Parson’s Grove Visit

by Carl Strang

One evening last week I paid a visit to Parson’s Grove at Danada Forest Preserve. I felt that Nebraska coneheads were due to start singing, and Parson’s Grove has the largest population I have encountered in DuPage County, which makes it the northernmost significant population I have found to date in the Chicago region. There seemed to be more individuals singing that night than I remember from previous years. I tracked one down for a photo.

He proved to be a brown one. The conehead katydids all can be green or brown, but this is the first brown one of this species I have seen.

He proved to be a brown one. The conehead katydids all can be green or brown, but this is the first brown one of this species I have seen.

Another goal was to photograph a male rattler round-winged katydid, if any were going there. I have photos of a couple females, but lacked one of a male. I heard three at Parson’s Grove, and caught one in the open on a giant ragweed leaf.

My headlamp didn’t seem to disturb him as he casually groomed his feet.

My headlamp didn’t seem to disturb him as he casually groomed his feet.

The brown area on his back, which is part of the wings’ song-producing apparatus, is one distinguishing feature of males.

Parson’s Grove is a great place to hear a wide variety of nocturnal singing insects. DuPage County’s forest preserves provide a huge advantage to the region’s nature lovers, in that the preserves close an hour after sunset rather than right at sunset as is the case in the less enlightened surrounding counties.

OK, Spring

by Carl Strang

In my idiosyncratic 6-season calendar, Late Winter begins March 1, and ends on the day that I see the first native wildflower blooming away from the warming influence of buildings. Last week that criterion was met when I saw a spring beauty flowering in Parson’s Grove at Danada Forest Preserve. This was a little earlier than usual, but we’ve had plenty of warm weather to date, so that is to be expected.

Spring beauty, though not this year’s first. Didn’t have a camera on me.

Spring beauty, though not this year’s first. Didn’t have a camera on me.

Yesterday many spring beauties were in bloom at St. James Farm as well.


Seasonal Transition

by Carl Strang

We have long been waiting for spring, and the seasonal transition at last is under way. Soon the snow birds will be heading back north.

Dark-eyed juncos have begun to sing and to chase each other.

Dark-eyed juncos have begun to sing and to chase each other.

The earliest migrants have begun to come through, or to pass over.

A flock of sandhill cranes flies over Mayslake Forest Preserve.

A flock of sandhill cranes flies over Mayslake Forest Preserve.

They hit a thermal, break formation and use its rising air to gain altitude.

They hit a thermal, break formation and use its rising air to gain altitude.

Breeders have begun to arrive and set up shop.

Great blue herons at the Danada colony

Great blue herons at the Danada colony

A recent arrival at Mayslake Forest Preserve has the smaller birds nervous.

The Cooper’s hawk pauses in its patrol…

The Cooper’s hawk pauses in its patrol…

…then resumes.

…then resumes.

The next mini-stage of migrant birds has begun.

Ruby-crowned kinglet at Fermilab, Sunday

Ruby-crowned kinglet at Fermilab, Sunday

Soon I expect to reach my personal criterion for the arrival of spring and the end of winter.


Bumblebee Mimics

by Carl Strang

There are mimics, and there are mimics. A couple years ago at Mayslake Forest Preserve I found a syrphid fly that mimics bumblebees.

This is the narcissus bulb fly, Merodon equestris.

This is the narcissus bulb fly, Merodon equestris.

It was comparable in size to a small worker bumblebee, though none of our local bumblebee species match this color pattern, and it doesn’t really pass for more than a few seconds’ examination.

But there are others, like the one I saw yesterday:

This is more like it. It’s big, the size of a bumblebee queen, and it’s hairy, and its color pattern resembles those of a couple local species.

This is more like it. It’s big, the size of a bumblebee queen, and it’s hairy, and its color pattern resembles those of a couple local species.

This is a robber fly, a predator known to catch bees as well as other relatively large flying insect prey. There are a couple species in the East which are very similar to one another. Their larvae tunnel in rotten logs, preying even then on other larvae they encounter. After maturing, they perch in sun flecks on leaves or on more solid perches. The more common one in DuPage County appears to be Laphria thoracica.

Here’s another individual I photographed in July 2008 at Danada Forest Preserve.

Here’s another individual I photographed in July 2008 at Danada Forest Preserve.

Note the long black hairs on the top, front and sides of the head. If those were a dense solid yellow this would be a different species, Laphria grossa. I encountered those in south central Pennsylvania, and the impression was much the same. That beak probably could deliver a nasty bite if you grabbed this critter, but why would you want to? These take a longer, closer look to distinguish them from bumblebees. That beak is one giveaway. Another is the single pair of wings rather than two. Also, the perched fly frequently snaps its head to different angles, tracking possible prey. Bumblebees don’t do that. These robber flies are on my short list of niftiest local mimics.

