BIOLOGICAL DATA AND HABITAT REQUIREMENTS
WILDLIFE SPECIES: Tympanuchus phasianellus | Sharp-Tailed Grouse 



TIMING OF MAJOR LIFE HISTORY EVENTS : 
Courtship and breeding - Sharp-tailed grouse are a true lek species:
The males defend small territories on traditional "dancing grounds"
where they compete for mating opportunities.  Typically only a few males
mate.  The height of male displaying occurs in the spring [33].  The
female begins to make a nest at about the same time she begins to visit
the dancing grounds or possibly even before.  After successfully mating
she leaves the dancing grounds and probably does not return.  Males also
display at dancing grounds during autumn.  The autumn display is thought
to recruit first-year males into the lekking group and to maintain or
improve territorial position among established males [24].

Age at sexual maturity - Young male sharp-tailed grouse probably begin
establishing peripheral territories their first fall of life, and these
are held again the following spring [24].  Females probably breed for
the first time as yearlings [15].

Clutch size and incubation - Sharp-tailed grouse generally lay 12 eggs.
Eggs are laid at a rate of one per day and incubation begins when the
last egg has been laid.  The incubation period is 23 to 24 days.  The
precocial young all hatch on the same day [24,33].  Renesting attempts
sometimes occur but probably contribute no more than 10 percent of the
offspring in an average season [24].

Fledging - After the young hatch they are led away from the nest.
Chicks are able to fly to a limited degree when they are 10 days old,
and rapidly become independent. By the time they are 6 to 8 weeks old
they are fully independent, and broods gradually break up and disperse
[24].

Fall and winter flocks - Sharp-tailed grouse sometimes form fall and
winter flocks.  In Wisconsin, sharp-tailed grouse formed flocks when
they could not borrow through snow because snow depth was less than 7
inches (18 cm).  They left flocks when snow was greater than 7 inches
(18 cm) deep and burrowing was possible.  Flock sizes decreased when
availability of ground food decreased [15].


PREFERRED HABITAT : 
Courtship habitat - A common characteristic of sharp-tailed grouse leks
is low, sparse vegetation allowing good visibility and unrestricted
movement [37].  Height and density of vegetation appear to be important
factors in selection of leks [17].  Sharp-tailed grouse leks have been
reported on mowed wet meadows, cattle-trampled areas around windmills,
low ridges and knolls, and recent burns [37].

An excess of woody cover can adversely affect leks [17,37].  In
Minnesota, sharp-tailed grouse leks occurred where there was a 0.12 mile
(0.19 km) diameter area relatively free of woody vegetation [17].  In a
Michigan study, woody cover rarely exceeded 30 percent of the area of
the lek [17].  In Alberta, density of displaying male sharp-tailed
grouse was inversely related to total coverage of quaking aspen within
0.5 mile (0.8 km) of leks.  Sharp-tailed grouse leks in quaking aspen
parkland of Manitoba were abandoned when the area dominated by grasses
fell below 58 percent [37].  In Michigan the average distance from the
center of a lek to dense brush was 690 feet (210 m); the average
distance from the center of the lek to the nearest tree was 900 feet
(274 m) [17].

Leks are often located relatively close to dense herbaceous cover from
the previous year's growth ("residual" cover) [37].  Females frequent
heavier cover than do males during the breeding season, so heavy cover
may be used by males to locate leks in heterogeneous habitats.  The
distribution of leks used by sparse populations in east-central North
Dakota was influenced by the proximity of dense residual herbaceous
vegetation.  Eleven of 14 sharp-tailed grouse leks were within 590 feet
(180 m) of grassland or cropland areas which had not been mowed or
grazed for several years and supported heavy stands of residual growth
each spring.  New leks were established in Montana following substantial
increases in residual cover, and the largest leks were located in areas
surrounded by dense stands of residual vegetation [37].

