Pennsylvania Game News - September 2018 - 63

grounds only by stealth.
Researchers have found Lincoln's
sparrows difficult to study because of
their skulking, secretive nature.
J. Murray and Dorothy Huestis
Speirs, who studied Lincoln's sparrows from 1955 to 1957 near the north
shore of Lake Superior, noted they use
shrub growth less than 8 feet high for
concealment and singing perches for
males, and grass-carpeted openings,
heaths, or annuals less than 2 feet high
in which they can forage.
Ground surfaces might contain
brush cuttings, grass clumps, or sphagnum that the nest may be sunk into.
A female Lincoln's sparrow digs
out a small depression in the ground
and using willow bark, grasses and
dried sedges weaves a 4- by 2-inch
nest, which she lines with a thick layer
of thin, soft plant material. In it, she
lays three to five pale greenish to pinkish eggs, specked and blotched with
brown.
She incubates the eggs for 13 days.
The Speirs had difficulty locating the nest of a breeding pair they
observed, even though it was nearby.
Even joined by another couple, and
crawling on hands and knees where
they'd seen the female land twice, they
still couldn't locate it.
When a young school boy found
the nest and took them to it, it was
right where they'd looked, "set well
down into the ground under a pile of
last year's brush cuttings.
"It looked like a little black hole,"
they wrote.
When a female returns to the nest
after leaving to eat, she engages in
what ornithologists refer to as the "rodent-run."
Holding her wings against her
SEPTEMBER 2018

body, she lowers her head and breaks
through a tunnel in the vegetation,
or later, during incubation, she flaps
her wings and noisily breaks through
vegetation, especially if she is defending the nest from an intruder, such as
a short-tailed weasel, shrew, or gray
jay, all of which might prey on eggs
or nestlings.
The male remains solicitous,
guarding his mate, particularly during egg-laying. He also pitches in to
feed young as soon as they emerge
from their shells, although the female
mostly broods the helpless hatchlings
early on.
The Speirs' sparrows were fed
green caterpillars, small white moths
and young grasshoppers, but adult Lincoln's sparrows consume both insects
and small seeds in equal amounts.
Young Lincoln's sparrows mature
quickly and leave their nest at 10 to 11
days old.
Although they can't fly yet, and
spend most of their time hiding under
dense shrub cover, they often return to
nests for several nights to sleep.
They practice flying during the day
by first hopping and wing-flapping to
nearby branches, gradually making
short, and then longer flights. They
usually fly well by 18 days of age.
While much of the biology and
ecology of Lincoln's sparrows still is
unknown, their numbers seem high
during migration, so they wouldn't
seem to be in danger of disappearing.
Now that I know they visit First
Field, I look forward to seeing and
hearing their singing this fall.
To me, they are examples of wonder from the natural world, where I
can always find something new even
on familiar ground.
63
Pennsylvania Game News - September 2018

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