St. James Farm, Lately

by Carl Strang

This has been a relatively slow winter at St. James Farm Forest Preserve. There has been little snow, so my tracking has been limited. Coyotes have been covering the preserve, and the relatively few deer tracks have not revealed a consistent pattern. That in itself suggests buck group, and eventually in January I saw them: a huge buck, a good-sized but clearly subordinate forkhorn, and a newly minted buck fawn. Since that first sighting, I have spotted them twice more in widely separated parts of the preserve.

The boss buck

The boss buck

As I mentioned in an earlier post, the great horned owls’ nest tree of last winter was a casualty of the autumn’s controlled burn. My practice is to wait until mid-February to do the annual nest search. I had my inventory of candidate cavities, made last winter, but it didn’t take long to find the incubating female on last year’s red-tailed hawk nest. In a related note, I spotted a newly available candidate cavity along one of my monitoring routes. The top of an old oak recently broke off, leaving an open top of sufficient diameter that great horneds might consider it. A forest this old probably has some equilibrium of candidate cavities as old ones are lost and new ones form.

The new candidate nesting cavity

The new candidate nesting cavity

With that task out of the way, I decided to see if I could find a little nest in the area where the hooded warbler had his territory last summer. He has been a regular there in recent years, but as far as I know, no one has seen a female or young. I found that his territory has scattered bush honeysuckles and lots of Japanese barberries, bad for forest quality but probably good from the warbler’s viewpoint. Descriptions of hooded warbler nesting suggest that barberry would be an ideal platform. I didn’t find a nest, and ended the search when I found a dense thicket of barberries, with a few multiflora roses mixed in, at least 100 feet in diameter, worthy of Brer Rabbit.

 Part of the thorny tangle

Part of the thorny tangle

As I circumnavigated this patch, which is in a part of the forest with relatively dramatic surface relief, I noticed a few tipped trees whose fall had turned up rounded stones in the soil.

Rounded stones exposed by a tipped tree’s root tangle

Rounded stones exposed by a tipped tree’s root tangle

This suggests that the preserve’s forested hills may in fact be kames, places within the melting continental glacier where the meltwater piled its flow-rounded stones into mounds. St. James Farm is very close to the western edge of the Valparaiso Moraine.

 

Where There’s Smoke

by Carl Strang

Mid-November brought forest preserve district crews to St. James Farm to conduct controlled burns in the forest. These burns are a normal part of oak woodland ecology in northeastern Illinois, and they help control invasive plants. Occasionally the consequences of the burn extend beyond the brief time when the flames consume the dry leaf litter on the ground, and I noted two such incidents this time around.

Carpenter ants commonly hollow out the base of a tree as they tunnel through the dead wood at the core. If the accumulated sawdust catches a spark from the controlled burn, a slow growing smoldering coal can expand to the point where it consumes a significant amount of the remaining wood.

A victim of that phenomenon was the large white oak that harbored the great horned owl nest last winter.

A victim of that phenomenon was the large white oak that harbored the great horned owl nest last winter.

There had been a larger live stem, and a smaller dead stem (the fractured one in the photo) where the nest had been. The live stem’s base was thinned by the growing coal to the point where it went down, taking the nest stem with it.

The same burn had the remarkable effect of catching in another tree, already knocked down by a storm, which then smoldered for weeks.

Here is the tree 2.5 weeks after the burn, on December 5. The underside of the fallen stem was burning slowly from west to east, and the top of the stem protected the coal from the snowfall.

Here is the tree 2.5 weeks after the burn, on December 5. The underside of the fallen stem was burning slowly from west to east, and the top of the stem protected the coal from the snowfall.

Another heavier snowfall still did not stop the burn, here on December 12. This was a cold day, but a moderate west wind kept the coal alive.

Another heavier snowfall still did not stop the burn, here on December 12. This was a cold day, but a moderate west wind kept the coal alive.

At that point, however, the coal was no longer sheltered. When I returned on the 16th, I found the fire had gone out. It had lasted nearly a month.

 

Branched!

by Carl Strang

I wanted to minimize my disturbance of the St. James Farm great horned owls by checking their nest every other week until the young no longer needed to be brooded, then making weekly checks until branching seemed imminent. That plan quickly has become moot. As reported earlier, I first saw the young in the nest on April 21. A week later, the mother was standing watch. It was a cool day, but apparently the young were judged warm enough to be on their own.

Nothing is quite like the glare of a great horned owl who doesn’t want you around.

