Introduction to St. James Farm III: Forest, Field, Restoration

by Carl Strang

The dominant wild habitat at St. James Farm Forest Preserve is its forest, the largest wooded block in the western half of DuPage County to survive from the original land survey to the present day.

[SJF forest 1. Caption: Portions of the forest are dominated by red oaks, some of which are huge. This is very unusual in DuPage County. ]

Portions of the forest are dominated by red oaks, some of which are huge. This is very unusual in DuPage County.

White and bur oaks, more typical of the county’s woodlands historically, are well represented as well.

White and bur oaks, more typical of the county’s woodlands historically, are well represented as well.

Not as big as the oaks, but equally remarkable, is this ironwood. It has a stem diameter of 11 inches.

Not as big as the oaks, but equally remarkable, is this ironwood. It has a stem diameter of 11 inches.

Ironwood seldom grows big enough to become part of the canopy.

Ironwood seldom grows big enough to become part of the canopy.

Significant portions of the forest recently have been cleared of invasive buckthorn and honeysuckle, and a first response has been a heavy growth of white snakeroot, a native forest annual.

Significant portions of the forest recently have been cleared of invasive buckthorn and honeysuckle, and a first response has been a heavy growth of white snakeroot, a native forest annual.

Trails ultimately will be improved to provide ready access through the preserve.

Here a recently constructed trail curves through a meadow. It also extends into the southern part of the forest.

Here a recently constructed trail curves through a meadow. It also extends into the southern part of the forest.

At the moment, the northern part of the preserve is closed as a major restoration project proceeds.

The focus of the project is this stream, once a straight ditch, now improved with meanders and streambed improvements.

The focus of the project is this stream, once a straight ditch, now improved with meanders and streambed improvements.

Following the ensuing growth and development of that area will be one theme of my monitoring observations to come.

 

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Whitetail Deer Dossier

by Carl Strang

It’s time to start sharing some of my larger files of notes from personal observations of our vertebrate wildlife. This week’s feature is our local hoofed critter. The preliminary notes, written in the mid-80’s, are more extensive than usual. The dated notes that follow provide many illustrations of the value of tracking in behavior studies.

Deer, Whitetail

Buck in a bed

Buck in a bed

Deer can be seen in a variety of habitats. Their home range always includes some woodland, brush and meadow or marsh areas. They travel on well used trails, occasionally wandering off them to feed. Commonly they enter meadows to feed at dusk. In winter, they feed on browse. In northern Illinois they hit Rosaceae (blackberries, roses, etc.) early in winter, then eat a variety of woody plants, then by mid-February are eating poison ivy almost exclusively. Cottontails follow the same sequence of foods, but deer-browsed twigs usually are bitten off higher and have a torn edge from the deer’s lack of upper incisors. Through January (though mainly in October and November), bucks attack certain shrubs and saplings along trails, breaking twigs and usually also eating a couple (antler rubs). At Herrick Lake Forest Preserve I noticed that pioneer bur oaks in fields were especially exposed to this abuse.

Shrubs missing bark after being rubbed by a buck’s antlers

Shrubs missing bark after being rubbed by a buck’s antlers

Does in spring have fawns which at first remain quietly curled up on ground, freezing when approached. If they do wander, they will call for mother with a sheep-like bleating sound. As their size and strength improve they begin to travel with mother, although on occasion they will drop into a frozen curled position when a threat is detected. Spots can remain into late summer.

Deer flushed close have tail-lifting display, spreading the white hairs underneath (on small fawns the display is disproportionately large). At a distance, when at least partly in cover, they give a high-pitched, whistling snort, often accompanied by a stomping of the feet.

Bony antlers grow slowly through summer, covered with velvety skin. In late fall they dry, the skin comes off. By spring the antlers have been shed.

Tracks usually are 2-toed hoof marks. Leaping deer or those in deep soft substrates also will make 2 smaller dewclaw prints. In deep snow, the tips of the nails often make drag marks. I have seen deer leap over 6-foot fences, and tracks have shown horizontal jumps of more than 12 feet.

In May, deer on Reineman Sanctuary (PA) fed on fiddleheads of hay-scented ferns, but didn’t touch them after they unfolded. Among summer foods were leaves and twigs of greenbrier.

