Birds in Transition

by Carl Strang

Soon the first wave of birds that overwintered in the tropics will reach northern Illinois. April has brought a transition from wintry weather to the warmth, plant growth and insects that make the trip worthwhile for the many species whose ancestors were content with tropical conditions.

For most of the month we see birds that are year-round residents or are newly arrived from their wintering grounds in the southern states. They have to deal with the season’s variability, though. Early in April a cold spell brought a thin snowfall. There still were insects to be found, but they were on or close to the ground. A selection of species foraged on the banks of the stream at St. James Farm Forest Preserve.

These included an eastern bluebird that abandoned his practice of hunting from tree branches, and shifted to hopping around in the open.

These included an eastern bluebird that abandoned his practice of hunting from tree branches, and shifted to hopping around in the open.

The preserve’s first yellow-rumped warbler of the year also searched for prey there, though such bank foraging is a common practice for that versatile species.

The preserve’s first yellow-rumped warbler of the year also searched for prey there, though such bank foraging is a common practice for that versatile species.

Even an eastern phoebe was forced to a ground-foraging interval.

Even an eastern phoebe was forced to a ground-foraging interval.

On other days, getting set for the nesting season was a priority.

Cooper’s hawks occasionally called in wooded areas, considering whether to nest at St. James Farm.

Cooper’s hawks occasionally called in wooded areas, considering whether to nest at St. James Farm.

Song sparrows sang as they began to sort out their territories.

Song sparrows sang as they began to sort out their territories.

Cardinals have been singing since January, as they are the songbirds most sensitive to day length change.

Cardinals have been singing since January, as they are the songbirds most sensitive to day length change.

Pairs of hooded mergansers hung out on ponds where there are wood duck boxes.

Pairs of hooded mergansers hung out on ponds where there are nest boxes.

The preserve’s red-tailed hawks completed their nest and were good to go.

The preserve’s red-tailed hawks completed their nest and were good to go.

A second pair of geese chose St. James Farm for nesting, but their site is a risky ridge beside the stream, with water on each side but reachable from either end by a coyote.

A second pair of geese chose St. James Farm for nesting, but their site is a risky ridge beside the stream, with water on each side but reachable from either end by a coyote.

April 21 was warm enough that the great horned owl young did not need brooding. This was my first look, and I could not be certain there was more than one.

April 21 was warm enough that the great horned owl young did not need brooding. This was my first look, and I could not be certain there was more than one baby.

And now, with the warm days forecast ahead, the big push of migrants soon will diversify the preserve’s avian picture.

 

SJF Miscellany

by Carl Strang

There has been a gradual buildup of photos from my monitoring excursions at St. James Farm, and it’s time to empty the bin. Some are pictures of birds.

Ruby-crowned kinglets have been common migrants around the forest edges.

Ruby-crowned kinglets have been common migrants around the forest edges.

A pair of adult red-tailed hawks frequently patrols the sky overhead.

A pair of adult red-tailed hawks frequently patrols the sky.

This juvenile red-tail was tolerated or unnoticed by the residents as it perched near the preserve’s boundary on Sunday.

This juvenile red-tail was tolerated or unnoticed by the residents as it perched near the preserve’s boundary on Sunday.

These young red-tails often are naïve and approachable. This was one of the first photos I took, from just a few yards away. I had to back off to get the entire bird in the frame for the previous photo.

These young red-tails often are naïve and approachable. This was one of the first photos I took, from just a few yards away. I had to back off to get the entire bird in the frame for the previous photo.

Proper awareness in monitoring includes looking in all directions and all size scales.

A small mushroom and moss growing on a fallen log.

A small mushroom and moss growing on a fallen log.

Elsewhere on the same log, a raccoon left a record of its passing. Its five toenails left characteristically spaced scratches when it leaped up to the log. It did not gain purchase here, so either fell back to the ground or otherwise had enough momentum and grip to gain the log.

Elsewhere on the same log, a raccoon left a record of its passing. Its five toenails left characteristically spaced scratches when it leaped up to the log. It did not gain purchase here, so either fell back to the ground or otherwise had enough momentum and grip to gain the log.

