple ruby-crowns seen among numerous golden-crowns at Greene Valley Forest Preserve. One of them occasionally sang.

20OC01. A kinglet foraging alone in a tall herbaceous patch (mainly goldenrods that have gone to seed) at McKee Marsh. I have seen several others behaving similarly the past couple of weeks. It flies from stalk to stalk, perching just below the seed/flower heads and looking all around, apparently for insects. Occasionally makes a hover-gleaning move, often against a seed head.

13OC02. An individual giving a quick, 2-noted call similar to chattering of house wren or perhaps yellowthroat.

9OC05. West DuPage Woods. Golden-crowned kinglets foraging in crowns of trees while ruby-crowneds are mainly within 4 feet of the ground in herbs and shrubs beneath, only occasionally and briefly venturing into the lower canopies. Ruby-crowneds have a quick, chattering-quality “checkit” call. Hover-gleaning their most common foraging method today.

5-11NO05. During my southern vacation, I found golden-crowned and ruby-crowned kinglets all the way to the Gulf of Mexico

23OC07. Fullersburg. A ruby-crowned flashed red in a brief squabble with another.

9AP13. Mayslake. A ruby-crowned kinglet was perched in place and chattering much like an irritated house wren.

Sound Ideas: Say’s Trig Variations

by Carl Strang

As I listen for singing insects in the summer, at this point I recognize nearly all that I am hearing. Sometimes I hear something that obviously is new and different, as was the case with the green-winged cicada last summer, and I put in the effort needed for an identification. Sometimes a sound is so rarely heard that I am inclined to pass it off as an anomalous sound from a familiar species, though I store it in memory in case it turns up again. Today’s story is a case in point. On a couple occasions last summer I heard songs with the pattern of a confused ground cricket, brief trills with brief spaces between them, in a fairly regular rhythm. The problem with this was that the singers, which I was unable to see, seemed to be above the ground, and they were in wetland edges rather than upland woods. The sound quality was similar to that of Say’s trig, and I figured that this might be an alternate song of that species.

Say’s trig is a common small cricket.

Say’s trig is a common small cricket.

The typical song of this species has been well described as a “silvery trill.” Here’s a recording:

As I dug through my past recordings, I was surprised to find that the one I had made of a temporary captive in my house had the interrupted pattern:

There was no question of the singer’s identity. I also found a field recording of this pattern, at Fullersburg Woods near Salt Creek:

In this example the rhythm is less regular, and leads in the end to an extended normal trill. I am not finding a reference to this interrupted version of the song in the literature I have. It could be a context-driven alternative, or possibly individual variation. I’m certainly not prepared to suggest a different species, though new species in this genus continue to be sorted out.

Seeking the Lyric Cicada

by Carl Strang

Last Thursday I searched for the northernmost lyric cicadas, having found them superabundant in Kendall County and absent in the portions of McHenry County I surveyed. This is a woodland species that seems especially common in bottomland forests, so I took advantage of our glacial legacy and followed rivers north and south (rivers developed in low zones between the concentric end moraines), but also stopped at other woodlands along the way.

Lyric cicada, Tibicen lyricen

Lyric cicada, Tibicen lyricen

There clearly is a gradient in density from south to north. In Kendall County, and along the Des Plaines River at the south edge of DuPage County, large numbers of lyric cicadas form loud choruses. In central DuPage County, at locations such as Fullersburg Woods and Mayslake, this is a regular part of the insect fauna, but they are down to countable numbers of individuals.

The clearest indication came as I followed the West Branch of the DuPage River, and continued north beyond it.  At Blackwell Forest Preserve, in west central DuPage County, there was a ratio of 11 lyric cicadas to 18 or so Linne’s cicadas (= 0.61; Linne’s has a fairly uniform density through the area). At Elsen’s Hill, a few miles farther north, the ratio was 4:7 (0.57).  Several miles farther north, at West Branch Forest Preserve, the ratio was 3:7 (0.43). The farthest north I found this species was at Shoe Factory Woods, in north Cook County, where the ratio was 2:12 (0.17).