Nesting habitat - Sharp-tailed grouse nest on the ground, preferably
among tall, rank grasses, but may also nest in brushy or woody areas
[8].  Residual herbaceous vegetation is important nesting cover because
little current growth is available in early spring when most nests are
constructed [37]. Female sharp-tailed grouse usually do not travel far
from leks to nest if suitable cover is available.  The mean distance from
known leks to 78 nests in western North Dakota was 0.8 mile (1.3 km),
with a maximum of 2 miles (3.2 km).  The mean distance between nests and
leks in Saskatchewan was about 0.5 mile (0.9 km); all nests were within
1 mile (1.6 km) of leks [37].

In the Nebraska sandhills, plains sharp-tailed grouse preferred to nest
on northern slopes dominated by residual cover of warm-season grasses
[43].  Of 78 plains sharp-tailed grouse nests found in North Dakota, 62
were in rolling grassland and 11 were in lowland draws; most were more
than 164 feet (50 m) from woody cover.  Females selected tall vegetation
within a pasture for nest sites; plant height was more important than
species [24].

Nesting cover for prairie sharp-tailed grouse tends to be less grassy
and more shrubby than that for plains sharp-tailed grouse [37].  In
Michigan, most prairie sharp-tailed grouse nests were protected by
overhead cover or were within a few feet of such cover.  Of 29 nests
found, none was more than 10 feet (3.3 m) from brushy or woody cover.
Of 10 nests studied, 6 were in open aspen, 3 were in cutover pines, and
1 was in an open marsh.  These sites averaged 43 percent shrub cover,
from 3 to 6 feet (1-2 m) high, and 4 percent tree cover more than 6
feet (2 m) tall [24].

Brood habitat - Favored brooding sites are those that contain relatively
dense herbaceous cover, associated with a mixture of shrubs and forbs
[24].  Broods use cultivated lands that are generally avoided before
nesting [17]. Openings in forested areas may also be used [19,24].
Woody cover is more important for broods than for nesting hens [34].  In
North Dakota, broods frequently used woody cover in draws or on uplands
for shelter from rain and midday heat [37].  Generally, dense brush is
used during early brood stages [24].  Sharp-tailed grouse broods in the
Wisconsin pine barrens used more woody cover than that chosen for nest
sites but in general remained in areas that did not exceed 50 percent
shading by woody cover [19].  Of 190 broods in the Wisconsin pine
barrens, about 80 percent were in open habitats, 14 percent were in edge
habitats, and only 5 percent were more than 150 feet (46 m) inside woody
habitats [19].  Shrubs are more important in brood habitat than trees,
since they provide cover and food for chicks [24].

Roosting habitat - After the mating season males gradually move away
from their leks to foraging and daytime roosting sites that usually
include brushy cover, aspen or willow thickets, or young conifer stands.
In Utah, during the day sharp-tailed grouse roosted in weeds and grass
during June and early July and in shrubs and bushes in late July and
August.  Night roosts located in fairly open upland sites with good
ground cover are preferred by sharp-tailed grouse over roosts in marsh
and bog vegetation [24].  Roost sites in the Nebraska sandhills were
typically dominated by grasses and were often interspersed with woody
vegetation [37].

Winter habitat - Winter use of habitats varies with snow depth [44].  As
food and cover are reduced in open habitats, sharp-tailed grouse move
into woody vegetation [24,37].  Sharp-tailed grouse also dig snow
burrows for shelter if snow depth is adequate; death may occur in severe
weather if no snow is available for burrowing [24].

Growth form of dominant grasses is important in late winter habitat.  In
late winter and early spring, when shrub canopies are open and dry snow
is unavailable for burrowing, heavy or deep (> 4 inches [10.2 cm]) snow
may collapse sod-forming grasses.  Bunchgrasses are more resistant to
collapsing under heavy snow and can provide cover when snow is up to 12
inches (30.5 cm) deep [37].

