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Species Accounts
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Henslow's Sparrow
(Ammodramus henslowii)
Banded Summer, 1998 - Jefferson Proving Ground, Indiana
General Information
The Henslow's Sparrow, first discovered in 1820 in Kentucky by J.J. Audubon, was named
by him in 1831 in honor of the famous Cambridge University professor John Stevens Henslow.
Once abundant, its populations are now scattered and much reduced. It is now considered a
species of special management concern.
The following photographs, taken by Jason and Teresa Lewis at the Jefferson Proving Ground
in southern Indiana, were kindly provided by them for this web page. Our thanks go to them
and to Dr. Joe Robb of the USFW for the opportunity to participate in
this important study.
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This grassland site at the Jefferson Proving
Ground in southern Indiana is the summer home to about 1,000 breeding pairs. The Henslow's
Sparrow is a secretive bird that breeds in moist, shrubby grasslands and winters in the
fields and open grassy areas of the pine forests of the southeastern US.
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Figure 1- Henslow's Sparrow Habitat
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Figure 2 - Adult Male Henslow's Sparrow
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Sexes are similar. The adult male prefers a
low perch to display and advertise its territory and to attract a mate. It is flat headed,
short tailed, with a pale bill and buffy or yellowish color on the upperparts and flanks.
It is 4.75 to 5.25 inches long with a wingspread of 6.75 to 7.5 inches. Weights range from
11.4 to 14.9 grams.
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To sing, it takes a deep breath, stretches
itself up and throws its head back. But for all of its effort, its song is a weak,
pathetic, easily overlooked note that sounds like "tsi-lick." It is, however, an
active songster that sings round the clock and even during rainy days.
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Figure 3 - Henslow's Sparrow Singing
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Figure 4 - Henslow's Sparrow Nest
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The cup nest of grasses and leaves is built
by the female on or near the ground. From 3 - 5 eggs are incubated by the female and hatch
in 11 days. |
Chicks are altricial, and are tended by both parents. They
leave the nest in about 9 days still unable to fly. This is likely a defensive behavior
for this ground nesting bird to get the chicks out of the nest and into protective cover
as quickly as possible.
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Figure 5 - Henslow's Sparrow chicks
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Figure 6 - Henslow's Sparrow Juvenile
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This juvenile is ready to fledge. Notice,
however, that its flight feathers are still emerging from their shafts, so it is still
unable to fly. It will take cover in the tall grasses near its nest where the parents will
care for it until it is able to fly and care for itself. |
A numbered metal band is placed on the leg to
identify this individual when it is recaptured. |
Figure 7 - Henslow's Sparrow banded
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Figure 8 - Henslow's Sparrow color bands
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Colored plastic bands are often used to
identify individual birds when they are resighted. In this way, it is possible to follow
the movements of individual birds without recapturing them. |
Measurements such as weight and wing cord are
taken on each banded bird for later study. |
Figure 9 -Henslow's Sparrow wing measurement
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The juvenile Henslow's Sparrow lacks the full
markings of the adult bird. This juvenile will migrate to the fields and open pine forests
of the southeastern USA to spend its winter. Hopefully it will return to this site next
year to raise its own brood. |
Figure 10 - Juvenile Henslow's Sparrow
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Banding Recoveries
The Bird Banding Lab web site reports that between 1955 and 1997, a total of 900 Henslow's Sparrows were banded. Of these, only 3
have ever been recovered, a very low recovery rate of 0.033%.
Banding studies show that the Henslow's Sparrows are short distance migrants that
winter in the southeastern USA.
If you should recover a banded bird, please report the band number to the Bird Banding
Lab by calling 1-800-327-BAND.
Economic Importance
and Conservation Status
The wholesale loss of suitable grassland habitat across the eastern and central USA
have greatly reduced the numbers of Henslow's Sparrows.
Henslow's Sparrows provide an economic benefit by consuming large numbers of crickets,
beetles, caterpillars, ants and other insect pests. They also consume seeds of weeds,
grasses, and sedges.
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All images are courtesy of CWBO. All image copyrights are owned by CWBO.
Any use of these images must have permission of CWBO. |
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