Deer tracks typically show two toes. Here, a deer was walking but accelerating.

Deer tracks typically show two toes. Here, a deer was walking but accelerating.

27DE86, Memorial Forest near Culver: deer recently browsed sassafras.

10JA87. Herrick Lake Forest Preserve. After last night’s heavy snow, tracks (made this morning, early) only abundant at a large patch of brush in SE corner of preserve, along N edge. All made early this morning except one flushed by a person who was tracking it.

11JA87. Waterfall Glen Forest Preserve. Deer were bedding in snow in same general area, had been there a while before my approach scared them up around 11:30 a.m. They had not cleared a place but just lay down, and the snow barely melted. Beds of the 4 deer were 5-20m apart. Other areas, similar in size and with sides pressed smooth by deer’s body (1 with hairs), had ground bare on the bottom (snow 6 inches deep). In the one with the hairs there were no clear signs of digging, but the others clearly had been dug out.

17JA87, Herrick Lake Forest Preserve. Half an inch of new snow fell the night before. I started tracking in the afternoon, but the tracks were difficult to follow as individual deer and small groups flowed together and apart, anastomosing their trails so that I couldn’t follow an individual for long.

18JA87. McKee Marsh. Better luck. 4 inches of new snow fell overnight, and I was able to follow a single deer for 2 hours, covering about a mile. I was able to stick with him (I believe it was a large buck). I began in the woods near the parking lot, where he followed a winding path, sniffing several shrubs and browsing on a Viburnum (3-lobed leaves and paired red basswood-like buds) and on buckthorn. In one spot where he urinated copiously there were symmetrical shallow hoof marks on either side of his trail, which had the effect of scooping snow into the spot where the urine fell. Then he emerged into open fields E of the woods, wound through a marshy spot, crossed Mack Road, then angled ESE. At one point he suddenly was spooked by a fresh snowmobile track, jumped to the left, then walked across the track and rejoined the trail. Occasionally I had problems when he joined another deer, but by finding every footprint I was able to stay with him until he re-entered the woods and joined 3 other deer. When they split I could not be absolutely sure which he was, but I have about 50% confidence that I followed the right one. He ate more Rhamnus, paused to browse heavily on a young bur oak, wandered up a hill, then joined another galloping deer (and 2-3 others), they all crossed Mack Road onto private property and I could not follow.

Where a buck urinated on his feet, blending tarsal gland secretions with urinary scents

Where a buck urinated on his feet, blending tarsal gland secretions with urinary scents

1FE87. Freshly browsed poison ivy, McKee Marsh. Also white ash within the past 2 weeks. Another deer browsed a woodland rosaceous small tree (probably crabapple), 2 inches dbh. Also a basswood. Twice, it defecated shortly after passing under low branches and browsing a few bites. I tracked the deer until I caught up with it in the cattail marsh north of the woods E of the marsh. It had turned to stand in a well hidden spot to watch me. When I got too close it burst from cover, bounded on through the cattails and through the field on the other side. Tracks in field took more of a bound pattern (not so spread front to back) before and after taller weeds, bounding high to clear them.

Later that same day, following another group of deer, I found where one had bedded briefly, at least, in the wet snow.

21FE87. At Greene Valley Forest Preserve. 5 bucks, still with antlers, traveling together as a group. They were moving fast when first seen, traveling through an open field between hedgerows at around noon. They stopped for a while after gaining a second hedgerow, then slowly moved in my direction (I was wearing a navy blue sweatshirt and dark brown pants, and kneeling). They always had one watching me, often all did, but didn’t run away until much later when I stood and walked. Once, a couple sparred with antlers. Mostly 4-6-pointers.

28FE87. At least 3 deer flushed from area thick with saplings and brush under scattered trees, only 150m from busy highway.

23MR87. Waterfall Glen. Deer dead beside creek near intersection of Cass Ave. and 91st Street. Lying in deer-beaver trail, hind feet in water (fracture of left hind tibia partly healed), head end up on bank. Dead at least a week, ribs largely gnawed away, head gone, muscle and internal organs mostly gone except hindquarters. Other tracks of beavers and dog or coyote (probably latter) nearby.