Shoe Factory Woods has some good prairie and savanna restorations going.

Shoe Factory Woods has some good prairie and savanna restorations going.

By that point, though, cicadas had entered their afternoon lull, and I wasn’t hearing many of any species. Shifting west and driving south along the Fox River, I heard the next lyric cicada at the north edge of St. Charles, a point close in latitude to West Branch Forest Preserve. For now I have a sense of what is happening in the northern edge of this species’ range, but I will continue to monitor them for changes, and to continue seeking that northernmost population in the region.

White-throated Sparrow Dossier

by Carl Strang

The white-throated sparrow is a common migrant and uncommon wintering bird in DuPage County, but it nests well north of here, so my observations are limited accordingly. Most of these notes were made before I knew there are dusky-colored adults, so some of the observations of “immature” birds no doubt were adults.

Sparrow, White-throated

White-throated sparrow

White-throated sparrow

This is a common migrant, observed around Culver, Lafayette, south central Pennsylvania, and DuPage County, Illinois. They occur in flocks, and forage on the ground in woods or old fields with at least some low brush. Often they scratch through litter. Their whistled song has been rendered “Old Sam Peabody, Peabody, Peabody.” The first two syllables are on the same higher pitch, the remaining ones on the same lower pitch.

6NO86. On dry leaf litter in dense brush in Willowbrook’s Back 40, one hopped along a straight course nearly upright, scanning the ground beneath and just ahead of it.

22AP87. First singing I have heard from this sparrow this spring.

27AP87. White-throated sparrows were foraging in the wooded riparian area at Willowbrook by kicking litter backwards with both feet while staying in place and looking down.

29AP87. Young sparrows were foraging up in shrubs and the lower branches of trees, making occasional “tseed” notes (high, thin, but fairly level in pitch). They used a probing-reaching-hopping foraging style.

1MY87. White-throateds are still abundant, adults using the in-place kicking technique on the ground. They also were hopping and looking (10-inch hops, pausing for 1-2 seconds). Two other adults on the ground and a youngster in the trees were probing, looking, hopping and walking among branches.

5MY87. Young birds were eating elm seeds (4 individuals doing so in the same treetop). They pulled seeds off with a sideways twist of the neck.

11MY87. There are still some white-throats around.

23SE87. First fall migrants in Willowbrook’s Back 40 riparian strip. Also observed SE25, 28, 30, and OC9, 11 (Pratts Wayne Woods), 13, 16.

4AP88. A number of white-throated sparrows have arrived in Willowbrook’s Back 40, but are only uttering high-pitched contact calls. A few were singing by 18AP.

13SE88. First fall appearance, Willowbrook Back 40.

21AP89. In the small park across from Newberry Library in Chicago, towhees, hermit thrushes and white-throated sparrows all were feeding out on the mowed lawn at noon like robins, the thrushes even with the run-and-pause.

2NO89. A few still at Willowbrook.

28AP99.  First white-throated sparrows of the season noted at Willowbrook. Also seen 5MY99 at McDowell Forest Preserve. Last seen this spring at Willowbrook 12MY, but only a few observed there this year.

13OC99. White-throated sparrows are much more abundant in fall than in spring at Willowbrook this year. One heard singing occasionally today.

26OC99. Willowbrook. White-throated sparrows are in the old field, brushy prairie area today (yesterday they were in the woods; today it is overcast, cold, calm; yesterday was clear, cool, breezy).

1NO99. At Willowbrook, sparrow eating dried gray dogwood berries.

18NO99. A sparrow eating Amur honeysuckle berries.

19JA00. Two white-throated sparrows at Willowbrook, on ground under dense brush, using the in-place kicking technique.

29-31AU01. Algonquin Park, Ontario. White-throated sparrows are in small groups, feeding on the ground and calling, once singing. Their behavior is the same as in migrants at Willowbrook, except that they are in smaller and very widely spread groups.

2FE04. Two at Waterfall Glen near Poverty Savanna, adult plumage.

