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.

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Yellow-rumped Warbler Dossier

by Carl Strang

Today’s species dossier selection focuses on the yellow-rumped warbler, the species in its family that winters the farthest north, with a few sometimes staying through the winter in northern Illinois. Mainly we see them in migration, however, as they nest in the North Woods.

Warbler, Yellow-rumped

Yellow-rumped warbler

Yellow-rumped warbler

This is a very abundant warbler, observed around Culver and Lafayette in Indiana, DuPage County, Illinois, and Cumberland and Perry Counties, Pennsylvania. Usually they travel in flocks, foraging from the low understory to the canopy top. Many stay late in fall, and some appear early in spring. They retain the yellow rump patch (an obvious “follow-me” signal) year-’round. Call of fall birds “tseeet,” slight slur down in pitch early in call, then up at end, again slightly.

21AP87. Has appeared at McKee Marsh, Blackwell Forest Preserve.

26AP87. Song “tsew, tsew, tsew, tli-tli-tli-tli” (short I’s). In late morning at North Blackwell, these are sitting on perches and looking, as palm warblers did, but traveling farther between perches, working higher (mostly mid tree canopy) and not hover gleaning so much as flycatching.

29AP87. Some have songs composed entirely of the “tli” syllables, others place “tsew” syllables in the middle, others have more “tsew’s” than “tli’s.” Any combination of those two syllables seems possible, 8-15 syllables total in a song.

1MY87. Still a predominantly sit-and-wait foraging style.

4OC87. First fall migrants observed at Maple Grove.

12OC87. A yellow-rumped warbler foraged on the ground, hopping, probing, and peering under the leaves of the plants. It moved slowly, less than 1 foot per minute, turning all around.

13OC87. I observed 2 in Willowbrook’s Back 40, and on the 16th, several in the old field there.

17AP88. A couple at Blackwell Forest Preserve.

29AP88. One observed foraging in trees, spending 1-5 seconds per perch scanning, and moving 3-several feet between perches. It pursued prey once, and also tore apart a cottonwood flower. Then it sally-foraged a while. Later, it switched to reaching and probing in the flowers, moving shorter distances (mostly 1 inch-1 foot). The song was relatively weak for a warbler, accelerating through its 2-3 second duration.

7MY88. Indian Trails, Culver. One flycatching.

8OC88. Hidden Lake Forest Preserve. Abundant in woods, and in fields.

11OC88. Observed in Willowbrook Back 40.

18OC88. Observed at Hartz Lake, foraging with or at least near chickadees and golden-crowned kinglets.

17AP89. First of year seen, Willowbrook Back 40. Next mentioned 30AP, McDowell.

9MY89. One at Willowbrook, flycatching low beside stream.

21OC89. Lots of them in West DuPage Woods Forest Preserve. Foraging mainly by flycatching and hover-gleaning. Air cool, 50F or less, sunny, breezy.

Male breeding colors are much brighter, but I have yet to photograph one.

Male breeding colors are much brighter, but I have yet to photograph one.

17AP90. First of year seen, Willowbrook Back 40.

23AP90. One foraging in silver poplars at Willowbrook, probing etc. in canopies, with song: “we-see’-we-see -we-see -we-see -we-see” very fast, with slight emphasis on 2nd syllable and 20-30 seconds between songs. Afternoon.

19AP99. First of season noted at Willowbrook. Last spring migrant there 13MY.

30SE99. First yellow-rumped warblers of the fall, many at Willowbrook, 2 eating poison ivy berries. Also seen eating them on 5OC, 12OC.

20AP00. First spring migrants at Willowbrook. (I saw my first of the year 18AP while running near Warrenville).

22AP00. East Woods Trail, Morton Arboretum. Several yellow-rumps feeding high in forest canopy. One observed in crown of a sugar maple in flower. The bird was mainly sitting still, reaching into flower clusters for insects. They are singing the weak sounding song that alternates between two notes, beginning weakly, crescendo and decrescendo into a trailing, weak ending. Also calling: a harsh, “pick” sound, dull and flat in tonal quality but a sharply pronounced, sparrow-like note.

7AP01. First yellow-rumps of the season at Greene Valley Forest Preserve, feeding in trees in chickadee style, with much searching of twigs and bark, and a flush-and-pursuit seen.

30SE01. Many yellow-rumped warblers along the Fox River and on Island Park, Batavia. Spread out all over, some hover-gleaning, some flycatching, others getting poison ivy berries.

27DE01: Yellow-rumped warbler at Willowbrook, foraging at the edge of the open stream, seen to catch a small worm prey.

19DE03. A yellow-rumped warbler at Willowbrook feeding on poison ivy berries and calling, the first seen there in weeks.

28SE10. Mayslake. Some yellow-rumps eating cedar berries.

26OC10. Mayslake. In recent days I have found that yellow-rumped warblers can produce the common warbler call-note (high pitched, briefer) in addition to their lower species specific note.

10DE10. Mayslake. Yellow-rumped warbler eating cedar berries near the mansion.

Yellow-rumped warbler eating a red cedar berry

Yellow-rumped warbler eating a red cedar berry

25AP11. Mayslake. A yellow-rump singing a patterned song repeatedly, very similar to Nashville warbler song but ending just different enough to distinguish.

29AP11. Mayslake. Another distinctive yellow-rump song, this one ending like the one earlier in the week but beginning with a rising sequence of notes as in a scale.

Literature Review: Kinky Plant Genetics

by Carl Strang

They look so innocent, those plants. Who would suspect that there were kinky goings-on? Well, apparently some scientists have tested such suspicions, and today I report on two studies.

