Mayslake Ecology

by Carl Strang

I’ll conclude the summary of my first year at Mayslake Forest Preserve with an ecological sketch. The preserve has diverse plant communities, some high in quality thanks to the restoration efforts I described yesterday. There are lakes, a stream, savannas, prairies, a couple small marshes, European meadows undergoing succession, a degraded former garden at the friary and brushland areas dominated by Eurasian species of shrubs, as well as lawn areas around the mansion and friary grounds.

Mayslake dog meadow to savanna b

This habitat variety leads to the diversity of plants and animals I mentioned a couple posts ago. Strongly reproducing populations of cottontails, squirrels and other small mammals, as well as various small birds, support a suite of predators somewhat surprising for such a small preserve: a pair of great horned owls, a pair of coyotes, a couple mink, Cooper’s hawks and, in winter, red-tails.

Red-tail Mayslake 1b

Of course, these predators do not limit their activities to the preserve’s borders. White-tailed deer pass through the preserve regularly, but Mayslake is not quite large enough at 90 acres to hold many or to be more than an occasional center of activity.

This summary of course hides a lot of detail, some of which I observed and reported here over the past year. I will continue to do so as the details and patterns of that place change over time, keeping it refreshingly interesting.

Jacqui, and Mayslake Restoration

by Carl Strang

When Jacqui Pearl got married, she had a decision to make. You see, the love of her life’s last name was Gleason. Older readers, at least, will see that this could be problematic. She chose to go with Jacqui Gleason. The things we do for love.

Jacqui 1b

A few years ago, Jacqui joined the Mayslake Forest Preserve garden volunteer team. Quickly she realized that this did not provide enough work to satisfy her, and at the same time she became aware of the impressive restoration progress being made out beyond the mansion grounds by Conrad Fialkowski. I can think of no better word to describe Jacqui and Conrad than dynamos. They are out there at least a couple times a week, often more, in all kinds of weather, through the entire year. Sometimes they work together, sometimes they are there individually, always they work hard, clearing brush, collecting seeds, planting seeds, assessing results.

Incidentally, another side to Jacqui is that she works with Chicago’s Lyric opera, dressing the women performers, a job which sometimes entails frantic quick costume changes in the middle of a scene (she mentions the pride that she and her colleagues have in effecting a complete makeover in 60 seconds or less).

Mayslake’s prairie, savanna and wetland areas are coming along nicely thanks to the dedication of Conrad and Jacqui. In the past year they have expanded the cleared area around the edges of the north savanna, fought off brush invasions in prairie and wetlands, collected and broadcast loads of seeds, and documented several newly appeared flowers in the savanna and prairie. Last winter they were assisted by District staff through a significant clearing of brush in the north savanna. The result of all this dedication is that Mayslake has one of the best restoration projects going in the entire Forest Preserve District of DuPage County.

Mayslake Species Counts

by Carl Strang

Earlier this week I completed my first year of observations at Mayslake Forest Preserve. Many of the posts in this blog, which also is approaching its first birthday, have shared pieces of Mayslake’s ongoing natural history. It’s appropriate to look back at what I have learned there so far. Today I’ll simply share some numbers, the counts of species I have observed on the preserve to date.

Barn Swallows b

Resident vertebrates include 14 species of mammals, 4 reptiles and 3 amphibians (though additional frogs have been observed at Mayslake by others in recent years). The bird species count is 130, many of which were migrants passing through. I saw evidence for successful nests, fledging at least 1 young, in the following 21 species: eastern bluebird, chimney swift, song sparrow, house wren, eastern kingbird, robin, northern flicker, blue jay, eastern phoebe (cowbird produced), chipping sparrow (cowbird produced), downy woodpecker, red-winged blackbird, red-bellied woodpecker, common grackle, black-capped chickadee, tree swallow, European starling, blue-gray gnatcatcher, Baltimore oriole, white-breasted nuthatch, mallard.

Banded hairstreak b

The insect species count is only 97 so far, but most of these belong to 4 groups to which I have directed most of my attention: 26 species of singing insects, 29 dragonflies and damselflies, 24 butterflies and moths, and 6 bumblebees.

Blazing star b

Likewise my attention to Mayslake’s vegetation has been limited to certain groups of vascular plants. These include 49 trees (including those planted by landowners prior to forest preserve acquisition), 23 vines and shrubs, and 184 forbs. I’ll elaborate the last a little by mentioning genera represented by 4 or more species: so far I know of 4 Asclepias (milkweeds), 6 Aster, 4 Erigeron (fleabanes), 5 Eupatorium (a diverse genus including Joe Pye weeds, bonesets, and white snakeroot), 4 Polygonum (knotweeds), 5 Ranunculus (buttercups), and 7 Solidago (goldenrods).

Cooper’s Hawk Dossier

by Carl Strang

It has been a while since I have shared one of my species dossiers. One of my practices is to keep records of what I have learned from my own observations of various species, as opposed to reading about them in other sources. Today I bring out my dossier on the Cooper’s hawk. In reviewing it I see that I have left out a lot of observations of this species, which has become common in the Chicago suburbs over the past decade or two, but those other observations would be much like the ones below. The observations begin with my date codes.

Cooper's hawk b

13SE85. Spring Valley Nature Center, Schaumburg. A Cooper’s Hawk pursued a frantic, cheeping young thrush in and out among the trees, in sharp twists, turns, and vertical climbs and plunges, for a good 15 seconds. Then the hawk broke off, and the thrush escaped. This took place in an old field between stands of trees. Could the cheeping have been a signal to the hawk that the thrush had plenty of wind? As soon as the hawk turned back into the woods, the thrush continued its flight over an open field.

2AP88. One passed through woods at Hartz Lake (in Indiana), occasionally calling “kip.” Flew and perched, flew and perched its way across woods.

12MR92, McDowell Forest Preserve. A Cooper’s flew, northerly, high above woods. Pursued by a crow that occasionally swooped at it, but the hawk itself was nearly crow-sized, and it often turned and flew at the crow. Flight faster and more twisty then, but the crow turned to pursue the hawk when the latter resumed its path. Three such cycles observed.

18AP92. Hartz Lake. Pair of Cooper’s hawks hanging around a clearing in the woods, often calling: a wild-sounding, almost woodpecker-like “eh-eh-eh-…” (15-20 repeated syllables).

20AU92. Cooper’s chased a couple crows at Herrick Lake F.P., not seriously. They rattle-called afterwards.

18MR99. An immature plumaged Coopers appeared, hung around the Willowbrook riparian area (SE corner of preserve) for the rest of March, calling frequently, but vanished in early April.

1SE99. Cooper’s hawk soared above Nature Trail area of Willowbrook, moving north to south. They soar from time to time.

15JE00. Morton 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.

18JL00. Willowbrook. In the early afternoon, a Cooper’s hawk soared low above the marsh and areas east and west of it, while 3 red‑tails soared high. One of the visiting red‑tails called once, but the Cooper’s, which has been resident all summer, called repeatedly.

26FE01. A Cooper’s called for a long time from the top of a tree near the islands in the river at McDowell Grove. A harrier was flying overhead, but the Cooper’s did not appear to be looking at it while calling.

14AP01. 2 Cooper’s, possibly a pair, at West DuPage Woods. One made an unusual flight through the open air, with exaggerated, moth-like wingbeats reminding me very much of a short-eared owl.

5MY01. A Cooper’s hawk incubating a stick nest high in a tree at Wayne Grove Forest Preserve. Tail visible from below.

10JA02. Two jays newly arrived at Willowbrook (for weeks there had been one, at most, and these were in addition to that one). They were mimicking crow caws, with lower volume and a brighter tone that made the mimicry clear, but an interesting sound. One of them also repeatedly imitated a Cooper’s hawk’s calls, both the string of notes and the isolated single notes. Again the volume was lower than in the hawk, but tonal fidelity was very good. They were in brush, low to the ground and close to me (the Cooper’s imitator was within 20 feet and clearly knew I was there). Before long I saw a Cooper’s hawk, almost certainly the same one that we saw hunting the day before by sitting and waiting on a tree branch for a minute or 2, then moving to a new perch. Today the hawk was perched about 100 yards from the jays.

