Striped Skunk Dossier

by Carl Strang

As striped skunks complete their mating season, this seems an appropriate time to share my dossier of observations on the species.

Skunk, Striped

Striped skunk

Striped skunk

I rarely saw skunks around Culver as a child, perhaps because of their nocturnal activity pattern. Saw one on a road south of town near S.R. 110 while on a run, at dusk, as a teenager. I took plaster castings of tracks at the Bird Sanctuary, Culver Military Academy. Later I saw some in the early evening, visiting picnic grounds at the state park on South Mountain in Pennsylvania. They moved with a somewhat rolling, unhurried walk. Individuals brought to Willowbrook in live traps almost invariably spray as soon as the trap is opened. The spray has a very sticky, lasting quality, and causes a sickening sensation when fresh and concentrated. Youngsters discover their spray ability when 6-9 weeks old. The distinctive black and white color pattern almost certainly is aposematic. That pattern is highly variable in detail, i.e., width and length of stripe, amount of white on head, and number and position of scattered small white spots. The skin beneath is white or black, corresponding to the fur color. Stomping, used as a threat, essentially is an emphatic dancing from one front foot to the other. It is employed against both conspecifics (littermates) and potential predators. The tracks have 5 toes showing, both front and back feet. In suitable substrates, the toenails of the front feet register distinctively distant from the ends of the toes. When toenail marks are missing, the track gives the impression of a miniature cat track (though with the extra toe). Generally, the entire footprint appears as a solid, unlobed block; creases across the soles of the feet are evident in medium-consistency substrates. Tracks rarely are encountered, however. Apparently there is very little activity in winter.

Skunk tracks, hind on left, fore (showing long toenail marks) on right

Skunk tracks, hind on left, fore (showing long toenail marks) on right

17/18FE86. I followed a fresh skunk trail. Gaits in deep snow (4-8″) were diagonal walk and lope, primarily, on an early spring ramble. This skunk ate some mushy crabapples from the previous fall. It went about half a mile on Willowbrook preserve plus an unknown distance on adjacent properties. The den (near Willowbrook picnic grounds) was a tunnel dug in a well-drained location, on an east-facing slope, sheltered by a crabapple. Tracks suggest it was shared with 1-2 cottontails.

4NO86. Diagonal walk in mud, probably the same skunk described in the previous account, at rehab area west gate.

28NO86. Sand seems to stick unusually well to the flat soles of a skunk’s feet, deposited on sticky mud to form roundish or oval spots of sand grains (Culver Fish Hatchery).

29NO86. Memorial Forest near Culver. Lope (bound?) In sand, 6″ between sets of tracks, each set 12″ long.

Sketch of track patterns in the string observed on November 29, 1986

Sketch of track patterns in the string observed on November 29, 1986

28JA87. One or perhaps more than one skunk on walkabout last night in Willowbrook Back 40. Paths extremely convoluted and interweaving, not enough time to sort them out. No skunk came out of the picnic grounds burrow.

3FE87. Skunk on walkabout again, same area. Suddenly it seemed to be taking great leaps. The snow crust froze in open spots at night, so the skunk did not break through in those places.

5FE87. Skunk pulled dead shrew (previously cached by fox) to center of trail but left it.

27OC87. A skunk ran across the road in our Warrenville neighborhood (Summerlakes subdivision) in early evening (around 6pm). It elevated the middle of its tail, giving it a strange, double-humped appearance.

18OC88. In Cactus Camp prairie, tracks show where a skunk dug out a yellow jacket nest recently. A few wasps still were flying in and out.

12JA89. A dead skunk on Park Boulevard at Willowbrook, came out mid-winter.

8SE89. Skunk diagonal walk, flat soft topsoil. Hind foot landing in front of and slightly overlapping front foot. HF 1-5/16″ wide x 1.25″ long.

8JA90. Willowbrook. On the night of the 5th or 6th, a skunk was out. Those were warm nights.

7MR90. Willowbrook. Skunks have been very active the past couple of nights. One has a burrow at the south edge of Willowbrook preserve, south of the stream. They made a couple stream crossings (water, not ice). One of these continued straight north all the way across the preserve.

Typical bounding gait pattern

Typical bounding gait pattern

1SE90. As I ran on the Prairie Path in Warrenville near the library in early evening, what appeared to be a large cat emerged from the vegetation at the side and then stopped in the middle of the path as I approached. Thinking to frighten it out of the way, I began to snap my fingers and accelerated. The cat was strange…it seemed to change shape. Then I saw the stripes and quickly backpedaled. It was a family of skunks, so tight together they seemed one animal in the distance in the dim light. There were at least 3 young with the mother. They had stopped and faced me, partly lifting their tails, all of which made the stripes easy to see even in the darkness. After I backed off they continued on their way.

25FE99. I found a skunk den in the far NE corner of the new Willowbrook preserve addition, under a pile of stacked old telephone pole segments. As many as 4 skunks were active on the preserve the previous night.

16FE00. A skunk on walkabout at Willowbrook last night, the first sign of skunk activity this winter there.

