Mayslake Animal Update

by Carl Strang

Every season contains the seeds of the next, and this was very true at Mayslake Forest Preserve last week. The migration season is well under way, though mainly it still features species that wintered in the southern U.S. rather than the tropics.

This winter wren was a classic example. Its kind invented skulking, but this one came out for a few seconds into plain sight.

This winter wren was a classic example. Its kind invented skulking, but this one came out for a few seconds into plain sight.

This male yellow-rumped warbler, in contrast, was not hiding. The challenge with him was that he seldom held still for more than a second. There was always another insect to chase.

This male yellow-rumped warbler, in contrast, was not hiding. The challenge with him was that he seldom held still for more than a second. There was always another insect to chase.

The wren and the warbler both nest well to the north, and will be with us only a short time.

Home hunting was another theme. The first bumblebee queen I saw this year was a Bombus bimaculatus.

She didn’t hold still, and didn’t stick around for long, but the yellow center of the second abdominal segment is visible in this blurry photo.

She didn’t hold still, and didn’t stick around for long, but the yellow center of the second abdominal segment is visible in this blurry photo.

Bumblebee queens in spring are probing for holes in the ground where they can start their colonies. Some animals make their own holes, and I found what may be a test dig by Mayslake’s pair of coyotes.

It was in an elevated site, and the hole was a foot in diameter, but not yet completely excavated. I’ll check on it occasionally. Coyotes only use dens to shelter their young.

It was in an elevated site, and the hole was a foot in diameter, but not yet completely excavated. I’ll check on it occasionally. Coyotes only use dens to shelter their young.

The abundance of the growing season still is in the future for most, however.

This fox squirrel was making do with some dried rose hips from the bush outside my office window.

This fox squirrel was making do with some dried rose hips from the bush outside my office window.

Clearly we are in a season of promise and preparation.

Advertisements

Scoured

by Carl Strang

With water levels returning to their usual lower levels in the wake of last week’s flood, some changes are evident in the stream at Mayslake Forest Preserve.

Strongly flowing water is a geological force. It carries away any loose particles whose weight cannot resist the current.

Strongly flowing water is a geological force. It carries away any loose particles whose weight cannot resist the current.

What remains are the larger pieces.

Just downstream from the location of the previous photo are newly sorted bars and piles of clean looking larger rocks.

Just downstream from the location of the previous photo are newly sorted bars and piles of clean looking larger rocks.

The stream at Mayslake no longer is a typical DuPage County muddy waterway.

There are gravel bottomed riffles and pools.

There are gravel bottomed riffles and pools.

This change will favor some stream dwelling organisms at the expense of others.

The effect of this resorting of stream material on the biological community could develop over several years.

The effect of this resorting of stream material on the biological community could develop over several years.

It will be interesting to follow this community, as I will be doing with the nearby marsh as it recovers from the drought, and as I will be doing with the insects in the portions of prairies and savannas impacted by this spring’s controlled burns. Balance of nature? Nature always is in flux. Ecological studies deal with moving targets.

Spring

by Carl Strang

By my own subjective criteria, I have to declare that spring finally arrived, with a whimper, on April 16. I wasn’t at Mayslake Forest Preserve that day to see it, but the next day was a cold one, and it was clear that a few trout lilies and spring beauties had bloomed but then closed up in the lowered temperature. The weather stayed cold then, and so it wasn’t until Monday of this week that spring was manifestly present. One of its heralds was a patch of white trout lilies.

A representative bloom.

A representative bloom.

Spring beauties were scattered in little patches across the savanna.

Pink guidelines point the way to the flower’s center.

Pink guidelines point the way to the flower’s center.

A bonus was a colony of bloodroots.

They formed a circle reminiscent of a fairy ring.

They formed a circle reminiscent of a fairy ring.

That warm day also brought the first green darner dragonfly, and mourning cloak and cabbage white butterflies. We haven’t seen the last of the cool weather, but winter appears to be done.

The Flood and Animals

by Carl Strang

Yesterday I shared some images of last week’s flood at Mayslake Forest Preserve. When I saw how high the water had risen, I expected to find the Canada goose nest washed out. She was in the bowl-like parking lot marsh, on top of a muskrat house. When I got there I found that the water was high, but it had found a new outlet that limited its rise.

The water came within a few inches of the nest, but did not flood it.

The water came within a few inches of the nest, but did not flood it.

As I walked the east shore of Mays’ Lake that day, I heard a sudden loud splash above the roar of the nearby stream. It reminded me of a beaver’s warning dive, but there have been no resident beavers on the preserve in some years, so I passed it off as something else. On the next day, however, I found this:

A beaver had been there indeed. The freshly gnawed cuts showed the wide grooves made by beaver incisor teeth.

A beaver had been there indeed. The freshly gnawed cuts showed the wide grooves made by beaver incisor teeth.

Until I have reason to believe otherwise, I imagine this beaver was passing through, following the course of the flood or perhaps using the elevated waters to make an exploratory trip.

A final image comes from the day after the flood, as a northern rough-winged swallow rested at the edge of the lake.

A number of rough-wings, tree and barn swallows were foraging close above the water’s surface.

A number of rough-wings, tree and barn swallows were foraging close above the water’s surface.

This was a reminder that the spring migration is accelerating as the end of April approaches.

Flood!

by Carl Strang

Transformations of familiar landscapes happen from time to time. Some of these are rhythmic: the changes of the seasons, which can bring in turn a blanket of white, an explosion of green, or a kaleidoscope of color; and the dawn-dusk alternation, which brings light or the cloak of darkness. Last Thursday brought a different kind of transformation, when a string of storms dumped more than 4 inches of rain overnight, elevating the northeast Illinois streams, and raising the lakes and marshes of Mayslake Forest Preserve to rare levels. Most dramatic was the Mays’ Lake outlet area.

This view down the trail shows how much of the trail became inundated.

This view shows how much of the trail became inundated.

One day later the flood had subsided.

The same viewpoint, 24 hours later.

The same viewpoint, 24 hours later.

As you can see, the culvert that normally feeds the outlet stream was unable to accommodate the outflow.

The pourover reminded me of my whitewater kayaking days, as I imagined running the drop and continuing downstream.

The pourover reminded me of my whitewater kayaking days, as I imagined running the drop and continuing downstream.

Transformations of familiar landscapes change us as well. In the case of a flood, our personal transformations can be tragic and sad, or they can fill us with wonder. The worse outcome, perhaps, is to be totally unmoved by such powerful events.

On the Verge

by Carl Strang

Having decided that, for me, the arrival of spring will be signaled by the first bloom of one of three species of plants, I have been watching for new growth. A week ago there was practically nothing, but by Saturday a number of white trout lilies had sent up leaves and a few flower buds.

The buds were not quite ready to open.

The buds were not quite ready to open.

Already this is the latest spring among my five at Mayslake. Today I return after being away a few days, and I hope the wait at last will be over.

The Burn Extended

by Carl Strang

As I reported earlier, Mayslake Forest Preserve had a thorough controlled burn of its highest quality restored prairies in late March. On Monday I discovered that had not been the end of it. The Forest Preserve District’s crew returned and conducted a burn of the north savanna and adjacent meadow areas.

The top of the savanna ridge after the burn.

The top of the savanna ridge after the burn.

This burn likewise was a good one, leaving little in the way of last year’s dead herbaceous growth. This is the most complete burn coverage of the preserve in the 5 years I have been there, and along with the vegetation went the eggs and nymphs of many species including tree crickets, meadow katydids, and greenstriped grasshoppers. From a scientific standpoint this is more opportunity than it is disaster, as there are no rare species at Mayslake. The remaining, unburned meadows and wetlands, as well as a few pockets that did not burn well, will be source areas for the spread and repopulation of the burned areas by survivors. Also, the fire probably did not affect the species whose eggs were in the soil or treetops, including fall field crickets, ground crickets, and some katydids.

The burn extended into adjacent meadows to the east and north.

The burn extended into adjacent meadows to the east and north.

I will be able to make a number of comparisons to assess the impact of the fire. How well will the affected insect species spread from the refugia, and where will they go first? Will there be differences between burned and unburned areas in the unaffected species, which stand to benefit from the higher quality plant growth in the wake of the burn? What will be the species count differences between years in the various habitat blocks? What about the impact of specialist predators and parasites? The first species to note will be the greenstriped grasshopper, which has been common in the early season.

Hypothetical Cicadas and Grasshoppers

by Carl Strang

Thanks to two publications, one very new and one very old, I have been able to fill out my list of singing insects that may occur in the Chicago region by adding possible cicada and grasshopper species. The new reference is a monograph published last year by the Entomological Society of America, The Cicadas (Hemiptera: Cicadoidea: Cicadidae) of North America North of Mexico, by Allen F. Sanborn and Maxine S. Heath. There is not a lot of natural history information in it, as its focus is on sorting out species and their relationships, but it is complete in its species coverage and at least outlines the range for each. It allowed me to add three possible cicadas to my list. Two of them are tallgrass prairie specialists that are known in Illinois but may not occur this far north: the common grass cicada (Cicadetta calliope), a tiny early season species, and the bush cicada (Tibicen dorsatus), a late season species. The third added cicada, Walker’s cicada (Tibicen pronotalis), is a large insect of woodlands along streams.

The old reference is W.S. Blatchley’s Orthoptera of Northeastern America with Especial Reference to the Faunas, of Indiana and Florida. This one was published back in 1920, and is available as a 2012 reprint by the Forgotten Books company. The text is generally readable, but somewhat faint. The taxonomy and nomenclature for the grasshoppers have been remarkably stable over time, and most scientific names haven’t changed. I was able to make the necessary updates by referring to the most recent popular guide to grasshoppers, katydids and crickets by Capinera, Scott, and Walker. Blatchley’s book contains considerable natural history information, and is reminiscent of the Bent’s Life Histories of Birds in its style.

There are two subfamilies of singing grasshoppers. The stridulating slantfaced grasshoppers, subfamily Gomphocerinae, sing while perched or resting on the ground, lifting and lowering their back legs to rub them against the wings, producing a rapid zuzz-zuzz-zuzz sound that is distinct from other insect songs, but to my ear this stridulation seems much the same in different species. The only one for which I have a photograph is a northern species.

Thomas’s broad-winged grasshopper at Whitefish Point on the Upper Peninsula of Michigan.

Thomas’s broad-winged grasshopper at Whitefish Point on the Upper Peninsula of Michigan.

That grasshopper does not occur as far south as our area, but another member of its genus, the sprinkled broad-winged grasshopper (Chloealtis conspersa) is one I’ll listen for, along with 7 other candidates in this subfamily. Though their songs probably are much the same, their habitats and details of their appearance are different.

The other singing subfamily of grasshoppers is Oedipodinae, the band-winged grasshoppers. These produce their sounds in a different way, crepitation, by rattling or rubbing together their wings in flight. The potential additions to the local list number a dozen species. One of these also was prominent at Whitefish Point.

A pair of clear-winged grasshoppers, Camnula pellucida

A pair of clear-winged grasshoppers, Camnula pellucida

The literature suggests more variation in the sounds produced by the crepitation method, but these grasshoppers are flying when they sing, and so should be easier to locate.

Measuring Marsh Recovery

by Carl Strang

Now that Mayslake Forest Preserve’s stream corridor marsh is full of water again after several months’ drying out, I am curious as to how fast its animal community will recover. Apart from simply observing what I can on the surface (waterfowl have been back, and last week there were a muskrat and a few singing western chorus frogs), my best tool is the amphibian trap.

Each end is capped by an inward-angling funnel with a 1-inch hole in the end. Animals that enter through the hole have a hard time finding their way back out. The top of the trap is out of the water so they can breathe if they need to.

Each end is capped by an inward-angling funnel with a 1-inch hole in the end. Animals that enter through the hole have a hard time finding their way back out. The top of the trap is out of the water so they can breathe if they need to.

Five traps placed around the marsh produced nothing for two days, and were absolutely clean, suggesting little or no activity around them. The third day brought the first capture.

One of the traps had a medium-sized White River crayfish.

One of the traps had a medium-sized White River crayfish.

I don’t believe this species could survive the marsh drying out, so this individual probably was a recent immigrant from the nearby stream.

Friday was the big day, however. The first three traps I checked were empty, but in the fourth I found these:

Five tiger salamanders.

Five tiger salamanders.

Prior to that moment, in two springs of trapping I had caught a grand total of one salamander. But that wasn’t all.

The final trap held two more.

The final trap held two more.

Most of these appeared to be males, but at least one appeared to be a female (proportionately shorter tail, with less tail fin, and much less swelling around the genital area). Furthermore, none of them had spot patterns matching the one I caught last year. With predatory insects diminished, this would seem to be a promising year for tadpole survival. A final observation as I released them was that they swim by folding their limbs against their bodies and propelling themselves entirely with their tails. This is interesting, given that they move about their terrestrial tunnels all the rest of the year with their legs.

Why this sudden success? Looking back, I suspect that in previous years I may have put the traps out too late, and the salamanders were done and gone. This year I got the traps out within days of the last ice melting away.

Dark-eyed Junco Species Dossier

by Carl Strang

We’ll soon say goodbye, for the summer, to our most familiar snowbirds, the dark-eyed juncos. Here are my notes on the species. This probably will also be the last dossier until next winter.

Junco, Dark-eyed

Dark-eyed junco

Dark-eyed junco

1986 initial summary: Juncos are common late fall, winter and early spring residents around Culver and West Lafayette, Indiana, south central Pennsylvania, and DuPage County, Illinois. They usually travel in flocks, and can be seen in any habitat. They have a follow-me signal in the form of white outer tail feathers that contrast with the dark central ones. They eat seeds, and feed almost exclusively on the ground or on elevated flat platforms in winter. The call note is 1 to 3 syllables (often 3): chi’-bi-dit’ (short I’s), very quick and chittering.

4OC86. First lone individual of fall, stayed around the Warrenville, Illinois, back yard for much of the day.

1987. Juncos still were present at Willowbrook on 6AP, and were singing by 16MR (trilling song), gone by 27AP.

24SE87. First juncos of fall have arrived, Morton Arboretum.

14MR88. Juncos maintain a constant chatter, foraging on and near ground, of minute twitters, trills, and complex combinations of soft notes, occasionally interacting more directly with little scuffles when one encroaches on another’s bit of feeding ground.

17MR88. Juncos singing a lot, Willowbrook Back 40.

20MR88. In east Meacham Grove, a large junco flock, as at Willowbrook very noisy with assorted twitterings, chasing, some singing. Birds were on the ground, in bushes and in trees.

21MR88. Willowbrook Back 40. Some juncos kick like fox sparrows, but not so loudly.

Spring 88. Flocks still present 30MR, gone by 5AP, a few individuals still present 8AP.

15OC88. First juncos of fall, at Red Oak Nature Center (near Batavia, IL).

Juncos most commonly are seen on the ground.

Juncos most commonly are seen on the ground.

18NO88. Willowbrook Back 40. I was watching a flock of juncos and listening to birdlife in general when a sharp-shin flew over, north to south. There was silence from the time it came into view to the time it passed from view. The juncos remained absolutely still, their twitterings and flutterings resuming after the hawk was gone. That hawk must have a quiet view of the world, just as police see orderly traffic when in their patrol cars.

9MR89. Juncos starting to sing, Willowbrook.

21MR89. Willowbrook Back 40. Considerable social activity on this clear but very cool day, among juncos. Some vigorous chasing, and in one case two birds feeding on ground close together, in what seemed to be a synchronized way. They appeared to be male and female. Warming up for start of breeding season? (Have been singing off and on for weeks, now).

21OC89. First junco of fall seen at West DuPage Woods Forest Preserve.

24SE91. First junco of fall seen at Willowbrook.

19FE99. Juncos starting to insert bits of song into their calls.

11MR99. Junco song a trill, sometimes varying in speed and with small chirps sometimes added before or after. Trill a bit more musical than the call. This morning at Willowbrook there are many juncos on the preserve, especially along the creek north of the bridge. They are foraging mainly up in the trees, also singing and chasing one another.

17MR99. Today another wave of juncos at Willowbrook. Some are appearing in places where I haven’t seen them all winter, so I’m inclined to regard them as new birds, migrants drifting north. Very active, like those on the 11th.

11OC99. First junco arrived at Willowbrook.

29JA00. Juncos along with Brewer’s blackbirds and others are at Fermilab buffalo feeders picking up spillage.

5FE00. Juncos common along roadsides near Culver.

22FE00. Willowbrook. First junco songs of the year (2 individuals).

10MR00. Willowbrook. Juncos singing regularly now. Today one fed from an open silver maple flower cluster.

13AP00. Willowbrook. Several juncos still present, have been there daily.

9MR01. This is the first day I’ve observed both singing and much chasing and other play-territorial behavior by juncos this year. A couple singers earlier in the season. It’s a much colder spring than last year, and there have been fewer juncos on the Willowbrook preserve.

30AU01. Juncos are in small groups at Algonquin Park, Ontario, usually associated with hemlock groves.

5OC10. Mayslake. Heard the first juncos of the season.

« Older entries

%d bloggers like this: