Essay/Term paper: Management techniques for the red-cockaded woodpecker on federal lands

Essay, term paper, research paper:  Society

Management Techniques For The Red-Cockaded Woodpecker On Federal Lands


Sean Fraser

NRM 304

ABSTRACT

The red-cockaded woodpecker (Picoides borealis) has been listed as an endangered
species since October, 1970. This species inhabits pine forests in the
southeastern United States where the majority of prime timberland is privately
owned. Private ownership of preferred habitat and historically destructive
silvicultural practices create unique problems for federal wildlife managers.
This report analyzes three management techniques being used to assess and
augment red-cockaded woodpecker populations on federal lands in the region,
primarily military installations. Seeking cooperation between diverse
government agencies, wildlife managers attempt to accurately assess species
abundance, alter woodpecker nesting cavities, and construct nest sites in an
effort to enhance red-cockaded woodpecker habitat on limited federal holdings in
the American southeast.

Key words: Picoides borealis, Global Positioning System, Geographic Information
System, cavity trees, cavity restrictors

The red-cockaded woodpecker (Picoides borealis) is an endangered species
that inhabits pine forests in an historical range from Texas to the Atlantic
coast (Jackson, 1986; Reed et al., 1988). Picoides borealis nest in clans or
family groups that usually consist of one breeding pair and 2 non-breeding male
helpers (Jackson, 1986 ). This group establishes and defends a territory that
includes foraging habitat and nesting "cavity trees" (Copeyon et al., 1991;
Jackson et al., 1986; Rossell and Gorsira, 1996). Red-cockaded woodpecker
clans excavate cavities in living pines, and have established a living and
foraging routine in conjunction with the southeastern pine forests and the
historical occurrence of fire, which reduces hardwood understory while sparing
fire-resistant pines (Jackson, 1986). Much of the prime nesting and foraging
habitat for this species has been systematically eliminated due to development,
timber harvest and intensive fire suppression (Jackson, 1986). The emergence
of dense hardwood understory and midstory as a result of fire suppression in
red-cockaded woodpecker habitat has resulted in the abandonment of many
otherwise undisturbed areas (Jackson, 1986; Kelly et al., 1993).
The red-cockaded woodpecker has been listed as endangered since 1970
(Federal Register, 1970 as cited by Ertep and Lee, 1994). Four requirements
for sustained red-cockaded woodpecker populations that are lacking in the
species historical range are identified as critical to species stabilization and
recovery: 1.) Open pine forests with shade tolerant understory controlled by
cyclical fire seasons; 2.) Old growth Pinus palustrus aged > 95 years and Pinus
taeda aged > 75 years; 3.) Approximately 200 acres for nesting group or clan;
4.) Multiple clans per area to maintain genetic stability and variability
(Jackson, 1986). The opportunity to establish or preserve these habitat
qualities on private timberland is largely lost due to historical harvest
practices and development, and research on expanding populations on federal
holdings is the most vital component in red-cockaded woodpecker stabilization
and recovery (Jackson et al., 1979a; Jackson, 1986). Exacerbating the problem
of habitat loss due to encroachment and fire-suppression are natural hazards
such as hurricanes, pine-beetle infestations and usurpation of red-cockaded
woodpecker cavities by other species (Carter et al., 1989; Rossell and Gorsira,
1996). Effects of historically natural hazards are multiplied in the context
of a diminished species abundance (Carter et al., 1989; Jackson, 1986).
Land management for wildlife is subject to unique difficulties in the
Southeast, as the majority of forested land is privately owned (Jackson, 1986).
In western states, approximately 2/3 of undeveloped land is federally
administered, making the enactment of widespread management policies feasible,
and controversies are apt to center around questions of access and use, rather
than the more difficult problems concerned with private property rights.

MATERIALS AND METHODS
This report will focus on the current techniques being explored and
enacted to stabilize and increase red-cockaded woodpecker populations on federal
lands throughout its previous range. Three areas of concern regarding the red-
cockaded woodpecker populations on federal lands interact to define current
management practices (Jackson, 1986). Wildlife biologists, foresters, and the
military have tested and combined specific techniques involving habitat
assessment and identification, cavity alteration, and cavity construction to
manage limited habitat for the red-cockaded woodpecker on federally administered
land (Carter et al., 1989; Copeyon, 1990; Ertep and Lee, 1994). Analysis
of specific studies and practices in these three areas serve as a description of
the technique for managing limited federal lands for the enhancement and
stabilization of red-cockaded woodpecker populations.

