Dark-eyed Junco Species Dossier

by Carl Strang

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

Junco, Dark-eyed

Dark-eyed junco

Dark-eyed junco

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

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

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

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

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

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

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

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

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

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

Juncos most commonly are seen on the ground.

Juncos most commonly are seen on the ground.

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

9MR89. Juncos starting to sing, Willowbrook.

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

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

24SE91. First junco of fall seen at Willowbrook.

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

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

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

11OC99. First junco arrived at Willowbrook.

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

5FE00. Juncos common along roadsides near Culver.

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

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

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

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

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

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

Osprey Species Dossier

by Carl Strang

This dossier centers on a couple days from my kayak circumnavigation of Isle Royale, when weather compelled a 2-day stay at Hay Bay. It proved to be a highlight of the trip, and I learned most of what I know from experience of moose and ospreys during that stop. Otherwise, my knowledge of ospreys consists of limited snapshots of observations.

Osprey

Osprey

Osprey

I saw ospreys regularly over the Tippecanoe River, in Indiana, in summer in my childhood and early teens, but then they declined. By 1970, ospreys had become rare enough that a sighting in fall at Hawk Lake was remarkable. Then we saw some at Assateague Island, Virginia, occasionally carrying a large fish in their talons or catching one from the water’s surface. They had large nests of sticks there and on buoys in the Eastern Shore area of Maryland.

Osprey nest on buoy, Chesapeake Bay

Osprey nest on buoy, Chesapeake Bay

4SE88. Osprey flying south along the Fox River between North Aurora and Batavia, Illinois, at Red Oak Nature Center.

18AU96. Hay Bay, Isle Royale National Park. At around 12:30 an osprey appeared, coursing over the bay at 30-50 feet of altitude. After about 5 minutes it dove from more than 30 feet and plunged into the water, catching a good-sized, silvery looking fish (appeared to be about as long as the bird’s wing width). With much effort the bird flew up to the ridgetop across the bay. Between 3 and 3:30, two ospreys hunted over the bay, one started a dive but aborted, one after the other drifted over toward the bay entrance. They returned around 4:00, one perching on a tree and calling with loud, high-pitched chirps. The other aborted several dives and completed one in the 10 minutes I watched, but caught nothing. By 5:00, water had greatly calmed in Hay Bay. An osprey with a fish landed in trees back from shore, opposite me. A few minutes later one flew over the bay while another called. At 5:30 an osprey flew over camp with a fish. By then it was clear that there were 3 individuals, one possible youngster calling while the other two hunted. One successful catch, a larger fish, was carried out of view. Those plunges are dramatic, the birds highly specialized. Try to talk politics with an osprey, it’ll just say, “What’s that got to do with catching fish with your feet?”

After catching a fish, the osprey turns it around head first for easier handling in flight.

After catching a fish, the osprey turns it around head first for easier handling in flight.

19AU96. Hay Bay. Ospreys were hunting by 7:30 a.m. Their ker-plooshing plunges are audible at some distance. I saw an osprey catch a good-sized fish. “Kibitzing” calls increased from a bird on shore, but then it flew out and I saw that it had a fish, too. Both flew toward the ridge across the bay, but carried their fish up and over it. Around 11 a.m. an osprey hunted the bay for a good 20 minutes, with few dive attempts. It hovered in place 2-3 seconds a couple of times. On the third complete plunge, it caught a fish and flew with it in the same direction that the two went earlier. Much calling by another, perched bird during the first half of that hunt. 2:00 decisions, decisions: do I watch the moose feeding or the osprey hunting? The osprey dove close enough to me that I could see how it holds its feet up by its head. A miss. They always shake water off in mid-air, a few wing beats after clearing the surface. 3:00 There are at least 4 osprey, all at the bay now. 5:00 An osprey caught a good-sized fish (half its length), and carried it in the same direction, followed by another, fishless bird. Ripples only, still, in the bay.

16AP00. Willowbrook. An osprey flew over, SW to NE, with a fish in its talons possibly caught in one of the ponds at the College of DuPage campus.

19AP01. Willowbrook. An osprey flew over with a large goldfish in its talons. I’m not sure what direction it was coming from, possibly north.

2009. Tri-County (JPP) State Park. Ospreys nested atop the very high utility pole at the boundary of this park and Pratts Wayne Woods Forest Preserve.

Osprey nest, James Pate Philip State Park

Osprey nest, James Pate Philip State Park

2009-12. In most springs an osprey has spent some time (most of a week at times) at Mayslake, perching on trees at the edges of the lakes and occasionally fishing.

Beaver Species Dossier

by Carl Strang

The species dossier idea came from my realization in the 1980’s that much of what I “knew” about wildlife came from the scientific and popular literature rather than personal experience. I went species by species, writing what I could remember about each one from memories of my own observations. Then I built the dossiers with added notes. The dossier begins with the initial paragraphs, followed by notes dated by a code that uses two-letter combinations to signify months.

Beaver

Beaver, Salt Creek at Fullersburg Woods

This aquatic rodent lives in ditches, rivers, and lakes. Observations to date have been in the Culver, Indiana, area (Maxinkuckee, Tippecanoe, Yellow River, Fish Hatchery), southern Ontario, and DuPage County, Illinois. The signs are seen much more often than the animals themselves; they are crepuscular/nocturnal for the most part, although the Canadian ones occasionally appeared in daytime, and I have seen them during the day in northern Lake Michigan and the West Branch of the DuPage River (mid-winter). Alarm signal: dives noisily, augmenting the splash with its flat tail.

Stand-alone lodge, Canada

They feed on bark and twigs of willow and other woody plants, storing large underwater piles of branches in fall for winter use. They also stripped bark from the 1-4″ diameter X 1-3′ long sticks used in building dams and lodges. The den can be in a bank or in a stand-alone built lodge. Bank dens are used in larger, deeper rivers and lakes, although built lodges also can be seen in such places. I have seen built lodges in Canada, Lake Maxinkuckee (Venetian Village), DuPage Co. (e.g., Churchill F.P.), Isle Royale. They have a distinctive appearance because of the white sticks, though some lodges on riverbanks are not rounded and so at first glance resemble piles of drift from the last flood. Mud also is used in construction. Lodges have been 8-15′ in diameter, 2-4′ high, usually on a bank.

Beaver dam, Tri-County State Park

Small streams may be dammed to create a pool (the most ambitious dam I’ve seen was on the West Branch of the DuPage River at Blackwell in mid-winter). Dams, like lodge coverings, are built of stripped sticks, mud, vegetation, usually have a slight U-shaped bend pointing downstream, and are not particularly high above the contained water level, though some on Isle Royale were taller than me on the downstream side. Very long dams can have a more sinuous shape; I’ve seen them more than 50′ long.

High beaver dam with trail, Canada

Beavers will carry branches from other bodies of water to the home pool. Cut trees are distinctive with large tooth marks and pointed (cone-shaped) ends. Beaver tracks are large, and have the rodent formula (4 toes front, 5 back), the webs of the hind feet not always making noticeable marks.

Beaver front footprint

31AU86. Beavers at Culver’s fish hatchery have reinforced the base of their dam with a heavy plastering of marl.

18DE86. Month-old beaver sign, Willowbrook Back 40: several black cherry trees had their bark chewed off on the stream side of the trunk. No others in the vicinity (willow, box elder) were damaged.

11JA87. At the mouth of Sawmill Creek, Waterfall Glen F.P., beavers this morning fed on bark of a box elder 7″ dbh, they had cut down earlier. They had made a trenchlike single path in 6″ snow between stream and trunk.

8MR87. 2 ash trees 8″dbh cut down but only some bark removed from trunk. Otherwise untouched, for months.

Beaver-felled tree, Fullersburg

28MR87. Beavers at Waterfall Glen cut three 8″ dbh bur oaks, ate much of the bark from 2 of them, in an area with much willow.

23JA88. McDowell F.P. Beavers built a long winding dam on Ferry Creek, 20-30 yards long

15MR90. McDowell. Beavers were active in the evening dark during my night hike program. We heard one chewing: identical to the sound of a squirrel gnawing a nut, and as rapid, but much louder. Several of us shined lights on it. It was on the opposite side of the river, standing up on its hind feet, against the tree. After at least 30 seconds of being illuminated, it abruptly ran into the river. It swam for another 20-30 seconds, still in lights, then walked up the bank back to the same tree, and resumed gnawing. The alarm splash is like a big rock being thrown in. I didn’t detect a tail slapping component.

13NO99. A beaver dam has been built across the very low West Branch of the DuPage River, Elsen’s Hill at the eastern horse ford.

29MR00. While running past the borrow pit at McDowell Grove Forest Preserve, I frightened a beaver into the water. It swam under the surface for 20 feet or so, a stream of bubbles revealing its position, then surfaced. Immediately it dove again, but as it did so I saw it deliberately lift its tail and slap it on the water. I could detect the sound of it, but the splash made by the posterior part of the body (spread feet?) was the louder sound. Perhaps the double sound makes it a communication for beavers, to distinguish it from other splashes.

11MR01. A beaver lodge is on the shore of the old gravel pit on Timber Ridge Forest Preserve (at the intersection of County Farm and Geneva Roads). There has been much recent gnawing of nearby woody plants.

8AP01. At around 8:30 a.m. at Red Oak Nature Center I heard a gnawing sound down near the edge of the Fox River. It was a beaver, sitting in the shallow water and feeding on the twigs of a shrub or small tree overhanging the river (intervening brush too thick to get an ID of the plant). The beaver was reaching up, biting off a branch, then consuming the twig. Less than about 3/16″ in diameter, the twig was consumed by the beaver holding it like a piece of stick candy and nibbling on it with gnawing sounds reminiscent of a squirrel working on a nut but more rapid. After 2-3 seconds of biting off the end, the beaver chewed with its molars for a few seconds, swallowed, then worked on the end some more. When the diameter of the remaining twig became greater, approaching 1/4″, the beaver turned it sideways (always holding it in the front feet) and quickly stripped off the bark.

22OC01. Beavers have been very busy in recent days at the marsh beside South Blackwell’s Heron Trail (marsh full of water thanks to heavy rains in recent weeks). They have trampled a path through the cattails all the way to Heron Trail, and have been cutting the small willows and cottonwoods into pieces, eating the bark from some of the bigger chunks, and hauling the tops into the water (drag marks visible in the mud).

6JL07. Fullersburg. A beaver swimming up the main channel along Sycamore Peninsula went to the shore at 8:30 a.m. and ate some root bark and twig bark from American elms. It continued upstream past the Visitor Center.

Palm Warbler Species Dossier

by Carl Strang

Spring emphatically is here. Seasonal milestones are being passed earlier than usual this year. Migrant birds have been coming in, so far mainly the ones that winter in the southern U.S. Migrants that wintered in the tropics are not expected to appear much before they usually do, but among the first will be the palm warbler. Therefore it’s appropriate to conclude this winter’s series of species dossiers with that songbird.

Warbler, Palm

Palm warbler

This small warbler is a frequently observed migrant, both spring and fall, wherever I have lived in Indiana, Pennsylvania, and northeast Illinois. Usually they travel in small groups (2-6). Commonly they feed on the ground, but also forage in tree canopies. They are readily recognized by their distinctive tail-wagging behavior.

26AP87. North Blackwell Forest Preserve. The song can be rendered “witch-witch-witch-witch-witch-chyer-chyer-chyer-…chee.” Very rapid and chattering. An individual observed foraging alone 3-15 feet up in saplings with leaves beginning to open. It spent most of the time perched, turning its head to look every direction, staying at a given perch 3-10 seconds. Prey were obtained mostly through hover-gleaning, with sallies mostly of 2-5 feet out from watch perches. It sang every 10-20 seconds. It also probed into leaf clusters beside its perch once in a while, but more with a drinking motion.

29AP88. Pratts Wayne Forest Preserve. A palm warbler was flycatching in a leafless tree. It also searched, with 1-4-inch hops at 1-3-second intervals, in brush near the ground. Its song was a series of “jerv-jerv-jerv” notes, slightly juicy or buzzy, 4-6 quick syllables.