Habitat use by plains sharp-tailed grouse in eastern Montana was most
diverse during the winter [37,44].  During periods of deep snow on
mixed-grass prairie, plains sharp-tailed grouse used hardwood draws more
often than upland grasslands and croplands.  Grassy upland use was
greatest when snow depth was low [44].  As snow exceeded 5.5 inches
(14.0 cm), use of hardwood draws and riparian forest increased.  During
the winter in northern Montana, plains sharp-tailed grouse are commonly
found in coulees bordering streams with 10 to 15 percent shrub canopy
cover [37].  These habitats were critical for food during deep snow
conditions.  Wintering plains sharp-tailed grouse in Alberta parklands
roosted in the lee of quaking aspen trees and fed on their buds.

Columbian sharp-tailed grouse in California and Washington and
sharp-tailed grouse of an unspecified subspecies in Manitoba remained in
the open where grain foods were available during winter [37].


COVER REQUIREMENTS : 
Good quality grass and brushy cover are essential for sharp-tailed
grouse.  The height and density of vegetation is generally more
important than species composition in determining sharp-tailed grouse
habitat quality [37].  Sharp-tailed grouse prefer areas that contain
cover in scattered openings rather than evenly distributed [34].

Standing herbage or residual cover composed chiefly of grasses furnishes
protection for sharp-tailed grouse from inclement weather and predators,
especially in late winter and early spring [6].  In late summer and
early fall they are found mainly in open cover, grassy openings, or low,
scattered brush [8].  Scattered shrubs and shrubby breaks are more
important during late summer and fall than in midsummer, when grass
height is sufficient.  Woody vegetative cover generally becomes
increasingly important during fall and winter [37].

Prairie sharp-tailed grouse in Michigan are abundant in areas 20 to 50
percent covered by woody vegetation.  The following are recommendations
for sharp-tailed grouse habitat in that area:  Sparse or bare patches in
the ground cover should not exceed half of the total area, and the area
of open habitat in wooded vegetation should not be less than 1 square
mile (2.59 sq km).  Ideal summer habitat on a square mile should include
an open portion of about 6 percent of the total area to provide a
display site, loafing and foraging habitat for adult males and broods,
and roosting sites for displaying males.  About half of the total area
should consist of scattered large shrubs and trees, especially aspens.
Heavy ground cover serves for resting, feeding, and dusting, especially
by broods [24].  The remaining 44 percent of the cover should consist of
an alternating series of small (10 acre [4 ha]) brushy clearings and
heavier second-growth stands of mixed hardwoods and conifers, which
serve as a source of winter browse and protection from severe weather as
well as escape cover.  The scattered small clearings provide additional
nesting and brood-rearing habitat and winter roosting areas [24].

For the Columbian sharp-tailed grouse, shrubs and small trees are
important habitat components only during late fall and winter.  During
the rest of the year weed-grass cover and cultivated crops such as wheat
and alfalfa provide important food and cover [24].

The plains sharp-tailed grouse inhabiting the sandhills of central
Nebraska and the sand dune areas of north-central North Dakota are
relatively independent of extensive tree cover.  A minimum of 5 percent
brush cover to total land surface is tolerable to sharp-tailed grouse in
North Dakota [24].


FOOD HABITS : 
Sharp-tailed grouse are primarily herbivorous and utilize a variety of
leafy plant material including buds, fruits, and catkins of woody
species.  During the spring and summer herbaceous plants make up the
bulk of the sharp-tailed grouse diet.  During the fall and winter
sharp-tailed grouse rely more on woody species [24,37]. Sharp-tailed
grouse less than 10 weeks old feed primarily on insects such as
short-horned and long-horned grasshoppers, beetles, and ants.  At 12
weeks of age they consume about 90 percent plant material, which closely
resembles the adult diet [37].

During the spring and summer in Washington, green herbaceous materials
composed the bulk of the sharp-tailed grouse diet; grass blades alone
(especially Sandberg bluegrass [Poa secunda]) totaled 50 percent of the
spring diet and 75 percent of the summer diet.  Flower parts,
particularly those of dandelion (Taraxacum officinale) and buttercup
(Ranunculus spp.), made up the rest of the spring and summer food [24].
The summer diet of adult plains sharp-tailed grouse in Nebraska
sandhills was 91 percent plant material, 5 percent insects, and 4
percent unknown.  Important food items by volume included 54 percent
clover (Trifolium spp.), 9 percent rose hips (Rosa spp.), 6 percent
Bessey cherry (Prunus besseyi), 4 percent dandelion, and 3 percent
eastern poison-ivy (Toxicodendron radicans) [37].

During fall, a diverse array of seeds and cultivated grains are eaten,
especially in agricultural areas.  In nonagricultural areas shrub fruits
and seeds and green leaves of herbs, shrubs, and trees are eaten [24].
October foods of 53 plains sharp-tailed grouse showed a similar emphasis
on plant items (89%), including heavy use of fruits.  Important plant
foods during this period were rose (46%), clovers, (16%), American
nightshade (Solanum americanum) (11%), clammy groundcherry (Physalis
heterophylla) (7%), dandelion (3%), and western snowberry
(Symphoricarpos occidentalis) (2%).  Insects comprised 8 percent of the
October diet [37].

Fruits and berries were predominant in the fall diet of sharp-tailed
grouse in eastern Montana, followed by domestic grains.  Russian olive
(Elaeagnus angustifolia) was heavily used even though scarce on the
study area.  Grains were preferred during winter, although fruits and
buds were critical when snow became deep (>5.5 inches [>14 cm]).  Silver
buffaloberry (Shepherdia argentea), fragrant sumac, Russian olive, and
creeping juniper (Juniperus horizontalis) composed two-thirds of foods
used during winter [37].

Availability of grain, fruiting shrubs, or deciduous trees is important
in winter.  Paper birch (Betula papyrifera) and quaking aspen are major
winter food sources for prairie sharp-tailed grouse when snow cover
prevents foraging on grains or similar foods [24].  In central
Wisconsin, paper birch buds and catkins are the primary winter foods of
prairie sharp-tailed grouse, with aspen of secondary importance.  Among
shrubs, rose hips and hazel (Corylus spp.)  buds and catkins are
important.  In Ontario paper birch is the primary winter food for
prairie sharp-tailed grouse, supplemented by browse of willow, aspen,
blueberry (Vaccinium spp.), and mountain-ash (Sorbus spp.).  In North
Dakota, willow buds are the most important single winter food for plains
sharp-tailed grouse, but chokecherry, cottonwood, and rose are major
supplementary species.  During periods of heavy snow in Utah,
sharp-tailed grouse move into thickets of maple (Acer spp.),
chokecherry, and serviceberry (Amelanchier spp.), where they feed on
buds [24].  The fruits of black hawthorn (Crataegus douglasii) and the
buds of Saskatoon serviceberry (A. alnifolia) and chokecherry were the
main winter foods of Columbian sharp-tailed grouse in western Idaho
[33].


PREDATORS : 
Some predators of sharp-tailed grouse include red foxes (Vulpes vulpes),
coyotes (Canus latrans), and great horned owls (Bubo virginianus) and
other raptors [16].


MANAGEMENT CONSIDERATIONS : 
The populations and distributions of the Columbian, prairie, and plains
sharp-tailed grouse have all decreased from loss of habitat due to
intensive livestock grazing, conversion of range to cropland, and other
human activities [24].  Overstocking results in loss of vegetation
necessary for nesting and may reduce shrubby cover needed for broods.
Woody vegetation frequently deteriorates in areas where livestock are
concentrated.  In such areas it would be desirable to fence off some
woody stands to provide cover for sharp-tailed grouse [33,43].  In
western Idaho, mountain shrub and riparian cover types were the most
important winter habitats for Columbian sharp-tailed grouse.  These
cover types are sometimes heavily damaged by livestock.  Any disturbance
that may damage or eliminate these cover types may have severe negative
impacts on Columbian sharp-tailed grouse [33].  In general, grazing
should be regulated so that approximately 15 percent of an area remains
unused during a season [43].


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Tympanuchus phasianellus | Sharp-Tailed Grouse