12MR02. As 2 Cooper’s hawks began to call in the woods at Willowbrook, a jay flew to the treetops above them and began the bobbing “teakettle” call. Another jay arrived and began to “jay” call as the first continued on away in the direction it had been going.

26OC07. A Cooper’s hawk still calling at Fullersburg.

2006-2008. Cooper’s hawks nested at Fullersburg. The great horned owls there prefer to use a hawk nest from the previous year. In at least one year the Cooper’s were successful, as fledglings frequently were to be seen. In at least one year, and perhaps two, the hawks started to incubate but then abandoned. In one case this happened shortly after a pair of broad-winged hawks arrived and began to advertise their territory nearby.

24MR09. Mayslake. Scattered feathers of a Cooper’s hawk in the prairie south of the stream corridor marsh. The location, and nature of feather damage pointed to great horned owl as the predator.

Coopers kill 2b

 Late summer 09. Mayslake. One day a Cooper’s hawk caught a young-of-the-year robin in the woodland east of the mansion.

 Autumn 09, Mayslake. A Cooper’s hawk, flying low, could see through the windows of the library wing, and attempted to fly through as it would a space within a forest canopy. Unfortunately the windows were closed. It was not flying fast, and after bouncing off flew away, apparently unharmed.

With the winter’s slower season arriving, I expect to be sharing more dossiers. I encourage any student of natural history to be careful in separating what you know out of personal experience from what you have heard second hand.

Culver Seedling Survived

by Carl Strang

One thread of investigation from earlier this year followed the early growth of a mysterious seedling that appeared in the middle of winter in a swampy spot at Culver, Indiana. The seedling proved to be a common privet. It soon was overtopped by the large leaves of surrounding skunk cabbages, and I was curious as to whether it would survive. I returned in the last week of October, and after digging carefully through the leaf litter found the seedling.

Ligustrum seedling OC1b

It was alive, and like nearby mature shrubs of its species still had green leaves that late in the season. I was interested to find that the surrounding skunk cabbages already had prepared their flowering structures.

Skunk cabbage OCb

These will complete their development and begin blooming in late winter, an early sign of that season’s doom.

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.

Understory Leaf Miners 2009

by Carl Strang

In a series of posts last winter I outlined my results to date in a study of several species of leaf mining moth caterpillars that occur on black/sugar maples at Maple Grove and Meacham Grove Forest Preserves. This study, begun in the 1980’s, continues to be worth pursuing; I put in a total of about one full field day per year.

ACNI tent mine b

Tent mine formed by Phyllonorycter larva

One aspect of the study is a comparison of leaf miner occurrence in the canopy versus the understory. Today I’ll report this year’s results for the understory, having gathered those data in September. The story can be told simply, as I found very few leaf miners of any kind at either study area. Out of the 300-leaf samples from each preserve, the greatest number of leaves bearing a leaf mine type was 9 (Caloptilia boxfolds at Maple Grove). That number itself represented the only statistically significant change from 2008, having dropped from 42 leaves in last year’s Maple Grove sample. In comparisons between study areas, only the linear mines which I believe are produced by Stigmella showed a difference. Technically, however, the 8 leaves at Maple Grove versus 0 leaves at Meacham do not meet the criteria for the statistical test I use.

Maple leaves 19SEb

So in the understory the maple leaves were about as clean as I have ever found them. I’ll go out to collect the canopy data soon.

A Salute to the NYC Cricket Crawl

by Carl Strang

When I began to study singing insects a few years ago, one of my hopes was that I would be able to develop protocols for a monitoring program. I was a participant in the dragonfly monitoring group, and I was aware of hearing-based monitoring programs for frogs and breeding birds. In subsequent years I have found that there is no clear way to comprehensive, all-species monitoring of singing insects. Because of the odd pitch ranges and harmonics, different people hear insect songs differently. For example, older people like me begin to lose their capacity to hear higher pitches, and need to rely on devices like the expensive Songfinder to hear some species. There are many insect songs to learn, in comparison to relatively few frogs and toads. Though the number of breeding bird species is greater, birds are popular. Few people will make the kind of effort needed to learn so many insect songs.