Richard J.A. Buggssend, et al. Rapid, Repeated, and Clustered Loss of Duplicate Genes in Allopolyploid Plant Populations of Independent Origin. Current Biology, 19 January 2012 DOI: 10.1016/j.cub.2011.12.027

As described in a ScienceDaily article. They looked at a hybrid species of goat’s beard which appeared 80 years ago in North America, resulting when complete genomes of separate species combined to produce a polyploid offspring. This appears to be one mechanism by which polyploidy could occur. When compared to a more ancient example of duplicated genomes within this plant group, the authors found similar patterns of gene retention and loss, improving understanding of how the evolutionary process would proceed from the establishment event.

The flower head of our common goat’s beard.

The flower head of our common goat’s beard.

Normally separate species cannot hybridize successfully, and in fact that is an important part of what defines a species. In this case, however, instead of the normal process in which offspring get half the genes of each parent, this new species got all the genes of both parents. Plants, and rarely animals, occasionally double the genetic complement of their offspring in what is essentially an error (the offspring have two copies of each gene). This doesn’t usually lead anywhere in animals, but in plants it has been an important contributor to species diversification, and there have been several episodes of plant species explosions that have followed genome duplications. This apparently is because, with a spare set of genes, there are fewer consequences of mutations and so the stage is set for massive evolutionary experimentation. The usual case is that both parents contributing to the genome duplication belong to the same species, but this goat’s beard provides an example combining the genes of two separate though closely related species.

S. Stegemann, M. Keuthe, S. Greiner, R. Bock. Horizontal transfer of chloroplast genomes between plant species. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1114076109

From ScienceDaily. They found that horizontal transfer of chloroplasts and their constituent genes can occur when different species grow in physical contact, for instance when trees grow so close together that their trunks fuse. This complicates genetic taxonomy studies.

Two trees side by side, almost with fused trunks. The possibility of gene transferal between them seems merely of academic interest until we look closer and realize that one of these “trees” is poison ivy.

Two trees side by side, almost with fused trunks. The possibility of gene transferal between them seems merely of academic interest until we look closer and realize that one of these “trees” is poison ivy.

Of course, the study found the transfer only in chloroplasts, which don’t carry the genes that make poison ivy a plant of concern to us. Nevertheless, chloroplasts and the similar mitochondria carry their own genes useful in evolutionary genetic studies, so this paper provided a significant cautionary note.

Literature Review: Leaf Mine Diversity

by Carl Strang

This week’s literature focus is on a paper that provided information suggesting why leaf miners produce such diverse mine structures.

Leaf miners are larval insects so tiny that they fit between the upper and lower leaf surfaces, feeding on the tissues in between. This example is a twisting linear mine on Heracleum.

Leaf miners are larval insects so tiny that they fit between the upper and lower leaf surfaces, feeding on the tissues in between. This example is a twisting linear mine on Heracleum.

Ayabe Y, Ueno T (2012) Complex Feeding Tracks of the Sessile Herbivorous Insect Ophiomyia maura as a Function of the Defense against Insect Parasitoids. PLoS ONE 7(2): e32594. doi:10.1371/journal.pone.0032594

They looked at linear mines in a fly that develops in a French aster. In their review they mention research that has been done on various mine forms and how they may deter parasitoids. Parasitoids focus mainly on the upper leaf surface, so lower surface mines (including tentiform mines of Phyllonorycter moth caterpillars in some of our local plants) provide some protection, and upper surface miners sometimes shift to the lower surface to pupate. Blotch mines provide more escape space for their occupants. In this study they found that complex linear mines, especially ones that have branches and crossing tunnels, reduce parasitoid effectiveness.

We can see a wide range of leaf mine types on our local plants.

Expanded blotch-type mine on poison ivy (the leaves aren’t always 3 leafleted!).

Expanded blotch-type mines on poison ivy (the leaves aren’t always 3 leafleted!).

The outline of a tentiform mine shows on this maple leaf. The mine is on the underside of the leaf, not readily reached from above.

The outline of a tentiform mine shows on this maple leaf. The mine is on the underside of the leaf, not readily reached from above.

According to this research, it boils down to a game of hide-and-seek. If a leaf miner can make its mine complex enough, or in a place where it is difficult to reach, or expand the mine to the point where finding the miner is somewhat needle-in-haystackish, it gains an advantage over the insects that would parasitize and kill it. Furthermore, the diversity of mine types provides a more complex evolutionary puzzle for the parasites as a whole to solve.

Eastern Cottontail Dossier

by Carl Strang

My species dossiers focus on vertebrate animals, and as there are many more birds than other terrestrial vertebrates, most of the dossiers I have shared had avian subjects. Today’s focus is a mammal.

Cottontail, Eastern

These live in weedy and brushy habitat. Occasionally enter forests, especially in fall and winter. Maintain a network of trails and runs. Have aboveground forms or beds used for much of the year, but take cover in sheltered spots (in firewood pile at Warrenville, IL, for instance, during daytime in a neighborhood with little cover) and in burrows (woodchuck burrows at Culver’s fish ponds, skunk burrow at Willowbrook), and culverts. Predators may influence this: in winter of 1998-99, cottontails seldom appeared in the open, but coyotes were omnipresent and often dug at ends of drainage culverts under the nature trail, where rabbit tracks led.

Cottontail nest, opened slightly to show hairless infant.

Young born blind and hairless. Nest in short grass areas (e.g., lawns, examples seen at Boiling Springs, PA, and in IL), in shallow depression lined and covered with a mix of fur and grass. Nest well hidden. Young become independent when about 4 inches long, when ears stand up and fur becomes shaggy. Mother simply abandons nest (normally she visits it only at night), young find their way out. Observed a youngster at Lombard, IL, learning to recognize food. Sniffed every plant, occasionally nibbling one, occasionally chewing one down to ground. Can be tame and easily caught first day or two out of nest.