MY87. New Jersey Pine Barrens. Deer browsing blueberries, a little on oaks.

4AU87. Lebanon State Forest, NJ. 4-5 deer flushed from blueberry undergrowth, bounded until out of sight. Then one snorted a couple of times. I could hear them walking in even steps, without the hitching, explosive quality of a towhee. A little sharper and louder than the sound made by the gray fox seen shortly before. That night, as I walked barefoot in the dark, I came within 10 feet of a bedded deer. The deer detected me, and made a terrific racket getting to its feet. By the time it snorted so I knew what it was, I had taken 2 steps back.

Bumps on the head identify this newly spot-free fawn as a male.

Bumps on the head identify this newly spot-free fawn as a male.

3JA88. McDowell Forest Preserve. Following deer tracks, at least 4 days old. Browsed black maple, as well as several scotch pine branch tips (a broken-off branch, about 0.25 inches in diameter where browsed off; twisting and tearing of adjacent needles. Soon thereafter, browsed from a rose bush (prior to all this eating had followed a slightly sinuous path through maple woods, walking steadily). Tracks probably made New Year’s Eve (day before cold front). Feet compacted very wet snow, so probably late afternoon. Stopped to rub antlers on 0.75-inch dbh maple sapling, on its trunk from 1 foot to 2 feet up from ground, bark removed from one side. Soon thereafter it fell in with 2 other deer. Tracks same age, difficult to distinguish, but I believe the one I’m following has a longer stride. They paused to browse buckthorn, maple, rose (mainly the other 2?). Eventually the 3 bedded down beside a multi-stemmed, branchy silver maple in the midst of a field, about 100m from I-88 (in clear view; dark by then). 2 bedded together, third 10 feet from them. They stayed a little while, but still slushy when they left. They headed for the West Branch of the DuPage River, meandered, browsed, another antler rub. Lots of beds in that area. Tracks turn back along stream toward center of preserve. Lots of deer tracks enter and are present in that area by the stream, but none leave. The deer must cross the stream. I backtracked a bit. Buck had been with the others just before I picked up trail, probably was within sight of them throughout.

9JA88. Most of the needles on that pine branch now are browsed away. Deer commonly cross the river just opposite that grove, though routinely bedding among the yews and other ornamental shrubs between there and the stream. Once across, there is a tall fence paralleling the river and about 30 yards on average from it. The deer remain between river bank and fence. A heavily traveled corridor, a bedding area not far from that crossing site. Opposite the zone where I presume they also crossed the river last week, the fence is low enough for them to jump easily, and they either do that, or go under it at a nearby creek (more common), or continue along fence (also common). But soon comes I-88, and it appears to be a complete barrier on that side. A few cross the river there, a few go around the end of the fence. A very few go under I-88, on west side of river. None have crossed in that presumed crossing zone, but the ice probably has been thick enough to support them for only a couple days, and an open lead about 3 feet across runs along the entire east side along that stretch. That might explain why the tracks were running the opposite direction from last week on the stretches-in-common.

When you hold still and allow a deer to approach, it will stare at you and occasionally stomp a foot as though to startle you into moving and revealing yourself.

When you hold still and allow a deer to approach, it will stare at you and occasionally stomp a foot as though to startle you into moving and revealing yourself.

16JA88. McDowell deer crossed the preserve entrance road just west of the bridge, followed trail steadily between road and river (top of bank). Night before last, not last night. Lost in human and dog tracks, just before widening of area and feeding signs spread out from trail. Well below dam (at least 200m). There signs of much deer activity. Several beds in hill and old-wall area. More feeding and trails (well-used) in even wider area S of there. I flushed a large doe and 2 non-spotted fawns from beds in a pole-tree area a little farther down. They soon circled back around me (to my N). Visible parts: sharp dark horizontal line of back, horizontal white streak of belly cutting through trunks, from side; narrow white outline of tail from back, black nose and eye; brownish cast of fur against gray of trunks (not as distinct).

23JA88. McDowell. Deer recently browsed bur oak sapling. Tracked group of 4-8 deer into NW corner of preserve, brushy area seldom frequented by people, W of beaver pond (dam long, a winding 20-30 yards).