30AP89. McDowell Grove Forest Preserve. Some palm warblers were performing mid-air sallies (perches achieved at 5-10 second intervals between flights, and the birds did not return after making a grab but continued to a branch straight ahead, after flights of 7-15 feet). Others were foraging on the ground, hopping on paved or graveled areas. One sang a loud song: “Der-see’, der-see’, …” fast, the first syllable barely there, much emphasis on second syllable, ~10 syllables per song, many seconds between songs.

8MY89. Last bird of migration noted.

1OC89. Hidden Lake Forest Preserve. Palm warblers were in woods at a field edge, with white-throated sparrows.

25AP99. Palm warblers were at the Morton Arboretum in an area with pine warblers and chipping sparrows.

3MY99. A palm warbler was foraging 10-15 feet up in box elder at Willowbrook, the first of the year observed there.

5MY99. McDowell Forest Preserve, afternoon. There was little bird activity, generally, except for lots of palm warblers (and yellow-rumped warblers) feeding.

15MY99. A late bird seen at Red Oak Nature Center.

1MY00. A flock of palm warblers fed on the ground in the center of the cleared prairie at Willowbrook. Some also moved into scattered trees in the prairie area.

24SE00. A couple palm warblers were at the Sparrow Hedge, Fermilab.

20OC01. Blackwell, McKee Marsh. A palm warbler gave call notes similar to those of a yellow-rump.

12OC02. Several palm warblers were at Fermilab in old field areas.

28AP08. Fullersburg. A palm warbler was giving a call note similar to the distinctive one of the yellow-rump, though possibly higher in pitch.

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.)

Wood Duck Dossier

by Carl Strang

I established my vertebrate species dossiers in the 1980’s as an antidote to relying too heavily on the scientific literature and the stories of others for my natural history knowledge. I wrote everything I could remember about each species from personal experience, which generally was embarrassingly little. Then I began to add notes as I made new observations to beef out the files. Each subsequent entry begins with my date code: the day of the month, two-letter month code, and year.

The male wood duck is one of our most beautiful birds.

Duck, Wood

 These are common around Culver, Indiana, in the Lafayette area, and in DuPage County. They nest in tree cavities, and commonly roost in trees. Wood ducks feed on land and in shallow water. The female has a loud squealing call that rises in pitch: “Coo-ah-lee”. The downy young are more cream colored than those of mallards, and lack the black stripe between eye and bill. They stay with their mother at rivers or wooded ponds. In flight, the wood duck appears dark, with a long tail and very narrow white rear edges of wings.

My experience with wood ducks began early. Here I’m 18 months old. We didn’t hunt wood ducks often, focusing more on other species, but a mounted one shot by my grandfather occupied a prominent place in the home.

 18AP87. A pair landed on elevated oak limbs (2 trees near one another) at the edge of woods between Mack Road and McKee Marsh, Blackwell Forest Preserve. One duck immediately took off, the other disappeared. Its tree has several holes about 30 feet up which could be nest entrances, and is 100m from the edge of the marsh.

26JL87. A mother with at least 3 half-grown young swimming out on Hawk Lake near Culver.

4AP99. First of year arrived, DuPage County, IL.

22AP00. Male spotted standing on high tree branch near East Woods Trail, Morton Arboretum. The tree was near the edge of a clearing with a wet area. He was uttering a faint, rising, zipping-whistling note, and occasionally throwing his head straight back until the beak pointed straight up momentarily before the head quickly returned to the neutral position. The female, who had been several trees away, came into view after I had been watching the male a few minutes. He seemed to be watching me, too, and it is possible the display was a displacement behavior.

23AP00. Red Oak Nature Center. Here beside the Fox River, there are lots of wood ducks this morning. One pair behaved much like yesterday. The male and female were perched in adjacent trees, the male higher than female. He did the same call and display as before, both birds watching me, then they flew off (female flew first, followed by male).