Summer food green plants, for instance dandelions (watched one at Boiling Springs, PA, as it ate fruiting stalks, biting them off near ground then nibbling them into mouth endwise, seed poofing out as it reached the end). Browses in winter. In DuPage County, rose family preferred (or at least eaten first, then when other foods depleted, larger rose and Rubus stems cut to bring twig ends within reach), others eaten include twigs of maple, elm, bittersweet Solanum dulcamara, poison ivy (the last toward winter’s end). Patches of red to orange urine at this time. Bark of cherry, elm, sumac, taken in leaner winters.

Often the toenail marks are the only clear indicators of a cottontail track. The furry feet do not make a clear impression in hard soil.

Droppings distinctive, round. Tracks occasionally show the 4 nailed toes in good conditions. Hard substrates sometimes reveal 4 toenail marks in wedge shaped pattern. In snow, typically nothing more than round depressions for front feet, elongate ones for hind feet. Rarely anything but a gallop gait with one front foot in front of the other.

16AP86. Rabbits eating gray dogwood bark in Willowbrook Back 40, both of standing shrubs and of stems I cut earlier this week.

9JL86. Watched a half-grown cottontail through the window at Willowbrook as it grazed. Seemed to select younger grass blades (pointed rather than mower-cut; lighter in color).

9FE87. Inside Willowbrook main building, cottontail escaped from intensive care room during night. Droppings and smears of dust suggest that it got into the clinic, somehow got up onto 3 foot high counter top, then another 4 feet up to cabinet top. [I asked Tom Brown about this; he has seen even higher vertical leaps onto ledges by cottontails].

This is the cottontail that escaped in the Willowbrook Wildlife Center hospital and hid by jumping from the floor to the countertop, then from the countertop to the top of the wall cabinet.

12FE87. Cottontail recently gnawed on crabapple beside trail.

15MR87. Meacham Grove. Rabbit moving fast, but turning: the space between the front feet and hind feet decreased as it approached the turning point, revealing a slight deceleration; the front feet pointed in the direction it had been going, then the hind feet pointed in the new direction. This rabbit placed its front feet side by side. The distance between the front and hind tracks was not related to the distance of the leap: large and small for long and short hops. I tracked this rabbit to its hiding place, partly under a log in open woods. I had passed within 8 feet of him twice, then stood 3 feet away for at least 2 minutes puzzling over tracks that seemed to go into there but not out, when he burst from hiding and ran away. The rabbit had climbed up on sticks and logs a few times (crossways to his route).

A typical cottontail footprint pattern with the more elongate hind footprints side by side, rounder front footprints one before the other. In each step the hind feet carry past the front feet.

MY87, NJ Pine Barrens. Cottontail browsing blueberries, oaks.

AU87, NJ Pine Barrens. Cottontails smaller here than elsewhere.

12AU87. Assateague Island, morning. Young cottontail eating clovers (several patches well nibbled, English plantain flower stalks, a wiry upright narrow-leafed composite, and another plant that resembled common ragweed. Avoided the abundant Senecio. Had several ticks in its ears, and appeared to have a partial cataract in the right eye.

18DE87. 4 days after an abrupt 1-foot snowfall, little but rabbit and squirrel tracks in Willowbrook Back 40. Former’s mainly at edge of field and woods.

23JA88. McDowell Forest Preserve. Rabbits and foxes highly active last night (an inch of snow fell just after sunset). One rabbit, at least, was in underground burrow during snow. Unusual amount of side-by-side front foot placement by rabbits: slippery or uncertain new surface? One rabbit fed on grasses, edge of a tall grass field.

On slippery or unfamiliar surfaces (e.g., the first snow of the season), cottontails often lock their front feet together side by side. I assume this gives them more stability. You can see in the dossier text when I discovered this.

27JA88. Willowbrook. A rabbit had moved along left edge of path, paused and looked back down path over right shoulder. Both front feet to right of their usual position and pivoted, right foot 45 degrees. This is enough to allow the rabbit to look behind it (eyes on sides of head).

28JA88. Willowbrook. A rabbit did heavy browsing on a rose bush last night.

3FE88. Willowbrook. In the 2 nights since the last snow, not real cold, lots of activity. Rabbits, squirrels, mice, fox, raccoons, cats. Icy beneath. Again, lots of rabbit track sets with side by side front footprints.

LateFE88. Tracker Farm, NJ. Rabbit browsed rose since 1 JA.

6JE88. Baby rabbit tasting rocks, licking them, in Willowbrook streambed. Ate silver maple seed, elm seedling.

13DE88. Rabbits commonly placing front feet side by side on longer steps after about an inch of snow fell early last night atop the half inch that was there from 3 days previous.

1MR89. Rabbit’s front feet indicate the direction from which it came more reliably than the hind feet point to where it’s going, at least when it is traveling slowly. Look to pressure releases as well. In today’s crusty snow, the rabbit leans in the direction it’s going, so that in forward hops the toes are deepest. In an abrupt left turn the left edges of both hind prints were deepest.

12MR89. Hartz Lake. Dense poison ivy area between cemetery and prairie heavily browsed recently, mainly by rabbits.

25AP89. A rabbit nest, now empty with lining scattered. In the low, flattened blackberry tangle beside the nature trail at Willowbrook. Scattered taller brush on all sides.

These baby cottontails are weaned or nearly so. The mother simply stops coming to the nest and the young, driven by instinct and hunger, leave the nest and start learning which plants are good to eat.

3MY89. Willowbrook. Another rabbit nest yesterday on the side of the hill constructed of fill from marsh excavation. Like the nest last summer on the steep hillside at Clarks’, this hole was deep.

4MY89. Willowbrook. Yet another rabbit nest, this one in fairly thick brush 5 feet beyond the cleared edge of the main trail.

