Bird Feeder Lessons

by Carl Strang

Except for my yard, my neighborhood contains mainly lawns and some foundation shrubs, along with the small trees planted to replace the near monoculture of ashes killed by emerald ash borers. My own plantings had grown to the point where I thought they might provide enough cover to make it worthwhile to put out bird feeders.

I hung a tube feeder above a platform feeder set on the ground. Through most of the winter, safflower seeds were the main fare.

One day I saw a meadow vole popping out from the snow to grab one seed at a time from the platform.

Its main residence appeared to be beneath the inverted water garden container, but underneath the platform feeder it also had excavated a network of tunnels.

Most birds were infrequent visitors. The regulars were a small flock of mourning doves. They are not limited to small winter territories, and their longer distance patrols allow them to find scattered food sources. I hosted up to 20 of them in the early mornings, and 3 or so at dusk.

Eight or so of “the troops,” as I came to call them, are visible in this blurry photo through the kitchen window.

After the morning feed, they often rested a bit before moving on.

One dove that came at mid-day gave a demonstration of limited intelligence.

It happened to land inside the little decorative fence that surrounds the water garden. Reaching through the bars, it fed for a bit but then appeared to become frustrated.

The bird walked back and forth for a good ten minutes, sticking its head through various holes but unable to reach the seeds it wanted. It never figured out that all it had to do was go over the little fence and stand in the feeder to take all the seeds it wanted.

Eventually the dove decided to leave, and jumped up to perch on the fence before heading on its way.

 

More Mayslake Mammal Action

by Carl Strang

As the snow rapidly melts away, mammals have adjusted. Meadow voles used the snow to advance their tunnel network into the lawns, but these now are exposed.

The voles had to retreat to more sheltered runways.

The voles had to retreat to more sheltered runways.

The voles’ larger relatives, the muskrats, at last are getting some open water to work in.

This one was quick to take advantage of the first few square feet of open water to appear in the parking lot marsh.

This one was quick to take advantage of the first few square feet of open water to appear in the parking lot marsh.

Coyotes now find the going easier.

This one’s muddy feet left a trail easy to see on the black-sealed pavement.

This one’s muddy feet left a trail easy to see on the black-sealed pavement.

Close-up of hind and front footprints

Close-up of hind and front footprints

Rabbits are better camouflaged now, but they have lost some of their advantage as the running surface hardens.

This cottontail lost a race with a coyote.

This cottontail lost a race with a coyote.

And I am happy to add myself to the list of mammals glad to see the snow departing.

Mayslake Mammal Update

by Carl Strang

The deep snow is receding, now, but it certainly has posed challenges to some of our mammals.

Not all of them, though. The muskrat could function with underwater excursions from its secure lodge.

Not all of them, though. The muskrat could function with underwater excursions from its secure lodge.

Voles, the muskrat’s smaller terrestrial relatives, have enjoyed a winter relatively safe from predators. Other species have had to deal with it. We entered the mating season for skunks and raccoons, and they could not wait out the winter.

Skunks, with their relatively short legs, had a particularly difficult time until the snow crusted enough to support them.

Skunks, with their relatively short legs, had a particularly difficult time until the snow crusted enough to support them.

The snow forced this raccoon into a rare, diagonal walk gait.

The snow forced this raccoon into a rare, diagonal walk gait.

A few clear tracks confirmed that the above string was raccoon-created.

A few clear tracks confirmed that the above string was raccoon-created.

With the thaw on, and overnight lows crusting the snow, only deer and humans still are inconvenienced where the snow remains deep.

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

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.

Great Horned Owl Species Dossier

by Carl Strang

Today’s species dossier is one of my largest. Great horned owls simply attract my attention and interest more than most other animals, and so I have accumulated more notes on them. Great horned owls haven’t been as easy to follow in the years since West Nile virus came into our area. Formerly the crows were reliable blabbermouths as to where the owls were. If our local crows develop resistance to the disease, those days will return.

