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.

 

Vertebrate Miscellany

by Carl Strang

Today, a few vertebrate notes from Mayslake Forest Preserve last week. The redtail youngster still is around.

Though it mainly sits perched in trees or, in this case, on a light fixture, calling frequently, occasionally it changes locations.

One skillful fisherman pulled a nice largemouth from May’s Lake despite the heat.

The bass looked to be 2 pounds or so. The man was fishing early in the morning.

Another example of fishing success was provided by a great blue heron in the stream corridor marsh.

The question is, what was the prey?

The bird was way over on the other side of the marsh. The prey was floppy when the heron shook it, shiny and smooth from the reflected light, and somewhat elongate and irregular in shape at times as the bird shifted its catch. My impression, supported by the dark color (though it was somewhat backlit) is that the prey was a bullhead, which is news because I didn’t think there were any fish in that marsh. The other possibility is a frog, which might better fit certain irregularities in its shape. I’m left with some uncertainty on this one.

Dragonfly Monitoring Run

by Carl Strang

On the 4th of July I made my first dragonfly monitoring run of the year, on my assigned stretch of the Des Plaines River at Waterfall Glen Forest Preserve. With a total of 378 individual dragonflies and damselflies tallied, it was far higher than any other count since I took this route beginning in2009. Of course, there was a lot more to enjoy than just Odonata.

A string of great blue heron nests between the boat launch and the start of my route still had some youngsters approaching fledging. Their loud rhythmic guttural calls signaled the arrival of a parent, back from fishing the river.

The carp fence I saw under construction when I last paddled the Des Plaines in the fall is complete. Am I being ignorant or properly skeptical in doubting this will achieve the desired result of keeping Asian carp from moving between waterways?

My thinking, for what it’s worth, is that even if the mesh is fine enough to block tiny youngsters that might slip through at flood stage, there will be breaches from floating logs.

Later, when my run was nearly complete, I encountered this northern water snake.

I was surprised that it seemed undisturbed by my close approach. Then I saw that the eyes were obscured. The snake either was on the verge of shedding, or the scales over the eyes remained stuck when the rest of the skin came off during the last shed.

Entertaining as these sideshows were, dragonflies and damselflies were the main event. Jade clubtails were the most abundant of the 5 species of dragonflies that day; I counted 46 altogether.

Jade clubtails mainly are to be seen perched on objects like this stump.

Common whitetails also were regular sights, some laying eggs.

Here a male common whitetail shares a stump with a bluet and a clubtail.

Most of the individuals were damselflies, however, in 8 species. The largest were a few American rubyspots.

This one was so steadfast that I was able to bring the camera to within a few inches of it.

The largest count of any species was 108 blue-tipped dancers. I didn’t get a photo of any of them, but one of the 82 powdered dancers, a close relative, posed on my deck line.

Such accommodating individuals make identification easy.

The most abundant bluets this time were stream bluets.

The stream bluet is one of the black-type bluets, having a mainly black abdomen.

Stream bluets and hordes of dancers were laying eggs in floating vegetation mats.

The several tandem pairs, perched on the vegetation and laying, may not be as visible here as the unattached and hopeful males hovering above.

I had thought I might do a little fishing on the way back, but the time and mental effort required to identify and count so many insects left me glad simply to paddle back up to the put-in.

Birds Around the Marsh

by Carl Strang

The area with the greatest diversity of birds at Mayslake Forest Preserve, now that the breeding season is well underway, has been the stream corridor with its adjacent marsh. The corridor itself is wooded, attracting Baltimore orioles, warbling vireos, yellow warblers, common yellowthroats, indigo buntings and downy woodpeckers.

This male downy worked on a nest cavity earlier in the season.

The marsh itself has been a place of interest. During the earlier part of the migration it held a pair of buffleheads for two weeks. More recently I saw one of the most unusual birds of the year there, the preserve’s first least bittern (gone before I could get the camera up; I wasn’t going to pursue and harass it just for a photo).

On Friday the marsh had a trio of herons. I didn’t get a photo of the great blue heron, which nervously departed as soon as I came into view. I had better luck with the green heron.

He landed on this stub after being chased from a preferred corner of the marsh by the bird in the following picture.

The third heron visits Mayslake less often than the others.

Great egrets always are a welcome sight, perhaps to be seen more often in summer now that they are nesting in DuPage County.

I have been most fond of another little group of birds, a momma wood duck and her young.