9MY89. I mistook moss for a cottontail. Sometimes the agouti pattern resembles mossy mottling.

22JE89. Rabbits eating common ragweed at Willowbrook.

31JL89. Willowbrook. Rabbits bending down Queen Anne’s lace and common ragweed and eating tops, along Nature Trail.

18AU89. Cottontails reaching common ragweed tips 4 feet off ground. Apparently, from bruise patterns and broken stems, they are pulling the plants down.

24NO89. Hartz Lake. Rabbit stopped, sat, turned. Entire left edges of both hind feet show pressure releases.

13DE89. Hartz Lake. No consistent ratio of track-set length to space between sets. A ratio of 3-4 common in shallow snow (front feet side by side, mostly). Degree of forward lean or toe-dig of back feet a better indicator of step length.

16FE90. Rabbit sitting on top of snow in Warrenville, IL, back yard, out of reach of anything edible, chewing cud. Bent down a couple of times to get feces for re-ingesting, taking them from anus with mouth.

16MY90. Rabbits have been eating fleabane tops.

12SE90. Watched young (nearly full grown) cottontail feeding, at close range. Eyes cranked forward, showing the tiniest bit of white at the back, as the rabbit examined and ate plants. Ate fruits and leaf blades of roadside rush and crabgrass. Seemed, however, to be using smell more than vision in checking out potential foods. I could get away with some movement when the eyes moved forward.

5JL96. Cottontails chasing each other 11a.m., picnic shelter area at Willowbrook. The chases were brief, sometimes extending into brush, but generally about 20 yards at most and often half that. They then would stop as the pursuer peeled off, but then often the chased animal approached, clearly soliciting another chase. Sometimes the chases were moderate in speed only, sometimes there were brief very fast spurts in the middle.

16MY98. Cottontail at Willowbrook eating blue violet leaves (nearby: flowering motherwort mint, garlic mustard).

28JA99. Cottontails this winter not visible during the day. Tracks indicate they are hiding in metal drainage culverts. Coyotes occasionally vainly try to dig them out or, perhaps are trying to spook them out.

10MY99. Cedar Springs, Michigan. Cottontails mating. Smaller adult chased larger, caught up, mounted and very quick small thrusts for a couple of seconds, then larger ran away and pursuit resumed. In woods clearing.

Here a mother rabbit at Mayslake covers her nest shortly after giving birth.

29AP09. Mayslake. As I drove in, I saw a rabbit digging in the lawn of the long parking lot island beside the drive. Three other rabbits were nearby, and one eventually chased her away from where she was digging and I saw him mate with her once. I thought she was still digging soil, but perhaps she was digging out grasses to cover the nest with (supported by her relative skinniness in photos). I returned at mid-day, found 5-6 babies in the nest there. Soil still beside the nest, but flattened. Babies born last night or this morning, it appears. (These rabbits eventually weaned and left the successful nest).

Literature Review: Vines

by Carl Strang

Here’s a word for you: liana. It’s ecologist-speak for “vine.” Hey, why limit yourself to one syllable when you can use three? Still, I think it’s a beautiful word. This week I want to highlight a study of temperate zone lianas published last year (Ladwig, Laura M., and Scott J. Meiners. 2010. Spatiotemporal dynamics of lianas during 50 years of succession to temperate forest. Ecology 91:671-680).

Poison ivy is a vine, though it doesn’t always look like it. Sometimes it grows along the ground, sending up shoots that look like separate plants.

Ecologists associate lianas mainly with tropical forests, where they are an important component of the plant community. They climb the tree trunks and occupy a significant place in the canopy. Lots of species. Lots. So, it was refreshing to see a study of vines in the temperate zone, specifically, New Jersey.

These researchers looked at data from a long-established study area, asking how vines fared at different times as abandoned fields succeeded to mature forests. In addition to poison ivy, dominant vine species were Virginia creeper, grapes, and Japanese honeysuckle. The combined liana cover peaked mid-succession (20-30 years post-abandonment). At that point the area was in an herbaceous stage with the vines climbing scattered trees and shrubs or growing over the ground. As the trees grew, became dominant, and closed the canopy, the liana cover decreased but the number of vine plants continued to increase so that small suppressed individuals were well placed to take advantage of openings. At least, that was the strategy taken by most species.

Grapes were the exceptional lianas in this study.

Grapes were exceptional, increasing their coverage more as canopies closed. Living successfully up in the canopy, the grape tops made them late successional while the other 3 dominant species were early successional. Thus, grapes were the closest lianas to the classic tropical idea for this group.

Black-capped Chickadee Dossier

by Carl Strang

I have mentioned black-capped chickadees from time to time in this blog, most notably when introducing the topic of mixed flocks. Today I want to share my dossier on this species. In my dossiers I try to summarize what I know of a species from my own observations, as opposed to information from the literature or other outside sources. I began writing the dossier in the mid-1980’s. Observations begin with my date codes.

Chickadee, Black-capped

Ca. 1979. I remember sitting on the hawk watch at Reineman Sanctuary in PA in fall and watching as a sharp-shinned hawk zipping along the ridge suddenly turned its course so as to enter the tree canopy and caught a chickadee.

Boiling Springs, PA, 1980. A pair nested in hollow Ailanthus branch. One bird was electrocuted by a nearby electric fence. The other completed incubation and at least began to rear the brood alone. “Cheeseburger” call (more formally known as the fee-bee call) used early as apparent territorial signal.

Lombard, IL, 1981. A pair nested in a wren house, raised a brood, then returned and raised a second brood in the same house. In both cases, the pair traveled the neighborhood with their groups of fledglings.

Maple Grove Forest Preserve (F.P.), 1986. A pair was cleaning out an old cavity in a 10 foot snag in the maple forest. The excavating bird periodically removed beaks full of sawdust. Other bird remained nearby, giving occasional “chickadee” contact call.

