Managing Habitat for Grassland Birds A Guide for Wisconsin
Glossary
Acreage Conservation Reserve (ACR)
Part of the now-defunct U.S. Department of Agriculture Feed Grain Program
that took former row crop fields out of production (set-aside), typically
for one year, but sometimes for more than one year. Planted or volunteer
vegetation provided soil erosion protection.
Biomass energy crops
Plant-derived materials (such as harvested woody or herbaceous crops)
that supply useful energy either by direct combustion or by conversion into
liquid or gaseous fuels.
Brood parasitism
An example of brood parasitism: female brown-headed cowbirds laying eggs
in the nest of a host species. The host species may then raise the cowbird
chick(s) at the expense of their own young.
Conservation Reserve Program (CRP)
A U.S. Department of Agriculture program that takes highly erodible or
environmentally sensitive cropland out of production for 10 to 15 years.
Farmers receive an annual rental payment in return. Most enrolled land is
planted to perennial grasses and grass/legume mixtures. Some land is planted
to trees.
Conservation tillage
A set of practices in which varying degrees of crop residue remain on
the soil surface before and after planting agricultural crops.
Cool-season grass
Any grass species that reaches its peak growth and photosynthetic activity
in the relatively cool weather of spring and fall. These grasses usually
flower before July 15. The plant goes dormant or growth slows in the heat
and dryness of summer. These grasses include both native and non-native
species; the majority, however, are non-native.
Ecological trap
A habitat that attracts nesting birds in the spring but supports only
low or no nest productivity, adult survival, or juvenile survival.
Edge effects
The apparent phenomenon of low nest success near certain kinds of habitat
edges due to high rates of nest predation and brood parasitism.
Extirpated
Refers to species that formerly occurred in Wisconsin but no longer include
the state within their range.
Forbs
Non-grassy herbaceous plants, typically broad-leaved species.
Habitat guild
A group of bird species that tend to occur in similar types of habitats.
Wisconsin bird habitat guilds include grassland, forest, wetland, urban/farmstead,
and edge/generalist guilds.
Heath
Low-growing (<1 m tall) woody plants, usually referring to ericaceous
shrubs but here meaning any low woody plants.
Height-density
One of the tools managers use to assess habitat structure in the field.
It is a measurement that represents the height below which vegetation is
too dense to permit sight of a graduated pole from a distance of 4 m. This
is sometimes also called a visual obstruction measurement (Robel et al.
1970).
Idle grassland
Any habitat that is not cut, burned, cropped, heavily grazed, cultivated,
or otherwise disturbed during the bird breeding season.
Linear edge
Structural features in a grassland or agricultural landscape that form
linear, sharply defined boundaries or breaks between woody and herbaceous
habitat types and that can provide habitat or travel corridors for nest
parasites or predators. Examples include brushy ditches and fencelines,
hedge rows and tree rows, and woodlot edges.
Litter layer
A horizontal layer of dead herbaceous vegetation on or just above the
soil surface.
Mesic (dry-mesic, wet-mesic)
Pertaining to an environment with a moderate amount of moisture; as opposed
to wet (hydric) or dry (xeric) environments.
Monotypic stands
Plantings dominated by one species; monocultures.
Openness
Dominance of herbaceous vegetation in landscapes characterized by the
absence of major woody vegetation and the absence or low density of farmsteads
and other major above-ground structures.
Refugia
Places where organisms can avoid life-threatening disturbances.
Suitable
Used in reference to grassland bird habitat. Refers to habitats that are
high quality (e.g., habitats that typically attract good densities of at
least some grassland bird species and have relatively high nesting productivity)
or that at minimum do not have significant negative impacts on grassland
birds (e.g., habitats such as small grains that do not support high diversity
or density of nesting birds but that may increase the effective size of
an open grassland landscape, buffer other high quality habitats from woody
edges, etc.).
Warm-season grass
Any grass species that reaches its peak growth and photosynthetic activity
during the warm summer monthstypically between June 15 and August
30. These grasses usually flower after July 1 to 15.
Waterfowl Production Area (WPA)
Upland fields and wetlands purchased and managed by the USFWS to provide
grassland nesting habitat for waterfowl.