She started out with 9 ducklings. Only 4 remained when I took this photo.

With the diversity of birds, plants and insects around that marsh, it has been my favorite part of the Mayslake preserve this year.

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.

Mayslake Birds Update

by Carl Strang

It has been a while since I have reported bird observations from Mayslake Forest Preserve. The neotropical migrants, including the eastern wood-pewee, have departed for their winter homes.

Pewee 2b

Wandering youngsters like this great blue heron have turned up from time to time.

GBH youngster Mayslake

Some members of this species will stick around through the winter, and some will make the attempt and fail to survive. One of the more unusual sightings at Mayslake this fall was a heron relative, an American bittern, which flushed from an unusual location in the middle of an upland meadow.

Mixed flocks of warblers and other songbirds stopped by the preserve for fuel in September, and gave way in October to birds that winter in the U.S. These included blackbirds, with large grackle flocks foraging on the mansion lawns on some days.

Grackle flock 2b

Sparrows frequented the habitats suitable for their various species. Meadows and prairies attracted song sparrows, some of which had nested there in the summer.

Song Sparrow 3b

One of the more unusual looking sparrows was this one.

Savannah Sparrow 4b

It proves to be a savanna sparrow, but with very white and high-contrasting plumage compared to most members of its species. Many white-throated and white-crowned sparrows have been refueling at the preserve as well.

The most exciting “maybe” was reported by an experienced birder who got a glimpse of a tiny black bird flying near the stream. He was not willing to commit to it, because his sighting was so brief, but Mayslake may have hosted a black rail this fall.

In the past week the latest of songbirds have been appearing, including a brown creeper, hermit thrushes, fox sparrows and dark-eyed juncos. Some of these may stay for the winter.

Dragonflies on the Deck

by Carl Strang

I have been part of the regional dragonfly monitoring program since it began in 2003. I started counting dragonflies and damselflies at Willowbrook, Songbird Slough and Waterfall Glen Forest Preserves, in recent years focusing on the last two. Though I continued to find new species from time to time, the past couple of years I have felt the need to try something new. The major gap in my knowledge was in river species, so this year I decided to combine my loves of kayaking and dragonfly monitoring by trying out a river route. Water levels have been high, and cool weather has been suboptimal for monitoring, so I didn’t make my first excursion until last weekend. I launched my sea kayak from the forest preserve boat ramp at Des Plaines Riverway, and headed downstream into Waterfall Glen Forest Preserve.

Des Plaines monitor view b

Experienced kayakers know to tie everything to the boat. I didn’t want to risk wetting my digital voice recorder, so I tied a waterproof notebook to a deck line, tied two pencils to the notebook, wore my waterproof small camera and binoculars, and tucked everything else into my yellow deck bag.

Monitor deck 1b

I used the strongest current in the center of the river to go downstream, taking moments along the way to enjoy sights such as scattered great blue heron nests.

GB heron nest Des Plaines b

The only American rubyspot of the day made it easy by landing on my bow.

American rubyspot kayak b

Dragonflies were tougher, however. The low, seated vantage point made flying dragonflies look different, and it took a while to recognize even familiar species. They were flying fast over the center of the river, making photography impossible, and even tracking them with binoculars was very difficult. My frustration was limited by the low number of insects active in the center of the river that day. I reached a convenient turn around point after an hour, and started back following the sunlit north shore. (Current is slower near the bank, making the upstream paddling easier.) Odonata were much more abundant along the edge. Some damselflies continued to land on the boat. Here a powdered dancer and a blue-fronted dancer chose to land on the deck bag, providing a comparison shot.

Dancers kayak 1b

Other damselflies kept their distance, landing on sticks or debris. The small camera’s telephoto was adequate to get shots of the abundant blue type bluets, which proved to be familiar bluets.

Familiar bluet 5JL 1b

There also were many black type bluets, which I identified as slender bluets.

Slender bluet 5JL 1b

The most abundant dragonflies were jade clubtails, some of which liked my deck.

Jade clubtail kayak b

I was pleased to see a Cyrano darner along the way, though I was unable to get a photo. Toward the end I got a nice view of some Illinois roses.

IL roses Des Plaines b

All in all there was a nice variety of species, most of them familiar but some I missed. I look forward to a continuing learning experience as I return to this route on future weekends.