Building the story of a preserve also means looking for clues to the landscape’s human history.

These corroding pieces of metal slowly are being engulfed by the continued growth of this tree. They are 30 feet above the ground. At some point I hope to learn the story here.

These corroding pieces of metal slowly are being engulfed by the continued growth of this tree. They are 30 feet above the ground. At some point I hope to learn the story here.

Accumulating experiences of an area’s beauty and blemishes leads to an internal transformation: falling in love with a place.

 

Gray Squirrel Species Dossier

by Carl Strang

For several winters, now, I have been sharing my notes on various species of our vertebrate wildlife. The main idea is to step away from the literature and other second-hand sources, and document what I know about each species from my own observations. At last I have reached the end of the list of dossiers which contain enough information to post here. There may be more in the future, as I add to the limited notes presently in unshared dossiers, but this will be the last for a while. I hope the main point has been clear: to remind you, as well as myself, to pay attention and learn from experience rather than rely on the sometimes limited or misleading second-hand reports (I shouldn’t need to point out that from your perspective, this dossier is itself a second-hand report!)

Squirrel, Gray

Gray squirrel

Gray squirrel

This species is more typical of larger forests and cities. Its relative the fox squirrel is the savanna and small woodlot species, though both can occur together (this one is not found around Culver, Indiana, however). Many notes from the fox squirrel dossier also apply to this one.

27JL77. Gray squirrels fed on unripe red oak acorns at Reineman Sanctuary, Perry County, Pennsylvania. The next day, one was eating Nyssa (black gum) seeds (discarding the fruit).

29JE86. One gray squirrel foraging on the ground in an old pine plantation at Waterfall Glen Forest Preserve, DuPage County, IL. It moved slowly (diagonal walk), nose to the ground, sometimes pushing the nose beneath the litter and walking several inches with the face thus submerged. Stopped and ate 3 small objects. Later investigation of the site revealed small oval shells with tough skins, possibly coccoons, flattened ovals viewed from side with a circular cross section, with one end neatly removed and empty inside.

20OC86. Squirrels in dense brushy old field of Willowbrook Back 40. Sounds, when alarmed, like 2-3 steps or jumps, the last louder, then quiet. Is squirrel getting to bigger shrub or a tree, jumping onto trunk then freezing and watching?

23FE87. Much renewal of nut-digging (removal) past few days (and continued next 10 days or so).

28FE87. Wayne Grove Forest Preserve. Gray squirrel stuffing itself with American elm buds in top of 8″dbh tree. Later another, also in a 5″dbh American elm. Much recent excavation of buried nuts. A third individual ate a few black cherry buds.

6MR87. Squirrel high in a black willow, cutting twigs 4-12 inches long and carrying them one at a time to the top of a major 3-branch crotch high in the tree, where it was stuffing or sewing them into a mass of them.

7AP87. A gray squirrel on the ground responded to chipmunk’s chip-trill at my approach, jumping onto low branch and looking alert.

28SE87. Lots of them on the ground in Willowbrook old field. Old and young of year, both.

23JA88. McDowell Forest Preserve. Gray squirrel dug up shallowly buried hickory nut, cutting a 1.5′-tall elm to get face in close for leverage in digging. Carried nut into tree, spent about 4-5 minutes consuming it, then ate snow off top of branch it was sitting on (about 1′ worth, a powdery, thin 0.5″ wide), went down tree and continued. Paused and looked back at me.

20MR88. A gray squirrel at Meacham Grove gathering dry leaves from ground, stuffing them into its mouth with its paws then taking them into cavity nest up in old white oak. Also gathering from among the few leaves still attached to the tree itself.

10AP88. Touched a squirrel at Hidden Lake Forest Preserve (tips of his tail hairs as he “hid” on the other side of a tree trunk barely too big for him to look around).