Meacham Grove F.P., 24MY86. For the first time, I saw a chickadee taking advantage of tortricids hidden in folded leaves. One individual moved from one folded leaf to the next, vigorously tearing them open. I expected to see it more frequently than I have, given the lack of other birds with the appropriate foraging behavior in their repertoire, and the abundance of this food resource.

Willowbrook F.P., 1984-86. Chickadees have broods in the wooded riparian strip each spring. One pair appears to control the entire 1/4 mi. X 100-foot strip. Groups of more than 2 chickadees stay together through the winter. “Chickittaperk” vocalization appears to be an interspecific agonistic (dispute) display.

Chickadees weren’t common in Culver, Indiana when I was growing up. I remember being pleasantly surprised that a pair was present, nesting, at Miracles’ house in summer. This implies they were more easily seen in winter, at the feeder. Old trees and branches were scarce in our neighborhood.

Alarm call: one used a sharp “chiburr,” another answered with the same call.

11FE87. Willowbrook. Widely scattered chickadees in the Back 40 old field are maintaining contact mainly via the feebee call.

28FE87. A group of a half-dozen chickadees in trees: much sneeze-calling and chick-chick-chick-chick, but few chickadee calls, with much chasing and displacement. Later, many individuals made chickadee calls from widely separated perches. Then a period of silence followed.

14MR87. Maple Grove F.P. Seven chickadees moved together with a mix of chickadee and sneeze calls, occasionally briefly chasing one another. The group spread out widely, then used very high-pitched brief “cheeks” for contact.

29AP87. Chickadee caught adult noctuid moth, pecked body (scales puffed into the air), removed wings one at a time and they drifted to the ground, landing at least 3 feet apart.

1JL87. Willowbrook F.P. Chickadee pecking at mulberries.

10SE87. 0.5-3 seconds per perch in foraging, flying or hopping a few inches to 6 feet or occasionally 10 feet between perches, acrobatic hanging or hover-gleaning, pecking at dried leaves, turning and lowering body almost to upside down position to peer different ways.

13SE87. At West DuPage Woods F.P., several chickadees in a mixed flock with a redstart and a bay-breasted warbler.

17JE89. A broad-winged hawk callied repeatedly, in north end of Maple Grove F.P. Jays, flickers and grackles were highly agitated, flickers the most continuously vocal with “keels” every 2 seconds (2 birds). Grackles gacking frequently, too. A great crested flycatcher near, also vocal, but not clearly in response to the hawk; same with chickadees. Robins definitely disturbed, with nervous dee-dee-dee’s every 20 seconds or so. Jays in bursts, with several birds mobbing.

10JE90. Warrenville Grove. Chickadee saw me at sit near edge of woods. Alarm call “chicka-chicka-…(rapid)-dee-dee-dee”

3JL90. Chickadee plucked 2 unripe (white) mulberries from the branches. Dropped the first, then went for the second. Worked on it several seconds, holding it against a twig with its toes. I couldn’t tell if it ate the whole berry or just extracted seeds. Suspect latter.

7SE90. 2 chickadees eating dried crabapples, eating, pulling out and eating little bites.

30SE90. Chickadee and downy woodpecker eating poison ivy berries at Ann’s business property near Lafayette.

8FE00. Chickadees heard singing for the first time of the year at Willowbrook, and continuing in the following days. Also vigorously chasing each other this day, with agonistic vocalizations.

10FE00. Chickadees singing (feebee song) at Willowbrook.

1AP00. Morton Arboretum, Heritage Trail. A mixed flock with at least 1 brown creeper, 2-3 chickadees; juncos and robin in area. Chickadees longer on each perch than golden-crowned kinglets observed yesterday. A lot of looking around, not so constantly moving between perches, and making larger jumps between perches, 3′ common. Later, another association of chickadees, golden-crowned kinglets and a white-breasted nuthatch. These mixed flocks stand out because after going through a long segment of forest path where there are essentially no birds, suddenly there are many at once of several species. Again, chickadees sitting longer in one place and moving farther between perches. All moving together in same direction through forest, and moved away from me as I observed them. Later still, a couple of chickadees without associates. Perhaps this is the kind of observation that led to the local core species idea.

25JE00. This spring I have observed 3 chickadee groups with parents and fledglings, one at the Arboretum on 1JE, one yesterday at Willowbrook, and a third in another part of the Arboretum today. Instead of being spread out, in each case the groups were clustered in a small area no more than 20 feet in diameter, and they moved only very slowly. Feedings were frequent, so apparently the parents directed or led their young to food-rich locations.

11MR01. A chickadee at Timber Ridge Forest Preserve with a variation on the fee-bee song: the “bee” syllable is repeated, and each syllable has the usual hinged quality, i.e., “fee-bee-ee-bee-ee.”

More recent observations have focused on the role of black-capped chickadees in mixed flocks.

29AU01. Algonquin Park, Ontario, Mizzy Lake Trail. Flock 1: Golden-crowned kinglets, a young-of-the-year black-throated green warbler, black-and-white warbler, black-capped chickadees. Flock 2: At an edge between mixed forest and a lake. Black-capped chickadees, several black-throated green warblers (appear to be sticking together to form their own group within the flock), at least 1 blue-headed vireo, 1 female or young blackburnian warbler, 1 chestnut-sided warbler, and 1 Tennessee warbler. The black-capped chickadees are very abundant here, the most apparently numerous birds in the forest (because of their frequent calling and frequent presence). It is easy to see how migrant birds accustomed to forming mixed flocks with them here in the north could attach to resident birds they encounter on the trip south. Flock 3: Black-capped chickadees, Swainson’s thrush.