Nothing is quite like the glare of a great horned owl who doesn’t want you around.

Monday was the first warm sunny day in over a week, and I decided to check the nest. It was empty, and the young were high up in a nearby white oak stem.

There were two, and this was the smaller one. Its sibling was nestled in a dark shaded spot, not easily photographed.

There were two, and this was the smaller one. Its sibling was nestled in a dark shaded spot, not easily photographed.

Young great horneds leave the nest before they can fly, walking and climbing with their strong feet, often into a tree other than the nest tree. That is why their departure is called “branching” rather than “fledging.” In this case their climb was impressive, as the bark of the tree they chose appeared relatively smooth. They are growing rapidly, and it is possible this is the last week I will see them for a while. It will be easy enough to monitor them as I wish through the summer, though, as their distinctive loud screeching-whining calls will give them away in the evenings.

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 March Summary

by Carl Strang

Weather in March at St. James Farm Forest Preserve was variable, but on the whole was relatively warm with frequent rainy periods. At the beginning of the month there was a little lingering snow on the ground, and ponds were frozen, but all of this quickly was gone.

I used my old GPS unit to map my survey routes and to locate positions of previously discovered cavity trees that might harbor a great horned owl nest. One of these indeed proved to hold the nest, and the female still was present on March 25, late enough to indicate that hatched young were being brooded. Two attempts to find displaying woodcocks were unsuccessful, but during the first evening visit on March 17 I heard what I thought was a short call by a barred owl in the eastern portion of the preserve. Scott Meister reported hearing the species in the forest one evening the following week. No pileated woodpecker observations in March, but recent observations in preserves to the north along the West Branch suggest that the bird or birds seen here earlier may be wandering widely. Canada geese were down to small groups and pairs early in the month. By March 31 a nest was under incubation on the small island in the pond below the former house site.

Canada goose incubating on March 31.

Canada goose incubating on March 31.

Many killdeers were displaying in the restoration project area around the stream early in the month, but these were down to just a few individuals by month’s end. Bird activity generally increased as the season progressed, with the first cowbirds arriving March 8, a pair of hooded mergansers and 2 pairs of wood ducks present in the pond in the NW corner of the preserve for much of the month, sandhill crane flocks frequently passing overhead, a northern flicker and the first golden-crowned kinglets appearing on March 14, tree swallows on March 25, and two pairs of green-winged teals in the restored stream on March 26.

This hooded merganser pair may nest in one of the wood duck boxes at the northwest pond.

This hooded merganser pair may nest in one of the wood duck boxes at the northwest pond.

A shed antler found on March 17 in the forest near Winfield Road matched the buck photographed in the same area on November 1.

Someone found an old deer skull and propped it against a trailside tree.

Someone found an old deer skull and propped it against a trailside tree.

The first snake observed on the preserve was a midland brown snake on March 29. That same day several painted turtles were sunning in the eastern pond.

Western chorus frogs began singing on March 11, and ultimately displayed in three locations. The largest number were in the fringes of the eastern pond, and many also were in two temporary ponds in the meadow north of the entrance drive. Numbers of bullfrogs, large and small, had emerged by March 21.

One of the March 21 bullfrogs.

One of the March 21 bullfrogs.

The first butterfly of the year was a mourning cloak observed on March 21. A cabbage white appeared on March 29. The former overwinters in the adult form, the latter as a pupa. Several small brown moths were active on the forest floor on March 31. One was photographed and appears to be a tortricid, close to several similar species of Pelochrista or perhaps Eucosma.

A possible Pelochrista

A possible Pelochrista

Silver maples were blooming by March 11, and spring beauties by March 31.

Spring beauties were the first native herbaceous wildflowers to bloom at St. James Farm in 2016.

Spring beauties were the first native herbaceous wildflowers to bloom at St. James Farm in 2016.

Restoration clearing of the forest was completed by mid-March, and a new set of stakes presumably marking the new trail route was placed in the final week.

Concluding the Search

by Carl Strang

This year’s great horned owl nest search was the most intimidating I have done. There are 344 acres in the area I monitor, the portion of St. James Farm Forest Preserve that is north of Butterfield Road. A large portion of that acreage is forested, and it’s an old forest with many large trees that might harbor an owl nest. Furthermore, despite excellent restoration of the forest, a significant portion still has a difficult-to-negotiate understory dense with thorny barberries and roses mixed with way-blocking honeysuckles. Over a two-week period I went through the preserve, noting locations of candidate tree cavities and open tree tops.