17AU88. A chase between squirrels, apparently not play. Gray squirrel pursuing a larger fox squirrel, which jumped out of trees twice from 15-20 feet up, landing hard, to escape (in the second jump it leaped out, seemed to sail a bit, and its fall was partly broken by a small shrub). The fox squirrel uttered a harsh call, short and sharp, like part of a mobbing call, on 2 occasions. There was an un-play-like seriousness about the pursuer.

27MY89. Young gray squirrels very curious, approach when you hold still (yesterday in the park at the Newberry Library in Chicago, today in Maple Grove Forest Preserve). They have a buzzing call, precursor of the adult’s bark.

22JE89. 2 gray squirrels eating red (not quite ripe) mulberries at Willowbrook. The berries began to ripen the previous weeks, so many other ripe ones were available.

29AU89. Many twig ends, some more than 1 foot long, cut from a sugar maple in Back Yards exhibit by Sciurus sp. The twigs were laden with developing new seeds, but only a few of these were eaten. Happened in last 24 hours (lawn mowed yesterday). No nest visible in nearby trees, and this tree 25 feet from edge of lawn, similar distance from nearest other tree.

3SE89. Gray squirrel youngster (from spring litter) passing through yard, east to west (not a neighborhood where squirrels lived).

20MR90. Gray squirrel chased fox squirrel away from Willowbrook crow cage area, then came back (note: squirrels often enter Willowbrook cages to take food from dishes. A squirrel nest has been found in the bullwinkle in that cage).

22AP90. Winfield Mounds Forest Preserve. 2 gray squirrels eating enlarged cottonwood buds high in the tree. They ascended together, the larger almost seeming to pursue, certainly to follow, the smaller. The smaller climbed in 2-foot spurts, the larger following, beginning its move as soon as the smaller’s ended. Larger flicked tail in rippling pattern reminiscent of fish or salamander courtship. The smaller may have done so once or twice, but less forcefully. Slow and deliberate, not a rapid play chase. When they were high up, it appeared the smaller would leap to another branch to escape. Larger broke off chase, and they fed. Didn’t take every bud, examined many without taking. Later, larger followed smaller to ground, then up another tree, same way. Larger sometimes sniffed where smaller had been. Larger got ahead of smaller and turned to face it, flicking tail. Smaller turned away. Etc.

1JL90. Gray squirrel in mulberry tree, feeding on ripe berries, West DuPage Woods.

26JA92. Hidden Lake Forest Preserve. Lots of nut digging by squirrels, last 24 hours. Fresh snow, overnight low 20F.

21SE97. Gray squirrel eating gilled mushroom cap, Petoskey State Park, MI. Both gray and black individuals common. One chased by red squirrel briefly.

4MR99. At mid-day a gray squirrel emerged from a hole in a large, dead willow across from the Safari Trail/Glen Crest Creek junction at Willowbrook to drive away an approaching fox squirrel. The gray immediately returned to the hole.

27OC99. Fox and gray squirrels active. Former have been eating nuts in recent days, one this morning in a box elder eating seeds, another appearing to work on a broken down old nest. Gray squirrels on ground this morning, some in woods, at least one in base of savanna finger at Willowbrook.

28OC99. Gray squirrel with nut, fox squirrel eating box elder seeds.

17NO99. A gray squirrel (young) and a fox squirrel both eating box elder seeds at Willowbrook.

2DE99. Several gray squirrels and 1 fox squirrel foraging on ground.

9FE00. Gray squirrel using an exposed (though low) leaf nest at Willowbrook.

14FE00. Many gray and fox squirrels this winter in nests only 12‑14 inches outer diameter at Willowbrook.

4MR00. A gray and 2 fox squirrels feeding on the expanding buds of an American elm near the Joy Path of Morton Arboretum. As I left the path to approach the tree to ID it, the gray squirrel immediately left and ran to other trees. As I walked up to the trunk, the lower of the fox squirrels finally left, but the higher one remained.

15MR00. Willowbrook. A gray squirrel carrying a walnut, in vicinity of trail willow den (have seen a squirrel eating a walnut near there recently).

11JE00. In a morning’s hiking south of Langlade, WI, 1 gray squirrel seen.

21OC05. Willowbrook. Gray squirrel, tail curled over its head, giving its growling-snarling-whining call with an education raptor volunteer holding a red-tailed hawk on a glove nearby. Squirrel holding still, oriented so that its right side is toward the hawk.

25JA06. Fullersburg. 2 pairs gray squirrels chasing one another, probably courtship.

10JL06. Gray squirrel eating ripening hackberries, Fullersburg’s Willow Island.

5OC10. Mayslake. A fox squirrel chased a gray squirrel on the ground in the south savanna.

Mayslake Bird Action

by Carl Strang

Bird news, like the spring, has been slow in coming to Mayslake Forest Preserve this year. One of our earliest migrants to appear is the red-winged blackbird.

The males usually show up in February, but they did not arrive at Mayslake until well into March this year.

The males usually show up in February, but they did not arrive at Mayslake until well into March this year.

A safe bet was that the large muskrat lodge that sheltered a couple of the rodents through the winter in the center of the parking lot marsh would have a goose nest on it this spring.

This location should be secure from coyotes.

This location should be secure from coyotes.

A week later it was empty, a basking spot for a large snapping turtle. I do not know when incubation began, and so cannot give a likelihood that the nest was successful.

A week later it was empty, a basking spot for a large snapping turtle. I do not know when incubation began, and so cannot give a likelihood that the nest was successful.

A single red-tailed hawk has been hunting the preserve. Its mate no doubt is on a nest somewhere, but if it’s at Mayslake I haven’t found it, yet.

Keeping an eye on things

Keeping an eye on things

Residents, like the downy woodpecker, no longer are keeping the quiet low profile they maintained through the winter.

This one checks out a staghorn sumac stem in the north savanna.

This one checks out a staghorn sumac stem in the north savanna.

Another resident, a white-breasted nuthatch, pauses between bouts of courtship.

Another resident, a white-breasted nuthatch, pauses between bouts of courtship.

The later early-season migrants were abundant last week.

Yellow-rumped warblers actively foraged in Mayslake’s woodlands.

Yellow-rumped warblers actively foraged in Mayslake’s woodlands.

Soon we can expect the floodgates to open and the air will be filled with diverse migrants’ songs.

Still Winter at Mayslake

by Carl Strang

The calendar claims that spring has arrived, but it’s still winter at Mayslake. A while back I mentioned my 6 seasons framework for northeast Illinois. The first of March brings the start of our sixth season, Late Winter. I once held too rigidly to the idea that Late Winter ends in mid-April, but especially after last year I feel the need to modify the framework and acknowledge that this season is variable in length. I have an idea of how to mark the end of Late Winter, which I will share later. For now, it is shaping up to be a relatively late spring. Consider the lake ice at Mayslake Forest Preserve. This year the ice was thick enough to support people, though few took advantage of the opportunity.

Forest Preserve District rangers placed these fish structures out on the Mays’ Lake ice early in March.

Forest Preserve District rangers placed these fish structures out on the Mays’ Lake ice early in March.

In my previous 4 springs at Mayslake, the latest there was ice on the lakes was March 18. This year it has been slow to depart.

Mays’ Lake was almost entirely ice covered on March 13.

Mays’ Lake was almost entirely ice covered on March 13.

By March 19 the fish structures had sunk, but the lake still was largely in ice. The previous late date for lake ice in my 5 years at Mayslake was March 18. The ice still was there through yesterday (the 21st).

By March 19 the fish structures had sunk, but the lake still was largely in ice. The previous late date for lake ice in my 5 years at Mayslake was March 18. The ice still was there through yesterday (the 21st).

Meanwhile the stream corridor marsh, though open and frozen in turns, has filled to capacity and beyond.

The marsh on March 6.

The marsh on March 6.

Snows have allowed the continued opportunity for tracking.

A mink has been passing through the preserve on a weekly basis.

A mink has been passing through the preserve on a weekly basis.

A pair of coyotes has been a more regular presence on the preserve as well, as have red-tailed hawks. I am thinking I should soon conduct a search for a new den and a new nest, respectively. It has become clear, though, that if the great horned owls are nesting this year, they are off the preserve to the south.

Mourning Dove Species Dossier

by Carl Strang

This week’s species dossier features a bird that is familiar and common. Over the course of my developing this dossier (established in the mid-1980’s) there seems to have been a change, with mourning doves wintering this far north with increasing frequency.

Dove, Mourning

Mourning dove

Mourning dove

Mourning doves usually live in open areas with some trees. In winter, they sometimes roost in thick evergreen plantations. They feed on the ground, picking up seeds. Nesting begins early in spring (March), with adults’ walking around, picking up sticks the first sign. Usually the first nest is in the branches of a conifer; subsequent nests may be in deciduous trees. The nest is a flimsy, loose platform of sticks. Two eggs almost always complete the clutch. Both adults incubate; early morning is a common switching time. The call is a mournful “cooweeoo, coo, coo-coo” (“bachelor song,” after literature). They produce a loud whistling of wings in flight. Generally they are not seen in northeast Illinois in winter, though occasional adults stick it out around feeders in Culver, Indiana. (Some were present all winter of 1998-9 at Willowbrook). There is a distinctive pumping of the head while walking. Mourning doves were very common in Texas, in brushlands, mountains and desert.

Mourning dove fledglings. This species lays 2 eggs per clutch.

Mourning dove fledglings. This species lays 2 eggs per clutch.

Late MY90, Hartz Lake. A mourning dove singing his bachelor song low in a tree flew off in a startle as a female sharp-shin landed in the same tree. The dove stayed within tree canopies as it flew.

27JA97. Morning. Snow fairly deep. A red-tailed hawk flew over the College of DuPage parking lot with something in its talons, pursued by half a dozen crows. The hawk perched on a flat-topped, wooden light pole and began plucking prey while crows sporadically left nearby perches and swooped at it. After 10-15 minutes it flew away, and I checked the feathers, which were scattered in singles and small clumps over a 20×30 foot area: mourning dove. Crow calls resembled owl mobbing, but smaller number of birds and less sustained.

MODO DE 3b

11MR99. First “bachelor calls” of the season at Willowbrook.

31OC01. At least 20 mourning doves, more than I have seen together in months in northeast Illinois, at a savanna area in the Nelson Lake property, Kane Co.

MODO DE 1b

18FE05. First bachelor calls of the season, Winfield Mounds.

Mourning dove incubating its nest

Mourning dove incubating its nest

30MR09. Mayslake. A pair of mourning doves has a nest in a spruce in front of the mansion. (This nest later was abandoned, possibly because of the heavy human traffic that was passing close by).

Red-tailed Hawk Species Dossier

by Carl Strang

I have heard reports that red-tailed hawks are starting to carry sticks, and March is the month when they begin to nest in DuPage County, so today I am sharing my species dossier on that raptor. As usual, the rule is that the dossier is limited to what I have observed personally rather than second-hand reports or through the literature.

Hawk, Red-tailed

Red-tailed hawk

This hawk is common in the eastern U.S. They nest in treetops in woodlots, sometimes on utility poles, and forage over nearby fields, soaring, or perching on trees or poles. Unless winter weather is severe, they remain all year round.

28MR87. Hawk carried a snake by the head, body dangling beneath, to treetop.

16JA88. McDowell. A great horned owl flew to a 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.

1MY88. Call a wheezing “preeyarrrr.”

7FE89. A red-tail “visited” Willowbrook’s outdoor animal exhibit. The captive red-tails called, caged crows gave short, uninflected (flat) caws with somewhat sharp beginnings but open ends. These were fairly rapid, but not chattering, and not clearly strung together.

Soaring red-tails usually seem to be patrolling territory rather than hunting.

12JA92. Hidden Lake Forest Preserve. A soaring red-tail gave the k-yer call, over woods. Moments later a second passed over, going in the same direction. Is that call given only when another hawk is in sight?

2DE95. West DuPage Woods. A red-tail called frequently. After 10 minutes I saw a second one, also flying. It seems likely that if one calls, another is in its view.