27JA88. Dan Ludwig flew over McDowell and passed on observations of deer: 8 in NW corner, 3 in NE near toll road (both groups west of river, and 6 SE, possibly off preserve.

30JA88. Hartz Lake. Deer trails through woods generally straight, and located to accommodate traveling from one goal to another (goals on either side of woods). Much interdigitation and side-paths abundant around the moist, tall meadows.

29AP88. Pratts Wayne Forest Preserve. Micro pressure releases in one or other toe show where push or pivot was greatest.

1MY88. Warrenville Grove Forest Preserve. Deer ate off tops of several Smilacina racemosa, plus a couple of Alliaria (and other plants, individually removed lower leaves). Not real recently, say 3-8 days ago.

7MY88. Deer tracks, Indian trails of Culver, also ate off tops of a few Smilacina stellata. At Hartz Lake, when one broke a twig loudly, jay responded with “thief” call.

15JL88. Deer heavily eating the Tradescantia at Fulton County museum property, not too long ago. Also eating Seymeria macrophylla.

Antlers nearly grown, but still covered in velvety skin as the bone matures

Antlers nearly grown, but still covered in velvety skin as the bone matures

1AP89. Patch of deer hair on ground in clearing at Hartz Lake. (I also saw some at Winfield Mounds last weekend). Shedding already.

2AP89. Hartz Lake. Deer in groups around clearing (in woods with very little understory) around 9 a.m. A deer snorted. I could just see it through the trees. The nose moved, perhaps a couple inches, but that was the largest motion I could see when it snorted.

13MY89. Hartz Lake, camping. In the dusk, 8 deer came to the prairie area (I was sitting at the opposite edge, by fire). Though basically a doe group, one yearling (small) buck was with them. He was chased a couple times, and a deer struck his back with a forefoot (not a mounting, but a blow). Smaller does still chase after mothers (presumed relationship) to be close to them, when alarmed. I kept still. They saw me, frequently moved heads side to side for parallax.

4JE89. Elsen’s Hill: deer trot pattern showing groups of two prints, 1 foot between prints in a group and 3 feet between groups. Two alternating group types, with front foot of each side ahead of hind foot of other side in that group.

21AU89. Deer tracks, Willowbrook Back 40. Emerged from run, NE corner. Walked down to pond, but stayed above edge (recently arrived, and had drunk from brook?). Nervous. Much starting and stopping, and stomping. Reached a small gulley, then broke into lope, as though the need for the longer step set off a release of nervous energy. 24-inch steps before the lope (toe-tip to toe-tip, measured diagonally). Tendency to splay left front foot and show its dew claws in the lope. While loping, set of 4 tracks 35 inches front to back, groups about 70 inches apart. The tracks were made last night (it had rained the night before last, the tracks made after the rain and after the soil surface had dried). About ten days later: In a hard lope up the hill, the deer showed dewclaws and spread toes on all but the right front. The deer stayed only a couple of weeks. We heard of someone who saw 2 bucks.

2SE89. Tracking deer across screenings trail, McKee Marsh. Stride tended to be slightly longer (23 inches toe tip to toe tip) in tall grass than on path (19-21 inches), except where adjusting stride to clear obstacles. At one point, a hind foot seemed to indicate a turn, falling and pointing to left of the front print, but in fact kept going in the same direction. Response to a disturbance as that foot came down? Implies independence of the 4 feet. Also happened the previous step with that foot.

15SE89. Hartz Lake, edge of open dune. Deer usually pause at edge of clear area before entering it. Shorter strides, and standing.

20SE89. McKee Marsh. A deer, steps 20-20.5 inches on packed screenings trail, became 25-27 inches in tall grass.

Sometimes deer tracks through tall grass are quite clear.

Sometimes deer tracks through tall grass are quite clear.

23SE89. Forest Park Nature Center, Peoria, IL. Deer have been browsing Aster shortii, a species of ridgetops, heavily in recent weeks. This has been their main food within the forest in this period, except for acorns.

24NO89. Hartz Lake. 2 deer beds, SE corner (behind cemetery) in woods. Windy day, saw 2 deer crossing road mid-afternoon, and as I studied tracks on the open dune a doe with a broken or injured right front leg limped past.