One of the many possible nest cavities, large enough to hold an incubating owl that might not be visible from the ground.

One of the many possible nest cavities, large enough to hold an incubating owl that might not be visible from the ground.

Another candidate cavity. The weather often was gloomy, the limited light reducing photo quality and making it difficult to see if anything was inside.

Another candidate cavity. The weather often was gloomy, the limited light reducing photo quality and making it difficult to see if anything was inside.

There also were many old trees that had lost their tops.

There also were many old trees that had lost their tops.

Another example of a topped tree that could host a nest.

Another example of a topped tree that could host a nest.

After that initial survey, I decided to dig out my clunky old GPS unit and determine the latitude-longitude locations of all the candidate trees, while also mapping the survey routes I follow in routine monitoring work.

Here is the resulting map. I created a grid, the finest lines separated by one second of latitude or longitude. The blue dots and white lines mark my survey routes. The red dots are locations of trees that might harbor a great horned owl nest.

Here is the resulting map. I created a grid, the finest lines separated by one second of latitude or longitude. The blue dots and white lines mark my survey routes. The red dots are locations of trees that might harbor a great horned owl nest.

I was a little embarrassed by my failure to re-find 3 candidates from the descriptions in my notes. I ended up with 23 trees, and that turned out to be enough, as I saw this in one of them:

Sometimes a single feather tuft is all you get. In this case I could see part of the top of the head, too.

Sometimes a single feather tuft is all you get. In this case I could see part of the top of the head, too.

I realized that I was fortunate that this was a sunny day, and the additional ambient light made the difference. Now I look forward to following the progress of this nest. The eggs should have hatched by now.

 

SJF February Summary

by Carl Strang

Beginning in the middle of the month, I went through all of St. James Farm Forest Preserve seeking the great horned owl nest. I did not find it, but did create an inventory of 25 large tree cavities where an incubating owl might not be visible from the ground. An additional possibility would be a hawk nest in the dense top of one of the spruces. Twice I saw an owl, presumably the male if they are nesting this year, in the same north central portion of the main forest. In past observations elsewhere, the male usually perched in the vicinity of the nest. I will continue to monitor the suspect cavities, but may need to see branched young later in the season to narrow down possibilities further.

I was able to eliminate this cavity, as it was otherwise occupied.

I was able to eliminate this cavity, as it was otherwise occupied.

Some photo processing in the computer makes the raccoon easier to see.

Some photo processing in the computer makes the raccoon easier to see.

I had not seen or heard a pileated woodpecker on the preserve for more than 6 weeks (though occasionally I heard suspicious loud, spaced tapping sounds), but in the second half of February heard or saw one on three different days. The one close sighting was of a male.

The pileated’s tongue-spear in action.

The pileated’s tongue-spear in action.

American coots and large numbers of mallards were a continuing presence on the stream. For much of the month the Canada geese roosting at Blackwell frequently passed over St. James Farm in large numbers, occasionally stopping to graze the lawns and meadow areas. Geese began to break off into pairs as ponds opened up during the last third of February. Interesting bird sightings included a bald eagle flying over, and a hermit thrush on February 16. Migrating sandhill crane flocks began to pass over beginning on the 21st. A small group of white-throated sparrows in the eastern part of the main forest were the first observed on the preserve this year. The first red-winged blackbirds arrived, and eastern bluebirds became a more consistent presence in the last part of February.

This male eastern bluebird seemed to be staking a claim in a corner of the grounds adjacent to a pair of bluebird houses.

This male eastern bluebird seemed to be staking a claim in a corner of the grounds adjacent to a pair of bluebird houses.

Fox squirrels fed heavily from Norway spruce cones in the south forest, and on tree buds elsewhere. Skunk and deer activity was much as described for January. The preserve’s deer minimally are a group of 3 does, a group of 2 deer which occasionally associate with those does, and a single buck. The snow was never deep enough to discourage raccoons. A mink used a den off the south edge of the pond in the preserve’s northwest corner.

Along the way during the owl nest search I found this curiosity.

Along the way during the owl nest search I found this curiosity.

The deer pelvic bone was well gnawed by rodents.

The deer pelvic bone was well gnawed by rodents.

The bone has been on this buckthorn twig long enough for the twig to grow several long branches.

The bone has been on this buckthorn twig long enough for the twig to grow several long branches.

The large area of restoration brush clearing in the main forest was expanded greatly by District staff, generally following the route of the new trail mapped in the preserve’s master plan. Among the more interesting plants encountered during the owl nest search were two of the most massive black walnuts I have ever seen, and a prickly-stemmed greenbrier (Smilax tamnoides).