27JA97. Morning. Snow fairly deep. A red-tail flew over the College of DuPage parking lot with something in its talons, pursued by half a dozen crows. The hawk perched on a flat-topped, wooden light pole, and began plucking its prey while crows sporadically left nearby perches and swooped at it. After 10-15 minutes the hawk flew away, and I checked the feathers, which were scattered in singles and small clumps over a 20×30-foot area: mourning dove. The crow calls resembled the ones they use in owl mobbing, but there were fewer birds and the mobbing was less sustained.

Red-tail fledgling at Mayslake, July 2011.

9DE99. Crows pursued a red-tailed hawk in the northeast part of Willowbrook preserve.

18JL00. Willowbrook. In the early afternoon, a Cooper’s hawk soared low above the marsh and areas east and west of it, while 3 red‑tails soared high. One of the visiting red‑tails called once, but the Cooper’s, which has been resident all summer, called repeatedly.

22AU04. Canadian side of Lake Superior. On a driving journey around the lake I passed through an area where there had been a big fire, and saw there both the first kestrel and the first red-tail of the trip, showing them to be associated with relatively early successional, extensive areas in this part of the northern forest.

20NO09. Mayslake. A pair of adult red-tails circled the west end of the savanna calling frequently, and a third call was coming from within the canopy. Eventually one of the adults flushed out a young red-tail, perched in one of the oaks, and it flew low out of the savanna and south across the lake. This could be the same bird that was perched near the dog parking lot yesterday. Clearly this was a defense of winter territory by the pair. It was not clear whether the young bird called, or whether that was mimicry by a blue jay that was nearby. Last winter a pair of adult red-tails stayed around Mayslake the entire season. They seemed to be investigating nesting possibilities, but ultimately vanished for the summer.

The 2010 red-tail nest at Mayslake

16MR10. A red-tail pair is building a nest at Mayslake, in the stream corridor woods adjacent to the parking lot marsh. They carried small sticks in their beaks while flying. (This pair fledged one youngster from this nest, and it stayed around the mansion grounds area for some weeks in the summer, calling loudly and frequently. In 2011 they did not nest on the preserve; their 2010 nest was used by the great horned owl pair. Apparently they nested nearby, however, as a fledgling came onto the preserve occasionally in the summer, and displayed the same loud calling behavior. The pair has been present on the preserve through February of this year, and I will be watching for nesting activity.)

The noisy fledgling from 2010

19JA11. Mayslake. A red-tail flushed from one of the trees near the chapel was carrying a dead gray squirrel and accompanied by its mate. They flew toward the S stream corridor.

Great Horned…On Watch?

by Carl Strang

For over a decade, now, one of my February rituals is to search for the great horned owl nest on whichever forest preserve I am stationed. It started at Willowbrook in 1999 when I saw a single feather tuft in an old willow cavity that gave away the incubating bird. The search in later years shifted to Fullersburg Woods, a much larger preserve but not so large as to contain more than one pair. Great horneds are big enough, and sufficiently constrained in their choices (either a large tree cavity or a previous year’s hawk nest), that with some experience and knowledge of the area one usually can find the local nest.

In recent years I have followed the tragic story of the pair at Mayslake Forest Preserve. The first winter I was there, they nested in a large cavity in a dead willow. A March storm snapped off the tree at the nest cavity, killing the young. The next winter they either nested off preserve or skipped a year. In any case there were no youngsters screeching their feed-me calls that summer. Last year they tried a red-tailed hawk nest, starting incubation just a few days before the “snowmageddon” blizzard that apparently drove the female off the nest and killed the eggs, for they did not hatch.

This year was not promising. I heard the owls duetting in October, but the only sign of them on the preserve after that was a killed duck in December. Nevertheless, I searched. And one day last week, I saw an owl.

The bird looked small, like a male.

He was perched not far from two tree cavities that might be big enough to hold a nest. The closest, in fact, I knew had been a raccoon den a couple springs before. The problem is that both cavities are too deep to look into. I will have to hope that, if one contains a nest, the growing young will force the brooding mother high enough for me to see one of those telltale feather tufts. In any case, I hope that this year they succeed. It would be nice to have some young owls to watch this summer.

