Habitat Management for Grassland Birds
Habitats change over time and are in constant flux. Some of these
changes are natural while some are directly linked to human involvement.
Since the last ice age (about 12,000 years ago), human activity has
been a major factor in how habitat is shaped around the globe, including
here in the Northeast. Native Americans were the first to create and
maintain habitat to suit their needs. They burned large areas in the
forest for travel and hunting purposes. These burned areas became
important habitat patches for many early successional species such
as deer, fox, rabbits, quail and other grassland nesting birds.
Beginning in the 1600s and through most of the 1800s, more
and more people colonized the Northeast. With this came an intense
increase in agriculture. The forests were cleared to make room
for fields to grow crops. This also had a positive impact on
these early successional grassland species and their populations
increased with the increase in agricultural lands.
But then something happened. Colonization continued westward.
The land to the west was more fertile and easier to farm than
the less fertile, rock filled soils of the Northeast. Farms
were abandoned, fields lay fallow and slowly reverted back into
forests. Early successional species and grassland related wildlife
In addition to the decrease in farms and early successional
grassland habitat, the remaining farms also were changing. Better
farming equipment made for more efficient farmers. Farmers began
haying fields two or three times per season, more and more pesticides
were used and fields were expanded using all of the possible
space for farming rather than leaving small natural areas that
wildlife used and needed.
All of these factors brought us to where we are today. Grassland
species are in severe decline. Upland sandpipers, vesper sparrows,
grasshopper sparrows, bobolink, and others are now listed on the NJ
Endangered and Threatened Species list, while other species such
as bobwhite quail and American woodcock have populations that are
severely on the decline. Steps need to be taken today to keep early
successional grassland habitat, and the species associated with it,
part of the NJ landscape.
Cool-Season vs. Warm-Season Grasslands
can be generally categorized into two groups: cool-season grasses
(grasses with growth rates that peak in the spring and fall when soil
and air temperatures are cooler) and warm-season grasses (grasses
with growth rates that peak during the warm summer months of June
cool season grasses also produce a toxin that inhibits other native
plant species from colonizing an area. This loss of plant diversity
has a direct negative impact on butterflies, moths, bees, small mammals
and birds. Cool-season grasses also offer little to no cover for wildlife
during the winter months as they easily fall over and mat down from
winter storms. This matting down also negatively affects the following
spring’s nesting season making it more difficult for many species to
successfully raise their offspring.
season grasses were introduced to the NJ area primarily as an
agricultural product because they are easily established, green
up earlier in the year allowing for excellent early season forage,
can be closely grazed, and can be easily maintained as a monoculture.
of cool-season grasses include timothy, Kentucky bluegrass,
tall fescue, and orchardgrass. Cool season grasses have several
disadvantages leading to high costs to the farmer and low productivity
for wildlife. Some of the costs include large amounts of fertilizer,
lime, herbicides and seed for replanting. These steps are all
needed to maintain a healthy stand of cool season grass.
Native warm-season grasses also have a very high wildlife and ecological
value. Most native warm season grasses grow in clumps or bunches. The
clumping nature allows for more bare ground under and between individual
plants. This allows for easy usage by wildlife for traveling, feeding,
dusting and nesting. Many wildlife species will not nest in a cool season
grass stand because after their offspring fledge from the nest, they
can not travel or walk through the dense vegetation to find food or
escape from predators.
the other hand, native warm-season grasses, or bunch grasses as
they are commonly called, have many positive attributes beneficial
to both farmers and wildlife. Maintenance costs are low once stands
are established as they typically do not need pesticides, herbicides
Warm-season grasses are also very dependable for forage production.
They are less influenced by severe weather fluctuations, such
as drought, due to their extensive and deep root systems, they
are more disease and insect resistant, they provide summer forage
when cool season grasses have slowed their growth, and they
are long lasting so they don’t need to be replanted as often
as cool season grasses.
grassland in autumn
The bunchy structure of warm season grasses also allows for
forbs, legumes and wildflowers to colonize the area, attracting
many beneficial insects and increasing the foraging conditions.
Warm season grasses also provide excellent winter cover as they
do not mat down easily under the stress from winter storms.
This leads to lesser winter mortality and an increase in spring
Examples of native warm-season grasses include: switchgrass,
big bluestem, little bluestem, Indian grass and broomsedge.
warm-season grasses provide habitat for many early successional
wildlife species. Many of the species that need and use warm
season grass fields, such as the vesper sparrow, savannah sparrow,
grasshopper sparrow, Henslow’s sparrow and bobolink, can be
found on the NJ Endangered
and Threatened Species list. Restoration and maintenance
of warm-season grass fields are crucial for these species survival.
Another species that benefits from the establishment of warm-season
grasses is the northern bobwhite quail. Bobwhite quail are declining
throughout the U.S. mostly because of habitat loss due to changing
land-use practices. Bobwhites require large open grassy areas that
can provide permanent, usable cover.
Quail spend most of their time on the ground. They need to be able
to run along the ground while remaining under cover. They also depend
on the seeds of herbaceous annuals for their major food source. Warm
season grasses provide this structure and forage. These grasses grow
in clumps allowing room in-between for quail to maneuver, and they
produce massive quantities of seed in the fall. Because of their growing
pattern, these grasses provide thick overhead cover that affords protection
from both predators and the elements.
Other species that benefit from the establishment of warm season
grasses include several species of Lepidoptera (butterflies and moths).
The Edward's hairstreak, frosted elfin butterfly, northern cloudy-wing,
and the swarthy skipper are grassland-associated species whose larvae
feed on grasses and legumes. Look for eastern cottontails to benefit
from this restoration as well.
The whole process of creating early successional grassland habitat
to benefit both landowners and wildlife can become costly and overwhelming
if attempted alone. The good news is, the public doesn’t have to go
it alone. Many conservation organizations, including the NJ Division
of Fish and Wildlife, offer technical and financial assistance and
incentives for creating beneficial wildlife habitat. To find out more
information about technical assistance and funding opportunities e-mail email@example.com
Information and assistance is available through the USDA's Natural Resources Conservation Service at www.nj.nrcs.usda.gov/.
The Conservation Reserve Enhancement Program (CREP) is a part of the Conservation Reserve Program (CRP) the country's largest private-land conservation program. It is administered by the Farm Service Agency (FSA).
Many New Jersey landowners have participated and have been very
successful in creating beneficial wildlife habitat on their properties.
Thousands of acres of non-productive farm fields have been converted
to early successional warm season grass fields and the surrounding
wildlife is responding. Breeding bird surveys and annual counts have
shown a positive impact on grassland nesting bird populations in and
near many of these newly converted grasslands. Farmers have reported
high hay yields during the difficult summer haying months and the
hay has been fed to horses, ponies, and cattle with no preference
towards the traditional hay crop or the new warm-season grass bales.