26FE01. The first wood ducks of the year were a group of 4 on the West Branch of the DuPage River at McDowell Forest Preserve. At least 1 bird of each gender was in the group. They were in a smaller stream going around one of the islands, but went to the main river (which is very high) after I flushed them.

3NO01. About 10 wood ducks were in a woodland pond at Herrick Lake, north of the big trail loop and south of the former youth group camp. Many mallards also were there.

20JL02. A mother wood duck with around 8 newly hatched ducklings were swimming off the west end of Culver’s Town Park in the early afternoon in the midst of Lakefest, with speedboats all around and one nearly running them over. Brice [my youngest nephew, now a student at Virginia Tech] and I were in kayaks going past. He was fine with going out to rescue them. We tried to stay far enough off to avoid alarming the mother too much, but it was necessary to stay closer than I would have liked, to keep the speedboats off them. Gradually we herded them in closer to shore and eastward, until finally she was 50 yards or so off a stretch of shore free of humans. She led her ducklings in, and they climbed up on shore. She had been trying to go west, toward town, and out farther from shore, but with the crowds and boats, I don’t see how the ducklings would have survived.

6MR09. Mayslake. First wood ducks of the year (2 pairs).

17MR10. Mayslake. First wood duck of the year (single female).

Last fall, Mayslake Forest Preserve’s stream corridor marsh hosted large numbers of wood ducks, often 30-40 at a time.

15MR11. Mayslake. First wood duck of the year (single male).

Fox River Goose Check

by Carl Strang

I have not had much time to check Canada goose roosts in DuPage County this winter. On the surface, at least, it appears that the pattern of recent years has been repeated, with severe cold freezing up most of the roosts in December (Hidden Lake exceptional) and pushing most geese out of the county. On New Year’s Day I found the Blackwell and McDowell roosts still empty despite being newly re-opened by a thaw. Remembering my observations at the Fox River last year, I drove out there on the morning of the 2nd. I found no large roosts, but there were numbers of geese in smaller groups along the river’s edge. At Red Oak Nature Center, a couple hundred birds could be seen.

Canada geese rest on ice at the edge of the Fox River while floes pass on a cold morning.

I was impressed by common mergansers as they dodged the newly formed ice floes and dove after fish in the frigid river.

Common mergansers stay close to the edge of open water in winter.

Another place I found geese both last year and this was at Glenwood Park Forest Preserve just south of Batavia.

Several hundred geese lined the shore across from Glenwood Park Forest Preserve.

People have been reporting bald eagles along the Fox River all winter, so it was invigorating, if not surprising, to have one perch nearby as I surveyed the geese.

One of the more positive developments of recent decades has been the increase in bald eagle numbers.

As far as I can tell, these geese are feeding mainly in Kane County, and so I am limited in what I can learn in DuPage for now.

Fox River Geese

by Carl Strang

As I have monitored the comings and goings of Canada geese in DuPage County over the past two winters, I have assumed that when deep snow and frozen roosting areas force birds out of the county they have been heading south to warmer locations in downstate Illinois. This assumption has been supported at times by observations I have made and reports on IBET (the Illinois birding e-mail list) of high-flying flocks of southbound geese. In the back of my mind, however, has been the possibility that some of the departing birds may not be going all that far, perhaps taking temporary roosting spots along the Des Plaines River or the Fox. Last Sunday morning I decided to check out reports of large numbers of geese roosting on the Fox River west of DuPage County. I made stops along the stretch of river closest to the Blackwell roost, because of the possibility I might spot either the leucistic bird or a numbered orange neck collar belonging to a recognizable individual.

I found thousands of geese roosting along the Fox between Fabyan Park (south Geneva) and the north part of the city of Aurora. There were scattered small groups like the one shown above, but also some enormous ones. Here is a fairly large group opposite the Red Oak Nature Center.

Just downstream from that group was a larger one.

Largest of all was a roosting group on an ice shelf just above the North Aurora dam.

Though I didn’t spot any recognizable individuals, I plan to return from time to time in the future. I couldn’t see every part of that stretch of river, and I also want to gain some sense of how the number dynamics along the river correspond (or not) to those in DuPage roosts I have been following.

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