Owl, Great Horned

Great horned owl

My earliest memory of young great horned owls was in a forest near Purdue, after they had branched one spring [branching is the term for owlets leaving the nest; it is different from fledging, because they reportedly climb down to the ground, walk to another tree, and climb up it]. I know this species primarily from observations in DuPage County, IL, where it is the common large owl, occurring in forests, even small ones. A pair nested annually in the Willowbrook riparian strip for many years, staying as year-round residents. They nested in large willows, 20-30 feet up, first in a nest on branches, then after a storm dislodged the nest, on a provided platform until that tree fell. Incubation begins January or February. The non-incubating male bird usually perches nearby in the daytime, flying away apparently to draw off people or mobbing crows. Owlets (usually 2) branch in May as trees are leafing out, can fly between trees by late May. Young have a distinctive begging call, a rising squeaky-scraping or -grating loud “scaip!” Young disperse usually by the end of October. Before then, they fly all over their parents’ territory, usually staying fairly close together. Branched young mostly sit still, observing all that goes on around them. November brings frequent late afternoon and evening territorial calls: the female’s call is a higher-pitched “WHO-whowhowho-whowhowho-who.” The male’s call has fewer syllables and a lower pitch.  Deep, booming voice. Willowbrook’s territorial birds had a running, never-ending conflict with the caged birds. I also heard calls during childhood campouts on the Tippecanoe River, Indiana, in summer, and later in the woods near the Boiling Springs, Pennsylvania, house in spring.

Pellets and food remains in late winter 1986 at Willowbrook were heavy in rabbit fur and bones in February, meadow voles in March. There were feathers of a gull in May. They covered a territory that included Willowbrook, adjacent residential neighborhoods, and much of the College of DuPage campus, for a total of perhaps 100 acres.

In the Basin of the Chisos Mountains, Big Bend National Park in Texas, they were calling around 5:30am in late July. We saw others there on the road in early evening in the upper desert. They were a bit paler than Midwestern birds.

Some contents of owl pellets at Mayslake, 2009. Prey species are meadow voles, white-footed mice, and a short-tailed shrew.

12FE87. Lots of recently molted breast feathers in Willowbrook Back 40.

8AP87. Photos of branching young owls.

Great horned owl, soon after leaving the nest.

29AP87. Crow remains found under nest area.

5MY87. The pair’s own nestlings now branching, in a willow 50m from nest tree.

6MY87. Remains of a consumed pigeon.

7MY87. The young are in another willow, closer to the nest tree, the one used most by last year’s young when branching. The third (foster, added by Willowbrook staff) youngster is on another branch of the same tree.

8MY87. Another tree change.

1JE87. The young are flying.

5OC87. Adult male beginning to hoot, in afternoon, Willowbrook Back 40.

9JA88. McDowell. Owl flushed from pine grove at south end of north field.

16JA88. McDowell. A great horned owl flew to tree on the west bank of the river, just north of where trees thin to a thread of willows, and where a housing development comes down to the river. There’s a top-blown tree nearby, also several large oaks. Then crows began raising a ruckus nearby in another direction, as though pestering a great horned owl. From that direction a red-tailed hawk soared, but they paid it no heed. It circled an adjacent riparian strip, but when the owl finally broke and flew with a flock of 10 crows in pursuit, the hawk fell in between, and also began to chase the owl. Once it got above the owl and swooped at it, brushing the owl’s back with its feet, but about then the crows caught up and chased both raptors down toward where I had seen the first owl perched, now out of my sight.

30MR88. Willowbrook. Fresh pellet with remains of 2 meadow voles.

25AP88. Both great horned owls off the nest, though in nearby trees.

17MY88. I hadn’t seen great horned owls of Willowbrook Back 40, or heard harassment by crows, in some days. Today I saw 2, upstream of their nest. Crows didn’t harass them for long or in numbers (2-3), apparently too occupied with their own nesting activity.

18JE88. Harassment of owls by crows gradually has increased this month at Willowbrook. Today I observed heavy harassment of a great horned owl by a large number of crows at McDowell Grove F.P. Owls branch at the same time crows are starting to nest, and becoming too busy to harass owls.

22FE89. Owl on a nest at Willowbrook (started incubating within the past 10 days).

26AP89. For the first day since February, there is no adult owl in the nest tree at Willowbrook (have been brooding several days, then a few days of adult perched beside nest with a youngster visible. 2 young. A fox squirrel climbed the nest tree. When it was just below the nest, the adult female flew from a nearby willow, and landed on the nest. The squirrel turned around and began to climb down as she flew in, but was not panicked.

31AU89. Jays vigorously “jay”-ing at an owl well hidden among leaves in a willow top. Chipmunks chucking nearby, below.

30NO89. Great horned owl flying, viewed from behind. Wingbeat of remarkably little amplitude, compensated by its more rapid rate. A fluttering sort of appearance. Wings kept straight. (A behavioral quieting of flight?)

14DE89. Willowbrook nature trail. The owl caught a mouse, according to tracks. Slight blood drops in snow. Many steps trampled snow just beyond the mouse burrow. Then the owl walked, either having swallowed mouse or transferred it to bill. Tracks: landed on mouse tunnel, then walked 5m. Noticeable straddle, up to 1 inch. Track 4 inches long, 3.5 wide, right angle toe pointing to outside distinctive for species. 8 inches center to center for length of step between tracks.

Sketch of great horned owl tracks.

3JA90. The Willowbrook owl pair perching near nest platform.

29JA95. Following a tip, I found a great horned owl on a nest at Maple Grove F.P. Stick nest was built last year by Cooper’s Hawks, according to informant. Nest solidly based in a main crotch 15-20 feet up. Owl had head and ear-tufts up, very noticeable but only from the front. Nest tree right beside a regularly used trail, but not a main trail, less than 200 yards from Maple Ave. and less than 100 yd. from the private school on the east border of the preserve. The owl reportedly has been on the nest less than a week.

18FE99. At Willowbrook, I found this year’s great horned owl nest (they probably have used this site before; not easy to find) in the top of a dead tree trunk, with most of branches gone, a large hollow with little in the way of a roof. Only part of the owl’s head is visible, and only from certain angles. A single fuzzy feather tuft was the give-away. Once while I watched, the bird appeared to stand and turn or shift eggs by moving feet, stepping from one to the other. The owls had been advertising consistently in the area around this tree in the early winter. Crows mobbing nearby earlier in the day (presumably after the non-incubating bird nearby) drew my attention to this area. Only one other candidate tree is nearby.

A sketch I made after finding the nest on February 18.

11MR99. The great horned owl was standing in the Willowbrook nest in the morning.

15MR99. A young bird was seen on the afternoon of the 12th. Today at least 2 young are visible. They were being fed between 3 and 3:30pm.

18MR99. The 2 young owls frequently are standing in the sun in the nest.

12AP99. The Willowbrook great horned young have branched.

A pair of branched young.

16AP99. One of the owl young somehow crossed the rain-swollen Glen Crest Creek to perch between it and the Nature Trail. Flew?

4MY99. At mid-day, a flock of 8 crows pursuing an adult great horned owl over much of Willowbrook Preserve.

27MY99. Both Willowbrook owl young still alive.

11AU99. Only one of the Willowbrook owl young remains.

18AU99. The young owl calling at mid-morning.

8MR00. A neighbor near the north edge of the Willowbrook preserve reported that the pair of great horned owls have been calling in his yard nightly since late January. He gave us permission to look for a nest, and we found it, in the top of a large blue spruce, built on an old crow or squirrel nest. 20 minutes were required to find a small hole through which to confirm the bird’s presence. The tree, perhaps 40 feet tall, is close to a dead‑end side street, in between his house and garage (the 2 buildings less than 20 feet apart), with no other tall trees right there though several others were in the yard. The bird appeared still to be incubating, occasionally turning eggs. We did not see the non‑incubating owl, but numerous potential roosting sites are nearby.

30MR00. We checked the nest again. After a few minutes the brooding bird flew away (sunny, warm afternoon). We could see one young bird clearly; there may have been more. Development seems behind last year at this date by at least a week. Still all white down, as far as we could see.

14AP00. In central Kane County, in a bur oak woodlot of perhaps 10 acres, a great horned owl nest. The nest is an appropriated crow or hawk nest in the top of a large oak. At least one young bird still is inside. The presence of the owls was made clear when the adult male flew past us, pursued by crows. He was small, appearing no larger than the crows. Later I found the nest when walking through the woods. The female flew a short distance, and a few crows called, but she settled in against the trunk of an oak, well camouflaged, and they left her alone.

17JL00. No sounds of great horned owl adults or young at Willowbrook in the evening.

2001: No signs of nest or young around Willowbrook this year, though in the spring an adult seemed to be decoying crows.

Great horned owl tracks. Owl tracks are distinctive in having one of the toes protruding out to the side at an odd angle.

14SE01. An owl called several times in the early dusk at Herrick Lake, south of the former youth campground. I see that this is my earliest record of territorial behavior, by about 3 weeks.

3NO01. Saw an owl, probably a male, at Herrick Lake F.P. in the forest behind a house, north of the big trail loop and south of the former youth group camp. That was in the morning. In the late afternoon, heard one hooting along the Fox River somewhere around Red Oak NC.

27SE02. While walking after a run at Herrick Lake, heard both members of the pair duetting strongly for at least 5 minutes (same area as previous 2 entries).

13FE07. At mid-day in the middle of a winter storm with heavy blowing snow, a great horned owl at Fullersburg holding a recently caught gray squirrel.

3AU08. Great horneds called for a long period, early morning, in my neighborhood. This continued into the dawn hour and overlapped with a cardinal’s singing, past 5 a.m.

21JA09. Mayslake. An elm branch, apparently broken from tree by storm, with bark being consumed by cottontails. Near there, one of the rabbits caught and consumed on the spot last night by a great horned owl (impressions of wing and tail feathers in the snow). Head, feet, a couple bones, and fur all that remain.

29JA09. Mayslake. I found where a great horned owl had walked on the frozen stream surface, heading S out of the woods, taking off before reaching the bridge. The tracks led back to a feeding site, with much cottontail fur and a bone, but no rabbit tracks. Continuing downstream 20 yards I found another area against the bank with fur and blood, and a couple great horned owl footprints again from last night, but again no rabbit tracks. On downstream another 30 yards I found yet a third such site, but again no rabbit tracks. Here there was no feeding, mainly just the impression of the rabbit in the snow. As the owl had walked a few steps before that impression, it must have had the rabbit in its beak. The owl had come from the N or NW. I searched all around but did not find a clear kill site. All of this was under trees with moderately thick brush that makes it seem unlikely the owl would carry prey in there from outside. The shift of location twice would seem to reflect a sense of vulnerability. I wonder if the owl would have removed the head and feet at the actual kill site. The body impression where it first landed on the stream ice was bloody.

Here is one of the stops made by the great horned owl described in the January 29 entry. There is an oval depression where the rabbit’s body was placed.

14FE09. Fullersburg. This year the great horned owls are nesting in last year’s Coopers hawk nest, just west of the Amphitheater. That nest has been available both the past two years, but the owls have chosen to use other hawk nests close to 31st Street in all of the previous 4 years but 1. In that year there were reports of a nest well south of the preserve, but I could not find one on the preserve.

19FE09 Mayslake. I found the great horned owl nest in a hollow willow near the west boundary of the preserve close to May’s Lake. It is not high up, and exposed thanks to the brush clearing, but facing away from the lake may limit its discovery by fishermen.

Great horned owl incubating nest in tree cavity, Mayslake, February 2009.

6MR09. Mayslake. Great horned owl is standing in the nest cavity, apparently brooding.

13MR09. Mayslake. The great horned owl nest tree snapped off at the point of the nest cavity, presumably in the wind storm 3 nights ago (gusts reached 45mph). A dead owlet at the base of the tree, none others nor adult seen, no sign of hurt adult but nest apparently abandoned (cold enough today that an adult would be brooding). There has been enough time that scavengers could have removed other young.

Dead nestling beneath storm-broken nest tree.

10DE10. Neighborhood. I heard a great horned owl calling early this morning.

27JA11. Mayslake. Great horned owl incubating on last year’s red-tailed hawk nest. It was not there yesterday.

Great horned owl incubating nest, Mayslake, January 2011.

10MR11. Mayslake. The owls have abandoned the nest. No sign of disturbance or dead nestling beneath, best guess is the eggs didn’t hatch, either infertile or perhaps the female was forced to abandon during the fierce blizzard at the beginning of February.

18MR11. Mayslake. At a bright mid-day, the great horned owl pair duetted for more than 15 minutes, the male in the west end and the female in the east end of the area 9 hilltop pines.

29MR11. Mayslake. A single hoot from GHO in pines, mid-day, the first I’ve heard since the 20th.  (In September I heard the pair duetting at Mayslake, so they remain at the preserve.)

Dead Vole Mystery

by Carl Strang

Perhaps a minute after leaving the snake I described yesterday, I encountered a small dead mammal lying on the trail.

What makes this finding of a deceased meadow vole surprising is that Mayslake Forest Preserve has no shortage of predators who include these little guys on their menu. Typically all that would be left would be bones in a raptor pellet or fur in a scat. I saw no signs of damage on the vole. Two most likely scenarios come to mind. First is that a well fed neighbor’s cat killed the vole and left it, the needle-like toenails and canines producing no obvious trace of their work. I haven’t seen any cats or their signs around lately, but I’ve known cats that were very good at staying out of sight. The other possibility is that the vole was victim of a short-tailed shrew’s poisonous bite, but some circumstance separated the shrew from its prey. Though I have no solution to this mystery, it’s enjoyable nevertheless to find such things and think about them.

Controlled Burn South Savanna

by Carl Strang

Before last week’s winds became strong, a crew conducted a controlled burn of the south savanna and an adjacent small meadow area at Mayslake Forest Preserve.

This is the first time that slope above May’s Lake has been burned, as far as I know. It was brushy beneath the oaks and other trees for 10 years, and had been a lawn before that. It was cleared of brush two Januarys ago. Enough leaf litter accumulated last fall to make the burn possible.

The fire moved slowly, consuming the litter and hopefully damaging the invasive herbs and shrubs, while apparently not harming the trees.

I like to take advantage of burns to see what they reveal. In the meadow area between the savanna and the off-leash dog area parking lot, I noted exposed vole tunnels.

There also was a little cluster of bones.

The size of the jaw bones, and their high-crowned molar pattern, revealed that they once were part of a muskrat.

This was on the side of a dry slope, too far from muskrat habitat to represent a brief terrestrial foraging trip.

My best guess is that this was a dispersing animal. Such muskrats often make long journeys over land, which exposes them to all sorts of hazards. The remaining bones revealed nothing I could read to indicate whether this animal had lost its life to a predator, disease or getting struck by a car on one of the nearby roads.

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.

Short-tailed Shrew

by Carl Strang

A few days ago I saw my first two short-tailed shrews at Mayslake Forest Preserve. Both were dead.

short-tailed shrew b

This one was in the middle of the trail. The other was in a mowed area, a few feet out from the edge of a prairie. These almost certainly were killed by coyotes. They appear to have been left as calling cards in the same way that coyotes deliberately place their scats in the centers of trails. Other coyotes coming along are sure to find them and know the area already is claimed.

I knew that short-tailed shrews were on the preserve, compliments of a great horned owl.

Owl pellet 1b

These skulls all were in a single owl pellet deposited in the center of the preserve last winter. The upper left one belonged to a short-tailed shrew. So, why would the owl eat these shrews, while the coyote leaves them after killing them? After all, if the coyote wants to use a small mammal as a marker, there are many more voles and white-footed mice, so we might expect the coyote to use them as markers, too.

Here I have no inquiry I can do myself. I must rely on what others have found. It turns out that short-tailed shrews are toxic. They have salivary poisons that help them subdue the voles that often are their prey, but some poisons are found all over their bodies. Owls, with their relatively poor taste and smell, gulp down any they kill (great horned owls also eat skunks, by the way). Coyotes are less inclined to do so. They pounce and kill a small mammal moving through the tall grass, then find it’s a shrew. Being resourceful while not wanting to eat something so vile tasting, they use it as a marker. At least, that is what I think is happening here. Another possibility is that the coyote deliberately kills the shrew with the intention of using it for communicating with other coyotes, incidentally taking out a competing predator.

Prairie Burn

by Carl Strang

 

Last week a forest preserve burn crew stopped by Mayslake and touched off the prairie. They arrived after I had left for the day, so I wasn’t able to get any action photos. The aftermath was of interest, however.

 

mayslake-burn-4b

 

Prairies are fire-adapted ecosystems. They need to be burned annually as they are being established, and regularly thereafter. The fire selectively removes or at least sets back woody plants, giving the prairie species the advantage they need. The prairie plants are not harmed, because while their dead tops from last year burn, their living roots are protected by the soil.

 

mayslake-burn-5b

 

The fire’s removal of dead plant material opens the way for the next season’s new growth, which doesn’t have to fight through all the dead stems. Also, the burn releases nutrients for the plants’ use, and the blackened soil heats quickly, lengthening their growing season. The bit of woods at the south end of the Mayslake prairie also was burned.

 

mayslake-burn-1b

 

Some types of open woodlands benefit from occasional fire. The tree leaves and dead tops of herbaceous plants on the ground burn quickly and do not harm the fire-adapted woody plants. These woodlands grow at prairie edges, where a topographic break or wetland barrier limits the frequency and intensity of fires.

 

Fires draw wildlife. As I arrived at the burn site the following morning, I was in time to see a raptor flying away, having hunted for newly exposed voles and other small rodents. The ground was filled with robins, blackbirds and starlings likewise seeking prey.

 

robin-in-burn-area-b

 

I, too, walked a zigzag route covering the burn. With the mass of obscuring vegetation out of the way, it was an opportunity to get a better idea of the contours of the ground, any hidden clues to past history, and signs of animal life. Here, for instance, are entrances to voles’ underground chambers.

 

mayslake-burn-vole-tunnels-b

 

While the blackened ground looks devastated at the moment, it soon will green with this year’s new shoots, bright with the additional nutrients, growing straight and fast thanks to the warmth of the soil and the lack of encumbering dead material.

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