13DE89. Hartz Lake. Deer heavily using main north-south trail past couple of days (since snowfall).

16DE89. McDowell Forest Preserve. Patterns of deer activity in west part of preserve much the same as last winter. The only difference is a possible shift from the old home site to the center of the adjacent field in the north part of the preserve. If anything, there is even more concentration of activity to the north end of the preserve than before.

4FE90. Recently shed antler near mouth of Sawmill Creek, Waterfall Glen Forest Preserve.

Late MY90. Hartz Lake. A deer appeared to stomp and snort as a gambit to make me move. Odor and sound spooked them more than small movements.

9JE90. Winfield Mounds. Heavy feeding by deer on goldenrods, past couple of weeks.

Wet forest litter from a recent rain foiled this fawn’s camouflage. Fawn spots form individualized patterns that permit recognition of individuals as long as they last.

Wet forest litter from a recent rain foiled this fawn’s camouflage. Fawn spots form individualized patterns that permit recognition of individuals as long as they last.

30JE90. West DuPage Woods. Fawn moving about and exploring on its own. Still small, but strong. I held still, it slowly moved toward me, sniffing and occasionally stamping like an adult. When mother appeared, and bolted, it ran, too. Tail flag.

13JL90. McKee Marsh. As I was running through the forest, I saw a fawn, approaching half adult size, on the trail ahead. I slowed and quieted my steps. It bolted when I was 10 yards away, and its mother and its sibling, who were close by, bolted as well. Unless the mother gave an audible signal I missed (unlikely, though I was so focused on the fawn that I didn’t see her), she was waiting for the fawn to make the move. If so, she was teaching it to run away from people and to react on its own without depending on her signal.

2JE91. First fawn tracks of the year, Pratts Wayne Woods Forest Preserve.

Doe and fawn. By November, the fawns’ spots are gone.

Doe and fawn. By November, the fawns’ spots are gone.

21DE91. Hidden Lake Forest Preserve. Followed last night’s tracks of a very large deer, sex uncertain but more likely male. Traveled relatively straight lines through open field, but began highly convoluted turnings in a brushier area as it began feeding. Principal (only?) food Geum laciniatum basal leaves, nosed rather than pawed snow to reach them. Ate many. Went out of its way to examine a coyote or dog bed. Bedded, itself, several hours. Note: outward tracks from bed looked older than inward ones. Snow apparently less compactable, or more easily self-kicked back into track, with less smoothly compacted bottom of track and less crisp edges. Wandered and fed more after leaving bed. Defecated several times.

17FE92. Elsen’s Hill (W. DuPage Woods Forest Preserve.). I kept mainly to deer trails, saw 2 deer in a brushy area and, later, in a forest, saw 2 getting up from their beds. I stood still for a while, there, listening, and soon caught movement. Three deer slowly moved into view. Almost certainly the ones I had spooked, a doe and 2 fawns. I kept very still and they approached, the doe doing the foot-stomping test. Sometimes it appears to be largely a nervous expression, others it is very deliberate and calculated, the deer staring hard and keeping its head still while doing so. The fawns kept back. Several times she gradually worked to within 20 yards, then abruptly turned and ran, tail flagging, the fawns doing so as well. On one of these occasions she snorted several times. But I kept still, she didn’t go far, and repeated the process. The closest she ever came was 40 feet. I was wearing the green and black wool coat, standing clear of trees, with a medium density of 2-4-inch dbh trees and a few large ones in that area. The deer finally left for good at the sound of human voices on a trail not too far away, but the deer walked away rather than ran. During all of this there were occasional crows and squirrels seeing me and vocalizing. The deer attended the squirrels, but not the crows, starting at the squirrel’s bark and becoming more wary of me.

3OC93. Rock Island Park, Wisconsin. 2 bucks facing one another, heads lowered near to ground, maneuvering antlers. Like arm-wrestlers seeking best grip.

Early in the 90’s I had a season of deer hunting. During a several-day cold rainy period I sat for hours without seeing any deer. On drier days they were active.

Deer visited several times during the 90’s at Willowbrook. Usually they stayed 2 weeks at most, but during the summer of 1997 a couple of them stayed from May into August.

JE99, Kansas, Konza Prairie. A deer snorted and ran as I approached, holding head and nose above horizontal a bit while snorting.

15MY06. Fullersburg. A deer eating Virginia creeper leaves from a ground vine.

During the 3 years my office was at Fullersburg Woods Forest Preserve, I mapped the winter movements of the preserve’s deer. In the winter of 2006-7 there were 4 groups which followed consistent daily routes as shown.

During the 3 years my office was at Fullersburg Woods Forest Preserve, I mapped the winter movements of the preserve’s deer. In the winter of 2006-7 there were 4 groups which followed consistent daily routes as shown.

28AP08. New antlers beginning to grow on bucks (similar stage photographed 3 May last year).

New antlers just starting to grow

New antlers just starting to grow

15SE10. Meacham Grove. While doing herbivory data collecting I saw 3 antlerless deer. One, a fawn that had become spotless, made a persistent effort to nurse from its mother for a minute or so until she pushed it away. The third I believe was another adult doe.

Sound Ideas: When the Prairie Fire Comes

by Carl Strang

This post resumes a series I started last winter, sharing sound recordings. Some of these are field recordings of such things as insect songs, while others, like today’s, are my own creations. “When the Prairie Fire Comes” was one of the songs I wrote for an extended story back in my storytelling days. The story, Dandelion, is about a boy’s growth in response to the challenge of moving to a new place. He meets various characters in his dreams, who help him along the way. One of these characters, Bur Oak, provides an exaggerated, hyper-vigilant, example that turns Richard away from his growing anxiety.

Bur oaks are the main savanna and prairie edge species of northeastern Illinois. As such, they have adapted to a fire-shaped ecosystem.

Bur oak twig showing the thickened bark, an adaptation that provides some protection from fire.

Bur oak twig showing the thickened bark, an adaptation that provides some protection from fire.

Controlled prairie burns, used in prairie and savanna management, may scorch the outer bark but seldom cause appreciable damage to the resident bur oaks.

Savanna Pioneers

by Carl Strang

I went up to the former friary site at Mayslake Forest Preserve on Monday, and found something new.

One of four recently planted bur oak trees.

The small trees at first glance seemed lost in the expanse of the site, separated as they were by distances of about 50 yards. This is, however, an appropriate spacing for a savanna, and even if no other trees were to grow there, when full grown these trees would look just right with prairie plants growing between them.

That condition will not be met, however. As I have mentioned in the past, the woodland at the north edge of the site is ready to send acorns and other propagules south, and with the aid of squirrels soon will expand into the open space. I am glad to see that the decision has been made to acknowledge and support that process through the planting of these four pioneers.

Oak Leaves Expand

by Carl Strang

Last week I described the preference migrating songbirds were showing for an inferior woodland, rather than the high quality savannas at Mayslake Forest Preserve. I thought the security provided by the woodland’s buckthorn understory might be the significant factor. This week I found some support for that idea. The oaks have expanded their leaves.

Bur oak is the dominant tree in Mayslake’s savannas, followed by white oak, shagbark hickory, and Hill’s oak.

The migration is winding down, but there has been a clear shift of warblers, vireos and others into the savannas. The few remaining in the degraded woodland are species like yellow-bellied and alder flycatchers, which like low dense brush. Now that there are lots of hiding places in the oak canopy, it seems, that is the place to be.

Baltimore Oriole Dossier

by Carl Strang

It’s time to share another of my species dossiers. This one brings together my experiences with a bird that at the moment is to be found in the tropics. Spring can’t come too soon.

Male Baltimore oriole.

Oriole, Baltimore

This bird’s song is very loud, composed of clearly defined, sharp notes, usually a bundle of several with mixed pitches. The Baltimore oriole stays near treetops in feeding, generally. They nest in residential neighborhoods and open woods, especially beside ponds, lakes and rivers. The nest is a distinctive, unusual hanging basket, usually attached to an exposed, slender branch tip over water or a road. One spring I watched part of a nest-building, the female bringing long fibers and weaving them into a bag that already had its basic form. The stroking, pulling bill movements of the bird used the new fiber to fill a space and strengthen the bag.