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.)

Starling Species Dossier

by Carl Strang

The European starling was one of the species that prompted me to begin my species dossiers. The first short paragraph contained everything I could say I knew about the species from personal experience when I set up the dossiers in 1985-86. It was embarrassing, and prompted me to pay more attention. Notes added later begin with date codes.

Starling

Starlings usually are associated with human structures.

A year-round resident throughout Indiana and Illinois, as well as southern Pennsylvania. Usually they are seen around human constructs, nesting in buildings, street lights, etc. They also nest in tree cavities and bird houses, even in open woods well away from people. In late winter they become vocal, mixing squeaky “querk” and “joo” notes with mimicries that are realistic but low in volume. Frequently they perch in and around tops of chimneys on cold winter days. Their plumage adds abundant white spots to feather tips in winter. Observations of a nest in a hollow catalpa on the Purdue campus, spring 1976, impressed me with the frequency of feeding trips and the domination of the diet with large caterpillars. They forage mostly on the ground in short grass. The young are very noisy, especially when a parent returns with food. Eggs are pale blue. The young are a uniform gray in color, forming into flocks of their own after leaving their parents. In fall, starlings often form large flocks, sometimes mixed with assorted blackbirds.

15JE86. A pair of starlings chased a broad-winged hawk in Maple Grove. It had paused briefly in the tree where they were, but I could not see if it carried anything. They uttered rattling calls throughout.

Starlings mobbing red-tailed hawk at Mayslake.

29MR87. Starlings on a road after rain, apparently eating worms.

6AP87. Starling at Willowbrook mimicking spotted sandpiper.

14MY87. Bird on horizontal branch of dead tree performing a display: bill pointed up, neck only stretched a little, wings lowered and fluttering more or less in coordination with a continuous calling, a mix of rattles, whistles and gurgles that continued for over a minute.

5MR88. Starlings imitating pewees, McKee Marsh.

21MR88. Starlings imitating purple martins, Willowbrook.

2MY88. Gathering nest material.

5MY88. First thin, high begging cries heard from a nest.

Older starling nestlings.

6JE88. First independent starling youngster seen, and the harsh “jeer” begging notes are not nearly as ubiquitous as during the past 10 or so days. First brood done.

4AU88. Youngster (independent) in Willowbrook Back 40 eating fruit from black cherry tree, spitting out seeds.

22MR89. Starling at Willowbrook loudly and accurately imitating the sound of a squirrel chewing on a nut.

24MR89. At Winfield Mounds Forest Preserve, starling imitations of nighthawk, meadowlark.

4JL89. Second brood of starling young chattering in nests, Myers Grove, near Jeffersonville, Indiana.

Starling pauses during a frigid mid-winter bath.

24JA90. Extended (at least 2 minutes) fight between starlings. They locked bills and beat one another with their wings, each trying to force the other onto its back. When beak grip lost, they sought it again. Finally one broke free and flew away. The other flew up to the top of an adjacent building and sang, with slight lifting of wings at 1-2-second intervals.

1NO99. Starlings mimicking killdeers at Willowbrook.

30JL00. Large flock of starlings, many or most of them immature, in trees on south side of McKee Marsh.

Starling flock on an early December morning.

9MR01. On 3 occasions this week, I have seen an interesting reaction by the flock of starlings hanging around the outdoor cages at Willowbrook to a hawk passing through. On 3 different days there were low flying hawks, an adult red-tail, a Cooper’s, and a young red-tail. Each time, the starlings all took off and flew in a tight flock. At first it reminded me of a mobbing flight, or a shielding as the red-necked phalaropes do, but soon it became clear that the flock was not pacing the hawk but adopting a course oblique to its path. The remarkable features were the flock’s tightness, which was a little greater and with no outliers in contrast to the usual, and the coincidence in their taking flight with the arrival of the hawk. They landed as soon as the hawk was gone.

1JA02. Starlings at the Morton Arboretum are feeding heavily on a bumper crop of red cedar fruit.

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