Some Mayslake Migrants

by Carl Strang

This has been a good spring for migrant birds at Mayslake Forest Preserve. Some are species that nest in DuPage County, but use Mayslake only for day stops.

The savanna sparrow is one of these, though as Mayslake’s prairies continue to expand, the day may come when one or more pairs nest on the preserve.

The savanna sparrow is one of these, though as Mayslake’s prairies continue to expand, the day may come when one or more pairs nest on the preserve.

Scarlet tanagers prefer forests to Mayslake’s more open woodlands.

Scarlet tanagers prefer forests to Mayslake’s more open woodlands.

One morning my walk across the mansion grounds was arrested by a distinctive, repeated “pick-a-tuck.”

Sure enough, a summer tanager, an immature male.

Sure enough, a summer tanager, an immature male.

Summer tanagers are among the southern birds that increasingly are appearing in the Chicago region. The point of all these birds stopping for the day is illustrated in the next photo.

A Philadelphia vireo refuels.

A Philadelphia vireo refuels.

Caterpillars and other herbivorous insects start early in the season so as to take advantage of the newly opened leaves’ relative lack of defensive chemicals. The caterpillars themselves have only camouflage for defense, and birds like the vireo have sharp eyes.


Mayslake Birds Update

by Carl Strang

It has been a while since I have reported bird observations from Mayslake Forest Preserve. The neotropical migrants, including the eastern wood-pewee, have departed for their winter homes.

Pewee 2b

Wandering youngsters like this great blue heron have turned up from time to time.

GBH youngster Mayslake

Some members of this species will stick around through the winter, and some will make the attempt and fail to survive. One of the more unusual sightings at Mayslake this fall was a heron relative, an American bittern, which flushed from an unusual location in the middle of an upland meadow.

Mixed flocks of warblers and other songbirds stopped by the preserve for fuel in September, and gave way in October to birds that winter in the U.S. These included blackbirds, with large grackle flocks foraging on the mansion lawns on some days.

Grackle flock 2b

Sparrows frequented the habitats suitable for their various species. Meadows and prairies attracted song sparrows, some of which had nested there in the summer.

Song Sparrow 3b

One of the more unusual looking sparrows was this one.

Savannah Sparrow 4b

It proves to be a savanna sparrow, but with very white and high-contrasting plumage compared to most members of its species. Many white-throated and white-crowned sparrows have been refueling at the preserve as well.

The most exciting “maybe” was reported by an experienced birder who got a glimpse of a tiny black bird flying near the stream. He was not willing to commit to it, because his sighting was so brief, but Mayslake may have hosted a black rail this fall.

In the past week the latest of songbirds have been appearing, including a brown creeper, hermit thrushes, fox sparrows and dark-eyed juncos. Some of these may stay for the winter.

Mayslake Birds Update

by Carl Strang

The first week of May continued the pattern of new migrant bird species appearing while others progressed with nesting and raising young. Among the new arrivals were indigo buntings, which immediately began to establish territories through singing and bickering between neighbors.

Indigo bunting b

The week’s bird highlight for me at Mayslake was this Caspian tern.

Caspian Mayslake 2b

It stayed only briefly, but I was privileged to watch it make two spectacular vertical dives from 20-30 feet into May’s Lake. It appeared to be successful at least on the second dive, as it took a few seconds to swallow the small fish it caught.

Among the earlier arrivals were chipping sparrows, and I am confident they will nest on the mansion grounds.

Chipping Sparrow 1b

I haven’t been seeing savanna sparrows consistently yet, but there is habitat for them around the off-leash dog fence, where I photographed this individual.

Savanna sparrow b

Nesting is confirmed for song sparrow, thanks to co-steward Jacqui G.’s discovery of this nest while she removed invasive weeds.

Song sparrow nest b

The red-bellied woodpeckers claimed this tree cavity early in the season, and the male’s frequent visits with tiny tapping signals suggest to me that they have eggs under incubation.

Red-bellied at nest b

Robins also are nesting. I don’t have a photo, yet, as the first nest under incubation I found is in a dense red cedar. I found the nest only because of the way the incubating bird’s mate reacted to an approaching blue jay. Meanwhile, the single duckling of the pair I reported earlier  is getting bigger.

Mallard family 3b

I commented then on the presence of the adult male, that this is a sign of a domestic background. During the week I watched him chase off another male who approached the female, probably to attempt a forced mating. That strange male’s interference might have endangered the duckling, and may point to a positive selective pressure maintaining this particular domestic trait in our suburban ducks.

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