24OC07. Fullersburg. I spshed out a sparrow that was giving the thin-ending call. It was a young white-throated sparrow, which immediately began emitting the “bink” call while turning in a rapid, jerking manner and turning its head quickly to look around. No other sparrows were calling in that area. (I have come to associate this “bink” contact call with young birds; certainly it is used much more often in the fall migration, seldom in the spring, when the thin whistled contact note predominates).

Coyote Species Dossier

by Carl Strang

I’ve been sharing smaller dossiers in recent weeks. Here is a somewhat longer one. This is a rare instance in which nearly all of my experience with a species came as an adult, in DuPage County.

Coyote

Coyote. The eyes, glowing from the flash, suggest the fearful image many suburbanites have of coyotes. They are actually relatively small animals, usually less than 30 pounds, but look bigger thanks to the long legs.

Coyote. The eyes, glowing from the flash, suggest the fearful image many suburbanites have of coyotes. They are actually relatively small animals, usually less than 30 pounds, but look bigger thanks to the long legs.

When I came to DuPage County in the early 1980’s, coyotes were known to live at Waterfall Glen and the West Chicago Prairie area. My first experiences were footprints at the Tracker Farm in New Jersey, and then a bed at the far end of a private (now destroyed) marsh in Glendale Heights, Illinois. I saw one briefly in the desert at Big Bend National Park, Texas.

30JA88. Hartz Lake area, near Monterey, Indiana. A coyote slow-loped across a dune. Front foot 2×2 inches, hind foot 2 long by 1.5 wide. The coyote loped with its body held at an angle so the front feet were on one side, hind feet on the other.

A computer rendition of the original sketch.

A computer rendition of the original sketch.

29JE89. Coyote at McKee Marsh. It stopped briefly as it came around a bend in the mowed trail and saw me coming toward it. Big ears, light build and size gave it away immediately. It held still only a couple seconds, then turned and ran. After I got around the bend I got a glimpse of movement to the right as it leaped through a tall grass meadow and ran into the forest.

19NO89. Tracking coyotes in the half inch of snow that fell last night on the McKee Marsh area. The coyotes’ activity was mainly on and around the frozen ponds. Frequent rolling, sometimes in urine. Fox tracks were absent from the wide area I walked in north Blackwell. Foxes were common there before; have coyotes driven them off? Trot the most common gait, in the diagonal position. Diagonal walk frequent, lope occasional. Prints’ actual size 2.25 long x 2 wide, 22-24 inches between corresponding track in each pair. A coyote picked up an old, small dead snake and played with it. Rolled in small amount of its urine on ice of marsh. Stopped and removed 2 burdock burs (some hairs still were attached). Coyote diagonal walk on ice 19-21.5 inches between steps. Lots of activity possibly by one individual, with lots of coming and going (small loops out and back), centering on a rotten goose egg, frozen in ice and apparently opened last night.

Diagonal trot gait, the usual pattern used by coyotes. In this case, the front feet made the right-hand tracks, the hind feet the left-hand tracks.

Diagonal trot gait, the usual pattern used by coyotes. In this case, the front feet made the right-hand tracks, the hind feet the left-hand tracks.

13DE89. Probable coyote scat, 3/4 x 3.5 inches, Hartz Lake.

16DE89. Both red foxes and coyotes present, yet, at McDowell Forest Preserve. Former about 12-16 inches between steps in walk, latter 15-20 inches.

20JA91. I saw two coyotes working together at McDowell. When first spotted they were about 20 yards apart, walking single file. I was able to approach within 60 yards on the path, then they detected me and bolted. They had been investigating a brushy area near a bridge over a small stream, they ran back north and east when escaping.

26JA92. Tracks of a coyote in woods at Hidden Lake, in an area also visited some nights by red fox. Strides were 20-inch steps compared to the fox’s 16 inches. Coyote followed deer trails sometimes.

The hind foot of a coyote, left, is smaller and has a rounder heel. The front foot, right, is larger and has a more triangular heel shape.

The hind foot of a coyote, left, is smaller and has a rounder heel. The front foot, right, is larger and has a more triangular heel shape.