12SE05. Caesar Creek campground, southeastern Ohio. There is much evidence of skunks in the area. In the dusk, a large beautiful individual whose broad back stripes had joined, giving it a white back with just a little black between on the lower back, passed my campsite. Later in the dark, a smaller individual was digging grubs in the lawn of the adjacent campsite. This one was all black with a tuft of white on the head and another at the tip of the tail. It turned away when I shined a light in its eyes, coming as close as 15 feet. It moved slowly, its head sweeping back and forth sniffing, but when finding something to dig it moved quickly, excavating and moving on within about 3 seconds. The next morning I took photos of some of the holes, and of a pile of scats. The holes were mostly neat, ½” diameter, dug out on one side with toenail marks clear, occasional larger ones up to 2” diameter. The scats were stacked weasel fashion, each ½” diameter X 2” long, 3 pieces, one broken with a tiny root sticking out.

One of the holes described on September 12, 2005

One of the holes described on September 12, 2005

The scats described on September 12, 2005

The scats described on September 12, 2005

19JA11. Mayslake. From the night before last, which was the warmest this month (only dropping into the 20’sF), tracks of a skunk. It may have originated from the known den in the north stream corridor. Its winding trail covered much of the north stream corridor prairie, parts of the main prairie, cut from the small savanna at the north end of the prairie across the driveway’s turning circle into the strip of vegetation along the west edge of the preserve, wound through that as it worked its way north, eventually crossed the driveway again at the 31st Street Woods, and continued heading east along the north end of the parking lot marsh.

21JA11. Mayslake. I went to the known skunk den hole in the north stream corridor to see if it was the home of the skunk I tracked 2 days ago. It had not been entered or exited. I picked up the skunk’s trail where it had gone around the N end of the parking lot marsh, and followed it to a hole in the top of the ridge between that marsh and the stream (created when the marsh was excavated), and even with the marsh’s center. It appeared that the skunk had emerged and entered the hole, but the tracks were obscured by large ice crystals developing around the hole’s edge.  Later it occurred to me how unusual those crystals were. Are they growing on moisture from the skunk’s breath?

Skunk den entrances usually are around 6 inches in diameter.

Skunk den entrances usually are around 6 inches in diameter.

23FE11. Mayslake. For a time I mistook a skunk’s trail for that of a mink. What threw me off was the first impression, where the toes spread an unusual amount in thin snow over slick ice. I failed to attend the other tracks carefully enough for a long time, though I was somewhat bothered by the long toenails and the animal following the trail rather than the lake edge. As I approached the den near the friary site I saw similar tracks, confirmed much coming and going and digging at that den, then went back and found that if I had paid closer attention to all the footprints I had been following, I would have realized sooner that they were skunk tracks. The main underlying condition was the thin layer of snow over ice, with enough of a percentage of round-looking tracks resulting to sustain my error.

Lessons from Travels: Alaska Predators

by Carl Strang

My thesis research back in the early 1970’s focused on glaucous gulls as predators.

Glaucous gulls, like the other gull species, have a very broad diet.

Glaucous gulls, like the other gull species, have a very broad diet.

My host, the U.S. Fish & Wildlife Service, was especially interested in the gulls as predators of goose eggs and goslings.

Goose egg probably consumed by a glaucous gull.

Goose egg probably consumed by a glaucous gull.

I found that coastal gulls were mainly after seafood. They were opportunists that took advantage of exposed nests and broods, but birds were not their main target. In fact, geese often nested within the gull nesting colonies.

A gull stands at its nest while a brant makes clear that they aren’t buddies even if they share a nest pond.

A gull stands at its nest while a brant makes clear that they aren’t buddies even if they share a nest pond.

Inland gulls were more focused on terrestrial prey, but they were widely scattered pairs and so their impact was limited. I spent many hours watching predator activity.

This observation tower built by Pete Mickelson, a previous researcher on the inland site, was one of several observation posts. A raven used the storage box, which was open on one side, as its overnight roost.

This observation tower built by Pete Mickelson, a previous researcher on the inland site, was one of several observation posts. A raven used the storage box, which was open on one side, as its overnight roost.

Even that far north, the number of species of both predators and prey was impressive, and as I watched the predators working the landscape I sensed the turns of the ecological dance they were performing in the summer. Here are some of the major players on the predator side, in addition to the glaucous gulls, in western Alaska.

Parasitic jaegers had a strong interest in shorebirds and waterfowl as prey.

Parasitic jaegers had a strong interest in shorebirds and waterfowl as prey.

The smaller long-tailed jaegers focused more on small rodents, but also fed on the smaller birds.

The smaller long-tailed jaegers focused more on small rodents, but also fed on the smaller birds.

Red foxes could prey on adults of the smaller geese, but ducks, eggs, goslings and rodents were more important to them.

Red foxes could prey on adults of the smaller geese, but ducks, eggs, goslings and rodents were more important to them.

Arctic foxes reminded me of little puppy dogs. I remember them systematically removing and caching goose eggs in the tundra for later consumption.