Fall field cricket female 1b

I was interested, therefore, to learn of a group in the New York City area which has come up with a different approach to singing insect monitoring. They call it the Cricket Crawl. They selected a date, September 11, on which they asked people to go out at night and listen to insect songs for one minute at one or more places, then report locations and species heard to the web site. Key to their plan was limiting the focus to seven species of insects with loud, distinctive songs that nearly everyone can hear. They acknowledged that others “form the background of soft churrs and trills that emanate from a series of different small ground and tree crickets.”

While results are not complete as of this writing, Sam Droege and other organizers immediately picked several patterns from the data. For instance, the fall field cricket (photo above of a female) proved to be the species most tolerant of the broad range of urban environmental conditions. The most common katydid was the greater anglewing (photo below).

Greater anglewing 4b

The species of greatest interest was the common true katydid, which historical data indicated at one time had become scarce or even extirpated locally. The September survey found several local populations, some of which may have become established from eggs transported on nursery stock from other parts of the country.

As I continue to ponder possibilities for insect song monitoring, the success of the Cricket Crawl will remain in mind as worth considering.

The Worms Crawl In, the Worms Crawl Out

by Carl Strang

Yesterday I described my check of garlic mustard seedling survival in study plots established last spring. While carefully removing fallen leaves to expose the seedlings for counting, I found that many of the leaves seemed stuck in the ground. Furthermore, these were in tiny clusters, and instead of the petiole (stem) end, usually the tips were imbedded.

Nightcrawler tunnel 4b

In the above photo you can see how the tip of the oak leaf seems stuck in the ground, and a couple of other leaf petioles radiate out from the same spot. As I removed these leaves, I found that they were in clearly defined holes in the soil.

Nightcrawler tunnel 2b

The holes were uniform in size, and I was finding a lot of them.

Nightcrawler tunnel 1b

I soon realized what must be the case, and sure enough began to spot the ends of nightcrawlers retreating down the holes as I exposed them. Here is one protruding from its hole.

Nightcrawler tunnel 3b

The conclusion seems inescapable that these large earthworms actively are pulling leaves into their tunnels and consuming them. Typically a hole had several leaves, with various proportions of their lengths having gone into the holes and with the ends missing. I hope the photos are making this clear. Certainly the feel of the clustered leaves stuck in the holes as I cleared the study plots was striking. I never would have encountered this if I had not been pursuing the garlic mustard seedling check. Inquiry leads to inquiry.

Garlic Mustard Seedling Survival

by Carl Strang

In the spring I began a study of how garlic mustard, a harmful exotic biennial, might best be controlled by manual means. In small areas where the plant is just beginning to invade, and where use of herbicides is undesirable, it is possible to uproot or clip the second-year plants. Results so far indicate that pulling is more effective than clipping, but there is a timing variable to investigate, and I need also to determine whether pulling stimulates an increased germination of seedlings in the following year.

GM October 1b

Last week I returned to my study plots to count seedlings at the end of their first season. As the above photo shows, some tree and shrub leaves had fallen, so I carefully removed these to make sure my seedling counts were complete.

GM October 2b

I had expected some attrition through competition, but was surprised at the numbers of seedlings that had died. Every single one of the 27 square meters in the study plots showed big drops in numbers of seedlings, even in cases where there were so few that competition between them would seem to be negligible. Where in May seedling counts ranged from 12 to 345 in the square meter areas, in October the counts were 0 to 55. Especially dramatic were the control squares, in which second-year plants had been allowed to proceed to fruiting before I clipped them. There, seedlings had looked weak, but plenty still remained in May. However, the total of 214 seedlings in May had dropped to only 3 seedlings in the 9 square meters of the control treatment by October. Apparently their inhibition by the second year plants had been too great for them to overcome. Attrition in pulled treatment squares had been from 747 to 236 between May and October, and the corresponding numbers for clipped treatment squares were 1002 and 107. Statistical computations supported the difference between controls and both treatments in October counts, but indicated no statistical significance between the two treatments.

GM October 3b

Now I wait for spring. I plan to set up new study plots next year, but will apply the same treatments a month later, to see what difference timing makes. I also will return to this year’s plots. I want to follow this year’s seedlings through to their fruiting times, and to see if the numbers of new seedlings in those squares support or reject the notion that pulling increases seed bank germination.

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