|
Greater
Prairie Chicken Management
by Gerald
J. Horak and Roger D. Applegate
NESTING
When managing large expanses of rangeland such as the
Flint Hills, allowing prime nesting habitat to occupy approximately
15% of the area provides optimum conditions for prairie
chickens. A minimum of 32 hectares (80 acres) of this nesting
habitat should be within 0.4 kilometers (one-fourth mile)
of a booming ground. Nesting habitat should be scattered
throughout pastures of good to excellent range condition.
This contrast between sparse vegetation on booming grounds
and heavy vegetation needed for nesting is the extreme in
vegetation density utilized by the prairie chicken.
Nest
initiation occurs during the height of courtship activities
in mid-April. After egg laying and incubation, the young
hatch during the last part of May and into early June.
Nests
are usually located on north and west facing slopes of well-drained
terrain generally having less than 20% slope. Visible changes
in habitat, such as trails, fencerows, or vegetation differences,
provide nest sites. Nests are constructed on the edge of
heavy cover. This allows adults to move easily to and from
the nest and permits young to quickly leave the vicinity
of the nest after hatching.
When
nesting begins in mid-April, dry or residual vegetation
from the previous growing season must be available for nest
construction. However, there is an upper limit of accumulated
residual that will be tolerated by prairie chickens searching
for nest sites. In well-managed pastures, this limit is
usually reached after four or five growing seasons. Again,
this points out the importance of burning every three to
four years. Nests are built in either natural ground depressions
scratched out by the hen. Fine grass material placed in
these depressions completes the nest. Surrounding vegetation
must be tall and dense to provide hen concealment from ground
and avian predators. The preferred height of nesting vegetation
is about 38 centimeters (15 inches), but nests have been
found in grass as short as 10 centimeters (4 inches) and
as tall as 97 centimeters (38 inches).
Nests
are found in a wide variety of vegetation types, from wheat
and alfalfa fields to both cool- and warm-season grasses.
The main ingredient is that a hen must be able to move easily
on and off the nest and lead her young from the area soon
after hatching. The species of vegetation is not as important
as the architecture it produces.
To provide
prime nesting conditions, two management techniques can
be used: 1) moderate to light grazing to maintain the proper
height and density of vegetation and create edges; and 2)
burning every three to four years to create nesting cover.
If occasional burning is not done on moderately grazed pastures,
the residual growth will reach a density discouraging hen
use.
A good
technique is to control burn only a third of the pastures
every year. Because cattle prefer recently-burned areas,
entire grazing units should be burned. Burning large pastures
often leaves a number of unburned areas. These areas are
usually of low quality for nest sites although hens may
utilize them for lack of better areas. If these "islands"
of grass are small, predators concentrate their feeding
activity in them. In large grazing units where a complete
burn occurs, prairie chicken populations will be adversely
affected due to the complete lack of nesting habitat. These
situations can be altered by back-firing potential nesting
habitat (at least 32 hectare or 80 acre blocks) located
in the vicinity of the booming grounds.
Quality
nesting cover is of primary importance. However, the quantity
and dispersion of this cover is also important. When the
quality and quantity of habitat is limited by intensive
agricultural use, overgrazing, or extensive annual burning,
nesting hens will concentrate in smaller areas. Due to this
overcrowding, they become susceptible to increased predation
and nest desertion. The end result is lower production and
reduced population levels.
Weather
plays an important role in annual nesting success. Heavy
rains and cool weather in the spring cause nest destruction
and desertion. Of course, weather is one element that cannot
be controlled, but knowledge of its effects can help explain
population increases or decreases.
Next:
Broods
|