28JA99. Cottontails this winter are not visible during the day. Tracks indicate they are hiding in metal drainage culverts. Coyotes occasionally vainly try to dig them out, or perhaps are trying to spook them out.

10FE99. A fresh coyote scat on the Willowbrook Nature Trail near the marsh contained both hairs and feathers, the latter from a bird in the cardinal to mourning dove size range.

Coyote scats, often deposited in the middle of trails, provide a dietary record. Either don’t handle them, or do so with disposable gloves or sticks, as they may contain parasite eggs.

Coyote scats, often deposited in the middle of trails, provide a dietary record. Either don’t handle them, or do so with disposable gloves or sticks, as they may contain parasite eggs.

25FE99. Willowbrook. Fresh snow fell yesterday evening, and reveals that 2 coyotes covered the entire preserve thoroughly last night, and more, going out into surrounding residential areas. Sometimes the coyotes were on the same route, sometimes they separated. Once they bedded down within 2 feet of one another in a dense brushy area roughly equidistant from the nature trail and residences, impossible to see by anyone more than 50 feet away.

Here a pair of coyotes traveled together, then one veered off.

Here a pair of coyotes traveled together, then one veered off.

26FE99. A coyote made a remarkable vertical 4-foot jump out of the creek at Willowbrook, having crossed to the point where the Safari Trail meets the stream at the high bank.

MR99. During the 90’s, coyotes have become much more abundant in the western suburbs. Tracks frequently encountered on the preserves, and in absence usually of fox sign until the past couple of years. One appeared at Willowbrook frequently around 1994-96, after the fox there was gone. Then the coyote vanished, after it was seen several times apparently weakened by mange. A red fox came in that winter, lasted a year, then it left. At that time coyote sign returned and have been frequent for more than two years, now. The common pattern has been for signs to be abundant for several weeks, then absent for several weeks, in alternation through the warm months, with 2 coyotes taking up steady residence on the preserve through the winter. I saw two different individuals one morning in winter of 1997-98, one missing all but a stub of its tail and so easy to recognize. They often deposit feces in the center of the nature trail, occasionally in other clear areas or smaller trails. Hair the most common dominant food remains in the scats, occasionally feathers or skins of fruits dominate. I saw a coyote crossing Kirk Road in Kane County at dusk one summer evening. Their howling, which I have heard at Pratts Wayne Woods, Hidden Lake, Lincoln Marsh and Fermilab, is extremely high-pitched and wailing in quality, and I have heard several animals howling together or howling back and forth in contact call style but not a single individual howling alone. During a night hike in September 1996 at Hidden Lake, a siren set off a probable family group of 4 individuals, and for the rest of the evening the scattered coyotes howled at regular intervals, producing the contact call effect.

Usually coyotes are shy and seldom seen.

Usually coyotes are shy and seldom seen.

14AP99. The goose nest has been destroyed, the eggs preyed upon, at Willowbrook. Tracks in mud show at least 2 coyote round trips wading out to the nest island. No other predator tracks.

25JE99. I heard a coyote barking at a neighbor walking dogs at Willowbrook.

30AU99. Coyote scats at Willowbrook have been rich in fruit. This remained the case for weeks, with fruit appearing to be the dominant food.

5OC99. A heavy red fabric strip, 10 inches long, possibly a collar, in a coyote scat on the Willowbrook Nature Trail. Fruit remains dominant food in scats.

1NO99. Hair becoming more common, fruit less, in scats at Willowbrook.

2NO99. A coyote scat at Willowbrook had a bit of candy wrapper in it (shortly after Halloween).

Half-grown coyote pup, in a meadow at Mayslake Forest Preserve.

Half-grown coyote pup, in a meadow at Mayslake Forest Preserve.

1999-2013. It has become clear that coyotes are everywhere in the Chicago area, with even centers of towns being parts of territories. The coyotes, unless someone feeds them, are very good at staying out of sight. Reports from neighbors suggest that the pair at Willowbrook had a home range that extended from the East Branch of the DuPage River to the Village Links Golf Course, and so they were absent from the preserve for weeks at a time, but in some seasons centered their activity on the preserve (they never denned there, however).