30AU01. Algonquin Park, Bat Lake Trail. Flock 1: Black-capped chickadees, a black-and-white warbler, the latter singing. Flock 2: Black-capped chickadees, red-breasted nuthatches, golden-crowned kinglets, 1 or 2 black-throated blue warblers, at least 1 Tennessee warbler, yellow-rumped warbler. The first three species are the vocal ones. These flocks are distinctive: you go for hundreds of yards seeing or hearing no small birds, then suddenly there is one of these diverse groups in a small area.

31AU01. Algonquin Park, Spruce Bog Trail. Flock 1: Yellow-rumped warblers, black-capped chickadees, red-breasted nuthatches, golden-crowned kinglets. Do more northern birds, living in more open forests, either not have chickadees to associate with, or perhaps the scattered trees (if they are) remove the advantages of mixed flocks? See if it’s true that the non-mixed-flock species tend to be more northern.

12SE01. Willowbrook. Flock 1 around west end of cross trail. 2 chickadees and 1@ of black-throated green, magnolia, Tennessee (sang a couple times), and 1 unidentified species. Flock 2 near the NW corner of nature trail, a magnolia warbler apparently alone.

13SE01. Willowbrook. A large but difficult to view mixed flock near office building: 3 chickadees, 2 redstarts, a blackpoll warbler, a red-breasted nuthatch, and many others.

14SE01. Willowbrook. Flock 1 around NW corner of nature trail: redstart, chickadee, downy woodpecker, Tennessee warbler, black-throated green warbler, magnolia warbler, red-eyed vireo. Flock 2 between eastern part of animal exhibit and bridge. Chickadee, 3 redstarts, downy woodpecker, blackpoll warbler (it is possible that the one seen earlier joined this flock; it was near this location).

17SE01. Willowbrook. Flock 1: 3 chickadees, 1 redstart, others perhaps; near west end cross trail. Flock 2, base of savanna, 2 palm warblers only. Flock 3, brush area east of Nature Trail, 2 chickadees only. Flock 4, another part of same brush area, 2 chickadees, a magnolia warbler, 1 other unidentified.

19SE01. Willowbrook. Flock 1, east exhibit area to bridge: 2 chickadees, 1 black-throated blue warbler, 1 redstart, possibly others. Flock 2, west end cross trail: staying around berry-feeding robins, waxwings and catbird, with no chickadees around: a black-and-white warbler, 2 downy woodpeckers, a redstart, a blackpoll warbler, possibly others.

25SE01. Elsen’s Hill, plateau above river. Flock 1: at least 8 vocal, active yellow-rumped warblers, and a ruby-crowned kinglet. Flock 2, very large and diverse, only some individuals identified: 2 chickadees, black-throated green warbler, blackpoll warbler, 2 Nashville warblers (1 low in an aster thicket another in low tree branches), downy woodpeckers, a parula behaving like the Nashville, 2 redstarts, a chestnut-sided warbler.

26SE01. Willowbrook, between bridge and animal exhibit. 2 chickadees, and at least one @ of vireos (Philadelphia, red-eyed, yellow-throated), warblers (Tennessee, magnolia, parula, black-throated green), scarlet tanager, red-breasted nuthatch.

27SE01. Willowbrook. Flock between bridge and exhibit fence. 2 chickadees, 1 Tennessee and 1 magnolia warbler.

30SE01. Fox River and Island Park, Batavia. Many yellow-rumped warblers spread out all over, some hover-gleaning, some flycatching, others reaching for poison ivy berries. With them, a chickadee, a male Cape May warbler in the top of a silver maple, very active in the short time I saw it.

14SE02. Elsen’s Hill. I walked for several minutes, seeing apparently independent Tennessee warblers (2 together) and a Nashville warbler before encountering a large flock. This flock seemed to be changing composition over time, i.e., after my initial observations I walked a short distance away, then returned, and when I came back, some birds were the same but there were several new ones, as well. Later, after following the flock for 50 minutes or so and losing them in a direction I did not want to pursue in the brush, I returned to the starting point and a small mixed flock was there, with some of the birds I saw initially (apparently, none were marked of course) and a couple added ones. Initial group: a blackpoll warbler, 2 red-eyed vireos, 2 redstarts, an essentially silent chickadee, a black and white warbler, a Tennessee warbler, a Swainson’s thrush, a female or young black-throated blue warbler that was the only flock member calling consistently, all foraging in brush understory within 15 feet of the ground (the redstarts were the only ones consistently going above 10 feet; this was after 9 a.m.). Flock after my return: golden-winged warbler (like the redstarts, up higher, and very active, including flush and pursuit), a male and 2 female or young black-throated blue warblers, 2 Tennessee warblers, a black-throated green warbler, 3 redstarts, 2 blackpoll warblers, a black and white warbler, a blackburnian warbler. After it had warmed up some, later, a magnolia warbler foraging 20-25 feet up and the other birds also have gone higher. Doing a lot of reaching, and spending much time looking from each perch. At 10:45 I returned to the starting point: 4 noisier chickadees, 2 red-eyed vireos, a blackpoll warbler, a male redstart, a magnolia warbler, all except the chickadees foraging higher, throughout the tree canopies. Also a downy woodpecker, black-throated green warbler, Swainson’s thrush.

25AU08. Fullersburg Woods. First mixed flock of the fall migration has 2 chickadees, a downy woodpecker, a Tennessee warbler and a Canada warbler.

28AU08. Fullersburg Woods. Mixed flock just S of Willow Island bridge: 2 chickadees, 2 Tennessee warblers, 2 magnolia warblers, a gnatcatcher.

