Grasshopper Sparrow (Ammodramus savannarum)
The Grasshopper Sparrow (Ammodramus savannarum)
belongs to the Order Passeriformes, Family Emberizidae.
Birds of the genus
Ammodramus are
typically small to
medium sized
sparrows with
relatively short tails
that prefer grassy
habitats. They are
rarely seen in trees or
bushes except when flushed and chased to a perch (some
occasionally perch on wires). The species name
savannarum describes the preferred habitat. The name
“grasshopper” refers to the insect-like song.
season mowing of hayfields and intensive grazing
practices. Grasshopper Sparrows belong to the
“grassland” bird guild as well as the “ground-nesting”
bird guild. Breeding Bird Survey (BBS) trends show that
many species within these two guilds have been suffering
population declines nationwide. The Grasshopper
Sparrow in considered a species of conservation concern
by North Carolina Partners in Flight and is listed on the
North Carolina Natural Heritage Animal Watch List
because of its known population decline and because of
habitat threats. In recent years, BBS trends show steep
population declines in the Piedmont of the eastern United
States and a severe decline nationwide for this species.
Grasshopper Sparrows are also on the U.S. Fish and
Wildlife Service’s MNBMC List (Migratory Non-game
Birds of Management Concern). The Florida
Grasshopper Sparrow, a subspecies of the Grasshopper
Sparrow, is on the United States Federal Endangered
Species List.
Description
A chunky sparrow with short narrow tail, large flat head,
scaly-looking rufous upperparts, buffy breast and sides
(adults usually without obvious streaking on underparts),
dark crown with a pale central stripe, narrow white eye
ring, and (in most adults) a yellow-orange spot in front of
the eye; juveniles have pale buff breast and sides, finely
streaked with brown,; average length 13 cm. In flight,
orange feathers can be seen at the bend in the wings.
Grasshopper Sparrows have a rather weak song. The
primary song has been described as 1 or 2 high-pitched
chip notes followed by a long, dry, grasshopper-like trill;
while the sustained song is a more musical series of short
buzzy notes.
Habits
Famously illusive, Grasshopper Sparrows dwell close to
the ground and are most often detected by their buzzy
insect-like song. Singing males can typically be found
perched in a crouched position high on a grass stem, lone
shrub, fence post, or power-line. When flushed, these
sparrows will fly a short distance and drop out of sight
into the grass. They feed largely on insects (primarily
grasshoppers), but also on grass and forb seeds.
This species is extremely secretive when nesting. Nests
are built by the female in a slight depression on the
ground, typically well-hidden at the base of a grass
clump, slightly domed on one side with vegetation arched
over the top. If flushed from the nest, a Grasshopper
Sparrow will sneak off the nest and run on the ground,
looking much like a rodent, then fly up at least 20 feet
away. The female may feign wing injury as a distraction.
Females are known to sing and males sometimes sing at
night during the breeding season.
Range
A resident of
North America,
the Grasshopper
Sparrow breeding
range extends
from southern
BBS range map 1994-2003
Canada to Central
America, and
across much of the United States. Grasshopper Sparrows
winter from North Carolina to Florida, west to southern
Arizona, and south to Mexico and Central America.
Grasshopper Sparrows can be found throughout North
Carolina, with the highest densities occurring in the
western Piedmont.
Habitat
Grasshopper Sparrows
need large continuous
open grassland habitat.
In the East, this type of
habitat rarely occurs
naturally and is
provided by abandoned weedy farm fields, hayfields,
pastures, and to a lesser degree, airfields and grassy
roadsides. Historically, natural prairies and savannas
created by wildfire, grazing bison, and Native American
disturbance may have provided the required habitat.
Status
Threats to Grasshoppers Sparrow populations include
habitat fragmentation and loss due to cultivation, urban
sprawl, and reforestation. Feral cats and edge predators
are serious threats as well. Nests are impacted by early-
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Grasshopper Sparrow (Ammodramus savannarum)
Estimated area requirements range from 10 to 100
hectares (25-250 acres). Grasshopper Sparrows are
found in various habitats ranging from low, sparse
vegetation cover to tall dense cover. Grasses around 1
foot in height are preferred and these sparrows are often
associated with clumped vegetation interspersed with
patches of bare ground. Forbs are an important habitat
component for attracting the insects on which they feed.

Defer mowing until the end of the breeding
season. Studies have shown the number of
Grasshopper Sparrow breeding pairs increase after
several years of deferred mowing. Mow only 60%
of the grassland at a time. Litter depth from mowing
may take anywhere from 1 to 3 years to rebuild
before another burn or mowing needs to take place.

Plant bunch grasses like Bluestems (Andropogon
sp. or Schizachyrium sp.), Switchgrass, or Indian
Grass that allow openings in vegetation to facilitate
foraging and provide escape routes. Many bunch
grasses are “warm-season” grasses that mature late in
the summer and therefore do not need to be mowed
until August, allowing for completion of nesting
activities. These grasses are also very adaptable to
drought conditions and provide good hay for cattle.