DISCUSSION

HABITAT ASSESSMENT AND IDENTIFICATION
A significant problem associated with the management of red-cockaded
woodpecker populations is obtaining an accurate assessment of habitat
availability and home range estimates (Ertep and Lee, 1994; Reed et al.,
1988). Differences in habitat quality and availability throughout the range of
the red-cockaded woodpecker affect population density and the range of foraging
and nesting activities within colonies, making general application of population
estimators difficult (Reed et al., 1988). This issue was addressed in 1988
during a study to evaluate red-cockaded woodpecker population indices. Reed et
al. (1988) set out to evaluate studies concerning red-cockaded woodpecker
population indices and, if necessary, develop a new techniques to more
accurately estimate adult population size. Reed at al. (1988) researched the
circular scale technique (CST) as described by Harlow et al. (1983) and found
that application of this method of population estimation is limited. CST
utilizes aerial identification of active cavity tree groups, and encompasses
said groups in a 460-m diameter circle that contains as many of the active
cavity trees as possible (Harlow et al., 1983 as cited by Reed et al., 1988).
While Harlow et al. (1983) and Lennartz and Matteaur (1986) used CST with great
accuracy in their study areas, estimating population sizes to between 92 and 95%
of the true number, the 1988 study by Reed et al. determined that the technique
cannot be used throughout the red-cockaded woodpecker range. Using CST in the
Sandhills region of North Carolina underestimated the number of groups in the
Reed et al. study population (Reed et al., 1988). In the Reed et al. (1988)
study area, red-cockaded woodpecker population density and the spatial
arrangement of colonies was frequently influenced by habitat fragmentation which
led to the violation of assumptions held necessary in the CST method of
population estimation (Reed et al., 1988). Conclusions in the Reed et al.
(1988) study indicate that CST may be generally used as an index, but further
research is necessary to establish a universal technique to estimate red-
cockaded woodpecker populations.
The development of sophisticated computer programs and topographical
analysis techniques may make assessment of red-cockaded woodpecker habitat and
species abundance more accurate and less time consuming (Ertep and Lee, 1994;
Reed et al., 1988). These advancements in geographic analysis and terrain
assessment technology have provided for an unlikely union between wildlife
managers and natural resource agencies on US military installations throughout
the southeast (Ertep and Lee, 1994; USMC, 1995). The coordination of
Geographic Information System programs (GIS) and Digital Multispectral
Videography (DMSV) at Fort Benning , Georgia adds a new technological advantage
in the search for red-cockaded woodpecker colonies and habitat by accurately
identifying longleaf pine stands (USACE, 1996). Image analysis and confirming
Global Positioning System information has been validated in initial tests by the
confirmation of three GIS and DMSV-identified red-cockaded woodpecker sites
through direct ground observation in the areas (USACE, 1996). Research is
ongoing to examine the initial findings associated with these new and highly
technical habitat assessment techniques (Ertep and Lee, 1996).

CAVITY ALTERATION
A significant problem in the recovery of red-cockaded woodpecker
populations involves the usurpation of nesting cavities by other species,
primarily southern flying squirrels (Gloucomys volans), northern flickers
(Colaptes auratus), European starlings (Sturnus vulgaris), and other species of
woodpeckers (Carter et al., 1989; Rossell and Gorsira, 1996). Invasive
species occupy or significantly alter cavities, preventing their continued use
by red-cockaded woodpeckers (Carter et al., 1989). Many nesting locations take
months or years to construct, and adequate old-growth pines are now less
frequent in the red-cockaded woodpecker range (Walters, 1986). Wildlife
managers and foresters have experimented with altering or reinforcing red-
cockaded woodpecker nesting cavities to discourage these invaders. Carter et al.
(1989) describe specific techniques for cavity alteration. Three types of cavity
restrictors alter the character of the cavity entranceway, acting as a deterrent
to enlargement or access by other species (Figure 1). Cavity restrictors
generally consist of a camouflaged metal plate fastened over the cavity entrance
(Carter et al., 1989).
A study by Rossell and Gorsira (1996) demonstrates the importance of
specific cavity parameters in assessing the availability of nesting and roosting
cavities for red-cockaded woodpeckers. The results of their study showed that
red cockaded woodpeckers nested only in cavities with normal entrances (Rossell
and Gorsira, 1996). Even if cavities with enlarged entrances contained normal
chambers and were not occupied by competing species, red-cockaded woodpeckers
avoided them (Table 1). TABLE 1¾Diurnal occupants versus entrance (ent.) and
chamber (ch.) characteristics of active red-cockaded woodpecker (Picoides
borealis) cavities in the Northeast Management Area, Fort Bragg, North Carolina,
May, 1993. (Rossell and Gorsira, 1996)