At Fullersburg Woods, the pair was active year-round in the more open northern part of the preserve and presumably extended into adjacent areas off the preserve. In winter, the pair regularly wandered into the forested southern part of the preserve, usually hunting apart but joining up as they returned to their northern center of activity. I never found a den on that preserve.

Former coyote den, Mayslake. The buried concrete had provided a stable roof, but its removal as part of the demolition process ended this den. Coyotes only use dens in late spring and early summer, to shelter their young pups.

Former coyote den, Mayslake. The buried concrete had provided a stable roof, but its removal as part of the demolition process ended this den. Coyotes only use dens in late spring and early summer, to shelter their young pups.

At Mayslake the pair had a den in the former friary garden area, but the den was destroyed as an incidental consequence of the friary demolition. Until then the coyotes were a constant presence on the preserve, but now they are there regularly but somewhat intermittently. They have been healthy and strong when I have seen them, and had pups most years. One odd observation was that one chewed up and swallowed a tennis ball discarded near the off-leash dog area. The fragmented ball passed completely through the coyote. Rabbits and voles are the more typical contents of scats.

Scat composed of tennis ball pieces.

Scat composed of tennis ball pieces.

Rose-breasted Grosbeak Species Dossier

by Carl Strang

As usual, the dossier begins with the paragraph that established the file in the mid-1980’s. In this case I didn’t have much to say because my experience with the species was limited. Since then, dated notes have appended observations that I felt added to my understanding of the species.

Grosbeak, Rose-breasted

This species was relatively rare around my home town of Culver, Indiana. My first were a pair in my neighborhood in the town. The male sang from high in trees or TV aerials. His song began with a phrase much like the theme of the “Guestward Ho” TV series which was current then. That mnemonic has helped me recognize it elsewhere in Indiana as well as Pennsylvania and Illinois. They also have a loud “pick” call distinctive in quality from their close relative the cardinal. Foraging movements are slow, taking their time while visually searching for insects at mid to high elevations in trees. They are uncommon during the breeding season (though abundant in migration) in DuPage County, with occasional single pairs here and there in savannah-like forests. They are especially common for a couple of weeks during migration in May.

Adult male rose-breasted grosbeak

Adult male rose-breasted grosbeak

5MY87. First song of the year heard at Willowbrook Forest Preserve.

25JL87. Hartz Lake, Indiana: An adult male fed 10-15 feet up in saplings. Deliberate: about 10 seconds per perch, looking apparently over a radius of several feet, moving 2-5 feet between perches.

A male reaches for a food item. They can look very parrot-like in this maneuver.

A male reaches for a food item. They can look very parrot-like in this maneuver.

13SE87. A female was in a mixed flock with a red-eyed vireo, a Tennessee warbler, and several catbirds and robins.

7MY88. First song of the year, Culver, Indiana.

11MY88. A female was in Willowbrook Forest Preserve.

8MY89. I saw grosbeaks today and on May 6th at Willowbrook.

Singing posture

Singing posture

4MY99. First migrant noted at Willowbrook. Last observed there 14MY.

26AU99. First migrant noted at Willowbrook. Last one noted 29SE.

4SE99. A grosbeak in female plumage at Willowbrook produced “pick!” notes and bits of low-volume warbling song.

11JE00. Rose-breasted grosbeaks were in a diverse forest near Langlade, Wisconsin, associated with the Wolf River riparian edge and with savanna-like areas where trees were more scattered. Deciduous trees were abundant in those areas. Other birds in those habitats were least flycatcher, Baltimore oriole and black-throated blue warbler.

23-4SE00. Grosbeaks were numerous along the Prairie Path just east of Industrial Drive and bordering the West Chicago Prairie, in the hedge-like edges.

21MY08. Fullersburg Woods. A rose-breasted grosbeak nest was on Willow Island, midway along the east side. It was 10 feet up in the top of a buckthorn, 15 feet in from the trail, female incubating. The nest structure resembles that of the cardinal but thinner so you can see through it in places.

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.

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