Prescribed burning may be used in place of
mowing every 3 years, except during drought years.
Drought reduces the above ground grass productivity
to levels unacceptable to the sparrows. Burns should
be performed during winter if it is determined they
will be used in place of mowing. Studies have
shown that Grasshopper Sparrows prefer areas 1-3
years after burning.

Avoid intensive grazing. Light to moderate grazing
outside of the breeding season can be beneficial to
Grasshopper Sparrows in lush grasslands or
hayfields. Graze areas of tall dense vegetation to
provide a diversity of grass heights and densities.

Treat portions of large areas on a rotational
schedule to provide a mosaic of successional stages
Nesting densities in cultivated cropland habitat are a
fraction of the densities found in native grassland habitat.
Nests are more successful the further they are from forest
edge, indicating the need for large habitat patches.
Grasshopper Sparrows are highly sensitive to subtle
changes in habitat and will easily abandon traditional
nesting grounds if the grass grows too high and
especially if woody plants begin to encroach. This
species requires perches on the breeding grounds in order
to defend territories. Grasshopper Sparrows are targeted
in many conservation plans as an indicator species
representing other grassland and area-sensitive bird
populations. Grasshopper Sparrows tend to respond
quickly to effective management and habitat restoration
efforts.
Management Recommendations



Regardless of management treatment, avoid
disturbing (e.g., burning, haying, heavy grazing)
nesting habitat during the breeding season,
approximately mid April to early August. Some
management treatments may be performed 4 weeks
prior to the arrival of adults from their wintering
grounds (early April) or in the fall (early to late
October). In fall, it is best to leave adjacent
untreated areas to provide a place of refuge for
fledglings or late or re-nesting adults.
SOURCES OF TECHNICAL INFORMATION
ON: HENSLOW'S SPARROW, GRASSLAND
BIRDS AND GRASSLAND MANAGEMNT
OPTIONS FOR LANDOWNERS AND
NATURAL RESOURCE MANAGERS
Create and maintain large (over 25 acres)
expanses of habitat. Grasshopper Sparrows are
extremely area-sensitive and are not found on
smaller grassland fragments. The smaller the
acceptable habitat area, the lower the nesting success
for these sparrows.
Scientific Papers:
Askins, R.A. 1993. Population trends in grassland,
shrubland and forest birds in eastern North
America. Current Ornithology 11: 1-34.
Create or maintain relatively sparse, grass
dominated vegetation resembling old (8-10 years
since planted) hayfields. Discourage woody
vegetation. If mowing, grazing, or burning are not
management options, hand cutting of woody plants
may be required and an herbicide like Garlon may be
used to control woody vegetation.
Bajema, R.A., T.L. DeVault, P.E. Scott, and S. L.
Lima. 2001. Reclaimed coal mine grasslands and
their significance for Henslow's Sparrows in the
American midwest. The Auk 118(2): 422-431.
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Barnes, T.G., L.A. Madison, J.D. Sole, and M.J.
Lacki. 1995. An assessment of habitat quality for
Northern Bobwhite in tall fescue-dominated
fields. Wildlife Society Bulletin 23: 231-237.
Heller, S., and K. Hughes. 1997. Song activity of
Henslow's Sparrow and Grasshopper Sparrow
over a 24-hour period. Indiana Audubon Quarterly
75: 61-67.
Bollinger, E.K., P.B. Bollinger and T.A.Gavin.
1990. Effects of hay-cropping on eastern
populations of the Boblink. Wildlife Society
Bulletin. 18: 142-150.
Herkert, R.H., R.E. Szafoni, V.M. Kleen and
J.E.Schwegman. 1993. Habitat establishment,
enhancement and management for forest and
grassland birds in Illinois. Div. of Nat. Heritage,
Illinois Dept. of Conservation, Natural Heritage
Technical Publication #1. 20pp.
Bollinger, E.K. 1995. Successional changes and
habitat selection in hayfield bird communities.
The Auk 112: 720-730.
Herkert, J.R. 1994. Status and habitat selection of
the Henslow's Sparrow in Illinois. Wilson Bulletin
106: 35-45.
Burger, L.D., L.W. Burger, and J. Faaborg. 1994.
Effects of prairie fragmentation on predation on
artificial nests. Journal of Wildlife Management
58: 249-254.
Herkert, J.R. 1998. Effects of prairie management
practices on grassland birds: Henslow's Sparrow.
Northern Prairie Wildlife Research Center,
Jamestown, North Dakota.
Chandler, C.R., and M.S. Woodrey. 1995. Status
of Henslow's Sparrows during winter in coastal