A Visit to JPPSP/Tri-County

by Carl Strang

 

Its official name is James Pate Philip State Park, but I prefer the shorter, more descriptive original name, Tri-County State Park. The park contains the point where Cook, DuPage and Kane Counties meet, though most of it is in DuPage. The park is remote enough that it has the capacity for unusual events. Arguably the most unusual this year so far is a growing osprey nest.

 

osprey-nest-b1

 

When I stopped by the park for a brief visit on Saturday, the ospreys were present but not at the nest.

 

osprey-b

 

Later they both flew to their nest, their size revealing how huge is the platform provided by the utility tower.

 

ospreys-in-nest-b

 

With that elevation and exposure, I wonder about the hazards of lightning and the winds that accompany thunderstorms. This almost certainly is the same pair that nested just northwest of the park last year, as I mentioned in an earlier post on the species.

 

There were no great blue heron nests in the dead trees that still stand in the marsh on the island that bears one of the beaver lodges. Earlier  I mentioned the tiny nesting colony that was sited there for a few years. Here is one of the nests in 2005.

 

great-blue-heron-nest-1b1

 

Elsewhere, I found the beavers’ dam just above the trail’s bridge in tidy order.

 

beaver-dam-b

 

This actually is one of a series of dams along this stream. There has been an ongoing tug-of-war between the beavers’ instinctive drive to maintain their pools, on the one hand, and peoples’ need to prevent the resulting overflow from washing out the trail. On Saturday there was at least a temporary equilibrium, with both dam and trail intact.

 

A final note from that visit was a killdeer nest, placed where the nervous parent is bound to be flushed many times, at least on weekends, by passersby.

 

killdeer-nest-jppsp-b

 

The incubating bird was quick to jump up and run away, but at least in my presence did not perform the famous broken wing act.

 

killdeer-jppsp-1b

 

I did not bother the nest, and left after taking a few quick photos. The park does not get huge volumes of visitors, so I’m hopeful the eggs have a chance.

Herons Return

by Carl Strang

 

A few weeks ago I shared photos  of the great blue heron rookery at Danada Forest Preserve. Here is why that visit had to be done in the middle of winter.

 

danada-gbh-rookery-march-1b

 

Already they are returning and reclaiming their nests. I took this photo from the regional trail. It would be an unjustifiable disturbance to approach any closer now. It looks like this rookery will continue for another season.

Rookery Trees

by Carl Strang

 

The great blue heron was the bird that first inspired my interest in learning about nature when I was a 7-year-old, watching several of them in a small lake one calm summer evening. A few years later a number of great blue herons established a new nesting colony near my hometown of Culver, Indiana, among the large branches of a grove of sycamore trees  in a swampy woodland.

 

great-blue-heron-closeup-b4

 

An interesting development over the past decade has been the proliferation of great blue heron rookeries in DuPage County. One on Danada Forest Preserve near the center of the county had 25 nests or so by 2001. Another large colony has been growing for several years at Pratts Wayne Woods. Close to there, at James Pate Phillips (Tri-County) State Park, an offshoot of the Pratts Wayne rookery existed for a few years in a group of dead trees, but this experiment is on the verge of ending as the trees lose branches. There is another small rookery at Churchill Forest Preserve, and a final one strung out along the Des Plaines River in and adjacent to southeast DuPage County.

 

Remembering the Indiana rookery, I was curious about what species of trees were supporting the Danada colony. On a recent frigid weekend morning I went there to find out. It had to be done in mid-winter, both to avoid disturbing the birds (which could begin to return by the end of February), and to take advantage of frozen ground and water for easy travel.

 

danada-gbh-rookery-3b

 

I found the colony to be situated in swampy woodland surrounding a large pond. Most of the 15-20 nest trees were living cottonwoods, and 90% of the nests were in these.

 

danada-gbh-rookery-2b2

 

Two of the nest trees were dead, and three were willows. One cottonwood had 16 nests, a couple had 13, and one had 11.

 

danada-gbh-rookery-1b

 

I counted a total of 142 nests. There may have been more; we have had some strong wind storms since the nesting season which could have dismantled some nests. Like sycamores, cottonwoods have open canopies and thick branches capable of supporting the relatively large stick nests herons construct. Most of the trees in the colony woods were cottonwoods, so a statistical examination limited to that bit of woodland would not reveal much about heron preferences. It appeared likely that the other trees there simply lacked the necessary support structure. A few willows were used, but each had the capacity for fewer nests. The better question is how the birds choose the rookery site in the first place. Trying to answer that would require a longer-term examination of many colonies.

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