Even as it deteriorates in winter, a Baltimore oriole nest is a beautiful object.

3JE86. A male foraged low in a crabapple, moving fairly quickly between perches, moving 2-3 feet at a time, looking among leaves, often burying his head among them and searching. Once he dropped to the ground in pursuit of a prey that jumped to evade him.

14JE87. Adult eating mulberries at Culver fish hatchery.

7MY88. Singing at Culver.

4MY99. First migrant noted at Willowbrook. Last spring migrant observed there 27MY.

11AU99. First fall migrant noted at Willowbrook. Last one noted 24AU.

This nest is relatively visible.

17JE00. Arboretum, Joy Path. Adult male foraging in the branch tips of a bur oak where leaves are clustered. It was searching and probing into clumps of dead leaves. It caught an adult moth, removed the wings, then flew straight to its nest overhanging the path at least 20 feet up. The moth was fairly large and heavy bodied, perhaps a noctuid. The nest is within a clump of leaves so that it does not appear suspended. Later, both the male and female were carrying food to the nest. When they were there, and for a few seconds after they left, a chorus of faint peepings was audible.

2JE01. Meacham Grove, east part. A female oriole led me to a nest that was so woven into the cluster of leaves at the end of a bunch of slender twigs that the nest was practically invisible.

There is a Baltimore oriole nest here, but it is well buried among the leaves.

16JE01. Newly fledged orioles still were close to the nest at the Arboretum, Heritage Trail. The nest was above a service road-trail just inside the fence separating the savanna area from Hidden Lake Forest Preserve, on the end of a descending oak branch’s lowest twigs. One of the fledglings was still perched just above the nest, the others were scattered on that branch and in nearby branches of other trees. They were essentially motionless for a long time, but very vocal, with distinctive calls: 3 quick identical notes that sounded like uninflected robin notes.

31AU02. A Baltimore oriole in full male breeding plumage, singing at Lincoln Marsh from the very top of a tall tree. Not full volume, and only little chattering phrases, but clear oriole voice tones, whistles. Sang for several minutes.

27JE08. Baltimore oriole fledglings have a call that is a rapid series of clear notes rising as on a scale.

2MY09. An oriole at Fullersburg was taking nectar from buckeye flowers.

4MY09. Mayslake. Series of photos of an oriole probing clusters of oak flowers and opening leaves.

Foraging oriole at Mayslake.

1JE09. Mayslake. Pair of Baltimore orioles mobbing a fox squirrel in the medium-sized cottonwood closest to the SE corner of May’s Lake. They gave frequent, loud, identical, slightly slurring notes but did not attack the squirrel. I found the nest at the end of the lowest branch on the east side of the tree, 15-20 feet up. The squirrel eventually jumped to another tree without finding the nest, escorted by the male oriole, and the female almost immediately returned to the nest.

Here is the female giving her alarm calls.

10JE09. The same pair of the previous entry is feeding a cowbird fledgling just outside their nest. In the brief time I watched, the female fed the cowbird once, the male fed it once and a nestling once.

Cowbirds and orioles are in the blackbird family.

Apparently this episode of nest parasitism doomed the orioles’ own young, as I never saw any oriole fledglings from that nest.

Black Oak, Maybe

by Carl Strang

Not being a botanist, primarily, I am inclined to miss plants unless I really focus on them. I count on their flowers or some other eye-catching feature to draw my attention. Such was the case last week with a particular oak in the north savanna at Mayslake Forest Preserve.

It doesn’t show so well in the above photo, but the leaves on the tree had turned yellow.

That is in contrast to the generally reddish and brown tones of the dominant white and bur oaks, as well as the bright red of the Hill’s oaks. I made my way to the tree, and found that its leaves were shaped like typical black oak leaves.

The lobes are shallow, unlike those of pin or Hill’s oak, and they don’t show the rhythmic size and shape of red oak lobes. The bark is consistent with black oak, though the tree is only a foot in diameter and so I can’t call that conclusive. The acorn caps are somewhere between those of black and Hill’s oak, though more like the former. For now I am calling it a black oak, though I think there’s a good chance that it’s a black/Hill’s hybrid. I am comforted by the fact that even botanists struggle with the oaks.