Mississippi. Mississippi Kite 25: 20-24.
Herkert, J.R. and W.D. Glass. 1999. Henslow's
Sparrow response to prescribed fire in an Illinois
prairie fragment. Studies in Avian Biology 19:
160-164.
Cully, J.F., and H.L. Michaels. 2000. Henslow's
Sparrow Habitat Associations on Kansas Tallgrass
Prairie. Wilson Bulletin 112(1): 115-123.
Johnson, H.L., and L. D. Igl. 2001. Area
requirements of grassland birds: a regional
perspective. The Auk 118(1): 24-34.
Dale, B.C., P.A.Martin and P.S.Taylor. 1997.
Effects of hay management on grassland
songbirds in Saskatchewan. Wildlife Society
Bulletin. 25: 616-626.
Johnson, R.G., and S.A. Temple. 1990. Nest
predation and brood parasitism of tallgrass prairie
birds. Journal of Wildlife Management 54: 106111.
Davis, S.K., D.C. Duncan and M. Steel. 1999.
Distribution and habitat associations of three
endemic grassland songbirds in southern
Sackatchewan. The Wilson Bulletin, 111(3): 389396.
Knopf, F.L. 1994. Avian assemblages on altered
grasslands. Stud.Avian Biol. 15: 247-257.
Davison, W.B., and E. Bollinger. 2000. Predation
rates on real and artificial nests of grassland birds.
the Auk 117: 147-153.
Mangun, J.C., and R L. Kolb. 2000. Effects of
grassland management on Henslow's Sparrow
populations in eastern North Carolina. Journal of
the Elisha Mitchell Scientific Society. 116(1): 4956.
Gabrey, S.W. and A.D.Afton. 2000. Effects of
winter march burning on abundance and nesting
activity of Louisiana Seaside Sparrows in the gulf
coast chenier plain. The Wilson Bulletin, 112(3):
365-372.
Owens, R.A. and M.T. Myres. 1973. Effects of
agriculture upon populations of native passerine
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birds of Alberta fescue grasslands. Can. Journal of
Zoology. 51: 697-713.
prairie. Bird Conservation International 6: 241253.
Plentovich, S., N.R. Hollar and G.E.Hill. 1998.
Site fidelity of wintering Henslow's Sparrows.
Journal of Field Ornithology 69: 486-490.
Vickery, P.D., M.L. Hunter, and S.M. Melvin.
1994. Effects of habitat area on the distribution of
grassland birds in Maine. Conservation Biology. :
1087-1097.
Plentovich, S., N. Hollar, and G.E. Hill. 1999.
Habitat requirements of Henslow's Sparrows
wintering in silvicultural lands of the gulf coastal
plain. The Auk 116(1): 109-115.
Vickery, P.D., and J.R. Herkert. 2001. Recent
advances in grassland bird research: where do we
go from here? The Auk 118(1): 11-15.
Pruitt, L. 1996. Henslow's Sparrow status
assessment. USFWS, Bloomington, Ecological
Services Field Office, Bloomington, Indiana.
Walk, J. W., E.L. Kershner, and R.E. Warner.
2000. Nocturnal singing in grassland birds.
Wilson Bulletin 112(2): 289-292.
Renken, R.B., and J.J. Dinsmore. 1987. Nongame
bird communities on managed grasslands in North
Dakota. Can. Field-Nat. 101: 551-557.
Whitmore, R.C. 1979. Short-term changes in
vegetation structure and its effects on
Grasshopper Sparrows in West Virginia. Auk 96:
621-625.
Reynolds, R.E., T.L. Shaffer, J.R. Sauer, and B.
G. Peterjohn. 1994. Conservation Reserve
Program: benefit for grassland birds in the
northern plains. Trans. Am. Wildl. Nat. Resour.
Conf. 59: 328-336.
Winter, M. 1999. Nesting biology of Dickcissels
and Henslow's Sparrows in southwestern Missouri
prairie fragments. Wilson Bulletin, 111(4): 515527.
Sample, D.W., and M.J. Mossman. 1997.
Managing habitat for grassland birds: a guide for
Wisconsin. Wisconsin Dept. of Natural
Resources, Madison, Wisconsin.
Winter, M. and J. Faaborg. 1999. Patterns of area
sensitivity in grassland-nesting birds.
Conservation Biology 13: 1424-1436.
Zimmerman, J.L. 1984. Nest predation and its
relationship to habitat and nest density in
Dickcissels. The Cooper Ornithological Society
86: 68-72.
Samson, F.B., and F.L. Knopf. 1994. Prairie
conservation in North America. Bioscience. 44:
418-421.
Shriver, W.D. and P.D. Vickery. 2001. Response
of breeding Florida Grasshopper and Bachman's
Sparrows to winter prescribed burning. Journal of
Wildlife Management 65(3): 470-475.
Zimmerman, J.L. 1988. Breeding season habitat
selection by the Henslow's Sparrow in Kansas.
Wilson Bulletin 100: 17-24.
Sutter, G.C., and M. Brigham. 1998. Avifaunal
and habitat changes resulting from conversion of
native prairie to crested wheatgrass: patterns at
songbird community and species levels. Can.
Journal of Zoology. 76: 869-875.
Swengel, S.R. 1996. Management responses of
three species of declining sparrows in tallgrass
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