Arctic foxes reminded me of little puppy dogs. I remember them systematically removing and caching goose eggs in the tundra for later consumption.

The mew gull, a species much smaller than the glaucous gull, seldom showed interest in avian prey, focusing on invertebrates and small fish.

The mew gull, a species much smaller than the glaucous gull, seldom showed interest in avian prey, focusing on invertebrates and small fish.

The lesson was to attend to the predators in any landscape, and it informs me to this day.

Coyote Species Dossier

by Carl Strang

I’ve been sharing smaller dossiers in recent weeks. Here is a somewhat longer one. This is a rare instance in which nearly all of my experience with a species came as an adult, in DuPage County.


Coyote. The eyes, glowing from the flash, suggest the fearful image many suburbanites have of coyotes. They are actually relatively small animals, usually less than 30 pounds, but look bigger thanks to the long legs.

Coyote. The eyes, glowing from the flash, suggest the fearful image many suburbanites have of coyotes. They are actually relatively small animals, usually less than 30 pounds, but look bigger thanks to the long legs.

When I came to DuPage County in the early 1980’s, coyotes were known to live at Waterfall Glen and the West Chicago Prairie area. My first experiences were footprints at the Tracker Farm in New Jersey, and then a bed at the far end of a private (now destroyed) marsh in Glendale Heights, Illinois. I saw one briefly in the desert at Big Bend National Park, Texas.

30JA88. Hartz Lake area, near Monterey, Indiana. A coyote slow-loped across a dune. Front foot 2×2 inches, hind foot 2 long by 1.5 wide. The coyote loped with its body held at an angle so the front feet were on one side, hind feet on the other.

A computer rendition of the original sketch.

A computer rendition of the original sketch.

29JE89. Coyote at McKee Marsh. It stopped briefly as it came around a bend in the mowed trail and saw me coming toward it. Big ears, light build and size gave it away immediately. It held still only a couple seconds, then turned and ran. After I got around the bend I got a glimpse of movement to the right as it leaped through a tall grass meadow and ran into the forest.

19NO89. Tracking coyotes in the half inch of snow that fell last night on the McKee Marsh area. The coyotes’ activity was mainly on and around the frozen ponds. Frequent rolling, sometimes in urine. Fox tracks were absent from the wide area I walked in north Blackwell. Foxes were common there before; have coyotes driven them off? Trot the most common gait, in the diagonal position. Diagonal walk frequent, lope occasional. Prints’ actual size 2.25 long x 2 wide, 22-24 inches between corresponding track in each pair. A coyote picked up an old, small dead snake and played with it. Rolled in small amount of its urine on ice of marsh. Stopped and removed 2 burdock burs (some hairs still were attached). Coyote diagonal walk on ice 19-21.5 inches between steps. Lots of activity possibly by one individual, with lots of coming and going (small loops out and back), centering on a rotten goose egg, frozen in ice and apparently opened last night.

Diagonal trot gait, the usual pattern used by coyotes. In this case, the front feet made the right-hand tracks, the hind feet the left-hand tracks.

Diagonal trot gait, the usual pattern used by coyotes. In this case, the front feet made the right-hand tracks, the hind feet the left-hand tracks.

13DE89. Probable coyote scat, 3/4 x 3.5 inches, Hartz Lake.

16DE89. Both red foxes and coyotes present, yet, at McDowell Forest Preserve. Former about 12-16 inches between steps in walk, latter 15-20 inches.

20JA91. I saw two coyotes working together at McDowell. When first spotted they were about 20 yards apart, walking single file. I was able to approach within 60 yards on the path, then they detected me and bolted. They had been investigating a brushy area near a bridge over a small stream, they ran back north and east when escaping.

26JA92. Tracks of a coyote in woods at Hidden Lake, in an area also visited some nights by red fox. Strides were 20-inch steps compared to the fox’s 16 inches. Coyote followed deer trails sometimes.

The hind foot of a coyote, left, is smaller and has a rounder heel. The front foot, right, is larger and has a more triangular heel shape.

The hind foot of a coyote, left, is smaller and has a rounder heel. The front foot, right, is larger and has a more triangular heel shape.

28JA99. Cottontails this winter are 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.

10FE99. A fresh coyote scat on the Willowbrook Nature Trail near the marsh contained both hairs and feathers, the latter from a bird in the cardinal to mourning dove size range.

Coyote scats, often deposited in the middle of trails, provide a dietary record. Either don’t handle them, or do so with disposable gloves or sticks, as they may contain parasite eggs.

Coyote scats, often deposited in the middle of trails, provide a dietary record. Either don’t handle them, or do so with disposable gloves or sticks, as they may contain parasite eggs.

25FE99. Willowbrook. Fresh snow fell yesterday evening, and reveals that 2 coyotes covered the entire preserve thoroughly last night, and more, going out into surrounding residential areas. Sometimes the coyotes were on the same route, sometimes they separated. Once they bedded down within 2 feet of one another in a dense brushy area roughly equidistant from the nature trail and residences, impossible to see by anyone more than 50 feet away.