DuPage Swamp Cicadas

by Carl Strang

Not long ago I mentioned that I have begun listening for songs of the swamp cicada, Tibicen chloromera, in DuPage County. Since then I have heard some songs that seemed close, but none that were completely convincing. That changed on Wednesday morning, when I heard unmistakable songs from several individuals of this species at Springbrook Prairie Forest Preserve, in southwest Naperville. The habitat and song perches were just as the literature would lead one to expect: the cicadas were singing from small bur oak trees in a mesic prairie adjacent to a stream. Specifically they were in the Springbrook “remeander” project area.

The photo, taken in 2007, shows the stream shortly after it was converted from a ruler-straight ditch to a stable channel shape with bends, or meanders. Alongside were planted the small bur oaks and a variety of prairie forbs. There is no historical evidence for a natural meandering stream at the site, so it is likely that a sheet-flowing swale, rather than a defined, meandering streambed, preceded the straight ditch. The meanders have the effect of reducing the stream’s steepness, slowing it down so erosion is minimized. Aided by the resulting diverse array of pools and riffles, the stream can support a greater diversity of life. The project rightly has earned several awards for the Forest Preserve District of DuPage County. Two Naperville high schools send Advanced Placement Environmental Science classes to collect data from the project each year, and I was there on Wednesday in connection with that educational dimension.

The cicadas did not sing for a very long time. I wonder if their being closer to the edge of the species’ range explains the more limited habitat variety, song perch choice and singing period I seem to be finding in DuPage County, compared to chloromera I have been observing in the more southern Culver, Indiana, area I referenced in the earlier post. Such thoughts will inform my continued search for swamp cicadas in DuPage.

Mayslake Savanna Autumn

by Carl Strang

I have enjoyed watching Autumn’s transition in the savannas at Mayslake Forest Preserve. Early in the season I found an aster growing, and blooming, in an unlikely spot: a crevice a few feet off the ground between forks of a bur oak.

Here it is close up.

Squirrels continued to take advantage of the oaks’ mast year. Here is the synchronized eating team.

Colors peaked, then faded. The sumacs provided a final burst.

Meanwhile, assisted by other volunteers, stewards Conrad Fialkowski and Jacqui Gleason continued removing buckthorn bushes from the edges of the savanna. They augmented the brush piles by piling on leaves.

 They had raked the leaves to clear space for spreading bottlebrush grass seeds.

That grass is their workhorse for initially reclaiming restored ground in open woodlands.

Mast Year

by Carl Strang

Mast is a collective term referring to nuts and acorns. Trees do not produce these in the same amounts each year. In some years very few nuts or acorns develop in a given species, and in other years prodigious numbers appear. High production seasons are called mast years. 2009 is proving to be a mast year for bur oaks and white oaks at Mayslake Forest Preserve, where the trails in places are littered with the fallen acorns. Here is an example for bur oak.

Bur oak mast b

Here, white oak acorns abound.

White oak mast b

Though elsewhere I am seeing lots of walnuts, this does not seem true for that species at Mayslake, which also is having an unremarkable year for hickory nuts. Nearby, at Fullersburg Woods Forest Preserve, I noted in 2007 that walnuts, hickories and red oaks had a mast year. It is common for members of the white oak group and red oak group of species to be decoupled from one another in their mast years.

Fox squirrel 1b

As you might imagine, animals such as tree squirrels are impacted by mast years. Mayslake’s gray and fox squirrels will have an easy winter with so much food available. They help their cause by biting acorns before burying them in an effort to kill them. The acorns, in a countermeasure, are quick to sprout when they fall to the ground. A study published in 2006 in Science (314:1928) found that red squirrels (which live north and south of us, but not in DuPage County) themselves reproduce more heavily in mast years (perhaps responding to an increase in flowering or other advance cue). Such adaptive interactions between species are referred to as coevolution. The phenomenon of the mast year itself likely is, at least in part, an evolutionary tactic by the trees. By coordinating their mast production they can limit their seed-predators’ survival in some years, overwhelm them in others. Such an episodic mass reproduction is reminiscent of the periodical cicadas.

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