29AU08. Fullersburg Woods. Mixed flocks: One with four chickadees, two Tennessee warblers, a magnolia warbler and a black-and-white warbler. Also, 2 Tennessee warblers together apart from mixed flock. At mid-day a mixed flock near the junction of trails with 3 chickadees, 3 Tennessee warblers, a white-breasted nuthatch, a magnolia warbler, a parula. Chickadees were doing a lot of hanging upside down, Tennessees less acrobatic running along tops of branches and reaching, magnolia and parula more rapid movements, hopping between branches, nuthatch on bark, all in top half of canopy.

13SE08. Kettle Lakes Provincial Park, Ontario. Large, mixed flock in an area around 75 yards in diameter: at least 2 black-capped chickadees, 5 golden-crowned and 4 ruby-crowned kinglets, 4 yellow-rumped warblers, 2 red-eyed vireos, downy woodpecker, black-and-white warbler, black-throated green warbler, redstart, red-breasted nuthatch. I’m hearing white-throated sparrows, but they seem all near the ground rather than up in the trees with the others. Weak songs from ruby-crowneds, the black-throated green and the black-and-white. This is mainly an area of aspens with some jack pines. Mixed flock: at least 2 chickadees, at least 2 golden-crowned kinglets, 2 ruby-crowned, and a yellow-rump. Aspen grove again with some jack pines and a couple white pines.

15SE08. Nagagamisis Provincial Park. On trails, encountered a little flock of at least 7 ruby-crowned kinglets. Nothing up with them first time through, but white-throated sparrows lower down in that area (on the way back a chickadee, a brown creeper, 3 golden-crowned kinglets and a Swainson’s thrush added). Birds have been few, and I cannot discount the possibility of an association of the white-throated sparrows with this group. On the Time Trail, balsam fir the dominant tree with plenty of white spruces, some black spruces, white cedars, paper birches. Another mixed flock with at least one chickadee, 2 ruby-crowns, 3 golden-crowns.

21SE. Mayslake. A mixed flock at edge of Area 9 and grounds containing a black-throated blue warbler (new preserve species), black-throated green, 2 redstarts, 2 blackpolls, chestnut-sided, Nashville, black-and-white, magnolia, and a chickadee.

Downy Woodpecker Dossier

by Carl Strang

This is another of my dossiers, a collection of observations that represents what I know about a particular species from my own experience. Following an initial description that summarizes what I remembered when I set up the dossier in the mid-1980’s, each individual entry begins with my date code.

Downy Woodpecker

This is an abundant, year-round resident of forested areas and savannas. They nest in small tree cavities. Feed by searching on small twigs up to the size of tree trunks, on shrubs, sturdier weed stems, occasionally on the ground. They crawl rather than hitch along. Voice a rapid whinny, individual tones mores musical than hairy woodpecker’s and lower in pitch; reminds me of a movie witch’s cackle. When feeding, they pick at twigs or flake bark. They do much pecking under bark edges, when foraging on a tree trunk. Nest in hollow branches or main tree stems.

30MR86. 2 male downy woodpeckers in an aggressive encounter. Frequent flicking of wings and spreading of tail. Assumption of posture in which body is upright and neck arched back so bill points straight up. Appeared to be trying to get above one another. Generally faced one another when in bill-up posture, and both did it at once. Red feathers conspicuous.

Late summer 1986. As a flock of ground-feeding grackles flushed at the approach of people, downies and jays at Meacham Grove Forest Preserve emitted contact calls, apparently as a final check of location and status before possible flight.

8MR87. Waterfall Glen Forest Preserve. Male appears to be exploring the acoustic properties of a white oak limb. Spiralling up it, drumming frequently. Full drum about 1 second, poor spots drummed 0.5-0.75 seconds. Repeatedly drummed fully the spots that gave the greatest volume and lowest pitch. As I wrote the above, I heard vocalizations. Three downies now in that tree. The drummer and a second, presumably its mate, chased a third which gave fragments of the whinny call. They held themselves flat against branches, tails fanned, and gave whinny fragments and a more chattering, flatter sort of vocalization. The third bird left, but a few seconds later I heard a brief drumming about 50m in the direction it had gone. The other two immediately flew in pursuit, and after a few brief whinnies all was quiet.

7MY88. Indian Trails area, Culver. One systematically probing and pecking bases of hickory buds, open with leaves about 1/4 expanded.

18OC88. Hartz Lake area, Indiana. A vigorous, repeated displacement of one individual by another, though they stick together.

7MR89. Extended confrontation between 2 male downies. Mostly jerkily hopped up small tree stems within 3 feet of one another, flicking wings almost constantly, approaching, withdrawing, occasionally expanding and flashing the red patches, changing trees together, occasionally getting out of sight of one another momentarily, overall appearance of jerky movement. After more than 5 minutes of this, one displaced the other several times in rapid succession, but then they returned to the jerky maneuvering, with occasional rests on opposite sides of the trunk, out of sight of one another. Before all this, one of them called repeatedly, loud single-note reps. Another bird (female? Not seen) called or drummed a couple times during this from at least 50 feet away.

26-31MY90. Hartz Lake area. A nest in a river birch, entrance 12 feet up. Both parents fed, about 10 minutes between arrivals for each parent. Young still small, faint cheeping voices. When screech owl family passed by early one morning, one adult mobbed at a distance with alarm notes.

30SE90. Downy woodpecker eating poison ivy berries near Lafayette, IN.

10FE99. Two pairs of downy woodpeckers are actively engaged in drumming, calling, displaying and chasing in an area that centers on the Willowbrook bridge but extends most of the way to the marsh in one direction, and up to the big willow near the marsh’s water intake pipe in the other.

23MR99. The situation has become very complex at Willowbrook and difficult to follow, with displaying and chases, drumming and calls going on all day. It appears that at least 3 pairs are involved, with the center of the activity between the creek and the center of the outdoor animal exhibit. A downy woodpecker also was drumming in the big cottonwoods in the center of the Nature Trail circle, the first I’ve noticed there this year.