Why the mimicry? One has to think it provides some protection from vertebrate predators. Also, these are among the largest of the robber flies, most of which are not mimics. That large size seems to slow them down, as they don’t fly nearly as fast as their smaller relatives. Perhaps the bumblebee coloration and speed leads prey to ignore them until it’s too late.

Killdeer Dossier

by Carl Strang

As in past winters I have been sharing my collected observations on various vertebrate species over the years. While this may have some value in providing information, and revealing how there can be a difference between one person’s experienced knowledge and the collective accumulation of information available through references, the main point is to encourage you to pay more attention to the familiar and to build your own knowledge base of personally gained information.



This plover generally occurs in large, short grass fields and pastures. It produces a loud “killdee” call, often repeated in clusters. Small downy young can produce this call at surprisingly loud volume. The parent has broken-wing distraction display. Practically all of them depart from northern Illinois and northern Indiana for the winter, but a few remained through the winter near open streams in pastures in south central Pennsylvania. Mudflats also are frequented for feeding purposes and in migration. Killdeers have a very smooth, rapid run over the ground.

Killdeer nests are simple scrapes in the ground, containing 4 mottled eggs. The nest site generally is chosen such that the eggs are well camouflaged.

4JL86. Jeffersonville, Indiana. A pair on a golf course ran ahead of me. They stopped about 20m away from me, and settled into small depressions in the lawn (small bare soil patches) exactly as though settling onto eggs. If I approached, they quickly got up and ran ahead of me; no eggs or young were there. If I approached very slowly, the bird slightly spread its wings and tail, and went into the broken-wing display.

15MR87. 3 calling killdeers flew high over Meacham Grove, west to east, the first of the year.

4AP99. First killdeer of the year I’ve seen in DuPage County.

1AU99. Swenson’s Road pond, Fermilab. A couple killdeers walked at the water’s edge in an upright posture, only occasionally reaching down to the surface.

Killdeers seldom enter the water.

30OC99. Several killdeers still are at Fermilab.

26DE99. A killdeer was on the shore at Lake Maxinkuckee, Culver, Indiana. Broken ice sheet pieces were floating along the shore, and there was some snow on the ground.

20OC00. Killdeers flew over the Maxinkuckee Wetlands, calling loudly as they flew over the area for an extended period of time. The flight seemed to be a display.

22OC00. Many killdeers were at the marsh in south Blackwell Forest Preserve (and only 1 at McKee Marsh in north Blackwell). Two appeared to be involved in an agonistic display, standing a few inches apart and bowing forward until their breasts nearly touched the ground, calling, holding their tails straight and sometimes fanning them, sometimes pacing around. Once one appeared to bite or peck toward the other.

The killdeer’s long tail, folded here, is largely a bright reddish color.

21JL01. Fermilab. Half a dozen killdeers at the Swenson Road pond are mainly staying well back on the drier mud.

13NO01. A couple killdeers still are at Rice Lake, Danada Forest Preserve.

1AU04. Greene Valley. A shallow large pond at 83rd Street and Rt. 53 has attracted many shorebirds. Pectoral sandpipers nearly all are feeding in the shallowest water with the vertical sewing-machine bill motions. A number of lesser yellowlegs are in slightly deeper water. On the mudflats are many killdeers, a couple spotted sandpipers and a solitary sandpiper. Between mudflats and the very shallowest water, several peeps (appear to be mainly least sandpipers).

The killdeer nest mentioned on April 18, 2009.

18AP09. Killdeer incubating a nest in mulch around a tree in the picnic area, Tri-County State Park.

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.

Geese Shift Gears

by Carl Strang

The goose family from the parking lot marsh nest returned to Mayslake Forest Preserve’s mansion grounds for a few days in mid-September. Dad is recognizable by the band on his left foot, the two surviving kids can fly now.

For now they are staying to themselves, but the last two weeks have seen goose families across DuPage County coalescing into flocks as they shift toward their winter pattern.

Last Friday this flock on Rice Lake at Danada Forest Preserve numbered close to two hundred birds. The coming couple months will see such flocks build on many lake, river and marsh roosting grounds. From there they will radiate out to lawns and fields to feed during the day. Soon they’ll be joined by northern geese, and the flocks will build to their peak sizes until the freeze concentrates them on the major roosting sites, at which time some will shift south. After that, much depends on the severity of the winter. Winter may not be my favorite season, but the past couple of years I have been enjoying my study of Canada goose winter behavior. As the weather turns frosty I can at least look forward to learning whatever new lessons the geese will have to teach me.

Tree Cricket Ambiguity

by Carl Strang

During a recent Take Your Kids To Work Day program at Forest Preserve District headquarters in Danada Forest Preserve, I was one of the teachers in an entomology unit. An adult tree cricket turned up in a sweep net sample, and I decided to try for photos.

As seems common with tree crickets, this one was interested in palpating my finger (often they’ll nibble as well). The shot I was seeking was a photo of the insect with its antennae held back, preferably taken from a quartering angle. I did get a usable one.

Those dark spots on the first two antenna segments often are distinctive enough for species identification. The most recent authoritative drawings and descriptions I have seen were contributed by a leading researcher on tree crickets, Tom Walker, in the Field Guide to Grasshoppers, Katydids and Crickets of the United States (2004, Cornell University Press), which he co-authored with John L. Capinera and Ralph D. Scott. The Danada cricket falls into a middle ground in the drawings, conceivably fitting four-spotted, prairie, or black-horned/Forbes’s.

Until I saw the photo I didn’t expect this. The cricket overall was very pale, and I had ruled out the black-horned/Forbes’s sibling species pair because they typically have dark areas on the head, pronotum (top of thorax), and underside of the abdomen. If I had to choose, though, based on antennal spotting alone, I would say this individual was a black-horned or Forbes’s tree cricket, albeit at one extreme end of their range of variation (for more on that species pair, see my post of last autumn).

In previous years I have examined a number of tree crickets from the area where this one was caught, and all have been in the black-horned/Forbes’s darker color pattern. The only clear result is that I need more experience with these four prairie-to-shrubby-meadow tree cricket species.

Goose Roost Patterns

by Carl Strang

A severe winter storm in early December quick-froze the surfaces of ponds, marshes and many lakes. This was disappointing, as I hoped for waters to stay open longer than they did last year. On the other hand, the repeat may allow me to get a sense of how consistent the behavior of wintering geese will be under similar conditions.

One departure from last year was evident on December 12 at the Blackwell roost. About 1200 geese were roosting on the frozen surface of Silver Lake.

Among them was one bird with the orange neck collar that marks it as a goose that nests in the Hudson Bay region.

I am not sure why these geese roosted where they did, given the availability of open water in last year’s roosting area on the nearby stream, where I counted an additional 2300 birds (including 3 more with orange collars).

Otherwise, patterns on that day were familiar. Around 700 geese were at the McDowell roost, 2500 at Hidden Lake, and geese were absent from frozen Herrick Lake and Rice Lake at Danada Forest Preserve. At the moment, counts are higher at all three of these roosts than my highest counts last year (which were 3000 at Blackwell, 500 at McDowell and 880 at Hidden Lake). The geese were moving out in familiar directions from the roosts to feed.

Whether these numbers will stay so high remains to be seen. On the days following the storm, which affected most of eastern North America, many geese from farther north were passing high over DuPage County and, according to reports from birders, continuing on at least to central Illinois. If last year’s pattern of severe cold and freezing roosts continues, the numbers of local birds will drop.

A respite of two warm days opened up the Blackwell roost and part of Silver Lake. On December 15, I found geese again on that lake, resting on the edge of the open area.

The main roost pond above the dam, just north of Silver Lake, also had opened.

I was able to photograph one of the collared geese from close enough range to read its collar.

The identification code for this individual is M8R1.

I have passed this information on to the Canadian Wildlife Service. The weather is turning cold again, so the possibility remains that DuPage geese will be forced to shift south.


by Carl Strang

The singing insect season is drawing to a close, and I have not mentioned one group to which I devoted some attention this season. The coneheaded katydids are a fairly diverse group of relatively large katydids characterized by cone-shaped structures that rise from the tops of their heads.

Nebraska conehead b

This is a Nebraska conehead. Its song consists of loud, shrill buzzes about 1.5 seconds long, with 1-second pauses between. It sings starting at dusk, in habitat that in my experience always has bushes and usually trees. The only location I have found so far with more than 3 or so singing individuals is Parson’s Grove at Danada Forest Preserve. The scattered bushes against the savanna edge seem to be ideal for this species.

There are two common, widely distributed coneheads in DuPage County’s meadows and prairies. The first to start singing, in the second half of July, is the sword-bearing conehead.

Sword-bearing 2b

Its rapidly ticking song has been compared to the sounds of a distant steam engine or a sewing machine. The other common meadow species is the round-tipped conehead.

Round-tipped conehead 3b

As you can see, these katydids look much alike. The round-tipped has a relatively short cone with a small black area at the tip (compare to the longer cone with a nearly all black surface on the Nebraska conehead, above).

Round-tipped conehead 5b

This one is more of a late season species, starting up in the second half of August and continuing through October. Its song to my ear is much like that of the Nebraska conehead, except that it has very long continuous buzzes rather than interrupted ones.

The possibility that I need to clear up is whether the robust conehead also is present. Its song is continuous, like that of the round-tipped, but reportedly is much louder and at a lower pitch. Its similar cone typically lacks the black tip, and body size is larger. I may have heard some of these at night while driving in past years, but so few in 2009 that I will have to hold this possibility for investigation until next year.

« Older entries

%d bloggers like this: