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declines in numbers prior to the initiation of the
BBS, habitat losses to agriculture and development,
and concerns over habitat fragmentation, the species
is listed as a species of management concern by a
variety of conservation organizations (see Management
Status and History). Additionally, Region 2 added the
long-billed curlew to its Regional Forester’s Sensitive
Species List in 2003.
The long-billed curlew is a native prairie
specialist, restricted to mixed-grass and shortgrass
prairies, and preservation and proper management of
these habitats remain key to its conservation. Viability
of this species could be impaired throughout Region
2 by continued fragmentation of habitats, which have
altered natural expanses of mixed-grass and shortgrass
prairies to a mosaic of pastures variably grazed by
cattle and fragmented by agricultural activities and
human development (O’Connor et al. 1999). Current
management does not appear to be placing demands on
the species, with the following major caveats:
v
shortgrass and mixed-grass prairies must be
grazed
at appropriate levels
v
prescribed burns may be necessary to
maintain vegetation stature and reduce the
shrub component on native prairies
v
the long-term effects (i.e., fragmentation,
disturbance, habitat loss) of oil and gas
development on curlew populations are
unknown and have not been investigated.
Because much of the long-billed curlew range falls
within Region 2 and because this species is restricted to
shortgrass and mixed-grass prairies, risks in Region 2
parallel continent-wide risks. Continued conversion
of shortgrass and mixed-grass prairies to cropland,
fragmentation of curlew habitats, indiscriminant use
of pesticides, prairie fire suppression, and oil and gas
development all put the long-billed curlew at risk.
Management of Long-billed Curlews in
Region 2
Implications and potential conservation
elements
Long-billed curlews prefer vast areas of native,
undisturbed, unfragmented prairie, where native
herbivores (i.e., bison, pronghorn, prairie dogs) and
domestic cattle combine to mimic historical grazing
patterns, and where uncontrolled wildfire or prescribed
burning are used to mirror historical fire regimes.
Preferred environmental conditions include:
v
native grasslands, usually a mix of short and
mixed-grasses
v
open areas of vegetation low in height
v
moist, low areas with taller, thicker grasses in
shortgrass prairies
v
a preference for grazed areas in mixed-grass
prairies
v
limited cover of shrubs
v
an average vegetation height <30 cm
v
no tall exotic grasses
v
no trees.
To replicate the native, historic prairie condition,
two primary management tools are available: prescribed
fire and grazing by cattle. Both of these tools can help
to create and maintain the vegetation profile favored by
this species on breeding and wintering grounds.
Fire
The fragmentation of the mixed-grass and
shortgrass prairies by agricultural conversion has
prevented uncontrolled wildfires, and those that do
occur are often contained to the smallest area possible
(Bent 1968). Fire may serve in maintaining the stature
of curlew breeding habitat (Bent 1968, Oberholser
1974). Prescribed burns can be used in shortgrass to
remove woody vegetation, cactus, and accumulated
litter and to improve grazing conditions for livestock,
but the grasses recover slowly, requiring 2 to 3 years
with normal precipitation (Wright and Bailey 1980).
Grazing
Grazing can be beneficial to curlews if it provides
suitably short vegetation, particularly during the pre-
laying period (Bicak et al. 1982, Cochran and Anderson
1987). Timing and intensity of grazing treatments
should be adjusted according to local climate and
habitat characteristics (Bicak et al. 1982, Bock et al.
1993). Curlews prefer grazed prairie, but they will
forage and occasionally even nest in cropland, including
fallow fields, forage crops, and grain crops (McCallum
et al. 1977, Pampush 1980, Renaud 1980, Cochran and
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Anderson 1987, Pampush and Anthony 1993). Grazing
during breeding can result in destruction of eggs or
entire clutches by trampling (4.2 percent of 119 nests;
Redmond and Jenni 1986). In Wyoming, nests in areas
that were grazed during the incubation period had lower
hatching success rates than nests in ungrazed areas
(Cochran and Anderson 1987). However, only very
heavy grazing would result in a significant source of
nest loss (Redmond and Jenni 1986).
Cultivation, seeding, exotics
Long-billed curlews prefer native grasslands
to non-native pastureland seeded with exotics. Older
plantings of crested wheatgrass and infestation of
knapweeds can severely degrade nesting habitat by
creating dense, tall stands of vegetation. Conversely,
because of its sparse, open growth characteristics,
cheatgrass appears to provide better nesting habitat
than natural bunchgrass habitats (Allen 1980, Jenni
et al. 1981, Pampush and Anthony 1993). In some
areas, numbers of breeding curlews have increased
in response to invasion by cheatgrass. Agricultural
cropland (e.g., hay meadows, alfalfa, some cereal
grains) also may benefit curlews in some regions
(Idaho, Jenni et al. 1981; Wyoming, Cochrane and
Anderson 1987; Oregon, Pampush and Anthony 1993).
Haying can be used to provide the short vegetation
preferred by nesting curlews, but it should be timed so
that short vegetation is available early in the season and
active nests are not damaged (Cochran and Anderson
1987). In north-central Oregon, curlews foraged in
alfalfa fields as long as vegetation remained <30 cm
tall (Pampush 1980, Pampush and Anthony 1993). On
the other hand, they will occupy former breeding areas
when croplands are restored to grasslands (Yocum
1956). Trees are not a historical element of the mixed-
grass or shortgrass prairie landscapes, and trees (e.g.,
plantings, treerows) may result in increased predation
by providing perches for avian predators such as
magpies, ravens, and raptors.
Tools and practices
Population or habitat management approaches
and their effectiveness
The historical impact of grazing by bison, prairie
dogs, and pronghorn as an ecological force established
the precedent of manipulating cattle grazing as the
primary wildlife habitat management tool for mixed-
grass and shortgrass prairies. The key management
goal for long-billed curlews is to provide adequate
size blocks of short- to medium-height grassland.
Mixed-grass areas or areas where the grass is too tall
or thick can be made suitable for breeding long-billed
curlews by implementing moderate grazing (Dechant
et al. 2003). Burning and heavy grazing by livestock
reduces vegetation coverage and density, improving
habitat; however, these practices must be conducted at
the right time of year. Areas where vegetation is already
sparse and short from overgrazing should be protected,
especially in areas of low precipitation. Prescribed
prairie burns may be appropriate for historically burned
areas where fire has been suppressed. New construction
for oil and gas exploration, wind-power development,
and water well drilling should be restricted during the
breeding season; this is already done in some areas of
Colorado, Wyoming, and Utah (Knopf 1996).
Management approaches that benefit the long-
billed curlew and address the factors that place this
species at risk include:
v
protect prairie areas from plowing and
cultivation.
v
provide large blocks of suitable habitat; blocks
should be ≥ 3 times as large as territories (~14
ha; Redmond et al. 1981)
v
provide areas of adequate size to support
multiple long-billed curlew territories
v
delay grazing until after the breeding season
(~15 July), and avoid grazing during the
incubation period
v
Use light grazing and occasional prescribed
burning to maintain vertical vegetation
structure
v
Remove tall, dense residual vegetation before
the pre-laying period (March to April) so that
adults do not have to leave their territories to
forage (Redmond 1986)
v
implement prescribed burns where fire will
improve habitat by reducing shrub coverage
and increasing habitat openness (Redmond
and Jenni 1986, Pampush and Anthony 1993)
v
avoid grasshopper control; adopt integrated
pest management practices to retain some
populations of prey species
v
maintain a landscape mosaic with vegetation
of different heights and densities to provide