Here a pair of coyotes traveled together, then one veered off.

Here a pair of coyotes traveled together, then one veered off.

26FE99. A coyote made a remarkable vertical 4-foot jump out of the creek at Willowbrook, having crossed to the point where the Safari Trail meets the stream at the high bank.

MR99. During the 90’s, coyotes have become much more abundant in the western suburbs. Tracks frequently encountered on the preserves, and in absence usually of fox sign until the past couple of years. One appeared at Willowbrook frequently around 1994-96, after the fox there was gone. Then the coyote vanished, after it was seen several times apparently weakened by mange. A red fox came in that winter, lasted a year, then it left. At that time coyote sign returned and have been frequent for more than two years, now. The common pattern has been for signs to be abundant for several weeks, then absent for several weeks, in alternation through the warm months, with 2 coyotes taking up steady residence on the preserve through the winter. I saw two different individuals one morning in winter of 1997-98, one missing all but a stub of its tail and so easy to recognize. They often deposit feces in the center of the nature trail, occasionally in other clear areas or smaller trails. Hair the most common dominant food remains in the scats, occasionally feathers or skins of fruits dominate. I saw a coyote crossing Kirk Road in Kane County at dusk one summer evening. Their howling, which I have heard at Pratts Wayne Woods, Hidden Lake, Lincoln Marsh and Fermilab, is extremely high-pitched and wailing in quality, and I have heard several animals howling together or howling back and forth in contact call style but not a single individual howling alone. During a night hike in September 1996 at Hidden Lake, a siren set off a probable family group of 4 individuals, and for the rest of the evening the scattered coyotes howled at regular intervals, producing the contact call effect.

Usually coyotes are shy and seldom seen.

Usually coyotes are shy and seldom seen.

14AP99. The goose nest has been destroyed, the eggs preyed upon, at Willowbrook. Tracks in mud show at least 2 coyote round trips wading out to the nest island. No other predator tracks.

25JE99. I heard a coyote barking at a neighbor walking dogs at Willowbrook.

30AU99. Coyote scats at Willowbrook have been rich in fruit. This remained the case for weeks, with fruit appearing to be the dominant food.

5OC99. A heavy red fabric strip, 10 inches long, possibly a collar, in a coyote scat on the Willowbrook Nature Trail. Fruit remains dominant food in scats.

1NO99. Hair becoming more common, fruit less, in scats at Willowbrook.

2NO99. A coyote scat at Willowbrook had a bit of candy wrapper in it (shortly after Halloween).

Half-grown coyote pup, in a meadow at Mayslake Forest Preserve.

Half-grown coyote pup, in a meadow at Mayslake Forest Preserve.

1999-2013. It has become clear that coyotes are everywhere in the Chicago area, with even centers of towns being parts of territories. The coyotes, unless someone feeds them, are very good at staying out of sight. Reports from neighbors suggest that the pair at Willowbrook had a home range that extended from the East Branch of the DuPage River to the Village Links Golf Course, and so they were absent from the preserve for weeks at a time, but in some seasons centered their activity on the preserve (they never denned there, however).

At Fullersburg Woods, the pair was active year-round in the more open northern part of the preserve and presumably extended into adjacent areas off the preserve. In winter, the pair regularly wandered into the forested southern part of the preserve, usually hunting apart but joining up as they returned to their northern center of activity. I never found a den on that preserve.

Former coyote den, Mayslake. The buried concrete had provided a stable roof, but its removal as part of the demolition process ended this den. Coyotes only use dens in late spring and early summer, to shelter their young pups.

Former coyote den, Mayslake. The buried concrete had provided a stable roof, but its removal as part of the demolition process ended this den. Coyotes only use dens in late spring and early summer, to shelter their young pups.

At Mayslake the pair had a den in the former friary garden area, but the den was destroyed as an incidental consequence of the friary demolition. Until then the coyotes were a constant presence on the preserve, but now they are there regularly but somewhat intermittently. They have been healthy and strong when I have seen them, and had pups most years. One odd observation was that one chewed up and swallowed a tennis ball discarded near the off-leash dog area. The fragmented ball passed completely through the coyote. Rabbits and voles are the more typical contents of scats.

Scat composed of tennis ball pieces.

Scat composed of tennis ball pieces.

Literature Review: North American Red Foxes

by Carl Strang

There has been some confusion about the origin of North America’s red foxes. Are they truly indigenous, or are they, as some have claimed, all descendants of European foxes transported here for the fox hunting sport? Today’s literature focus is on a study that investigated that very question.

This red fox in western Alaska apparently had just crossed a muddy tidal slough.

This red fox in western Alaska apparently had just crossed a muddy tidal slough.

Statham, Mark J., et al. 2012. The origin of recently established red fox populations in the United States: translocations or natural range expansions? J. Mammal. 93:52-65.

They looked at mitochondrial DNA of red foxes, and found no indications of Eurasian influences, though they concluded that some populations were established by translocation within this continent. Prior to European arrival, the foxes were in Canada, Alaska, and west of the Great Plains. Agricultural clearing allowed their spread into the eastern U.S. This emphasizes how forested the East was prior to the large-scale changes brought about by European agricultural practices. South of Canada we would have seen gray foxes, but not red ones in those days.