Goings On at SJF

by Carl Strang

Winter is relatively slow and quiet in places like St. James Farm Forest Preserve, but plenty still is happening. Today’s sharing will proceed north to south.

American coots have been a constant presence in the stream.

American coots have been a constant presence in the stream.

Entrance to a mink den just above the edge of the north pond.

Entrance to a mink den just above the edge of the north pond.

In mid-February I begin the search for the preserve’s great horned owl nest. I wait until then so that the incubation is thoroughly committed and my potential disturbance is minimized. This is the first time I have conducted such a search at St. James Farm. That relatively large, old forest provides a handicap.

So far, with less than a quarter of the preserve covered, I have found more than ten cavities where an incubating owl could not be seen from the ground.

So far, with less than a quarter of the preserve covered, I have found more than ten cavities where an incubating owl could not be seen from the ground.

The south forest also hosts wildlife activity.

Fox squirrels have been exploiting the abundant Norway spruce cones in the plantation.

Fox squirrels have been exploiting the abundant Norway spruce cones in the plantation.

The ground beneath those trees is littered with gleaned cone cores.

The ground beneath those trees is littered with gleaned cone cores.

The south forest receives its share of attention from bark-foraging birds like this hairy woodpecker.

The south forest receives its share of attention from bark-foraging birds like this hairy woodpecker.

Each visit to the preserve brings highlights like these.

Bark Birds Big and Small

by Carl Strang

As the season progresses, numbers of passing migrant birds at St. James Farm Forest Preserve have diminished. Residents, augmented by winter additions from the North, increasingly dominate the avian communities. Prominent among these hangers-on are the birds that forage on tree bark. Downy, hairy and red-bellied woodpeckers are year-round residents covering three body sizes and the particular foraging advantages of each. Nuthatches are still smaller, songbirds that have the ability to crawl sideways or upside down on the tree bark, finding hiding insects the woodpeckers might miss. Red-breasted nuthatches have become common in the coniferous forest this fall, while resident white-breasted nuthatches are scattered through the deciduous woodlands.

On Saturday this white-breasted nuthatch caught a harvestman that did not find a sufficiently secure bark crevice.

On Saturday this white-breasted nuthatch caught a harvestman that did not find a sufficiently secure bark crevice.

While photographing the nuthatch I heard in the distance a loud call which was entirely unexpected. Eventually my monitoring route took me into that part of the forest, and the calling resumed close by.

A pileated woodpecker!

A pileated woodpecker!

This huge bird is not one we encounter very often in DuPage County. I know of two resident pairs in the eastern half of the county. Others occasionally wander through, and this male at St. James Farm qualifies as one such traveler.

Continuing to call frequently, he actually flew closer to me. Here he cries from just above.

Continuing to call frequently, he actually flew closer to me. Here he cries from just above.

On Sunday I was in a different part of the same forest, but it was calm. I did not hear a pileated calling in the distance. I hope he moved on, rather than becoming dinner that night for the great horned owl I saw being harassed by crows not far from the woodpecker’s attention-drawing display. On the other hand, it would be nice if the pileated decided to hang around for the winter. As the largest block of old trees in the western half of DuPage County, the forest at St. James Farm is the place most likely to host our largest woodpecker species. Pileateds need lots of big old trees harboring carpenter ant colonies. In any case this was exciting, the highlight to date of my young monitoring program at St. James Farm.

Burn Season

by Carl Strang

The end of winter brings with it the prairie and savanna controlled burn season. Mayslake Forest Preserve got some of that attention, but it was more limited than the almost complete coverage of two years ago.

Only half of the north stream corridor prairie was burned, for instance.

Only half of the north stream corridor prairie was burned, for instance.

A thread of fire reached into the edge of the stream corridor woodland and ignited the tall stump which I regarded as the most likely nest site for the great horned owls last year. It continued to smolder for days.

Several feet of one side burned away, showing that the cavity had been wide open and quite deep.

Several feet of one side burned away, showing that the cavity had been wide open and quite deep.

I don’t know if any owl eggshell fragments could be found in the former base of the cavity, but it’s a moot point now as they won’t be able to use this platform again.

I don’t know if any owl eggshell fragments could be found in the former base of the cavity, but it’s a moot point now as they won’t be able to use this platform again.

It’s a moot point personally, too, as I will be retired next year and plan to shift my preserve monitoring to St. James Farm, a preserve closer to home.

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