29MY99. Maple Grove Forest Preserve. Young audible in nest.

5OC99. Willowbrook. Downy eating poison ivy berries.

23FE00. Willowbrook. Male downy woodpecker displaying toward female, body in a stiff posture, tail fanned, unusual chattering vocalization, following or chasing her, matches Stokes’ description of Bill Waving.

1-2JL00. Juvenile downies have large red patches on top of head.

27MR06. Downy woodpecker drumming is so rapid that individual strikes cannot be followed. Hairy woodpecker drumming very rapid, individual strikes can be distinguished. Red-bellied rapid but slightly less so.

2009. Mayslake. One successful nest was in a large weeping willow branch in the SE corner of the mansion grounds. Young were vocal for several days before fledging. There was at least one other successful nest on the preserve.

Poison Ivy as Browse

by Carl Strang

 

Each month brings its own features of interest, its own associations. I have already covered how skunks go on walkabout in February. Another peculiarity of February in northeast Illinois is the sudden preference deer and cottontails have for poison ivy as a food item. Poison ivy was last conspicuous to our eyes in the fall, when it displayed its bright autumn coloration.

 

poison-ivy-color-b

 

Since then it has been its dormant winter self, recognizable by its vine growth form (older vines connected to tree trunks by masses of dark brown or black hairlike projections) and the curved, yellow-brown, finger-shaped buds, visible on two of the three twig ends in the following photo.

 

poison-ivy-browsed-b

 

But it’s the third twig end that is of interest here. It has been browsed by a deer. If we had seen the deer taking this bite, it would have been standing to the right of the photo and facing left.

 

Through the winter, deer and cottontails change their diets, but in a given month both are eating much the same thing. They are mainly browsers in winter, nipping off live twig ends for the nutritious inner bark and buds. Early in the season they favor members of the rose family like raspberries and roses. In the middle part of winter they shift to a long list of favorites. Rabbits also eat the bark from parts of shrubs they can reach, and take advantage when live branches are broken off in winter storms, as the example from last month illustrated.

 

In February, northeast Illinois deer and rabbits favor poison ivy. Whether this is because that plant undergoes some chemical change that renders it palatable at that time, or whether that is when the more preferred plants have been depleted, or whether it is for some other reason, I do not know and haven’t the laboratory to test such hypotheses. But I suspect that deer and rabbits on the preserves would have a much harder time surviving late winter if it weren’t for poison ivy.

 

Distinguishing whether a cottontail or a deer is the browsing animal in a given case is fairly straightforward. Rabbits, in addition to being shorter and having a more limited reach, have incisor teeth on both jaws. When one nips off a poison ivy or other twig end, the bite is a clean cut at an angle. Deer have incisors only on the lower jaw. A deer bites part way through the twig, pinching against the hard upper jaw, then twists and pulls to remove the bite from the plant. The lower jaw side is cleanly cut, but the upper jaw side is torn.

Maple Leaf Miners: Introduction

by Carl Strang

 

Leaf miners are amazing insects, so tiny that they live between the upper and lower surfaces of leaves. They eat the succulent interior leaf tissues, and as they grow, the area they have depleted of these tissues expands to form a shape that is easy to see and is distinctive according to the insect species. Here are two common forms, linear mines in a cow parsnip (Heracleum) leaf, and blotch mines in a leaf for you to identify (note: this is a trick question! Plant identification given below).

 

Linear mines in Heracleum leaf

Linear mines in Heracleum leaf

 

Blotch mines in mystery leaf

Blotch mines in mystery leaf

 

 

There are flies and beetles that are leaf miners, but the ones I have been studying for more than two decades are minute moths whose caterpillars do the mining in maple leaves. The trees, at Maple Grove and Meacham Grove Forest Preserves, are either black maples (Acer nigrum), sugar maples (A. saccharum), or hybrids of the two. In the mid-1980’s, when I began studying leaf eating insects in these two forests, my attention was drawn by the large numbers of leaf miners in the understory maples on both study areas.

 

I was able to sort out five species of insects doing the damage. They include Caloptilia bimaculatella and C. packardella, of the moth family Gracilariidae. Their larvae begin with tiny mines which they soon leave, and their major growth takes place in folded, cone-shaped shelters (called here “boxfolds”) which the larvae construct at the tips of leaf lobes.

 

maple-leaf-mines-b

 

In the photograph, the boxfolds are unrolled and flattened to show how the green tissue has been scraped away by the tiny caterpillars’ mandibles. I have found both species on both study areas, and also two more members of the same family, Cameraria saccharella and Phyllonorycter clemensella. Cameraria form irregular blotch mines on the upper surfaces of the leaves, and Phyllonorycter produce tent-like mines on the under surfaces. I have not reared adults or identified larvae from the fourth mine type, a distinctive linear mine form, but it likely is the exotic (European) Stigmella aceris, of the moth family Nepticulidae.

 

There are a lot of questions that can be addressed in a system like this. For example:

  • Do the leaf mining species interact in such a way that they either avoid one another, occupying separate leaves as a rule, or do they congregate, clustering onto particularly attractive leaves?
  • These two study areas are separated by many miles of suburbs. Do the populations of the leaf mining species go up and down together on the different study areas (which might reflect responses to climate as it varies between years), or do they fluctuate independently (which might indicate biological regulation of populations)?
  • How does restoration management practice affect these organisms?
  • Do the moths have the same impact on the canopies of large trees as they have in the understory?

 

I’ll address these questions in future posts.

 

Mystery plant with blotch mine: did you recognize it as a rare, 4-leafleted poison ivy leaf? Probably most would regard this as less lucky than a four-leaf clover.

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