Lessons from Travels: Rodent Cycles

by Carl Strang

One of the phenomena of wildlife in the far North is the dramatic cycling of small rodent populations. I had the opportunity to witness this when I was doing my graduate research in western Alaska. I was studying glaucous gulls rather than small mammals, but there was some relevance because the gulls feed heavily on tundra voles early in the season, when the thaw floods the voles into exposed positions.

Tundra vole, enjoying a snack provided by a colleague at the tent frame.

Lemmings were present in small numbers as well, but the only rodent that we saw undergoing violent population fluctuations was the vole. At the low point in the cycle one was hard pressed to find an active runway, and sightings of the voles themselves were few and far between. At the high point the pingos (ice-elevated rounded hills) were riddled with runs.

The voles dug into the soil, chewed a dense maze of runways, and seemed to be everywhere.

I was there in four consecutive summers, and saw one high-density year.

In the peak year they invaded my home.

Now I want to refer back to my recent literature review on food web stability. Species diversity is relatively low in the North, and in general there is a gradient of diminishing diversity from tropics to tundra. Low species diversity is associated with lower stability, and stability clearly is lacking in the vole population. It is not, however, simply a matter of few predators available to exert top-down control. In addition to glaucous gulls there were mew gulls, parasitic and long-tailed jaegers, less common predators like short-eared owls, and foxes. The last were represented by two species.

Red foxes were larger. This one got muddy.

Arctic foxes were the smaller species. This one, which appears to have a tundra vole in its mouth, hasn’t yet molted to its summer pelage.

Furthermore, all of these predators have broad diets and so can switch to focus on the most abundant prey (birds and their eggs being the chief alternative for most of them). Switching, however, isn’t stabilizing the voles. I haven’t followed the literature on this, so I don’t know where the current consensus is, but I think it’s important to point out that for much of the year the voles are protected by a deep layer of snow, and the avian predators all are gone outside the relatively short breeding season. The long winters are depauperate of species indeed, voles can breed in every month, and that surely plays a role in this food web.

While modest cycling of small rodents occurs in Illinois, it doesn’t come close to matching what we saw in Alaska. We have many more kinds of plants, rodents and predators here, and the rodents are vulnerable year round. This seems to be enough to account for the difference in food web stability of the two places.

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).

Red Fox Dossier

by Carl Strang

This is another of my species dossiers, consisting of what I know about a given species from my own experience. I started the dossiers in the mid-1980’s.

Fox, Red

Initial summary: Common resident of mixed fields, brush and woods edges in northern IN, northern IL, south central PA. Also seen on tundra in western Alaska. Near Culver, IN, seen most commonly in winter, when they are frequently active and visible at a distance during the day. In summer, occasionally flushed from resting spot beneath a bush in an old field.

In Alaska they foraged for mice, birds, eggs and young waterfowl in summer. In tall sedges they attempted to pin birds and mice by listening for them, then leaping high and coming down with front legs together and extended straight down. Cached eggs singly, burying them near where found.

Den found on 2AU71 in high bank of tundra lake in bluffs area near Kokechik Bay, western Alaska. Entrance faced south. Well worn paths leading to water 15 feet below and to top of bluff 7 feet above. Entrance about 1 foot in diameter. A second entrance on top of hill. Fish remains.

At Blackwell Forest Preserve, in June, their contact calls heard at night: a high-pitched whining scream or “yipe,” beginning and/or ending with a harsher, rougher, strangled sound. In May 1986, on a walk through the forest at the Morton Arboretum, DuPage County, IL, I felt the need to freeze. Soon a yellowish-colored apparition came toward me, following a dry streambed that passed 30 feet to my left. Soon the red fox came into clear view, a chipmunk dangling from its jaws. It was walking fairly quickly and directly, not looking from side to side. Chipmunks gave single “chip” calls and were silent as it passed. It went by me, then after another 20-30 yards came to a sudden halt, spun around, and at a faster speed came back past me. I suppose it had caught my scent where I crossed the stream.

Trot on thin layer of snow over ice. Width of entire path 5 inches. Travel left to right.

           RF                               LF

RH       o                    LH      o

 o                               o         

     3.5″        10″              3.5″

13JA87. Red fox bed in Willowbrook Back 40. Snow 6″ deep, was compressed in a 15″ diameter area. May have been flattened with feet first. No hair, but claw marks in bottom of bed probably from stretch as the animal prepared to leave. Bed in area where brush slightly denser than average, and concealed well by grasses on one side. Photos next day after some melting (bottom of one part melted out). Odor of fox evident on day it was made, not detected following day.

17JA87. Red fox lope. Front feet bigger, back feet have rounder heels. Body held at an angle to direction of travel.

LF       RF                              

 o         o                     RH       LH

                                      o         o

4FE87. Fox at Willowbrook cached a short-tailed shrew, and apparently stopped by later to check on it.

6AP87. Willowbrook fox still present.

17AP87. I saw the fox.

27JE87. McKee Marsh area. A red fox passed just north of sawdust storage pile. In thin summer fur. Saw me as it came even with me, 50m away (I was standing, but still), and it ran into tall vegetation.

23DE87. Fox swam across Glen Crest Creek at Willowbrook several times in recent days.

3JA88. McDowell Grove Forest Preserve. Several pictures of newly excavated fox den, with rabbit remains at entrance. In gravel bank above floodplain of stream.

9JA88. The McDowell fox has used the river ice intensively as a corridor and for crossing (tracks especially heavy opposite den).

15JA88. Followed Willowbrook Back 40 fox’s wanderings through last night’s inch of new snow, Back 40. Nearly all the time in steady diagonal walk or trot. Relying on nose for clues? Occasionally deviated to investigate rose bush or brush tangle.

17JA88. Blackwell. Rain melting snow reveals a superabundance of meadow voles (also found 2 dead voles), near where kestrel had picked the one found on the 14th. Predators taking heavy advantage. Fox tracks all over.

23JA88. Alternative trot pattern, body straight with path of travel? McDowell. Even spacing throughout (within and between sets), 12 inches separating (slow lope? But so close together?). Travel left to right.

 LF       LH                   LF       LH

  o        o                         o         o

            o        o                          o        o

           RF       RH                     RF       RH

Foxes highly active last night (rabbits, too). 1″ snow fell just after sunset.

28JA88. Fox tracks in normal walk separated by 14-18″. After 2 full days of no fox tracks, suddenly after last night the Back 40 is filled with them.

29AP88. Fox seen at Pratts Wayne Woods Forest Preserve. Stopped many times to look back at me as it ran away.

10SE88. One seen Herrick Lake F.P. Seemed weak, or perhaps simply expected me not to notice it there.

2NO88. Willowbrook. Tracks have returned to Back 40, after disappearing during summer of marsh excavation and nature trail construction.

15JA89. Red fox tracks at Herrick Lake Forest Preserve: one fox’s set had a pattern for a long distance, on cleared path with ice and a thin snow cover that had partly fused to it, of a mix of walk and trot, i.e., two walking steps and a trot step.

24MR89. Winfield Mounds, tracks. Red fox moved from walk to trot (body angle version). Step increased from 16″ to 18-19″, and more on toes.

22JE89. Scats in Willowbrook Back 40 packed with mulberry seeds. The berries first ripened within the past week.

7SE89. Red fox tracks near marsh. Fox also crossed Park Boulevard last night.

8SE89. Back 40, fox walking stride average about 16 inches, heel to heel.

19NO89. Tracking coyotes in half inch of snow that fell last night on McKee Marsh area. Ponds frozen. Coyotes’ activity heavily on and around them. Frequent rolling, sometimes in urine. Fox tracks absent from wide area I walked in N. Blackwell. Were common before; have coyotes driven them off? (In late 90’s, foxes resurging; researchers say mange took them out).

20NO89. Red fox tracks, Willowbrook, soft soil (but true track size) 1 5/8L x 1 3/8 W.

14DE89. Willowbrook. Fox direction of travel when track partly filled with snow: slides foot in at an angle, lifts it straight out. Covered a lot of ground last night. Played a while with the caged fox. Below 0°F last night. Rabbits, mice and a muskrat active.

16DE89. McDowell. Foxes and coyotes present. Foxes about 12-16″ between steps in walk, coyotes 15-20.”

19DE89. Willowbrook. Fox carried stiff dry weed stem 1.5 feet long for some distance, dragging end in snow. Play? Were mink doing same at Herrick and McDowell last winter?

21JA90. West Chicago Prairie, on Prairie Path. Fox slow lope, maintained considerable distance. 9-14″ (variable) between footprints, tend to be greatest from the Left front to the pair of tracks. Gait developed out of a trot, body-angle version, with 11-12″ between pairs of tracks and 2″ (along axis of travel) between the members of a pair. The slow lope appears to be a common gait along here today, either an individual preference or controlled by the quarter inch of snow that had fallen earlier.

          LF       LH                  

            0         0                      0        0

 0                     0          0                    0

RH                   RF                              

26JA90. Willowbrook. 4 inches of snow dumped in heavy wind yesterday. Last night wind calmed. Sticky snow on all plants. Mice and foxes, some rabbit activity. Fox taking longer (16-24″) walking steps. Lifted leg to mark (male?). A common slow lope pattern, so similar to the diagonal walk as to be almost indistinguishable in this snow depth. Appear to be LF, RF+RH, LH. Space between sets of 4 tracks slightly greater than spaces between. Travel left to right:

 o                    o                    o                    o

          o  o                                      o  o

(actually, slightly longer hole in snow where right feet are close together)

22AP90. Winfield Mounds. Tracks near SE corner of preserve, near houses.

26JA92. Hidden Lake. A red fox in forest bedded for a time atop a fallen log, bed 8″ diameter at bottom, 12″ diameter overall. Fox removed a bit of a burdock bur with some hairs. Bed 2.5 feet above ground, on a hillside. Fox had walked along top of log to reach the spot.

From 1993 to 1997, red foxes were scarce in DuPage County. I don’t remember seeing any on the preserves during that period, and essentially no signs. Coyotes, meanwhile, became abundant. Beginning in 1998, I began seeing red foxes again. Coyotes remained abundant.

1AP00. Red fox scats on Heritage Trail, Morton Arboretum, near its southern boundary with Hidden Lake Forest Preserve.

In the 2000’s I seldom have encountered red foxes or their signs. Based on reports from phone calls to the forest preserve district, and occasional sightings of my own, I have the sense that red foxes now are mainly animals of residential neighborhoods, and are much less common than they once were in the county. Their place on the preserves has been taken by coyotes.

Eastern Chipmunk Dossier

by Carl Strang


The first chipmunks began to show themselves at Mayslake in the second half of March. Today I’m sharing my dossier  on the species. The codes are my representations of dates, the day followed by my month code, finally the year. The dossier was established in late 1986 or early 1987, entries added thereafter as needed. Since this one is relatively long, I have edited out some entries that simply give date and location observations.




Chipmunk, Eastern

Lives in underground burrows; often plugs some entrances with debris. Vocalizations include “chip-chip-chip…” and chip-trill alarm “chip-chip-churrrrr.” Single “chip,” birdlike. Lives in forests and at forest edges. Also savannahs with some bushy cover. Can climb trees but usually forages on ground. Disappears for most of the winter, apparently plugging burrows. In presence of red fox (passing with another chipmunk dead in mouth), they gave a couple quick chips and were silent (MY86). I have had one “singing” while watching me.

6MR87. Newly opened chipmunk burrows in Willowbrook Back 40 the first signs of that species this year.

7AP87. Chip-trill at my approach produced response by gray squirrel: jumped onto low branch, looking alert.

10MY87. Chipmunk pursued by another, stopped with 3 high chips in a lily-of-the-valley patch within forest at North Blackwell, as the other turned back. Then the first one came out into deep oak litter and foraged. Frequently stuck head under leaves, a few times burrowed completely under. In one spot munched several invertebrates, only remains found later were part of a striped slug (1/3 of head end missing, recently bitten off). Ate at least 3 items, 2 appeared to be slugs, the other had legs.

23AU87. When running hard (e.g. crossing open space), hold tails vertical. One ate an acorn.

27AU87. Chipmunk drank from small pool: barely put mouth in water, remained still until done except for rapid fluttering of cheeks. It drank for about 20 seconds.

16AP88. Morton Arboretum. An old chipmunk’s hoard of acorns, now reduced to shells, inside the hollow root of a dead oak. The top of the root has rotted away, exposing the shell fragments.

29MY88. Hartz Lake, in woods. A chipmunk saw me move my arm laterally, gave 3 chips increasing in speed, and ran. Immediately 2 jays feeding on the ground flew up. They were 40-50 feet away.

4AU88. Willowbrook Back 40. Chipmunks active. Early estivation this year because of drought?




31AU88. Willowbrook Back 40. Chipmunk 15-20 feet up, on slender branches of a 25-30-foot-tall black cherry, cheeks full.

1SE88. Willowbrook. Active past couple weeks, sniffing over the ground and quickly climbing high into cherry trees (and quickly down, head-first), filling cheek pouches.

5MR89. A cold (20F) windy day, ground frozen with crusted snow layer, yet some chipmunks active in a firewood pile at McDowell.

12MR89. Hartz Lake. An area hotly contested by 4-6 chipmunks, in low wooded area with many fallen trunks, standing hollow stems, and brush. Much chasing, sometimes turn around and chase back. Often make squeaking calls. I stalked successfully within 5 feet, lay down with arm alongside log for a while without being recognized, but none came close enough to touch (they had pretty much settled down by then).




8MY89. A foraging chipmunk appears to find its food mainly by smell, sticks nose into vegetation with eyes closed, takes object with mouth and pulls out to eat.

31AU89. Chipmunks producing lower “chuck” call with great horned owl above.

7SE89. Chipmunk eating a small (less than 0.5″ diameter) red crabapple fruit.

28JE&1JL90. Chipmunks up in mulberry tree canopies (15 feet up) at Willowbrook and West DuPage Woods (mulberries ripe more than a week now).

Late MY90. Hartz Lake. Chipmunks foraged by nosing and digging among oak leaf litter in area of scattered trees.

30AU90. Chipmunks in cherry trees, Willowbrook.

5SE90. Willowbrook. Chipmunk tracks, clear, in fine mud. 3-lobed heel. Hind tracks less clear; pushing off harder from hind feet.




18JE91. Chipmunks on ground, Willowbrook, stuffing themselves with fallen mulberries at midday.

13SE94. Chipmunks climbing high into box elder trees and eating seeds, this week. Go out to the finer twigs, look a little clumsy but undaunted.

5AU95. On Red River in WI, mink hunting along shore. As it came close, chipmunks gave a single loud “chip” apiece and were then silent (see red fox entry, in MY86).

Summer 1999. I listened and watched daily, and did not detect a time when there were no chipmunks active. No estivation, or overlapping among individuals?

2MR00. Willowbrook. First chipmunk of the year seen.

15MR00. Willowbrook. One chipmunk chasing another.

12NO01. Chipmunks still foraging, on a sunny day in the 50’s, Morton Arboretum.

Alphabet of Tracking: 4 Toes Front and Hind

by Carl Strang


To set the stage for future posts, I am beginning a series on basics of tracking, with an initial emphasis on mammal footprints. Tracking is a language. It has an alphabet, words, sentences, and these build to tell a story. The completeness of that story is limited mainly by the experience and skill of the tracker. Experience and skill are built only by what Tom Brown, Jr., calls “dirt time.” The more you study, the better you will be. Books and Internet postings like this one can provide hints to get you started, but you have to practice, and train your eye.


Reading any language begins with a mastery of its alphabet. The alphabet in tracking, as I learned it and teach it, is the identification of the species of animal which made the track. We’ll begin with animals whose feet typically register four toes on both the front and hind feet when leaving a footprint, and in our area of northeast Illinois this means members of the dog, cat and rabbit families.


Cat tracks are distinct in typically showing four toes per foot, with no toenail marks, and generally a circular shape to the track as a whole. The example usually encountered is the domestic cat.


Domestic cat

Domestic cat



I certainly keep my eyes out for bobcat tracks, but so far have found none in northeast Illinois. The photos are from other parts of the country. Note the lobed heel.


Bobcat track, Nevada

Bobcat track, Nevada



Bobcat track New Jersey

Bobcat track New Jersey



Mountain lion tracks have the same properties as other cat tracks, but are much larger and of course are not usually to be expected in our area.


Mountain lion track, Texas

Mountain lion track, Texas



Dog family members in our area include dogs, coyotes and foxes. In coyote and fox tracks the toes fit together so as to form an egg shape, with the middle two toes farther in front of the outer two toes. Coyotes have slightly larger footprints and a longer stride than foxes.


Coyote track

Coyote track



Coyote muddy foot on concrete

Coyote muddy foot on concrete



When the substrate is fine enough to register them, red fox tracks show ridges protruding through the fur in the heel and toe pads. In gray foxes, coyotes and dogs the pads are not so furry.

Red fox on the beach

Red fox on the beach



Red fox track, clay

Red fox track, clay



Red fox track, snow

Red fox track, snow



Dog tracks are relatively spread out, forming more a maple leaf shape, and the middle toes are not so far in front of the outer toes. This is a matter of degree which requires dirt (or snow!) time to learn.


Dog tracks

Dog tracks



Our local rabbit is the eastern cottontail. They are smaller animals, and their feet are furry, so unless they pass through soft mud or snow you will have to look for the 4 toenail marks of each foot.


Rabbit faced left, hind feet top and bottom, front feet center

Rabbit faced left, hind feet top and bottom, front feet center


Can you find the four toenails of this cottontail track?

Can you find the four toenails of this cottontail track?




I am providing just a starting sketch here. More will come later. If you want references, the best tracking books I have seen are by Tom Brown, Jr. (Tom Brown’s Field Guide to Nature Observation and Tracking; and, for more advanced study, The Science and Art of Tracking, both published by Berkley Books), and Mark Elbroch (Mammal Tracks & Sign, and Bird Tracks & Sign, both by Stackpole Books).

The Funnest Discovery

by Carl Strang


I have just completed my first month at Mayslake. As I learned the lay of the land and explored the various places I want to monitor as I tease out the natural history of my new work place, every moment held a discovery. But something had to stand out, and it came on my last November excursion. I found the coyotes’ den.




At least, I think it must be. I have seen fresh coyote tracks and scats on Mayslake’s trails, and the Mayslake staff report frequent sightings of coyotes in recent years. No sign or mention of foxes, at least not yet. The den was in a remote part of the preserve that I probably will enter only once a week at most. I was picking my way through an area dense with burdock, buckthorn and some tall red cedars, and came upon a den hole dug in the ground. Its mouth was filled with fallen leaves and so had not been entered recently. A few feet away there was another, larger hole. The excavated earth around the holes was well packed and clean of invading annuals, which makes me think the den was used this past season. Both holes in this elevated, well drained site are protected by buried concrete slabs around which the animals had to dig. The larger hole has a triangular shape with each side of the triangle at least 12 inches. This is too large for any local animal except fox or coyote. Also, there were no scattered bones of prey as I might expect at a fox den, though enough months have passed since the denning season that this cannot be an entirely reliable clue.




Neither canid uses its den outside the breeding season, so I don’t expect them to be there this time of year. Unfortunately I doubt that I will be able to monitor it during the breeding season without disturbing them. Coyotes can be quick to move their pups. I will look into the possibility of clearing a viewing hole in the surrounding vegetation for remote checking, but am not optimistic. Still, it was fun finding this den and the discovery leaves me feeling that I am starting to form a connection with this place.

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