CAVITY CONSTRUCTION
Techniques to artificially create red-cockaded woodpecker cavities have
been initially successful on federal holdings such as Fort Bragg, North Carolina,
which holds one of the largest red-cockaded woodpecker populations on federally
administered lands (Copeyon et al., 1991; Rossell and Gorsira, 1996). The
technique and effectiveness of artificial cavity construction is best examined
by analyzing the physical characteristics of artificial red-cockaded woodpecker
cavities, and reviewing studies wherein the cavities are used as a management
tool (Copeyon, 1990; Copeyon, et al., 1991; Rossell and Gorsira, 1996).
Perhaps the most comprehensive study concerning artificial cavity construction
for the benefit of the red-cockaded woodpecker was conducted by Copeyon, Walters
and Carter as part of a ten year study of red-cockaded woodpecker populations in
the Sandhills region of North Carolina (1991). Their work, Induction of Red-
Cockaded Woodpecker Group Formation by Artificial Cavity Construction, (Copeyon
et al., 1991) represents the most practical and valuable guide to red-cockaded
woodpecker population enhancement techniques to date (Conner and Rudolph, 1995).

In 1990, Carole Copeyon published an article describing a technique for
constructing artificial cavities for red-cockaded woodpeckers. Explaining that
excavation of suitable living cavities takes a minimum of ten months and
normally much longer to complete, Copeyon (1990) surmised that construction of
artificial cavities may be an effective management tool that would encourage
colonization of abandoned areas and reduce energy expenditure associated with
nesting cavity construction.
After making the decision to use artificial nesting cavities as a
management tool, wildlife managers should attempt to select older trees in their
respective areas of responsibility (Copeyon, 1990; Copeyon et al., 1991).
Selection of older trees mimics the natural inclination of the red cockaded
woodpecker and that older trees have sufficient heartwood development to support
large nesting and roosting cavities without sustaining damage (Copeyon, 1990).
As indicated previously, red-cockaded woodpeckers generally select trees between
80 and 100 years old depending on species availability. Copeyon (1990) reveals
that an adequate artificial nesting cavity requires an entrance approximately
4.4cm.-6.4cm. in diameter placed at 1-24 meters above ground level. An entrance
tunnel should be excavated into the heartwood with the nesting chamber extending
down at a right angle to the entrance tunnel to a depth between 20.3 and 27.3cm.
(Figure 2) (Copeyon, 1990). Small resin wells are drilled around the tree
above and below the entrance site (Copeyon 1990; Rossell and Gorsira, 1996).
Seepage from these wells act to discourage competitors and predators (Copeyon,
1990).

The results of Copeyon's initial study concerning red-cockaded
woodpecker cavity construction are contained in (Table 2). TABLE 1. ¾Use of
artificial cavities by red-cockaded woodpeckers (Picoides borealis) in the
Sandhills region of North Carolina (Copeyon, 1990).
Species Age #Constructed
#Active Longleaf Old
29 25
Moderate 7
4
Young 2
2
Total 38
31

Loblolly Old 4
3
Young 2
1
Total 6
4

Cavity construction for red-cockaded woodpecker management is an
effective tool for inducing the formation of new colonies in the species'
historical range, and may prove to increase reproductive success in already
established colonies (Copeyon et al., 1991).

RESULTS
Further research is necessary to establish the impact of management for
the red-cokaded woodpecker on other species (Masters et al., 1996). Initial
studies indicate that management practices involving the clearance of hardwood
understory and the initiation of prescribed burns in red-cockaded woodpecker
habitat increase forage for white-tailed deer (Odocoileus virginianus) (Masters
et al., 1996). Studies continue to examine concerns about possible negative
effects of single species management practices in association with red-cockaded
woodpecker recovery effort (Masters et al., 1996). In the 25 years since the
identification of the red-cockaded woodpecker as an endangered species,
establishing a unified recovery program among the diverse federal agencies
responsible for the administration of lands within the species' range has been
difficult (Jackson, 1986). In the first 15 years of listing, no programs
existed to effectively manage habitat for the red-cockaded woodpecker. Jackson
(1986) described the situation as especially urgent, as the red-cockaded
woodpecker was becoming dependent on widely dispersed islands of habitat,
isolating colonies and creating the potential for catastrophic losses due to
natural occurrences and inter-species competition for roosting and nesting sites.
Since 1986, research into habitat requirements for successful red-cockaded
woodpecker colonies have been identified (Copeyon et al., 1991; Jackson, 1986).
Improvements in identifying suitable habitat, altering existing cavities to
decrease competition for roosting and nesting sites, and initiating formation of
red-cockaded woodpecker colonies through construction of artificial cavities
have been synthesized into a specific technique of managing federal lands for
the red-cockaded woodpecker (Copeyon et al., 1991; Ertep and Lee, 1994;
Rossell and Gorsira, 1996).